Honest opinion on why I chose the V8 after being a long time rotary guy.
11-25-15, 12:44 PM
#26
LOF, the thing is that it is not a religious debate at all.
Facts have been stated by both parties and it appears that you want to mitigate the LSx's weaknesses. It is not some paragon of reliability. Is the rotary less forgiving of shitty tunes and lack of maintenance? Sure. Is the LSx, outside of 100% racing conditions, more likely (key word) to last more miles than a rotary? Yes. I think we can all agree on that. But it IS heavier, as is the trans typically used with it. By itself that means, without question, that if everything else is equal and "ideal gearing" for either engine is used, the non-LS car will be faster. End of Story. And we all know a 100lb (using your numbers) weight penalty is a lot in racing.
The other reality is that the rotary has nowhere near the R&D that piston engines have. We could all go back and forth of the why and meaning of it but that alone is a huge handicap as well.
Facts have been stated by both parties and it appears that you want to mitigate the LSx's weaknesses. It is not some paragon of reliability. Is the rotary less forgiving of shitty tunes and lack of maintenance? Sure. Is the LSx, outside of 100% racing conditions, more likely (key word) to last more miles than a rotary? Yes. I think we can all agree on that. But it IS heavier, as is the trans typically used with it. By itself that means, without question, that if everything else is equal and "ideal gearing" for either engine is used, the non-LS car will be faster. End of Story. And we all know a 100lb (using your numbers) weight penalty is a lot in racing.
The other reality is that the rotary has nowhere near the R&D that piston engines have. We could all go back and forth of the why and meaning of it but that alone is a huge handicap as well.
Yes I added weight to my 2500 lb NA FC when I put in the V8. I added about 100 TOTAL lbs after everything was said and done. (that is adding the entire V8 drivetrain, and the 8.8 rear, larger wheels/tires and brakes, etc.) It makes 3.5X the HP. A turbo rotary making that power would have added AT LEAST 50-75 lbs. As we have stated, the T56 trans is the only thing truly heavier when you condider the tow setups make equal power.
I'll take 50 lbs (on the high side) low and in the middle of the car for a flat torque curve and extra reliability.
The FC rotary guys that make similar power to my car weight pretty much the same as my car. I am not even saying that one engine is faster than another, although I believe the V8 is easier to drive, and you may get away with shifting less, but that will depend on the rotary setup.
Last edited by LargeOrangeFont; 11-25-15 at 12:58 PM.
11-25-15, 12:45 PM
#27
If I wanted to own a Corvette, I would have bought one. I made no mention about even drag racing the car. If there was no V8 swaps available, I would still be driving the RX-7 with the rotary. I've always love the FD when I first saw it when I was in middle school.
On a side note, I'm hoping to meet a 3 rotor owner and tell them you ruined the car. I would love to see their reaction.
I still love rotaries and even with the V8 hate, I still love you guys. The RX-7 community is a great , v8 or not.
On a side note, I'm hoping to meet a 3 rotor owner and tell them you ruined the car. I would love to see their reaction.
I still love rotaries and even with the V8 hate, I still love you guys.
The RX-7 community is a great , v8 or not.
11-25-15, 02:56 PM
#29
I think we have plenty of evidence that swapped cars are indeed NOT any heavier after the swap
Yes I added weight to my 2500 lb NA FC when I put in the V8. I added about 100 TOTAL lbs after everything was said and done.
I'll take 50 lbs (on the high side) low and in the middle of the car for a flat torque curve and extra reliability.
Yes I added weight to my 2500 lb NA FC when I put in the V8. I added about 100 TOTAL lbs after everything was said and done.
I'll take 50 lbs (on the high side) low and in the middle of the car for a flat torque curve and extra reliability.
Typically compliments on doing a fairly unique and expensive swap as they wanted to instead of swapping something because they felt that X was the bestest and will ignore everything that says otherwise.
11-25-15, 03:49 PM
#30
What were you saying? It doesn't seem like you even know. You cannot even agree with yourself on a general number for added weight and keep using an arbitrary "but rptary mods add lots too!" as well as implying that the CG of an LSx is not higher and it's weight in general is not less centralized. LOF, you're the one making this appear religious.
Typically compliments on doing a fairly unique and expensive swap as they wanted to instead of swapping something because they felt that X was the bestest and will ignore everything that says otherwise.
Typically compliments on doing a fairly unique and expensive swap as they wanted to instead of swapping something because they felt that X was the bestest and will ignore everything that says otherwise.
I posted evidence from someone with an FD that weighed their car before and after the swap. It was 20 lbs heavier AFTER the swap and they added larger wheels, tires, and other accessories, and you dismissed it and said they did "other mods". The complete story of weight differences are not just hanging individual drivetrain parts from a scale, there are other modifications that need to be done to the car for the conversion, and some of those remove some weight as well. The total package needs to be taken into consideration. Like I said before, I added right around 100 lbs to the curb weight of my car, and my car was an NA FC. were other things done at the same time.. of course, but I'm not driving the engine, I'm driving the entire car.
A stock turbo rotary car and a v8 swapped car are not in the same league, so lets be realistic here. You need to add more power to the rotary car to keep up. Like I said, if you want to low powered car, keep you car rotary powered.
I does not bother me if you like the rotary more.. it is fine and there are plenty of people that have success with them. As most people on this thread will admit to, if you line up the pros and cons of doing a v8 swap, aside from superficial "revving" and "turbo sounds" and the emotional response of "removing the soul", a V8 swap makes a lot of sense. It does not ruin the car, and it does not perform any worse. If you have a perfectly functioning rotary engine, it is probably hard to make the jump. If you have blown up 2 or 3, and have a broken car in your garage, I can see how you would be sick of dumping money into rotaries and want to try something else.
Last year my car was about a second slower around Big Willow than a similar Rotary powered car.. he had bigger tires, aero mods, and 50 more HP than me. I have go Karted with the guy, we have pretty even driving skills.
If you have not been in one, go for a ride in one. If you still can't respect the car for what it is with a v8, then just keep your head in the sand. All the die hard rotary guys that have ridden in my car have at least walked away respecting the car for what it is, if not being blown away.
Last edited by LargeOrangeFont; 11-25-15 at 03:58 PM.
The following users liked this post:
mkd (05-08-20)
11-25-15, 04:21 PM
#32
Penis Healthy
iTrader: (5)
Join Date: Jul 2013
Location: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Posts: 2,595
Received 775 Likes
on
444 Posts
We call it "spoiling". I used to ride a Suzuki RM250 back in ~2003. After riding a friend of mines 2003 CRF450, i was "spoiled". Had to make the change, had to get one. Being constantly in the power band no matter which gear you are in, not having to worry about shifting, power was always there.
Anyways, my point. Theres no equal footing anymore. 4 strokes dominate 2 stroke, bottomline.
11-25-15, 04:27 PM
#33
You've cherry picked an example and are saying that because the example shows something that the facts that the fully dressed engines are 100lbs different and the trans weights are also different doesn't matter because you and others who have spent thousands upon thousands of dollars doing something said so.
The total package doesn't need to be taken into consideration because it's the sum of its parts. Scales are different. Zero's are different. It shifts with time even on the same scale. Accuracy %, not mod for mod, etc.. In short, there is zero reason to believe that your example is anywhere close to reality and/or that the full matter has been disclosed.
You keep forgetting I have an LS1 in my FC.
No, there isn't anything to make me think that one of the most common swaps in the world is special or deserves praise simply because some one also did it.
11-25-15, 05:16 PM
#34
Anyways, my point. Theres no equal footing anymore. 4 strokes dominate 2 stroke, bottomline.
Racing politics is why you are comparing a 250cc 2 stroke and 450cc 4 stroke.
If the 4 strokes have a handicap of nearly double displacement and are better...
sounds like they don't need the handicap now?
I don't call that dominating.
Racing politics is why you are comparing a 250cc 2 stroke and 450cc 4 stroke.
If the 4 strokes have a handicap of nearly double displacement and are better...
sounds like they don't need the handicap now?
I don't call that dominating.
11-25-15, 05:35 PM
#35
Penis Healthy
iTrader: (5)
Join Date: Jul 2013
Location: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Posts: 2,595
Received 775 Likes
on
444 Posts
Anyways, my point. Theres no equal footing anymore. 4 strokes dominate 2 stroke, bottomline.
Racing politics is why you are comparing a 250cc 2 stroke and 450cc 4 stroke.
If the 4 strokes have a handicap of nearly double displacement and are better...
sounds like they don't need the handicap now?
I don't call that dominating.
Racing politics is why you are comparing a 250cc 2 stroke and 450cc 4 stroke.
If the 4 strokes have a handicap of nearly double displacement and are better...
sounds like they don't need the handicap now?
I don't call that dominating.
In a 250 vs 450 displacement the 250 2-stroke has an advantage, it fires twice as often as the 450. 4-strokes would need a displacement of 500 for the playing field to be even.
Are you saying theyre in the same class due to a handicap?
If that is true, why dont 250 4 strokes race with 250 2 strokes, after the new 4 stroke technology in 2000?
CRF450 VS CR500
Q: WHICH ONE MAKES THE MOST POWER?
A: Stock for stock there is no comparison?the CR500 two-stroke pumps out approximately 55 horsepower, to the 50 horsepower of the CRF450. If you doubt those numbers, you will be convinced by turning the throttle wide open on both bikes. The CR500 explodes, while the CRF450 churns its way forward.
In a test of sheer power, the CR500 wins. Unfortunately for the CR500, the only way to make all that power controllable is to tame it (which Honda did in later years by gearing the bikes taller) or turn it on with caution. The CRF450 doesn’t require as much care. It makes more power off the bottom and on the top than the CR500. And, it does it all in a manageable, torquey manner. The CRF450 is Dr. Jekyll. The CR500 is Mr. Hyde.
Q: WHICH ONE IS THE FASTEST?
A: First and foremost, our concept of faster is gauged by the ability to ride the bike faster?not just hang on and pray. The CRF450 turned faster lap times because it has a controllable delivery. It was less violent under acceleration and less chuggy under deceleration. The versatility of the four-stroke outweighs its shortcomings at peak horsepower. No contest.
But, and this is a big but, if you have the skill to pull the trigger, the CR500 would actually gobble the CRF450 up in deep loam, rough straights and steep hills. The big two-stroke was a rocketship when it had a rocket man at the controls.
Q: WHICH ONE IS EASIER TO RIDE?
A: The idea of easy-to-ride can’t even be applied to the CR500. It is a workout to hang on to it. When you build up the bravery or get it up to speed, things start to smooth out, but it takes talent, nerves and skill to leave it on. This category is all about the CRF450.
Q: AND THE POWERBAND WINNER IS?
A: Need you ask? The CRF450 wins the overall powerband category
Q: AND THE WINNER IS…
A: As the two bikes sit, the 2008 CRF450 is a much better race bike than the 2001 CR500. You don’t have to be Sherlock Holmes to figure that out?but even Dr. Watson would be surprised that the margin of victory wasn’t as great as everyone expected.
A: Stock for stock there is no comparison?the CR500 two-stroke pumps out approximately 55 horsepower, to the 50 horsepower of the CRF450. If you doubt those numbers, you will be convinced by turning the throttle wide open on both bikes. The CR500 explodes, while the CRF450 churns its way forward.
In a test of sheer power, the CR500 wins. Unfortunately for the CR500, the only way to make all that power controllable is to tame it (which Honda did in later years by gearing the bikes taller) or turn it on with caution. The CRF450 doesn’t require as much care. It makes more power off the bottom and on the top than the CR500. And, it does it all in a manageable, torquey manner. The CRF450 is Dr. Jekyll. The CR500 is Mr. Hyde.
Q: WHICH ONE IS THE FASTEST?
A: First and foremost, our concept of faster is gauged by the ability to ride the bike faster?not just hang on and pray. The CRF450 turned faster lap times because it has a controllable delivery. It was less violent under acceleration and less chuggy under deceleration. The versatility of the four-stroke outweighs its shortcomings at peak horsepower. No contest.
But, and this is a big but, if you have the skill to pull the trigger, the CR500 would actually gobble the CRF450 up in deep loam, rough straights and steep hills. The big two-stroke was a rocketship when it had a rocket man at the controls.
Q: WHICH ONE IS EASIER TO RIDE?
A: The idea of easy-to-ride can’t even be applied to the CR500. It is a workout to hang on to it. When you build up the bravery or get it up to speed, things start to smooth out, but it takes talent, nerves and skill to leave it on. This category is all about the CRF450.
Q: AND THE POWERBAND WINNER IS?
A: Need you ask? The CRF450 wins the overall powerband category
Q: AND THE WINNER IS…
A: As the two bikes sit, the 2008 CRF450 is a much better race bike than the 2001 CR500. You don’t have to be Sherlock Holmes to figure that out?but even Dr. Watson would be surprised that the margin of victory wasn’t as great as everyone expected.
Last edited by FührerTüner; 11-25-15 at 05:55 PM.
11-25-15, 05:57 PM
#36
The first is done for clear reason(s) and doesn't have one of the biggest automotive lies of "it's lighter!" attached to it. The later is typically done because the owner thinks X is true when it isn't.
You've cherry picked an example and are saying that because the example shows something that the facts that the fully dressed engines are 100lbs different and the trans weights are also different doesn't matter because you and others who have spent thousands upon thousands of dollars doing something said so.
The total package doesn't need to be taken into consideration because it's the sum of its parts. Scales are different. Zero's are different. It shifts with time even on the same scale. Accuracy %, not mod for mod, etc.. In short, there is zero reason to believe that your example is anywhere close to reality and/or that the full matter has been disclosed.
You keep forgetting I have an LS1 in my FC.
No, there isn't anything to make me think that one of the most common swaps in the world is special or deserves praise simply because some one also did it.
You've cherry picked an example and are saying that because the example shows something that the facts that the fully dressed engines are 100lbs different and the trans weights are also different doesn't matter because you and others who have spent thousands upon thousands of dollars doing something said so.
The total package doesn't need to be taken into consideration because it's the sum of its parts. Scales are different. Zero's are different. It shifts with time even on the same scale. Accuracy %, not mod for mod, etc.. In short, there is zero reason to believe that your example is anywhere close to reality and/or that the full matter has been disclosed.
You keep forgetting I have an LS1 in my FC.
No, there isn't anything to make me think that one of the most common swaps in the world is special or deserves praise simply because some one also did it.
No one propagated any notion that the v8 lighter in this thread. I have said the opposite. If you want to retort and argue the accuracy of peoples' scales you have clearly run out of mental capacity to continue this conversation. I came with facts that people have clearly stated on other threads of this website and facts from my own experience. If you don't believe them, or me, I don't care.
The total package DOES need to be taken into consideration. If you buy a new exhaust system for your car, do you just strap it to the old one under the car and run 2? No, you remove the old system and install the new one. These swaps are a package deal, and we build the car to accept the powertrain package. That means modifying the car in ways that we never would have if we kept a rotary in the car. If I took out 30 lbs of stuff I didn't need to run the v8, and added 100 lbs, the net weight gain is 70 lbs. So the shipping weight of the engine does not mean a damn thing.
I don't really know what your argument here is. If you want to tell me that a 13bt is lighter, sure. Then run your 300 HP 13BT, and I will run circles around you with my 475HP v8 that is 100 lbs heavier. Ok so now you want to keep up and mod your 13BT.. great. Now that you have thrown 50-60 extra lbs of stuff on the car, my car is now 50 lbs heavier but the two cars make the same power. We drag race, Yes you are lighter, but I have to make one fewer shifts down the track. Guess what, the cars are basically even. Same basic deal on a roadcourse.
Last edited by LargeOrangeFont; 11-25-15 at 06:10 PM.
11-25-15, 06:02 PM
#37
I always thought 250 2 strokes and 450 4strokes were in the same class because 4 strokes have twice the amounts of revolutions per combustion stroke. 2 strokes also tend to be about 30lbs lighter.
In a 250 vs 450 displacement the 250 2-stroke has an advantage, it fires twice as often as the 450. 4-strokes would need a displacement of 500 for the playing field to be even.
Are you saying theyre in the same class due to a handicap?
If that is true, why dont 250 4 strokes race with 250 2 strokes, after the new 4 stroke technology in 2000?
CRF450 VS CR500
Motocross Action Magazine | MOTOCROSS ACTION?S TWO-STROKE VERSUS FOUR-STROKE SHOOTOUT: 2004 CRF450 VERSUS 2001 CR500
In a 250 vs 450 displacement the 250 2-stroke has an advantage, it fires twice as often as the 450. 4-strokes would need a displacement of 500 for the playing field to be even.
Are you saying theyre in the same class due to a handicap?
If that is true, why dont 250 4 strokes race with 250 2 strokes, after the new 4 stroke technology in 2000?
CRF450 VS CR500
Motocross Action Magazine | MOTOCROSS ACTION?S TWO-STROKE VERSUS FOUR-STROKE SHOOTOUT: 2004 CRF450 VERSUS 2001 CR500
It truly similar to comparing a rotary to a piston engine. It is the reason piston displacement rules and rotary displacement rules differ for certain racing classes. A 1.3 L rotary would kill most 1.3 L piston engines.
11-25-15, 07:19 PM
#38
I don't have any issue with the V8 in an RX-7.
I would like to try it but it costs quite a bit and sucks for SCCA race classing.
I really like the idea of being able to get that power on cheap 91 octane and having stock engine reliability at that power.
as far as this-
I don't really know what your argument here is. If you want to tell me that a 13bt is lighter, sure. Then run your 300 HP 13BT, and I will run circles around you with my 475HP v8 that is 100 lbs heavier. Ok so now you want to keep up and mod your 13BT.. great. Now that you have thrown 50-60 extra lbs of stuff on the car, my car is now 50 lbs heavier but the two cars make the same power. We drag race, Yes you are lighter, but I have to make one fewer shifts down the track. Guess what, the cars are basically even. Same basic deal on a roadcourse
When you mod rotaries they get a lot lighter not heavier.
Stock 13B-REW is heavy for sure at 425-450Lbs with full accessories. Not much lighter than the LS V8.
A 13BT with full accessories is 370Lbs (to give you an idea what a full emissions full power accessories single turbo would weight).
Not many V8 or single turbo 13B guys put full emissions and AC back on the car and some skip power steering.
A typical single turbo race (non emmissions) 13B weights around 300-325Lbs.
You need to put in a big radiator, so that is some weight. I put in a aftermarket V8 radiator 28"x19"x3".
Obviously would want that with a V8 at the same power too since that is what the radiator was made for.
Even a big intercooler is really light at 5-10lbs.
I used stock FC TII drivetrain with an upgraded clutch, its tough.
Lots of V8 guys use the stock FC rear end. Problem is the gear ratios suck for daily driving lower revving V8.
FD rear ends are fragile- gotta spend $ and weight there whether V8 or rotary with 400ftlbs torque.
MY rotary TII dropped down to 2,5xxLbs (low to high depending on how much gas) by modifying it and it was still full interior.
Most that weight unfortunately came out from under the hood so it had an annoying to me 51-52% rear weight bias.
I am not arguing against V8 swaps, just arguing against the idea of gaining weight making more power with the rotary.
Not that the weight difference matters much.
I have never known 200lbs to make a difference in times on my car, I am often fastest with a passenger.
I would like to try it but it costs quite a bit and sucks for SCCA race classing.
I really like the idea of being able to get that power on cheap 91 octane and having stock engine reliability at that power.
as far as this-
I don't really know what your argument here is. If you want to tell me that a 13bt is lighter, sure. Then run your 300 HP 13BT, and I will run circles around you with my 475HP v8 that is 100 lbs heavier. Ok so now you want to keep up and mod your 13BT.. great. Now that you have thrown 50-60 extra lbs of stuff on the car, my car is now 50 lbs heavier but the two cars make the same power. We drag race, Yes you are lighter, but I have to make one fewer shifts down the track. Guess what, the cars are basically even. Same basic deal on a roadcourse
When you mod rotaries they get a lot lighter not heavier.
Stock 13B-REW is heavy for sure at 425-450Lbs with full accessories. Not much lighter than the LS V8.
A 13BT with full accessories is 370Lbs (to give you an idea what a full emissions full power accessories single turbo would weight).
Not many V8 or single turbo 13B guys put full emissions and AC back on the car and some skip power steering.
A typical single turbo race (non emmissions) 13B weights around 300-325Lbs.
You need to put in a big radiator, so that is some weight. I put in a aftermarket V8 radiator 28"x19"x3".
Obviously would want that with a V8 at the same power too since that is what the radiator was made for.
Even a big intercooler is really light at 5-10lbs.
I used stock FC TII drivetrain with an upgraded clutch, its tough.
Lots of V8 guys use the stock FC rear end. Problem is the gear ratios suck for daily driving lower revving V8.
FD rear ends are fragile- gotta spend $ and weight there whether V8 or rotary with 400ftlbs torque.
MY rotary TII dropped down to 2,5xxLbs (low to high depending on how much gas) by modifying it and it was still full interior.
Most that weight unfortunately came out from under the hood so it had an annoying to me 51-52% rear weight bias.
I am not arguing against V8 swaps, just arguing against the idea of gaining weight making more power with the rotary.
Not that the weight difference matters much.
I have never known 200lbs to make a difference in times on my car, I am often fastest with a passenger.
11-25-15, 07:29 PM
#39
In a 250 vs 450 displacement the 250 2-stroke has an advantage, it fires twice as often as the 450. 4-strokes would need a displacement of 500 for the playing field to be even.
"To make the playing field even."
That is the politics of racing.
The playing field isn't even because we agree the 2 stroke is superior in power production by having twice as many power strokes per crankshaft revolution and weighting less.
So the 4 strokes get a handicap in the form of being able to run higher displacement to make up for their inferior design.
"To make the playing field even."
That is the politics of racing.
The playing field isn't even because we agree the 2 stroke is superior in power production by having twice as many power strokes per crankshaft revolution and weighting less.
So the 4 strokes get a handicap in the form of being able to run higher displacement to make up for their inferior design.
11-25-15, 08:18 PM
#40
I don't have any issue with the V8 in an RX-7.
I would like to try it but it costs quite a bit and sucks for SCCA race classing.
I really like the idea of being able to get that power on cheap 91 octane and having stock engine reliability at that power.
as far as this-
I don't really know what your argument here is. If you want to tell me that a 13bt is lighter, sure. Then run your 300 HP 13BT, and I will run circles around you with my 475HP v8 that is 100 lbs heavier. Ok so now you want to keep up and mod your 13BT.. great. Now that you have thrown 50-60 extra lbs of stuff on the car, my car is now 50 lbs heavier but the two cars make the same power. We drag race, Yes you are lighter, but I have to make one fewer shifts down the track. Guess what, the cars are basically even. Same basic deal on a roadcourse
When you mod rotaries they get a lot lighter not heavier.
Stock 13B-REW is heavy for sure at 425-450Lbs with full accessories. Not much lighter than the LS V8.
A 13BT with full accessories is 370Lbs (to give you an idea what a full emissions full power accessories single turbo would weight).
Not many V8 or single turbo 13B guys put full emissions and AC back on the car and some skip power steering.
A typical single turbo race (non emmissions) 13B weights around 300-325Lbs.
You need to put in a big radiator, so that is some weight. I put in a aftermarket V8 radiator 28"x19"x3".
Obviously would want that with a V8 at the same power too since that is what the radiator was made for.
Even a big intercooler is really light at 5-10lbs.
I used stock FC TII drivetrain with an upgraded clutch, its tough.
Lots of V8 guys use the stock FC rear end. Problem is the gear ratios suck for daily driving lower revving V8.
FD rear ends are fragile- gotta spend $ and weight there whether V8 or rotary with 400ftlbs torque.
MY rotary TII dropped down to 2,5xxLbs (low to high depending on how much gas) by modifying it and it was still full interior.
Most that weight unfortunately came out from under the hood so it had an annoying to me 51-52% rear weight bias.
I am not arguing against V8 swaps, just arguing against the idea of gaining weight making more power with the rotary.
Not that the weight difference matters much.
I have never known 200lbs to make a difference in times on my car, I am often fastest with a passenger.
I would like to try it but it costs quite a bit and sucks for SCCA race classing.
I really like the idea of being able to get that power on cheap 91 octane and having stock engine reliability at that power.
as far as this-
I don't really know what your argument here is. If you want to tell me that a 13bt is lighter, sure. Then run your 300 HP 13BT, and I will run circles around you with my 475HP v8 that is 100 lbs heavier. Ok so now you want to keep up and mod your 13BT.. great. Now that you have thrown 50-60 extra lbs of stuff on the car, my car is now 50 lbs heavier but the two cars make the same power. We drag race, Yes you are lighter, but I have to make one fewer shifts down the track. Guess what, the cars are basically even. Same basic deal on a roadcourse
When you mod rotaries they get a lot lighter not heavier.
Stock 13B-REW is heavy for sure at 425-450Lbs with full accessories. Not much lighter than the LS V8.
A 13BT with full accessories is 370Lbs (to give you an idea what a full emissions full power accessories single turbo would weight).
Not many V8 or single turbo 13B guys put full emissions and AC back on the car and some skip power steering.
A typical single turbo race (non emmissions) 13B weights around 300-325Lbs.
You need to put in a big radiator, so that is some weight. I put in a aftermarket V8 radiator 28"x19"x3".
Obviously would want that with a V8 at the same power too since that is what the radiator was made for.
Even a big intercooler is really light at 5-10lbs.
I used stock FC TII drivetrain with an upgraded clutch, its tough.
Lots of V8 guys use the stock FC rear end. Problem is the gear ratios suck for daily driving lower revving V8.
FD rear ends are fragile- gotta spend $ and weight there whether V8 or rotary with 400ftlbs torque.
MY rotary TII dropped down to 2,5xxLbs (low to high depending on how much gas) by modifying it and it was still full interior.
Most that weight unfortunately came out from under the hood so it had an annoying to me 51-52% rear weight bias.
I am not arguing against V8 swaps, just arguing against the idea of gaining weight making more power with the rotary.
Not that the weight difference matters much.
I have never known 200lbs to make a difference in times on my car, I am often fastest with a passenger.
I am not going to necessarily argue with you about adding weight to a rotary. If you say its net the same or lighter than stock to make similar power I will believe you, but the guys I have seen seem to have a lot of extra "stuff" in oil coolers, v mount setups, etc to keep it healthy.
Keep in mind the same is true for the v8 - we strip some weight off of it. Shipping weight for an LS3 crate motor is about 430 lbs. It is 484 lbs in the crate with all the packaging. That is with the cast iron manifolds and a steel flexplate. I am ditching the cast manifolds for much lighter headers, and adding an alternator. That is it. I'm below the weight of the crate motor at that point. The steel flexplate is replaced with an aluminium flywheel. So all in I am at about +50 lbs on the engine over a 13bt and another 50lbs on the trans. I'm dropping a bit of weight on the trans crossmember and motor mounts for the v8
These engines come out of the car at around 500 lbs with everything on them and a heavy steel flywheel & clutch. Many of the oe brackets and manifolds get pitched.
My car being 80-100 lbs heavier than yours it would not surprise me. I have 10+ extra lbs of stuff just bolted to my roll bar. If I removed that and the accusump it would be around 60-70 lbs difference. That is almost not enough of a change to even notice. We are not pro drivers here.
Last edited by LargeOrangeFont; 11-25-15 at 08:39 PM.
11-25-15, 08:42 PM
#41
This may have been true about 15 years ago. Since the high compression 4 stroke engines came out, 2 strokes cant even compete with the torque of the 4 stroke engines. Thats why you dont see anyone racing 2 strokes anymore. The torque just isnt there. I can tell you this from personal experience, and being a witness to other 2 stroke riders who try out 4 strokes.
We call it "spoiling". I used to ride a Suzuki RM250 back in ~2003. After riding a friend of mines 2003 CRF450, i was "spoiled". Had to make the change, had to get one. Being constantly in the power band no matter which gear you are in, not having to worry about shifting, power was always there.
Anyways, my point. Theres no equal footing anymore. 4 strokes dominate 2 stroke, bottomline.
We call it "spoiling". I used to ride a Suzuki RM250 back in ~2003. After riding a friend of mines 2003 CRF450, i was "spoiled". Had to make the change, had to get one. Being constantly in the power band no matter which gear you are in, not having to worry about shifting, power was always there.
Anyways, my point. Theres no equal footing anymore. 4 strokes dominate 2 stroke, bottomline.
you got it sorta right. the engines got more valves, fuel injection, lightened rotating assemblies and run higher RPMs with slightly more compression. this lets them rev more like a street bike with the torque of a larger single cylinder, the old 2v thumpers still made more torque though where you have to wind out these new bikes higher.
course there is still the displacement to quantify, a 2 stroke can make more power from less displacement since it fires twice as often. but if you count the displacement of each firing sequence then the 4 stroke wins all out. you see this difference in motorcycle racing where 2 strokes are given heavy handicaps in displacement versus 4 strokes.
the rotary puts out a lot of power for its size due to the fact it fires more like a 6 cylinder 2.6L but it is much more compact like a 2 stroke engine due to the firing sequences.
my old 500 thumper would cry if i held it pinned at 10k like these new 4 strokes. all the 2 strokes i ever owned you could just pin the throttle all day long if you liked.
downside to the new 4 strokes is they do not last, they require rebuilding almost as often as their 2 stroke distant relatives.
but funny you say 2 strokes lacked torque, my brother's 1986 CR500 was a complete beast. not many bikes scared me but that thing was virtually uncontrollable, you could idle it at 20mph in 5th and tap the throttle while laying your chest over the bars and it would still lift the front wheel... a brand new 600cc 4 stroke wouldn't do that. my 1200cc 2 stroke Ultra 150 waverunner had 149hp and could literally tow a 20' boat with relative ease. it's all because the CC of a 2 stroke is virtually halved, if you double it, then yes it has a serious disadvantage numbers wise.
in a nutshell, if you put a 250cc 2 stroke against a 500cc 4 stroke, the 2 stroke will generally fall behind.
as LOF mentioned, 2 strokes aren't disappearing because people just don't like them anymore, it is because of emissions regulations being put on them. they simply don't meet EPA requirements and cannot be sold. i always preferred the lightweight of the 2 strokes and the rather notchy powerband that felt like a turbo kicking in, does that sound familiar?
i use this comparison because there is 2 types of people:
those who put throttle response and torque above all else
those who put smooth high revving RPMs with a spikey power band above all else
given the above, i wish people would quit bashing on people who put V8s in their cars, and inversely i wish the V8 owners would quit antagonizing the rotary owners for their choice either. i have always liked 2 strokes over 4 strokes, but i also enjoy the responsiveness and torque of a 4 stroke as well.
the biggest handicap the rotary still has is the cast iron plates, which make up nearly 1/4 the weight of the short block. the new V8's have overcome this weight handicap, but what if we got aluminum plates? then the rotary wouldn't be nearly equal to a short block V8 in weight anymore, again. when the V8s were cast iron and aluminum mixed... you'd have a heavy nosed RX7 and you knew it.
if the rotary engine survived long enough for technology in machining to advance far enough, i think a mostly ceramic rotary engine would be badass. revert to air cooling!
Last edited by RotaryEvolution; 11-25-15 at 09:13 PM.
11-25-15, 11:11 PM
#42
Penis Healthy
iTrader: (5)
Join Date: Jul 2013
Location: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Posts: 2,595
Received 775 Likes
on
444 Posts
you got it sorta right. the engines got more valves, fuel injection, lightened rotating assemblies and run higher RPMs with slightly more compression. this lets them rev more like a street bike with the torque of a larger single cylinder, the old 2v thumpers still made more torque though where you have to wind out these new bikes higher.
And btw, I'm pretty sure xr400s have 4 valves.
the rotary puts out a lot of power for its size due to the fact it fires more like a 6 cylinder 2.6L but it is much more compact like a 2 stroke engine due to the firing sequences.
my old 500 thumper would cry if i held it pinned at 10k like these new 4 strokes. all the 2 strokes i ever owned you could just pin the throttle all day long if you liked.
downside to the new 4 strokes is they do not last, they require rebuilding almost as often as their 2 stroke distant relatives.
downside to the new 4 strokes is they do not last, they require rebuilding almost as often as their 2 stroke distant relatives.
but funny you say 2 strokes lacked torque, my brother's 1986 CR500 was a complete beast. not many bikes scared me but that thing was virtually uncontrollable, you could idle it at 20mph in 5th and tap the throttle while laying your chest over the bars and it would still lift the front wheel... a brand new 600cc 4 stroke wouldn't do that. my 1200cc 2 stroke Ultra 150 waverunner had 149hp and could literally tow a 20' boat with relative ease. it's all because the CC of a 2 stroke is virtually halved, if you double it, then yes it has a serious disadvantage numbers wise.
as LOF mentioned, 2 strokes aren't disappearing because people just don't like them anymore, it is because of emissions regulations being put on them. they simply don't meet EPA requirements and cannot be sold. i always preferred the lightweight of the 2 strokes and the rather notchy powerband that felt like a turbo kicking in, does that sound familiar?
i use this comparison because there is 2 types of people:
those who put throttle response and torque above all else
those who put smooth high revving RPMs with a spikey power band above all else
those who put throttle response and torque above all else
those who put smooth high revving RPMs with a spikey power band above all else
given the above, i wish people would quit bashing on people who put V8s in their cars, and inversely i wish the V8 owners would quit antagonizing the rotary owners for their choice either. i have always liked 2 strokes over 4 strokes, but i also enjoy the responsiveness and torque of a 4 stroke as well.
the biggest handicap the rotary still has is the cast iron plates, which make up nearly 1/4 the weight of the short block. the new V8's have overcome this weight handicap, but what if we got aluminum plates? then the rotary wouldn't be nearly equal to a short block V8 in weight anymore, again. when the V8s were cast iron and aluminum mixed... you'd have a heavy nosed RX7 and you knew it.
if the rotary engine survived long enough for technology in machining to advance far enough, i think a mostly ceramic rotary engine would be badass. revert to air cooling!
the biggest handicap the rotary still has is the cast iron plates, which make up nearly 1/4 the weight of the short block. the new V8's have overcome this weight handicap, but what if we got aluminum plates? then the rotary wouldn't be nearly equal to a short block V8 in weight anymore, again. when the V8s were cast iron and aluminum mixed... you'd have a heavy nosed RX7 and you knew it.
if the rotary engine survived long enough for technology in machining to advance far enough, i think a mostly ceramic rotary engine would be badass. revert to air cooling!
Last edited by FührerTüner; 11-25-15 at 11:30 PM.
11-25-15, 11:46 PM
#43
Penis Healthy
iTrader: (5)
Join Date: Jul 2013
Location: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Posts: 2,595
Received 775 Likes
on
444 Posts
In a 250 vs 450 displacement the 250 2-stroke has an advantage, it fires twice as often as the 450. 4-strokes would need a displacement of 500 for the playing field to be even.
"To make the playing field even."
That is the politics of racing.
The playing field isn't even because we agree the 2 stroke is superior in power production by having twice as many power strokes per crankshaft revolution and weighting less.
So the 4 strokes get a handicap in the form of being able to run higher displacement to make up for their inferior design.
"To make the playing field even."
That is the politics of racing.
The playing field isn't even because we agree the 2 stroke is superior in power production by having twice as many power strokes per crankshaft revolution and weighting less.
So the 4 strokes get a handicap in the form of being able to run higher displacement to make up for their inferior design.
11-26-15, 12:40 AM
#44
No one propagated any notion that the v8 lighter in this thread. I have said the opposite. If you want to retort and argue the accuracy of peoples' scales you have clearly run out of mental capacity to continue this conversation. I came with facts that people have clearly stated on other threads of this website and facts from my own experience. If you don't believe them, or me, I don't care.
Just to be sure we're on the same page, we have two idealized cars with the same hp but one is lighter than the other. Which is faster?
The total package DOES need to be taken into consideration. If you buy a new exhaust system for your car, do you just strap it to the old one under the car and run 2? No, you remove the old system and install the new one. These swaps are a package deal, and we build the car to accept the powertrain package. That means modifying the car in ways that we never would have if we kept a rotary in the car. If I took out 30 lbs of stuff I didn't need to run the v8, and added 100 lbs, the net weight gain is 70 lbs. So the shipping weight of the engine does not mean a damn thing.
I don't really know what your argument here is. If you want to tell me that a 13bt is lighter, sure. Then run your 300 HP 13BT, and I will run circles around you with my 475HP v8 that is 100 lbs heavier. Ok so now you want to keep up and mod your 13BT.. great. Now that you have thrown 50-60 extra lbs of stuff on the car, my car is now 50 lbs heavier but the two cars make the same power. We drag race, Yes you are lighter, but I have to make one fewer shifts down the track. Guess what, the cars are basically even. Same basic deal on a roadcourse.
Having stated my position so many times in so few posts it really makes me wonder if you're actually reading my posts since you cannot seem to figure out my position when it's been stated clearly and in a variety of way and often.
I was under the impression that there were aftermarket aluminum plates...
11-26-15, 09:24 AM
#45
You have continually tried to mitigate the fact that an LSx swapped car is heavier than its non-swapped counter part. That has been my point from the beginning but you have turned it into the religious debate and bring a cherry picked example to the table while ignoring the basic facts, saying they don't matter, and saying that my calling into question your example means that I don't know what I'm talking about.
As I have explained numerous times, both in this thread and others, and as I would think would be apparent to someone of your background, is the simple fact that everything you can do during the swap you can do without doing the swap. There is no synergy here. It is the sum of its parts.
The total package doesn't need to be taken into consideration because it's the sum of its parts. Scales are different. Zero's are different. It shifts with time even on the same scale. Accuracy %, not mod for mod, etc.. In short, there is zero reason to believe that your example is anywhere close to reality and/or that the full matter has been disclosed.
In closing, please quote me where I have ever said that an LS swap will always be lighter. I cited an example of one FD that was lighter, and my personal car that is heavier. I have always said the weight is nothing more than CLOSE. I would call a 2-5% weight gain on an FC close, and it is less than that for an FD.
Last edited by LargeOrangeFont; 11-26-15 at 09:31 AM.
11-26-15, 10:03 AM
#49
I am not and FD swap expert, but in the FD I know you remove the PPF and associated hardware. You also swap the front subframe for a lighter one. That is part of what keeps the post swap weights closer in an FD.
11-26-15, 10:47 AM
#50
LOF likes to be obtuse and use non-equal starting and finishing points so the math doesn't come out as horribly out of his favor as it otherwise would. For instance, he likes to compare a fully dressed rotary weight to a non-fully dressed LS3 weight. This is why he keeps posting 430lbs (not fully dressed LS3 weight) when the fully dressed weight (for an LS1) is 500lbs.
He also forgets that if you want to get into the nuts and bolts of it you can change to aluminum irons, make a custom subframe, etc. Basically, LOF doesn't want to admit that one is more extensively modded than the other and that if you actually wanted this to be as close to apples to apples as possible then it wouldn't be "only" 20lbs, 50lbs, or whatever other number he wants to use to justify a swap that can cost in excess of 10k. And at the end of the day, it is heavier and the weight is less favorably placed which means it's slower on a track if other things are equal. These numbers also assumes that the person is actually using an all aluminum block in the first place which is hardly the universal case.
Perhaps the biggest thing that almost never gets mentioned, except on SBC/LS/etc. forums, is that if you're buying a junkyard motor, something very common, it is recommended to perform a rebuild before you even put it in the car. Or at the very least change all the seals, gaskets, and depending on the motor perform reliability upgrades like a new/different oil pump, cross over lines, etc.
Yes, I keep saying "LOF" but in reality it's only because he's the one responding. Like I touch on previously, this lack of forthrightness in swap vs. not is shared by many who do swaps and ignored by those who don't simply because it's not thought of or just to tolerate them on that particular subject.
Coming from someone with a working, driving, LS1 swap in their FC I can tell you this. I can retain just about all the custom work I've done if I were to "simply" just put a rotary back in the car. Making the assumption that the accessory weights are similar if I were to simply put a 13bt back in the car while keeping the rest of my setup (trans, driveshaft, alternator, no PS, etc.) the same I would lose ~120lbs. Just from changing the engine.
Anywho, Happy Thanksgiving.
Last edited by valley; 11-26-15 at 11:11 AM. Reason: clarity
