13B-REW to LS1 Perspective
04-16-08, 05:12 PM
#76
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I completely subscribe to the notion that it's your car to do with what you want so it's not about rotary "loyalty" like it's my gang colors or something... but what I see as an annoying common thread amongst V8 conversion guys is this bitter attitude from having been burned by the rotary.
Was there not plenty of information out there on the 3rd Gen RX7 to tell you what they require and what's involved? These cars are thoroughbreds, just like most every high performance car and they require extra maintenance and care. If you don't have the time, money, patience, etc., what the hell did you buy an FD with a blown motor for? Don't tell me about logic.
Per my original "marry a pornstar" analogy, you were expecting the car to be something it isn't.
Was there not plenty of information out there on the 3rd Gen RX7 to tell you what they require and what's involved? These cars are thoroughbreds, just like most every high performance car and they require extra maintenance and care. If you don't have the time, money, patience, etc., what the hell did you buy an FD with a blown motor for? Don't tell me about logic.
Per my original "marry a pornstar" analogy, you were expecting the car to be something it isn't.
I have a other things I'd like to do with my time outside of blowing kisses to an engine when there's a better alternative.
Thoroughbred? This isn't a Ferrari were talking about—it's a GD Mazda. And I'm not taking it to the track and driving in circles for 3 hrs. I just want to drive the damn thing to Sonic and buy a hot dog.
04-16-08, 05:17 PM
#78
ya'll are so civil here in the 3rd gen seciton... this would've been locked by the first page in the 2nd gen sec.. LOL
From what all the old piston dudes tell me, they have just has many problems with their cars when they start adding NOS, blowers and turbos. So that makes me wonder if it's the rotary or the Forced Induction...?
Is it cheaper to build a FI rotary than it is to build a FI piston? I'd think the piston motor would cost more... There are more parts. Two V8 turbo manifolds cost what, at least 2k a peice...?
I am lead to beleive that rotary owners may have it easier when it comes to down time and building cost once you start cramming boost through the motor... I know some FD guys who will de-turbo thier car, work out ALL the kinks, maximize the tuning software, maximize all runners (intake, exhaust) then go for the turbo. 2a+ron comes to mind.
The draw to an LSx is that it makes similar numberes with out FI, thus lowering the chances of detonation.
From what all the old piston dudes tell me, they have just has many problems with their cars when they start adding NOS, blowers and turbos. So that makes me wonder if it's the rotary or the Forced Induction...?
Is it cheaper to build a FI rotary than it is to build a FI piston? I'd think the piston motor would cost more... There are more parts. Two V8 turbo manifolds cost what, at least 2k a peice...?
I am lead to beleive that rotary owners may have it easier when it comes to down time and building cost once you start cramming boost through the motor... I know some FD guys who will de-turbo thier car, work out ALL the kinks, maximize the tuning software, maximize all runners (intake, exhaust) then go for the turbo. 2a+ron comes to mind.
The draw to an LSx is that it makes similar numberes with out FI, thus lowering the chances of detonation.
04-16-08, 05:34 PM
#82
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. Either way, I like to rev, you don't. **** off
.
04-16-08, 05:42 PM
#83
Umm correct me if im wrong but december was only less than 5 months ago lol.
What does that tell you when a person who has the almighty "LS1 FD" for sale for 5 MONTHS, yet still cant sell it? This leads me to believe that people DO THE SWAP just for the sake of being busy, for the sake of actually "doing some real car work" for their car.
04-16-08, 05:44 PM
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I, personally, as a human being, can make 400 lb-ft......do I get a cookie? On the other hand, I don't think I could even make 60 hp.
Just goes to that torque doesn't matter as much as you think.
Personally, I like the rotary engine for it's size and low center of gravity. Swap in aluminum side housings and you have an engine that makes great power, can hold power in the gears around a race track, and weighs almost nothing.
The rotary engine is great for racing.
On the street, it's debatable, as other factors besides just going fast matter.
Just goes to that torque doesn't matter as much as you think.
Personally, I like the rotary engine for it's size and low center of gravity. Swap in aluminum side housings and you have an engine that makes great power, can hold power in the gears around a race track, and weighs almost nothing.
The rotary engine is great for racing.
On the street, it's debatable, as other factors besides just going fast matter.
04-16-08, 06:10 PM
#86
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lol are you kidding? 25mpg? if you want to do an stock to stock comparison that wouldn't even be possible. Then we can talk about ls1 in fd comparison then we can talk about making the rew the same hp as the stock ls1 comparison.
sorry but low mpg is the nature of the beast. esp since its fi.
sorry but low mpg is the nature of the beast. esp since its fi.
04-16-08, 06:50 PM
#87
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First there is no way to quantify engine stress in a way to compare it across engine families.
Second, how can we compare a forced induction rotary to an NA piston engine in any resonable and logical terms...we can't...they don't compare.
Third, As has been mentioned before a better comparison would be power to physical size, or power to physical weight. O
Fourth,Or how about we try another angle, $ per mile driven between major services (rebuilds), at each given power level?
(2) Society constantly does it to all things from American Idol to Miss USA.
My test is a valid logical test. Disprove it.
(3) There are more rotary powered aircraft than LS1 powered. Aircraft depend on power to weight to improve performance.
(4)You finally have a valid point.
04-16-08, 06:54 PM
#88
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This thread has kind of gone off the deep end now. I think I have said all I need to say previously. The rest of this is just rehashing that which has been stated many times previous.
I averaged about 15mpg with the rotary in the city/highway combined circuit.
Highway only taking fuel out of vacuum because I knew I was in for extended cruise I could pull about 23mpg... it is possible, but not in normal everyday commuting conditions.
With the same effort I wonder what I can do with the LS1. I am a financial analyst and with this project i am treating it with the utmost attention to financial tracking detail. I will have a lot of data on how much it costs to convert, and what fuel economy is once it is done. I will report back when I have crunched the numbers and we can revisit the conversation with a little more hard evidence.
I averaged about 15mpg with the rotary in the city/highway combined circuit.
Highway only taking fuel out of vacuum because I knew I was in for extended cruise I could pull about 23mpg... it is possible, but not in normal everyday commuting conditions.
With the same effort I wonder what I can do with the LS1. I am a financial analyst and with this project i am treating it with the utmost attention to financial tracking detail. I will have a lot of data on how much it costs to convert, and what fuel economy is once it is done. I will report back when I have crunched the numbers and we can revisit the conversation with a little more hard evidence.
04-16-08, 06:58 PM
#89
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(1) Which experts says you can't. More power stresses an engine more than less power. This is the simplest form of testing, power per liter until you bust.
(2) Society constantly does it to all things from American Idol to Miss USA.
My test is a valid logical test. Disprove it.
(2) Society constantly does it to all things from American Idol to Miss USA.
My test is a valid logical test. Disprove it.
2) Since when is American Idol and Miss USA (reasonable and logical?) as I explicitly stated in my comment? If you think those competitions are such, then we have another difference of opinion.
04-16-08, 07:03 PM
#90
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I look on supraforums other cars for sale at least once a week to see whats out there. A few weeks ago there were 5 LS1 FDs for sale and 1 rotary powered. Pretty crazy how many of them are actually out there and for sale.
I am 23 and plan to keep my FD for the rest of my life so long as it is not stolen/totaled. Although going LS1 is really tempting right now, I know that when I am old the car will mean more to me with the original engine.
I am 23 and plan to keep my FD for the rest of my life so long as it is not stolen/totaled. Although going LS1 is really tempting right now, I know that when I am old the car will mean more to me with the original engine.
04-16-08, 07:09 PM
#91
I look on supraforums other cars for sale at least once a week to see whats out there. A few weeks ago there were 5 LS1 FDs for sale and 1 rotary powered. Pretty crazy how many of them are actually out there and for sale.
I am 23 and plan to keep my FD for the rest of my life so long as it is not stolen/totaled. Although going LS1 is really tempting right now, I know that when I am old the car will mean more to me with the original engine.
I am 23 and plan to keep my FD for the rest of my life so long as it is not stolen/totaled. Although going LS1 is really tempting right now, I know that when I am old the car will mean more to me with the original engine.
I didnt know i was older than you but you are totally right.
When i bought this car, i promised myself i would never sell it. I even told my brother and my dad if i die, dont sell it unless YOU HAVE to, like you need money etc etc.
And when you do the swap, you sorta take away what the rx7 is. Who cares if the swap is 100x better. In the end, like i have said, you have a jap car with a v8. The point gets boring, people get bored from looking at it cause its plain, and in the end, gets sold lol. Something i have been arguing all along.
04-16-08, 07:11 PM
#93
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Most people compare CRT to PLASMA to LCD to DLP tvs.
They use different families of technologies, we still compare them.
Same diff as American idol.
I am not a rotary nut/purist. It is just my current ride. In fact I would prefer to have 16 valve 4 cylinder twin overhead cam cross flow hemi head turbo 4 in the car.
They use different families of technologies, we still compare them.
Same diff as American idol.
I am not a rotary nut/purist. It is just my current ride. In fact I would prefer to have 16 valve 4 cylinder twin overhead cam cross flow hemi head turbo 4 in the car.
Last edited by cewrx7r1; 04-16-08 at 07:21 PM.
04-16-08, 07:49 PM
#95
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Most people compare CRT to PLASMA to LCD to DLP tvs.
They use different families of technologies, we still compare them.
Same diff as American idol.
I am not a rotary nut/purist. It is just my current ride. In fact I would prefer to have 16 valve 4 cylinder twin overhead cam cross flow hemi head turbo 4 in the car.
They use different families of technologies, we still compare them.
Same diff as American idol.
I am not a rotary nut/purist. It is just my current ride. In fact I would prefer to have 16 valve 4 cylinder twin overhead cam cross flow hemi head turbo 4 in the car.
First the Rotary fires each combustion chamber for a 360 rotation of it's e-shaft, in piston terms this would qualify it as a 2 stroke, as the V8 requires a 720 degree rotation to fire each of its combustion chambers. You have scaled for this fact in calling the rotary a 2.6L....cause in essence it is. Next we must scale for the fact that the rotary is force induced and the v8 is not. The only logical line I can draw here is from Formula One back in the 80s when both forced induction and NA engines were allowed to run in the same class. If a vehicle was turbo charged it was allowed 1.5L in displacement vs. 3.0L for the NA counterparts. If memory serves me, the 1.5L cars were at such a power advantage here that the 3.0L cars got certain aerodynamic benefits and chassis tweaks that the 1.5L cars didn't get... for simplicity sake we will just scale the 2.6L turbo rotary x 2 (like F1) to get to an NA equivalent 5.2L of displacement.
When we compare the 5.7L LS1 to a 5.2L (scaled) rotary displacement we see that the numbers no longer are so far out of whack.
400whp (5.2L - scaled single turbo rotary) = about 438 whp for the 5.7L v8
If we had both these engines sitting in front of us, the rotary is far more taxed from a mechanical standpoint. It is under far more stress than the 5.7L counterpart, and as such displays far less reliability. It would be very easy to make the 438whp in the 5.7L with near stock drive-ability and emissions compliance. Also said engines, are very similar in weight and physical size.
Thus, the main part of your original argument that I would refute, would be how you scaled displacement. This alone would prove your HP/L argument invalid. It is also why originally i, as did others, suggested we evaluate by another means...such as power/engine weight, or power/physical size, or other such measurement that did not require scaling of displacement (which cannot be done with mathematical precision as the aforementioned alternatives very well could be).
04-16-08, 07:55 PM
#96
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Airplanes require very little torque. Apples to oranges. Getting closer to the torque required to move a car would be a boat. I'm quite certain there are more LS1 powered boats than rotary powered boats.
04-16-08, 07:57 PM
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04-16-08, 08:01 PM
#98
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The LS1 can do what our rotary does in similar space and generally with less fuel. The rotary simply is not known for fuel efficiency. The amount of energy stored in a unit of fuel is static. Simple fact is that a piston engine can usually harness that energy more efficiently than can we.
04-16-08, 08:25 PM
#99
HP/L is not a valid comparison at all. That's like taking two semi-related variables and pretending that their relationship is the end-all be all relationship. It would be the same as comparing hp increase / psi on turbos. Kind of useless if you ask me.
All power comparisons should be done via the same induction method. NA vs. NA, FI vs. FI. FI vs. FI is even hard to compare. Unless the two power adders give the same CFM, and that's even a hard compare.
HP/BSFC is more useful.
You shouldn't focus on how many rotary aircraft engine vs. LS1 aircraft engine. You should look at how many 13B aircraft engine vs. LS1 aircraft engine OR how many rotary aircraft engine vs. reciprocating piston air engine. Anything else is apples to oranges.
Torque comparisons are also meaningless, since at the end of the day, power is what moves a vehicle and is directly comparable. Torque must be manipulated beyond its raw lb-ft number. Really, the only time you can compare torque is if the rpm range and peak power is very similar.
All power comparisons should be done via the same induction method. NA vs. NA, FI vs. FI. FI vs. FI is even hard to compare. Unless the two power adders give the same CFM, and that's even a hard compare.
HP/BSFC is more useful.
You shouldn't focus on how many rotary aircraft engine vs. LS1 aircraft engine. You should look at how many 13B aircraft engine vs. LS1 aircraft engine OR how many rotary aircraft engine vs. reciprocating piston air engine. Anything else is apples to oranges.
Torque comparisons are also meaningless, since at the end of the day, power is what moves a vehicle and is directly comparable. Torque must be manipulated beyond its raw lb-ft number. Really, the only time you can compare torque is if the rpm range and peak power is very similar.
04-16-08, 08:27 PM
#100
I am going to try to approach this from a more mathematical perspective. Since in your previous post, I agree I didn't refute anything you said I just stated my own opinion so first we must try to get both the Turbo Rotary and the piston V8 on similar ground to be able to compare them.
First the Rotary fires each combustion chamber for a 360 rotation of it's e-shaft, in piston terms this would qualify it as a 2 stroke, as the V8 requires a 720 degree rotation to fire each of its combustion chambers. You have scaled for this fact in calling the rotary a 2.6L....cause in essence it is. Next we must scale for the fact that the rotary is force induced and the v8 is not. The only logical line I can draw here is from Formula One back in the 80s when both forced induction and NA engines were allowed to run in the same class. If a vehicle was turbo charged it was allowed 1.5L in displacement vs. 3.0L for the NA counterparts. If memory serves me, the 1.5L cars were at such a power advantage here that the 3.0L cars got certain aerodynamic benefits and chassis tweaks that the 1.5L cars didn't get... for simplicity sake we will just scale the 2.6L turbo rotary x 2 (like F1) to get to an NA equivalent 5.2L of displacement.
When we compare the 5.7L LS1 to a 5.2L (scaled) rotary displacement we see that the numbers no longer are so far out of whack.
400whp (5.2L - scaled single turbo rotary) = about 438 whp for the 5.7L v8
If we had both these engines sitting in front of us, the rotary is far more taxed from a mechanical standpoint. It is under far more stress than the 5.7L counterpart, and as such displays far less reliability. It would be very easy to make the 438whp in the 5.7L with near stock drive-ability and emissions compliance. Also said engines, are very similar in weight and physical size.
Thus, the main part of your original argument that I would refute, would be how you scaled displacement. This alone would prove your HP/L argument invalid. It is also why originally i, as did others, suggested we evaluate by another means...such as power/engine weight, or power/physical size, or other such measurement that did not require scaling of displacement (which cannot be done with mathematical precision as the aforementioned alternatives very well could be).
First the Rotary fires each combustion chamber for a 360 rotation of it's e-shaft, in piston terms this would qualify it as a 2 stroke, as the V8 requires a 720 degree rotation to fire each of its combustion chambers. You have scaled for this fact in calling the rotary a 2.6L....cause in essence it is. Next we must scale for the fact that the rotary is force induced and the v8 is not. The only logical line I can draw here is from Formula One back in the 80s when both forced induction and NA engines were allowed to run in the same class. If a vehicle was turbo charged it was allowed 1.5L in displacement vs. 3.0L for the NA counterparts. If memory serves me, the 1.5L cars were at such a power advantage here that the 3.0L cars got certain aerodynamic benefits and chassis tweaks that the 1.5L cars didn't get... for simplicity sake we will just scale the 2.6L turbo rotary x 2 (like F1) to get to an NA equivalent 5.2L of displacement.
When we compare the 5.7L LS1 to a 5.2L (scaled) rotary displacement we see that the numbers no longer are so far out of whack.
400whp (5.2L - scaled single turbo rotary) = about 438 whp for the 5.7L v8
If we had both these engines sitting in front of us, the rotary is far more taxed from a mechanical standpoint. It is under far more stress than the 5.7L counterpart, and as such displays far less reliability. It would be very easy to make the 438whp in the 5.7L with near stock drive-ability and emissions compliance. Also said engines, are very similar in weight and physical size.
Thus, the main part of your original argument that I would refute, would be how you scaled displacement. This alone would prove your HP/L argument invalid. It is also why originally i, as did others, suggested we evaluate by another means...such as power/engine weight, or power/physical size, or other such measurement that did not require scaling of displacement (which cannot be done with mathematical precision as the aforementioned alternatives very well could be).