owen is fat

so, what are you putting in there? ...is that page missing fromy our manual still?

lol.
very good points on the book, I see a lot of guys get too wrapped up in the rotary motor to realize an RX7 can still function the same if not even better with an LS1 inside the engine bay.

Maxthe7man

I beg to differ, Yamaguchis book offers alot of insight into the development of the fd, I dont even own an FD, but it still taught me alot about the principles of the car. Perhaps Jim you could have spent a little more time reading the section marked "engine" in your shop manual, before simply giving up, but thats besides the point, if the car wasn't designed around the 13b, a certain someone would be driving their car instead, of redesigning it around the new motor they have selected....
I don't mind swapping engines, I have probably done more engine swaps than most of you put together, however I only consider a swap when I know I am at the end of the line with a motor, even with my current 13b/T51 combo, I don't think I have reached its maximum output yet, even though the motor is still using 95% of its oem internal parts...
I can see why a swap for some is viable option, making the rotary work takes some homework, and some commitment.. Patience beyond what most people have... I know what its like to be the only rotary guy around , to have no one to turn to when there is a problem, not being able to go and buy a definitive guide book on rotary tuning, not having any shops locally that can help you , or even get parts for you..You can buy small block chevy parts pretty much at 7-11... And sometimes thats a nice thing to have...
But whats the fun of that, there is no learning in that, really, do I want to be like everyone else at the car shows, and have the same engine as everyone else, no not really... I know with the swaps I have seen locally, they created more problems than they solve, be it lt-1, ls-1 or windsor blocks, despite what owner say, even the guy who keeps begging me for coilovers helpers for the front, denies he has a handling problem, how would he know, he never drove the car with a rotary..

I don't know if I asked this before, but exactly how much does an Ls-1 weigh? Car Craft has published the crate version at 430 pounds with water pump and corvette ex manifolds, dry with flex plate, and 538 wet ready to run, anyone dispute those numbers?....
I have the 13 p-port at 214, the 3 rotor p-port in 246 , 4 rotor p-port at 279, , and the 13b-rew at 361, all in wet, ready to run configuration...
Don't get my wrong, I have nothing against swapping, but to me it has to make sense to me, given where my own car is power wise and handling with a 13b in comparison to the local swap jobbed rx-7's I just can't see doing that to my car...Max

wingsfan

That's a pretty cheap shot IMHO. Jim was one of the first people to start heavily modifyng his 13brew. He went through enough motors to give him a pass on giving up on it.

I hope you haven't just popped back in to pick a fight and stir up some ****.

That weight for the LS1 is probably pretty close. My pallette weight was somewhere around 700# (I don't remember exactly what), but figure 125# for the tranny, 50# for all the wood and strapping material, 50# for the extra clutch and flywheel, 20# for a driveshaft, 10# for a torque arm, the extra set of pedals, etc., etc. I'm sure you get the point. 430 is not unreasonable.

Does that 361 you're quoting for the 13brew include all the turbos, intercoolers, piping, precat, etc. (seems like it should for that high a number)?

All told, my car gained about 60 pounds (don't know the exact weight because we didn't weigh it, I can only go off of what a similar car with similar mods weighed). ~15 of that is the transmission.

Anyhow, regardless of what it adds, you can still keep the car plenty light, and plenty balanced. The corner weighting posted earlier in the thread is a nice example

https://www.rx7club.com/showpost.php...9&postcount=31

Anyhow, my car isn't affected to the point that I can tell any difference in handling, but it's always been a better machine than I am a driver.

I let Turbojeff autocross my car a couple times and he seemed pretty impressed by it. I also let DamonB, Artguy. and an assortment of other pretty serious rotorheads drive the car. Pretty much everyone I've taken for a ride, or let drive the car has been suitably impressed. I don't think any of them would do it to their own cars, but I'm under then impression that's more of a personal preference than an indictment on my car.

Maxthe7man

Here is a list of rotary engines I found on line, this differs from what I have here in books, but lets compare these to dressed v-8's.
Mazda 12A and 13B 260 (109)
Mazda 10A rotary 224 (20) (Cosmo) (bare)
Mazda 10A rotary 268 (20) (R100) (bare)
Mazda 10A rotary 190 (27) (R100) (without thermal reactor)
Mazda 10A rotary 280 (27) (R100) (with thermal reactor)
Mazda 12A rotary 348 (20) (RX7) (with oil and water)
Mazda 12A rotary 356 (20) (Japanese model turbo, EFI)
Mazda 12A rotary 275 (85) (w/flywheel, t.reactor, no alt.)
Mazda 13A rotary 301 (20) (R130 Lucia - Japan only) (bare)
Mazda 13B race 242 (95) 2-rotor race motor, with accessories
Mazda 13G 3-rotor race 319 (95) 3-rotor race motor, with accessories
Mazda 13J 4-rotor race 396 (95) 4-rotor race motor, with accessories





I searched some of the ls-1 forums but could not find a defintive agreed up on weight for the ls-1, its kinda all over the place, depending on what argument people were trying to win, I saw that 497 lbs, dry bare block with manual flywheel seems to be the most popular number, but its not from any actual GM official site...Anyone disagree with that?....max

jimlab

Do you truly think it was lack of understanding that led to my choice to ditch the rotary?

Yeah. How do you go from 430 to 538 just by adding fluids? No small block with an aluminum block and heads and a composite intake could possibly weigh 540 lbs. Even a fully equipped (all accessories, stock cast iron exhaust manifolds) LT1 only weighs ~520 lbs. The LS1 weighs in at about 460 in the same trim from every source I've seen, or about 60 lbs. less.

Where did you get those figures? Jeff Hoskinson weighed a 13B-REW with full accessories and turbos and got ~420 lbs. on a very accurate truck scale. The margine of error of the average truck scale is +/- 20 lbs., so that could be somewhere in the 400-440 lbs. range, but not 360.

The proof is in the scale weights of converted cars, like Andrew's. Even Bill Hagen's LT1/FD with cast iron exhaust manifolds, full accessories, twin cats, and 50 lbs. of ballast only came in at 2,950 lbs.

Maxthe7man

Yes that number includes turbos, acc, etc, etc, I found some number for the cosmo 13brew with all accessories and they are within 4 pounds so I would take that number as accurate for a wet 13b -rew. If I take a wet ls-1 at 538 lbs wet and compare it the weight of 13-brew at 361 lbs that is a difference of 177 lbs in the front of the car, lets tak 17 lbs off for the intercooler and call it 160, thats still alot of weight added to the front of car, no matter how you slice it... What else is not counted ,on top of that is, the ls-1 engine managment and harness, which by as much as I can find adds another 30 lbs. No matter how creative I get with the math, this engine is alot heavier than a 13b turbo motor....I actually thought it was gonna be lighter than that to tell you the truth, for an aluminium based v-8...
I don't disagree that some things could be moved around the car to even it out, but it seems, its not so black and white as some would like to make it out to be..Max

wingsfan

What can I say, I published a picture of my car on the scales after the swap, and Mike was kind enough to post his corner weighting. How much more black and white does it need to be? Forget the "published" numbers. Look at the actual emipirical data.

Is my LS1 heavier than a rotary? Yes. You know what else it is? Torquier. I made 300 lbs ft of torque at 2300 rpm, and didn't dip back below that until 6200 or so. More torque + better throttle response = more fun regardless of what nebulous number I added to the front of the car.

jimlab

Hardly.

Brian Hinson's LS1 FD...

LF: 746
RF: 677
Total Front: 1,423 lbs. (50.3%)

LR: 675
RR: 733
Total Rear: 1,408 lbs. (49.7%)

Total: 2,831 lbs.

Brian Goble's non-sequential R2...

LF: 701
RF: 690
Total Front: 1,391 lbs. (50.9%)

LR: 684
RR: 655
Total Rear: 1,339 lbs. (49.1%)

Total: 2,730 lbs.

Wow... 101 lbs. heavier overall (and only 32 lbs. heavier in the front), and static balance as good as a rotary FD, not that it matters.

Now... what were you saying?

Maxthe7man

Then why else would you ditch it..
[/quote]....

I just typed 13b engine weight into google, and among the 117 trillion pages that came up, that was a very popular repeated number. Not only that I have some the Japanese tuner mags laying around that publish such data and that number is repeated in that..
I took the ls-1 weights from Car Craft, ls-1 forums, and aircraft comparison pages, the difference from 430 to 538 depends on flexplate or flywheel, amount of accessories mounted on the engine, if you add a power steering pump, alternator, manual flywheel etc etc, I could see there being a 108 lbs difference between bare dry shipping weight and wet ready to run ....
I am not going to bicker now about the weight of the ls-1 compared to what you might "think" its, to compare the to, all I can do is use the most unbiased neutral data I can find, which is the ls-1 discussion boards, v-8 specialty mags and the like....I don't think Car Craft would have any reason to lie about the wieght of an ls-1...max

jimlab

Lack of low end power, reliability, and exhaust note/noise.

red 7

Did you type those weights in the right spots? Why are the LF and RR so heavy, does that car need some corner balancing? Not bad overall weight. Its not for me but more power to u guys, whatever motors in there it still looks great!!!

Maxthe7man

Only for those with a lack of understanding I guess.. ...

Its proportional Jim, I can give a dodge cummins turbo diesel 50/50 by dumping weight in the rear as well, making the car heavier seems to be accepted though?..
In the end there is an undeniable weight difference between the 2 powerplants, yes you can give the ls-1 a balance with more mods, but in the end the car ends up heavier, the question is, does it then negate the performance gain, over a stock 13b-rew...
You consider Yamaguchi propoganda, but not Hinson, tisk tisk, there is no vested interest there is there....

wingsfan

LF is where the power steering pump and alternator are on the LS1. RR because of the exhaust path, and maybe some ballast to even it out?

wingsfan

Yeah, the lack of low end grunt is because of a lack of understanding.

Get off your high horse already.

red 7

Gotcha that explains it, thanks

Maxthe7man

Sorry for posting engine weights, I should remember when posting here, to leave all hard fact data at the door, and just swallow the user supplied mantra..

wingsfan

I haven't seen you site an official source for any of those weights. Magazines, webpages, other car forums. Your data is less reliable than the guy that weighs his car before and after.

Hell, you pretty much went out and found the heaviest weight you could find for the ls1, acepted it as fact, and ran with it.

No, you're just picking and choosing whatever "data" supports your argument.
I'm sure you'll continue with the chicken little bullshit, over and over again. "The rotary's lighter, the rotary's lighter!"

You're not going to convince anyone here they're wrong, and you're obviously not going to beleive anything anyone tells you otherwise, despite pictures, hard numbers, and non-biased third party opinions.

You're obviously here to stir up some ****. Perhaps the DOO forum would be a more appropriate venue?

jimlab

What's with the turbo diesel crap? I guess that's your way of admitting that you're losing the argument? Don't you think a lighter engine can make low end power?

The only one who dumped weight in the rear of the car was Bill Hagen, because he was told (by Grant Robbins, who has been wrong about a lot of things) that it would be necessary to balance the weight added to the front. Even so, his car came in at ~2,950 lbs., or about 25 lbs. heavier than a stock Touring automatic, and that's a "worst case" scenario.

Let me clue you in on something... when the lightest C5 and C6 Corvettes tip the scales at ~3,100 lbs., anything under 3,000 lbs. is damn good, and the LS1 FDs are considerably lighter than that.

That may be true, but once you get rid of the intercooler and piping and a few other things and move the battery to the rear of the car, it's not that big of a difference, obviously.

Ask Jeff Hoskinson or DamonB. Both have driven Andrew's (wingsfan) car, and both are heavily into autocrossing.

Don't get me wrong. There's some great information in his book, but the way it's been interpreted by some people is absolutely ridiculous. Nowhere does it say that the car could not have been just as strong a contender with a V8 under the hood (assuming Mazda could make one without ******* it up), and anyone who reads that into the book needs to pull their head out and take a breath of fresh air.

No, not really. I don't have much respect for Hinson to be perfectly honest.

RX-Ben

Why is there even an argument going on? Are you doubting the weights from people that have actually done the swap? Maybe everyone is involved in a coverup involving the F/R weight distribution??
What seems to be going on is that since you have anecdoctal evidence about a local swap and you've decided that everyone else is lying. Brilliant reasoning there.

Posting the various engine weights is useless. Put the engine in the car and then measure the F/R distribution.

Have you ever driven an LS1 swapped FC/FD? It should tell you something when people that have actually driven one(even the rotary fans) aren't the ones complaining about handling issues.

Ben

jimlab

And if that doesn't convince you, read this...
https://www.rx7club.com/showthread.p...46#post4087546

gnx7

iTrader: (10)

My buddy weighed his stock FD before the conversion at 2800lbs.... post conversion with LS1/T56 a/c and p/s it weighed 2840lbs. Most of the gain was over the front end.

40lbs isn't going to make the FD handle any worse. A local road racer with a fully sorted FD did the LS1 swap and said the car handles the same... but his lap times are faster..... go figure .

THe main motivation for the swap is reliability and a wide powerband with lots of low end grunt. Until the turbos on the FD spool up it is a dog. When you have done your 3rd, 4th, 5th engine rebuild on the 13B-REW you realize the "pony keg" isn't perfect and is very fickle. I have many friends that still don't realize this and continue to pour money into their rotary turbo setups to only have them pop a few months later once again.

CloudyPrism

Jesus man, how hard is it to understand the numbers that ACTUAL cars are giving? We arent talking about speculation, guessing, or magazine racing here. We are talking about ACTUAL cars that were weighed before, and weighed after.

No matter what you say the numbers are proving otherwise. You can argue CG if you like. That isnt the topic of the thread.

the topic has to do with weight distribution, and the numbers PROVE YOU WRONG. get over it. you are just wrong in this case.


You were the one claiming that the V8 guys were ignoring some info, and stressing others to make thier case, but the only guy doing that here is you. despite being shown cars with before and after weights, INCLUDING cornerweight, you still argue fact. I just dont understand how you can suspend logic to embrace your ignorance.

The numbers are there, and short of leaving this planet they arent giong to change, no matter how much research you do.

CloudyPrism

See above post.

owen is fat

hahhaaaaa, so how do you know what WE have done? also it seems you dont MIND swapping motors but you see, we PREFER to swap motors... I would guess that you aree swapping motors because of part/system failures where we are building something better no matter the condition of the current motor (rotary).


what you call patience I call freetime... I dont have tons of it so I need my motor to run, especially since its also a daily driver.

you can argue about published (in books) weights for LS1's and such, but we have been comparing actual cars with real world measurements that are accurate.. and you still dont believe us? aaaaaaaargh!
the FD's rotary has two turbos, an oil cooler, etc... you cant compare an FD shortblock to an LS1 longblock, its just not accurate. you know, we arent trying to trick you, we stand to gain nothing by tricking you, our cars are already built and we are enjoying them while you argue about them, thats silly.

krautrocket

i got an A in thermo... where's my LS1FD