WOW. Now that's a stretch. Rape and Cars....that's funny.

Anywho. Sure, I agree, the horse is dead.

 

I realize there will probably be no end to this debate but to hell with it everyone on this forum has given there two cents so why not me? I keep hearing about how the ls1 is lighter and more realiable and powerful. I do believe this but.... I believe that the rotary can be just as light and powerful provided that the gobs of power that is being generated by the ls1 is even usable horsepower in such a light car. I want to make a few observations.
1) the fastest rx7 so far ( to my knowledge) is Pica Racing's Rx7 and it has made a low 7 sec or high 6 sec pass and if im not mistaken that was with a 13b.
2) i have two wonder if all that power can even to be put to the ground that well when you get past 500. The heavier 13b car with its lack of torque in comparisson and supposidly more weight can hardly stick it so i dont get how an ls1 is going to with the supposidly lighter weight and the signifigantly larger amounts of torque.
3)The overwhelming majority of my friends are die hard ls1 guys and i have to admit they are top notch motors ( if with the right platform) but even they say that once you start talking 500-550 whp range you really need to use the 1500's iron block if you drive it hard often or if you use forced induction. that equates out to roughly another 100lbs all of a sudden this longer heavy motor just starts to throw the front weight off a bit.
4) I do want to put credit where it is due the ls1 will almost without a doubt always outlive most rotaries. but I do have to say when you blow it, it costs quite a bit more than when you have to replace an apex seal and a gasket kit.

I would like to say in the end that I really think both motors are great for this car the rotary is obviously my favorite but they both do well I just dont see why the rotary is looked at as being inferior to the ls1 by so many people.

 

ok, first off, the 13b is way lighter then the ls1. it only displaces 1.3 litres and hauls insane ***. this topic has been covered as well. just search for "ls1 perspective" for the title.

personally, i would go with the 13b, throw in 3mm nrs seals, pineapple viton water seals, stud it and it should be good to go for a while.

the ls1 is heavy, will throw off the 50/50 and will handle like poop. i can only see if you want to make big power or something, but then the rx7 is not special anymore. i dont know where the hell you got this information, because where ever you got it, they are full of ****.

PS: do you even own an rx7?

 

i dont know where these people get this genious idea that an ls1 is lighter than a 13b. It most certainly is not. lol i cant wait to find an ls1 rx7 on the street because im going to destroy it

 

There was a light discussion at a local meet i go to where someone actually HAD an LS1 FD and we were talking about what is heavier.

He claimed that as the 13B-REW sits (with ps, turbos etc), is ONLY 50lbs lighter than a fully setup LS1.

The LS1 is all aluminum you know.

 

block vs block, i'm sure a 13b is lighter. but the stock twins, cast manifold, etc really add to the weight of the rotary long block.

 

Have you been alive for the last 10 years? that debate has long been settled and put to rest. The LS1 FD is almost exactly the same weight as stock +/- 30lbs. Weight distribution has been shown to be BETTER than stock in most cases (ie more rear).

corner weighted FD


This debate will last forever, or until you sell your car or kill your third rotary, both are inevitable... at least thats how I see it

 

Is that pre or post corner weighting? With corner weighting, you can pretty much get the static distribution where you want.

If it's post-corner weighting, I wonder what the weight distribution of the LS1 FD is with stock FD suspension.

 

That will depend on your car. Mine corner weights to almost 50/50. I'm actually lighter up front by a small amount.
https://www.rx7club.com/showpost.php...&postcount=100

The corner weight topic of LSx and Rotary was beaten to death here: https://www.rx7club.com/race-car-tech-103/ls1-fd-corner-weights-versus-stock-fd-477370/

Knock on wood, but I still haven't blown a rotary in over a decade of driving rotaries.

 

Mine was exactly 50/50 as well... and that was with the battery still up front, airpump, TT's, A/C, no PS and no roll bar, and only 1/4 tank of gas.

Something tells me the two RX7's in the comparo have more differences than just the motor block. Even if the LSX was the same wight as the 13B, I don't see how that would gain 75 lbs in the back of the car.

 

Sig worthy

 

The thing is, I know Scott's LS1FD has coilovers, don't know if it had them at the time of that post, but if it did, you can set your corner weights where you want by raising and lowering your ride height per corner.

Stock FD vs. LS1 engine in a Stock FD chassis is pretty much the only compare you can do to find out how the LS1 affects chassis balance, for better or worse.

 

The weight fully dressed vs, fully dressed is similar. The t-56 is heavier however that weight is centered low in the car, not to mention is FAR STRONGER then the Mazda transmission.

 

Hmm, care to back that statement up? I've always heard that FD trannys are very strong. On the contrary, I've heard that T56s are fragile.

 

Care to what? Ok, My "Type R" Mazda transmissions input shaft is smaller in diameter then a T-56 input shaft.

I could go on about how many mazda transmissions I've broken(under normal non-drag use) vs how many T-56's I've seen broken (under normal non-drag use) but that would be speculative.

 

The LS1 itself is most likely lighter than the 13b in fully dressed trim. The difference is the T56 tranny is more than 50lbs heavier than the Mazda 5 speed. Hence the difference in total weight of the car and why the weight is shifted toward the rear.

T56 fragile? Wow! Maybe I will get a chance to take a picture of them side by side and you can see. The T56 was built to handle a ton of torque due to the nature of the engine(s) it backs up. The Mazda tranny is strong compared to other Mazda trannies...but I dont know of any Mazda torque monsters. Plus the Mazda tranny has quite a few of its own issues. 5th gear synchro being a big one.


Turbotommy:

How much power are you making? You really like to talk about 'killing' or 'destroying' an LSx FD but in what context is this taking place? Are you talking a freeway roll on race? A race around a road course for time? A standing quarter mile?

The funniest part of this is the fact that he is probably talking about a drag race or freeway roll. Most people whom swap an LSx are doing so to run it on a track (road course) more often and the argument you get from the Rotary guys is that you are killing the spirit of the car. I thought that was the spirit of the car? A road course terror? This whole argument is of which CAR is better is so pointless...


ON TOPIC:

I have argued engine for engine never saying what is best, but saying the facts. The LS1 is more efficient at producing XXX levels of horsepower. I dont think that is arguable. At XXX level of horsepower the LSx uses less fuel and takes less air to do so. You can measure that, it is quantifiable. The LSx is very similar in weight and space requirments to a TT 13b-rew... Therefore the LSx can fit in the same area, produce the same power, while weighing the same...and do so more efficiently.

Whether you want that or not is up to you. This is Ptrhahn's point, he doesn't want that and I do. I agree with him in a couple of points he had...but I have never once said the LSx is better or best. I have said it is more efficient. To me that is better, to YOU, maybe it isn't. But the whole point of this thread was not, whose car is faster... It was a comparison of the ENGINES! I have tried very hard to stay on topic but some of these posts in here are foolishness.

 

care to share info source?


as for weight, my car is an FC. i had it weighed last week. i dont have AC or PS, but i do have a 40-50lb battery, i had prolly about 10-15lbs of tools in the back and about 1/2 tank of gas. full interior from the front seats forward. and no interior behind the front seats. i weighed in at 2840. I know there are some super light FC's out there, but mine has a full working dash(minus radio). what do other daily driven FC's weigh?

 

Sorry if I came across as insulting, I didn't mean to, and I admit I worded that statement with a harsh tone. In fact, I wanted to change it, but it was too late to edit. I wish I had stayed out of this thread as there is way too much drama going on. It's just that I've seen quite a few posts on this site about how strong the FD trannys are, aside from the 5th gear synchro issue...will have to dig them up. You guys sure like to jump on people though...what I was trying to say was that what I had heard (not experienced or seen) was contrary to f1blueRx7's statement, and was looking for something to prove either perspective right or wrong, because I don't know. That said, I'd love to see some comparison pictures, cosmo kraemer.

Personally I am not a fan of the LS1 swap. Yes, I see all the benefits, and I see that there are really no drawbacks. But I'm not a fan of cross-platform swaps at all, not just this one. For me, it's not about whether I want what the LS1 has to offer. Of course I'd want better efficiency and more reliable power...who wouldn't? But I don't want it out of an LS1. The LS1 is a fine engine, and I'd love to have a Corvette with one in it. But hearing the pushrod V8 grumble coming out of an RX is just wrong to my ears. It'd be like biting into an apple and tasting a durian fruit. In the same manner, I wouldn't put an American V8 in any import car. It's all out of preference, not out of practicality or out of which engine is "better", and it's the same reason why I more than likely wouldn't buy a domestic car, with a few exceptions (such as the 'Vette mentioned above). I think it's interesting, but it's not for me. Maybe if my rotary blows up I'll change my mind.

Anyway here are a couple pages about the T56 being weak:

http://www.mustangforums.com/archive...3542981-1.html

http://www.rpmmotorsportstulsa.com/6speed.htm

That's all I could find at the moment, so it's mostly just hearsay in the end. But basically what I've heard is that it has weak synchros and a weak aluminum input shaft in stock trim...

 

 

This thread is totally misleading. The title "13B-REW to LS1 Perspective" suggests insight from someone who has owned and driven both. Instead it's more of the same garbage. As far as I'm concerned, unless you've owned and maintained both 13B and LS1 FDs that were in proper working order, you aren't qualified to share your "perspective". Everyone else is just bench racing or muck raking.

 

Most(not all) lsx Rx7 owners are previous rotary owners fed up with rebuilding the motor.

Do you lack reading comprehension?

 

Talking about LSx FCs in an LSx FD thread. Hmmm. I don't think its me that lacks the reading comprehension...

 

no, i think this discussion is a general 13b and lsx thread. i was throwing out solid factual numbers.

it just so happens this is in the 3rd gen section, it should prolly be in the OEC section

 

I owned 2 2002 ls1 fbodys, then i bought the rotary rx7, then a month after i bought the rx7 i started my ls1 swap.

I originally bought the rx7 with intentions of swapping in an ls1, but figured i would drive it until the rotary died.. well after i began driving the car with the rotary engine, i simply could not stand the slow starts from the line and the hit the gas .... wait for it wait for it then the car takes off. I drove the car for about a month, beat on it because i knew i was going to eventually swap engines, and i just didn't really like the fact that unless i got into boost my car felt like a sloth.

Im not saying the rotary is a bad thing, just not my cup of tea, coming from owning two ls1 cars for years i guess i was used to the torque all over the place and when i step on my gas pedal the car gets up and goes. So i guess for me what i saw with the rotary engine was a power band that didn't really fit my driving preferences, and an engine quite a bit less reliable than an ls1.

 

The you for got to look at the title. It screams 13B-REW about as loud as any thread title can.