bandit86

I was on a camaro board where someone seemed to think he knew a lot about rx7s.... He said the LS1 v8 engine swap in a complete car weighed as much as a stock rx7. I thought wankel motors were super lightweight. Would all the turbo plumbing make it comparable to a v8 weight?

Nowhere

HA, wholy snit! A blown lt1/350 weighs like 500 lbs with tranny!

I thought the rotaries only weighed about 300 ish with tranny.

bandit86

LS! have "plastic" intkaes, and aluminum heads. Very light, not much more than 450 pounds, plus tranny. I thought the rotaries to be at 250pounds plus trannies, but I dont know what the turbo and all the plumbing weigh.

Sideways7

iTrader: (7)

I dont have any concrete answers at the moment, but I see no way a chevy 350 and a 13BT weigh the same. Not to mention the fact that installing one in a rx-7 will mess up the handeling and weight dist.

Turblown

iTrader: (12)

I thought an all aluminum ls1 weighs very close to a stock 13bt (325#s)

Sideways7

iTrader: (7)

Good point revvin, I forgot about them being all aluminum. Theres a company that offers instructions and some equipment for v-8 converions on rx-7's using early 70's vette engines. Those are cast-iron, which is what I was thinking about.

Josepi

Swap website: www.grannysspeedshop.com or www.grannyspeedshop.com

in either way, I'd take the LS1 with a proper tuned EMS. Yes, I'm throwing myself into the flames of purist, but **** you sons of bitches, I appreciate the chassis and engine. To worship the engine alone would be ***-in-nine.

Sam

I remember a Ebay auction that had a 87 SE with a V8 swapped. The seller said it was about 300 pounds heavier with the V8 instead of the 13B

digitalsolo

iTrader: (2)

The LS1/T56 is about the same weight as a 13BT/tranny, and LIGHTER then a 20B/tranny....

The cast iron/AL head engines are around 150 lbs heaver (with a T56) and around 225-250 lbs heavier with an auto (though the rotary is heavier with an auto too, obviously).

This will be in V8 conversions soon... non negative mentions of pistons don't last long on the 2nd Gen board.

MtnRacer

What they don't tell you is that they've removed power steering, ABS, A/C and/or a number of other items, and often, the motor chosen uses a automatic transmission, and so on and so forth.

Steve

cdk 4219

The LS1 T56 88 TII that I have registers 2785# on the Longacre scales. The engines are heavier than a 13b (LS1 T56 completely dressed and with driveshaft is approx 535#) but the supporting hardware of the rotary makes up the difference. And yes my car has power steering, but it doesnt have AC which is usually dead weight on most FCs because it doesnt work anymore. All in all it made the car do everything much better than the rotary engine.

Sponge Bob Square Pants

Just like MtnRacer said 2 posts above this,
It's not just engine-to-engine weight comparisson. Different accessories are replaced, altered, even stuff you wouldn't think of like a new exhaust system, air ducting, new brake rotors, crap like that change the weight.

If you want to know which engine is heavier, then it's obviously the LS1 package, period.

Which car would be heavier betwen the LS1 RX-7 and a stock RX-7 Turbo, well that can vary from one project to the next, so you can't really say.

onikageka

I swear, if I see one more V8 RX7 weight bashing thread I'm going to lose my damned mind!

digitalsolo

iTrader: (2)

...this thread has been quite civilized... no real bashing, just good, somewhat informative discussion really. I'm quite happy to see it handled maturely...

P.S. rotaries suck! (I AM OF COURSE JUST KIDDING!!!)

1point3liter

mine weighs 2700lbs and has perfect 50/50 weight distrobution. *shrug*

blackkiller7

this is nothing but BS , their is only like a thirty pound difference

MosesX605

What people seem to forget is that no matter how light a 13B is, turbos and their associated manifolds tend to be REALLY heavy. I have no trouble believing that an all-aluminum V8 is similar in weight to a 13BT.

gnx7

iTrader: (10)

Here is a thread from another board on the weight of a Buick GN Turbo V6:

I weighed my motor complete minus the tranny, converter and starter. It weighed 420-lbs with everything just (including wiring harness and ECM)as you would sit it in a Regal. I weighed the 200-4R seperately w/ a 10-in non-L/U converter. It weighed in at 162-lbs. Add those two together and you have a grand total of 580-lbs for the T/R drivetrain.

Here is the same thread about the LS1:
Got the LS-1 motor weighed today with all the accesories attached (A/C, P/S, Alt, wiring harness, ECM; etc. Believe it or not it weighed in at 481-LBS !!! That is only 61-LBS more than the TB. Keep in mind that the Buick was weighed with all accessories inluding the turbo, intercooler, ECM, wiring harness, headers and DP.

I believe a T56 (6 speed) weighs around 140lbs. The 4L60E automatic version is about the same as a TH200-4R at 140-145lbs.

The fact that 1.3Litres LS1/FD weighs 2700lbs and has basically perfect 50/50 weight distribution should open some eyes. His car hauls butt as well.

Here is Hinson's LS1 powered FD:
TEA ported Heads, 231/237 Cam , ASP pulley
Ported TB, CNC Ported Exhaust manifolds, Cold Air Intake - Not installed during those runs
With 100hp NOS shot the car has gone 10.1@137mph with a T56 6speed nonetheless! I imagine with some road race oriented suspension and big wheel/tire combo this car could tear it up on a road race track.

-GNX7

tbielobockie

Wow.... you guys are like the flat earth people...

Despite huge amounts of proof to the contrary you still believe the Earth is flat.

Lets set the record straight: The LS1 conversion, with power steering and A/C weighs 2700lbs and still has 50/50 weight distro.

And contrary to the rotary purists hopes and dreams.. the v-8 RX-7 handles better. Here is why:

* flat torque curve. means you have power everywhere with no turbos to spool or lumps in the powerband to throw you sideways

* instant power at all revs meaning you can adjust the amount of power you want at the exact instant you want it

383Mazda

* flat torque curve. means you have power everywhere with no turbos to spool or lumps in the powerband to throw you sideways

This is a good point! Torque on demand is a HUGE plus no matter what type of racing you're into...

Here's something else to think of...
lets be VERY generous and say you have a 2,600lb rx7 making 250hp from the 13b motor... that's 10.4 lbs/hp. Now for the anti V8'ists, lets be bogus and ad 600lbs to your rx7 and say your V8 only makes 300hp... so you now have a "ruined" rx7 that weighs 3,200lbs and makes 300hp.. that's still 10.6lbs/hp
(Now imagine that you're in the real world, lets play it safe and say your cars weighs 3000 lbs and makes 450hp from the V8... I won't make you think, that's 6.6lbs/hp!!!!)

In the V8 swap, if car will gains weight it won't be because it's gotten fatter, it'll be because it's gained a lot more MUSCLE!!!!
Brandon

Dyre

While im in no way a rotary purist (inital stages of my LS1/FC are underway) there are some key differences in the weight distro of a LS1 FC/FD. While the balence is close to stock, the LS1 DOES sit further forward and higher in the engine bay. The weight is now dirrectly over the front steering and past it. Technically the car is no longer 'Front/Mid engine' with the LS1 like it is with the triangle motor. While it won't make a difference in most cars is DOES change some key factors of handling.

All things being equal (they arent- but just for comparisons sake) the weight placement with the rotary is far better for polar-moment of inertia and other such characteristics.

Fact is, though, the added low end grunt and power of the LS1 will make it faster around a road course/autox/drag strip than the rotary car despite the less than perfect drivetrain placement.

Really, both car setups have thier merits.

tbielobockie

That is nothing but pure marketing bullshit from Mazda. And you swallowed every last little bit of it.

If Mazda gave two ***** about any of that stuff they wouldn't have stuck the battery as far forward and as high as possible.

projekt

where would you put it mr. accomplished engineer?

thant

Well since they took all of that time and effort to put an insulated cover on it as well as making it an integral part of the hokey pokey intercooler and battery ducting, you would think that they could take some extra time and put it in the huge "package" compartment. Seems like it might be the right thing to do, evenif it has to be vented. That excerpt was taken directly from my Mr engineering book.

Dyre

It has nothing to do with marketing- Its called physics. You might try to read up on it. Polar Moment of Inertia is a key factory to how a car feels and reacts when racing.

How many people here consider leaving the battery in the stock location for a race car (road or drag)??? Anyone?? Anyone?? Didn't think so. We all know moving the battery improves the weight placement and feel of the car... It should be easy for you to under stand then how having the same ammount of weight 7 inchs futher back makes a difference when we are talking about an item like an engine.

Hell, the most popular MUSTANG k-members move the motor down and back as far as possiable for the same reason the rotary sits completely behind the front steering. It improves handling and feel.

Its not marking BS, its ******* fact. Unless you are going to cut out the firewall and move the LS1 back 8 inches it is always going to be a less desirable engine position than a 13b/12a. Can you compensate for it? Yes. Can you probably still be faster due to the extra hp? Yes. Is the LS1 just as good for overall chassis setup and drivetrain location? No.

Like I said, I like both options. Both setups have thier place.