Second gen. to first gen. TRANSPLANT:D ??????
 

Ok, I *wanted*to put a GSL-SE engine, tranny, suspension, in 1 of my SA's, but I would feel bad tearing down a perfectly good *FIRST GEN* rex, for my own selfish purposes. And besides the fact I cant find one CHEAP, or any ones at any junk yards, so, I have thought of another plan.

I thought, since the junk yards over here, have a shit loads of second gens, I could get one cheap, and not give a damn, about tearing down the ugly thing.

Which brings me to some questions :)
1.)Is the suspension better in a second gen car, than a GSL-SE????????????
2.)Which one has the *BEST* Suspension???
3.)Which one has the *Best* Tranny???
4.)Which one has the *Best*Engine???
5.)Should I have posted this in the 2nd gen. forum???

THANX, I APPRIECIEATE EVERTHING:D
LATERZ, Andrew

second gens went back to the 4-port 13b style (well at least the TII did, not sure about the n/a).

suspension is nicer, tranny is stronger.

THANX. I APPREICIATE IT :) ANY OTHERS??? SPILL YOUR GUTS PEOPLE:) ANYTHING

THANX LATERZ

you should not feel to bad about doing swaps though.. unless you are trying to restor the SA, and keep everything stock....

right now my engine is from an rx-4, and when ever i get around to it i am going to put on a rear axel from an 81 gsl.

I have NO clue to why, I would feel bad about tearing somthing down. Its just, everytime, I look at a car, I guess I see its potential. I just can only bear, to stand, a totalled rx, giving up its parts, but if its NOT totalled, I feel bad, like its a WAIST or somthing. I just dunno.
LATERZ

gotch ya

I think 1st gens had a solid rear axle, whereas 2nd gens have a 6-link IRS... pretty big difference there! (advantage 2nd gen). 2nd gen motors are also all fuel injected, giving better power, mileage, and driveability.

I'd agree with you on this one and go with the 2nd gen.

gsl and gsl-es first gens have a lsd rear end.

do ANY second gen, have an LSD IRS??? I am pretty damn good, at fabricating stuff, and this would be pretty easy to do. I am glad I did not stick that 240SX rear in it, when I had planned to:)
THANX, LATERZ Andrew
Oh yeah, how much do you think a yard, would sell one complete, if they had over 10??? THANX AGAIN

i am not sure, but i think that some of the second gens did have lsd

however, if you are thinking about doing some custom fab work to mount it to your first gen, i donot think that it would be worth it. an 81 or 82 gsl rear end will bolt right up. you would not even need to cut the drive shaft, all you would have to do would be change the brake lines, and e-brake line.

Well, most of it is for the "wow, cool" factor. And I was told that I couldnt put a IRS in there. :D So I will most likley wind up with IRS.
So, what model of car should I pull from the junk yard?
Do I need a T2 tranny, rear? WHAT???? I want to know which models have what:) I really, can care less about the T2 engine, because, of the fact, it will probably fail, 2 hrs after I start playin with it:) So, I might buy a T2 motor, to rebuild, and a N/A motor to first install:) What the diffs, between GTU, and GXL ???
THANX I GREATLY APPRIECIATE IT:D

the only difference between the TII and GTUs is turbos (the gtus does not have any) .otherwise, tranny, rear end, and everything else is identical... i donot know what the difference is between the GTUs and GTU but i would imagine that it is not much... GXL is different all together.. it has all of the bells and whistles inside the car, but everything that makes it run is similiar to the base models

The T2 and GTUs did not share the same tranny, the T2 has the Turbo tranny while the GTUs has the N/A tranny with a better rear gear. :)
The only thing better about the GTUs vs the GTU was minimal luxury's and the better rear gear, everything else was the same.
think of it as a base model with upgrade brakes = GTUs

Peejay pretty much covered the IRS swap in a post long, long ago. To much work, for no gain.
most of the racers that have commented said you will gain the wow factor, but loose handling.
So only put in an IRS if you want to do it for fun and the wow factor, not to improve the rear end handling ability.

how can you lose handling with an irs when that is what its supposed to improve?

Okay, I'm going to attempt straighten this out with my limited second gen knowledge. BTW, I would have posted this in the 2nd gen forum, the answers would have been much more informative.
86-88
SE=base model (not to be desired for parts)
Sport (became GTU)=Had some upgrades like LSD
GXL=Has LSD but tranny is same as SE
TII=You want it. Great LSD, strong tranny, best suspension
89-91
GXL=The high end model. LSD here.
GTU=Lower end model. Not sure on LSD.
GTUs=You won't find one. 100 made. The TII without the turbo.
Vert=Everything's a little different, but has LSD and good suspension
TII=Still what you want

If you're unsure whether it's an LSD or not, simply turn one wheel (if it's a decent junkyard it should be up on something. if it's not, you're SOL) and look at the other wheel. LSD means it will turn the same way. No LSD means it turns the opposite direction.
As for tranny's, all n/a's (except GTUs) had pretty iffy tranny's. Since you're already going to be fabricating a bunch, you may as well grab a TII tranny. With an n/a tranny, you can only make around the 200 hp mark before you start having situations. The same tranny internals were used 83-88. They were upgraded for 89-91, but I'm pretty sure they still were pretty weak.
CONCLUSION: Get TII parts. It's the best bet and it leaves you open to make more power later on.

thanks for the backup redwood.... i thought that the GTUs was simply a TII with no turbo..

Because you would have to duplicate the EXACT mounting points for the IRS and all related parts to keep the suspension geometry, be off a little and it won't work like designed and handle worse.
and since there is no way to mount it exactly on the first gen, without giving the rearend a 2" lift to clear everything. your out of luck.
even then, I've seen many First gen's set up properly have fast lap times then 2nd Gens at Mid-Ohio race course.

Fairly close.

(all cars run a 4.10 diff unless otherwise noted)

S4:

SE: Base model. Don't bother. 4 lug bolt pattern with crappy single piston caliper front brakes.
GTU/Sport: Same car. Some have LSD, some don't. All were 5 lug.
GXL: Luxo cruiser. All should have LSD.
Vert: Don't bother. Wussy ass 3.9 open diff. No verts ever had LSD.
TII: Strongest, all were LSD. However, the pinion flange is different from the NA's.

S5:
All the 89+ cars were 5 lug, and only the TII and GTUs (and maybe a couple GXL's) had LSD. The GTUs runs a 4.33 diff.

And, FWIW, the GTUs DOES NOT USE A TURBO TRANNY! :) And any FC that has an auto has a shitbox 3.9 open diff.

This would be a major project that would only be good for the wank factor.

Is the tranny stronger than the other n/a trannys?
This statement is about the most accurate made in this entire thread.

Hey, since there is so many 2nd gens out there, could you get me some parts?

Could you get an idea how much the yard would want for the following parts? I'd also pay you something for the time spent getting the parts, esp. the engine harness - you have to pull the intake to get at all the plugs. Thanks!

I want a TurboII air flow meter, ECU engine wiring harness, and the ECU itself. The ECU harness is the one that goes through the firewall on the passenger side. The ECU is below a kick plate on the passenger side floorboard, just under the dash. Might as well grab the injectors too.

Well, the junk yard I am going to, you have to be 18, so I have went there 5 times, and was only let in 3:(. They yank there motors out, most of the time. I found one GXL with its motor. As for finding a T2, I looked the last time I was there(6-8 months ago), and couldnt find SHIT!!! So, next time I go hunting, I will look to see if they have any:), I will try a different yard also, but most wouldnt let me in last time, because you have to be 18 shit. But I will look, and I might just get a complete T2 that has been totalled, but with a good drivline, and use it, and I will see if I keep it F/I or not. I will look for those parts you requested also:D
THANX LATERZ, Andrew

Whats the "wank factor"??? I am doing this, because I want a bad ass, first gen. It will be light*(its going into an sa) it will have awesome handling*, and plenty of power*. Also, it should b pretty cheap*. Those are the reasons, for doing this:) And for the factor, that the 12a, I think is about to die, and I want to yank it before it does, so I can rebuild it for my 80, to bring it to become a daily driver:)
THANX LATERZ, Andrew

what he is saying is that it would have to be for shits and giggles.. basically just to say look what i did..

is he talking about the IRS, or the hole idea??? I think everything is gonna be worth it when its all said, and done:) The only hard part is finding, a T2 at a yard, around here:)
THANX LATERZ, Andrew

The whole idea. No offense, but honestly, you couldn't even fix your carb, yet you want to re-engineer the whole rear geometry of your car? Come on now. :)

check out this thread i just posted in for all the gear ratios i just posted for rear ends,

gear ratios


the best tranny imo is a
1987-92 NA


that rear end is gonna be a bitch to mount,
i heard a couple did the swap though,
would love to see some pics.

the suspension is also way better,
its independant rear,like the vette

plus you will have 5 lug

:doh: :bash: I am better at fabricating then fixing a carb. I dont know SHIT about carbs. But if it wasnt me doing it, you would say it ok??? The hardest part, is FINDING THE DAMN CAR, IN A JUNK YARD. Why do people, underestimate me??? I know I can do it, I just gotta find the CAR, DAMNIT. I have a set goal, and I will follow through with it. I think it will be the easiest way to go. I am probably gonna stick with the T2 engine, and when it blows, I will unbolt it(gonna make bracket to except both 12a, and 13b) and I will slap a 12a, then do TWM EFI :D Should be fun, but I am gonna wait, until I have the 12a, before I "accidentally" blow the turbo engine up:) So, I will take pics, of the car , I will be tearing down before, and after:) And the parts that will be left over, I will part out, and get some of my money back:) Thank you V8kilr, and whoever else, that doesnt underestimate me:D
THANK LATERZ, Andrew

I don't care who is going to do it. Its not my car. Just don't expect me not to laugh when you cut the whole floor pan out of the rear of your car and never get it finished... Or do get it finished and wonder why the tires wear funny. Or why it pulls to one side. Or why you have a vibration. Or why you cant get the gas tank out now. Or where to get custom axles.

There is no benefit to the IRS (especially the crappy IRS used in the FC) compared to a well-sorted solid axle.

Well, what car has good IRS???? I am just curious. I want to know, what are the benifits, of a good setup IRS, against, a GSL/ GSL-SE, rear???
THANX LATERZ, Andrew

First, Max out your rear end, then if you still need better handling, buy another car, hehe
Unless you have $ to burn, give up the idea :)
best way if you want is backhalf the car, tube frame it, that way you can make your suspension mounts were you want, use a viper rear end, they hold up good.
$30,000 later, it will handle like a dream, oh wait, you still have that 70's design front end, DOH!
time from a complete tube frame frontend to hold the Viper front steering components.
$20,000 later, wow! this thing scream! why do I only have 100HP to make use of this awsome handling, hehe

I had always heard that a IRS was better for keeping traction on bumpy roads.

I've owned a TII and can say, be prepared for wheel hop even with new shocks.

Seriously tho, the 1st gen 7's have a pretty nice live axle setup. Why would you want to change it?

Can I go cry now :( No one likes my poor vert :(

ok, i'm going to call bs on that. maybe the fc's irs, but in general irs is far better for road handling. i think max7 had the best reasoning to why it wouldn't work in this case. you are the only person that i have ever heard to say that. basically you have defied every auto manufacturer, magazine, and track racer. solid axle will be fine as long as your on a smooth track. look at all major sports cars, or hell anything but trucks and suv's. all irs. now if you're drag racing, solid axle is better at this point do to it still being a stronger and more trouble free setup. it is also cheaper, so when you tear shit up you don't go broke throwing money at halfshafts.

That is exactly why a sorted solid axle is better than an IRS!

With a sorted solid axle you will have anti-squat. The torque reaction of the rear axle will work on the suspension and force the rear tires into the ground. Result - more traction! You can easily get over 100% anti-squat, which means when you accelerate the rear end actually rises up. Watch a drag racer launch - watch the rear tires get forced down OUT of the wheelwells. This isn't just a drag racing advantage, either - what happens when you're exiting a corner and apply throttle? Rear axle forced into the ground, you get more rear traction, and away you go shooting down the straight!

Now let's look at an IRS. There is no torque reaction against the suspension. The only reaction is the force of the hubs trying to move forwards. You can only generate about 25% anti-squat this way. Not as good, eh? Now let's look at the FC rear suspension. The trailing links angle upwards from pivots to the hub center, ESPECIALLY if the car is lowered. This means when the hub tries to move forward, the suspension will compress! This is PRO-squat and is exactly what you do NOT want in a rear suspension. When you accelerate it tries to pick the rear tires up off of the ground! No wonder you had wheelhop problems so bad even super-stiff shocks weren't a big enough Band-Aid fix.

My line of thinking on the bumpy roads aspect is, yes, a solid axle isn't so good on bumpy roads. But then, our front suspension sucks on bumpy roads too, since it doesn't have enough compression travel. Dragstrips and road courses and autocrosses are held on smooth roads anyway. If I wanted to fly across bumpy roads at insane speeds I'd get another Subaru with its nice long-travel suspension at all four corners.

ok, your only argument is anti-squat. true and more advantages in a straight line. i'm not going to pretend i know everything about suspension geometry but i'm looking at the people that do, the automotive engineers. if the put the pricier irs in all these cars, then they did it for a reason. bumpy also doesn't mean rally, but yes a wrx is fun pinned in a bumpy gravel strewn corner. since i don't have any other hard facts other the cornering traction, i let you explain to me why all major road race teams use irs. if they could get solid axle to accelerate out of a corner better, then hell, best of both worlds. why wouldn't they use the solid axle?

Hey, when its 80 degrees outside, the sunroof in my TII just isn't enough :( I'd love to have a vert, but the $600 shell of one I wanted got sold already.

MY TII handles fine. Also, it was SET UP for an IRS from the fatory. I think it'd be kind of funny watching an IRS transplanted SA getting its ass smoked on the road course by some good IT7 cars :)


I think you see so many IRS setups because people are moronic. About 2% could react to a solid axle car stepping the ass end out on them.

IRS has many advantages... It requires a lot less suspension room - more room for passengers, more room for fuel tank, more room for the exhaust (no need to snake up and over anymore) etc. The driveshaft doesn't move through much angle at all so there's less vibration. Also it requires less room because it doesn't move around. An IRS can be isolated better than a solid axle - mount the suspension to a subframe and attach the subframe to the body with bushings. And of course with the lower unsprung weight it will ride better. All of these are very good reasons for manufacturers and are why you're seeing IRS's even on trucks now, mainly for the better interior space so the floor can be lower but the other advantages are there too.

A solid axle does have significant benefits due to the anti-squat. And if you believe that corner exit is not important on a racecourse then you need to rethink that. If you can get the power down sooner, you will be faster around the course. Anti-squat allows this. Unfortunately, a solid axle takes up a lot of room, isn't so good on bumpy roads, transmits more noise to the cabin, etc so the manufacturers don't use it anymore. Plus there is the technogeek side - everyone "KNOWS" that solid axles are inferior, just like everyone "KNOWS" that pushrods are inferior, so people step up to spend more money for something just because it has a cool name, even though it may or may not work better than the "inferior" design.

The rear end skipping-out problem is not directly related to the fact that it is a solid axle. The IRS cars have a low roll center which makes the rear end's handling a lot more predictable. Mazda designed the RX-7 with a rather high roll-center in the rear so the car leans less, unfortunately it also makes handling less secure. Swap in a Panhard rod so you can get a nice low roll center. The car will lean a lot more though, and will plow like a pig even moreso than stock, so you'll have to put some very stiff springs in the rear (there goes ride quality) and you wouldn't believe the handling.

good answer, i wouldn't have thought of half that shit. but why racing teams? all the lemans cars, grand am, sports cars (which obviously are going to get whatever's best since rear seating, etc is not an issue) are irs. you can control the geometry of how the tire interfaces with the road far better with irs. you can control camber, etc, with irs far better then with a solid axle. it also seems that a solid axle car will try to lift its inside wheel and spin it more as the car leans and tries to lift the inner wheel via the axle acting as a massive anti-sway bar.

The axle doesn't act as an anti-sway bar. The anti-sway bar acts an an anti-sway bar. The axle, if the geometry is decent, will move freely throughout all of its travel and will not cause any binding.

Now, here's another place where Mazda screwed up. When they designed the rear suspension, they made the upper links rather short and canted at an odd angle. (I assume it's for clearance and fitment reasons) When the car leans over to a certain point, the suspension binds up because the geometry just doesn't add up - the upper links prevent the suspension from moving any more. This is the other half of the car's "twitchiness". (I had this happen just once, no it was not fun) You solve it by welding in a single upper link in the center of the diff, and throwing away the two stock upper links, or at least replacing the bushing material with rollbar padding so they don't do anything but satisfy the rulebook. Now the suspension can move freely to its heart's content.

Or you go with a torque-arm setup, which I plan on doing sometime down the road...

ok, but that still doesn't allow control over tire/road interface like an irs, especially multi-link. and i'm sure if it was that beneficial the audi and cadillac lmp cars wouldn't have irs. i'm not sying you haven't taught me a shitload about solid axle setups, but there is obviously something more to this.

by the way, i think my 79 just has one link on the diff. it attaches to the top center of the diff and then the left side of the unibody