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-   -   Chassis reinforcing for a t2 swap (https://www.rx7club.com/1st-generation-specific-1979-1985-18/chassis-reinforcing-t2-swap-628015/)

rx-freak 02-27-07 08:09 PM

Chassis reinforcing for a t2 swap
 
I am planning on installing a turbo II S5 motor into my 1982GS and I am wondering if I should reinforce the chassis. How much torque will a stock chassis take. I am sure this question has been asked a million times, however, I have spent the last few hours in the 1st gen archives and I still haven't found much info on this topic. If I do have to reinforce the chassis, how and where should I reinforce it.

85rotarypower 02-27-07 08:16 PM

The stock 1st gen chassis can handle a lot of torque. Its quite strong actually. I'd say it could handle at least 300lb ft of torque, much more than even a modded TII engine can put out.

andrewb70 02-27-07 08:16 PM


Originally Posted by rx-freak
I am planning on installing a turbo II S5 motor into my 1982GS and I am wondering if I should reinforce the chassis. How much torque will a stock chassis take. I am sure this question has been asked a million times, however, I have spent the last few hours in the 1st gen archives and I still haven't found much info on this topic. If I do have to reinforce the chassis, how and where should I reinforce it.

Considering the fact that many FBs have been swapped with V8s, I think you are OK.

Andrew

trochoid 02-27-07 09:26 PM

No, hasn't been asked a million times. For once, someone has come up with a new TII swap question, congratulations, you get a cookie, or 5 forum bucks, lol.

Guys are running over 400 hp with no body reinforcement. The thing I would watch/check is the normal rust areas and make sure they aren't compromised. If they are, the control arm mounts in particular, then I would look into adding some extra strength there when repairs are made.

680RWHP12A 02-27-07 10:11 PM

none needed for a rotary motor, a high torque v8, i would add a cage and some subframe reinforcements if i wanted too keep all the body lines in tact ;)

steve84GS TII 02-27-07 11:21 PM

I agree......even with super high HP numbers,turbo rotaries down put down super lowend torque......except maybe a 20B or bigger.

I wouldnt worry,except about the aforementioned rust issues.
I added a 4 point rollcage,and some strut braces front and rear,but thats about it.Youll break the stock trans,then the stock rearend, well before you have to worry about the unibody.Install a TII trans,then either be nice to the stock axle,or install an 8.8" Ford rear.At that point,you should be able to crank the power into the ridiculous levels for a 2 rotor,without much worry.

85rotarypower 02-27-07 11:39 PM

DirectFreak is running about 500hp and 430lbft of torque in his GSL-SE and AFAIK he only has an 8 point roll cage. There are no other subframe mods or anything, but I could be wrong. I won't speak fully for him.

But like I said, the 1st gen has a lot of torsional rigidity. It was actually one of the stiffest cars for its time I believe, and by todays standards its still up to par.

fluffysheap 02-28-07 12:24 AM

The biggest chassis upgrades for a 1st gen IMO are strut tower braces - it's pretty easy to make a front one and weld/bolt it to the firewall as well. After that, roll cage will help a lot. Mostly though at this point it's just about rust and mileage. These are old cars and metal fatigue is going to be adding up.

Directfreak 02-28-07 08:57 PM


Originally Posted by 85rotarypower
DirectFreak is running about 500hp and 430lbft of torque in his GSL-SE and AFAIK he only has an 8 point roll cage. There are no other subframe mods or anything, but I could be wrong. I won't speak fully for him.

But like I said, the 1st gen has a lot of torsional rigidity. It was actually one of the stiffest cars for its time I believe, and by todays standards its still up to par.

Currently 507 RWHP at 22 PSI, and 395lbft of torque. 6 point cage, although I removed the swingouts. (so only a 4 point 95% of the time).

No problems whatsoever. Like said before, I don't think you even need a cage. I only got it to be legal at the track.

Naegleria_Fowleri 03-01-07 02:49 AM


Originally Posted by Directfreak
Currently 507 RWHP at 22 PSI, and 395lbft of torque. 6 point cage, although I removed the swingouts. (so only a 4 point 95% of the time).

No problems whatsoever. Like said before, I don't think you even need a cage. I only got it to be legal at the track.

If this guy says it isn't needed - it isn't needed.

85rotarypower 03-01-07 02:51 PM


Originally Posted by Directfreak
Currently 507 RWHP at 22 PSI, and 395lbft of torque. 6 point cage, although I removed the swingouts. (so only a 4 point 95% of the time).

No problems whatsoever. Like said before, I don't think you even need a cage. I only got it to be legal at the track.

Wow, you made less torque with higher hp? I got the vid with 480hp and 440lb ft of torque at only 21psi. Thats kind of surprising. Sounds almost like you've pretty much reached the limit of your turbo.


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