Jza70 Chassis - How much is too much?

[Xynic]

For starters. I'm looking into the prospect of putting a fully built 2jz-gte into a mkiii. How much power is too much power for the chassis?

At what point do I need to start replacing the rear end? Transmission? Driveline material?

I've read around, but I cant seem to find the information I'm looking for.

The car in question is a 90 Hardtop Turbo 5 speed. I contemplated doing the work to my 89 Targa but realized it was a fools errand so I purchased another car for the express reason of putting it on the track and showing it.

Thanks for the help.

 

[scottiedawg66]

I think that really depends on what you plan to do with it. If you wanna use slicks and launch hard I would say that you want to massage the sub frame as others have done. As far as I know a multi plate clutch and a drive shaft hoop is all you will need to put pretty large TQ to the ground. The R154 trans, and LSD from a US car are pretty darn stout.

 

[Poodles]

Putting tons of power through parts that have 100K+ miles on them...

If you repair any issues (like the craptastic crush sleeve in the diff that ends up loosening), freshening the transmission, get a good clutch...

 

[GrimJack]

If it's got the TRD rear diff, that'll go pretty quick. If it's the regular clutch pack LSD, it'll hold lots - Duane is pushing 800 rwhp through his, hasn't broken it yet.

I've never heard of someone breaking the stock driveshaft or axles, and we've got guys pushing well above 700 rwhp through them.

Will Neely has been quoted as saying that he could pull the teeth off the gears in the R154 at will when he was running 733 rwhp... but I don't think he was running one of the upgraded Marlin Crawler units. Lots of folks pushing out 500+ torque seem to have no problems with the transmission - at least not due to power, many have roasted the first gear thrust washer from heavy duty clutch plates, though.

Bottom line, you shouldn't have much difficulty, most guys driving at the track can't really use the amount of power it's going to take to break the Mk3 Chassis / drivetrain.

 

[Xynic]

Thanks for the information. Definatly going to be looking into the chassis reinforcement.

Throughout the day, I've been thinkign about doing this to my 89 Targa instead of the Hardtop. Is there anything I need to be wary about with flex?

 

[tissimo]

Thanks for the information. Definatly going to be looking into the chassis reinforcement.

Throughout the day, I've been thinkign about doing this to my 89 Targa instead of the Hardtop. Is there anything I need to be wary about with flex?

Flex as in?

The hardtop is a more rigid chassis, but the targa will be fine for pretty much anything. I assume if you're going to race it you'll be adding a cage to the car so that'll strengthen it even more.

The R154 isn't proven much over 600-700 hp. With some of the Marlin Crawler magic I'm sure it can hold more power, but how much? No one knows. It all depends how you're driving the car too. With dyno pulls itll last a lot longer then racing it and trying to pull 1.40 60's with the car.

 

[Johnysupra]

I would say just reinforce the rear subframe. setup the rear diff possibly using something aftermarket. like getting a spool made or using an LSD the KAAZ unit i have seems pretty bullet proof. Set it up right, like its been said above use a spacer to preload the pinion not the factory crush sleeve. Put a cage in it. Modify the fenders if nessacary depending on your tire selection, and of course pending other common repair work you should be good to go. If it is a targa like tissimo said as long as you have a cage your fine.

 

[SupraClaou]

If it's got the TRD rear diff, that'll go pretty quick. If it's the regular clutch pack LSD, it'll hold lots - Duane is pushing 800 rwhp through his, hasn't broken it yet.

I thought the TRD rear diff is good for 1000 hp......:sarcasm:

 

[Poodles]

TRD rear diff is a clutch style

You meant the torsen...

 

[jmcboost]

So... I've got a 90 targa and I'm shooting for over 500whp. Should I be worried about anything happening without reinforcement to the chassis? If so, what do most guys do to help? I do plan on taking it to the track as soon as I get it tuned.

 

[GrimJack]

I thought the TRD unit was the torsen?

 

[Xynic]

I've been planning on putting a cage in it from the get go. I'd rather be doing this to a Hardtop, but I cant seem to find one in my area. Especially not in as good if not a little worse then my Targa. Believe me, if that was an option, I'd go for it.

So far as I know, I'm going to keep hunting for the Hardtop 89+ in decent condition while I put together all the pieces I need for the car.

Thanks for the help guys.

 

[Poodles]

Grim: they came stock with the torsen on the TTR (not sure on the normal 1J model), the TRD unit is a clutch type (probably made by kaaz or cusco) and I think it's a 2 way