big/Bigger diff

[Guest Anonymous]

With a 383 producing uhhhhhhhhh 500 horse.

what rear would i have to have. could the R200 with tires that just peel away before braking anything be ok????

[Guest Frank280z]

Pretty stout 383!!! I think you would be on the border with 500hp. I wouldn't test the tolerance too far from home. There are a couple threads in the Brakes,Susp,Chassis Forum Section that might help. I know Myron broke an R200 with his 425+ motor. lol.

 

Frank

 

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Build it. Drive it. Improve it.

[BLKMGK]

The builder I spoke to didn't seem to think 500 horse from a 383 would be a big problem I didn't even give him any real big details as to how he was to go about making all that power and I actually am targetting about 450. The real test will be the dyno and as little as I know about tuning carbs I'm probably going to need help from friends when that time comes (sigh). I'm just wondering what sort of exhaust I'll need for that power - the Hooker block huggers look a bit on the small side.

 

I did notice that Motorsport is selling LSDs bare for $750 or so in the new catalog - ouch! The 'Vette is supposed to to have a ring gear of just about 200mm like the Z so it's supposed that the ring and pinion ought to hold okay. It's the U joints that are a concern for me. I've also still got a R180 so there will certainly be no big clutch drops going on as if I'd do that anyway

 

Other than the R200, maybe the R230 (?) form th eQ45 - what are the options if we retain independant rears? Corvette? Jag? 9inch with stub axles (don't laugh they exist)? Any chance in hell of mounting something like that reasonably? What about the Cobra 8.8 rears? Of course they're breaking with modded Cobras so maybe that's a bad idea... Spicer U joints for now I suppose (sigh) and maybe a CV conversion when I'm more comfortable working with the Z rear.

[Guest Jason]

I have this book called "How to build Max Performance Chevy Small Blocks on a Budget!". In the back, the author has 10 dyno proven recipes under $3000, extensively tested. Recipe #8 has a 475hp 383 producing at least 400lb/ft between 1500 and 6000 RPM, with a peak of 465lb/ft. A very impressive street motor if you ask me, although it'll take a lot of skillful porting and bargain hunting to pull it off for under three grand.

 

While looking for my project car, I saw a 240z/v8 for sale with a corvette rear in ME. Seemed like a bargain too, but I was stupid and wanted to do my own conversion. Although I didn't go for a look, I guess its possible.

[Scottie-GNZ]

Zlm, personally I do not think there is any problem with an R-200 handling your setup. There are 3 problems I think you will you will run into. Using a 12-25 yr old diff that was not properly serviced, weak stub axles and weak halfshafts and/or CV shafts.

 

I have seen the extremes. I snapped a u-joint when I had the L6 turbo running only 8psi yet Derek Grubb is running GN power with standard halfshafts and solid joints and cutting 1.49 60' times (10.59@130) with 7" slicks. The torque from his GN probably equals or exceeds your 383 and he has over 200 runs on that setup. Locally there is a 86 300ZX turbo that runs 10.0@140 and he used to run the stock 300ZX setup. His problem was snapping the stub axles because he was running a 5-spd and 11" ET Streets.

 

With the light weight of the Z and using tires that spin (not smoke ) and reduces the shock I think you would be fine. The key is using components that are in good condition.

 

Scottie