My Twin-Turbo SBC 240Z Build

[paulr]

This was originally posted on HybridZ. Please see post:
http://forums.hybridz.org/showthread.ph ... post978291

Sometime back in 2004, after seeing Siliconeboy’s turbo project in process http://forums.hybridz.org/showthread.php?t=89810 , I got inspired to do a Twin Turbo set-up in my 350 Chevy powered 240Z. It didn’t take to long to find the Corvette manifolds and a pair of T3/T4 (.60/.63) from Ford Turbocoupes (inspired by Mike Sitar’s “toohighpsi” Capri http://www.toohighpsi.com/BudgetTT/BudgetTT.htm

These items sat in my garage collecting dust for the next 4 years

So, last spring I decided it was finally time to get this project in gear. I started by installing an intercooler and relocating the surge tank I was using to supply the Holley Commander EFI system.

I built an air hat using the tank from a “pancake” style air compressor that I had burned up the motor on.

Since I wanted to keep the car on the road for the summer, I ran the air hat and intercooler on the NA engine… that got some interesting comments from people peeking under the hood. I jokingly told them that it was a high-tech cold air intake system.

Around September of this year I parked the car in my shop and got busy building. Lots of stuff had to be relocated to make room and to avoid heat issues. Fuel lines, brake lines, and wiring was re-routed. I moved the battery to the back of the car and used the spaced to mount a bunch of other stuff where it would be out of the way (fuel filter, relays, 2-BAR MAP sensor, coolant overflow tank, Wide-Band O2 sensor module)

I fabbed up the manifolds (thanks again to Siliconeboy for the idea of using late model C4 manifolds, flipped)

Did some fit checks.
Built the down-pipes, cold side, etc

It’s now all together, (as of today) but I haven’t fired it up yet. Hopefully this weekend.

And, it all fits under the hood

 

[grumpyvette]

THATS both a very impressive idea and shows FAR better than average fabrication skills
LOVE the use of the compressor tank as carb hat that shows your thinking!

btw any idea on the current price for those turbos or where to get them at a good price in new or like new condition??

 

[paulr]

I bought the Turbos off of eBay 4 years ago for $200 and $165, but I don't see those particular ones (Garret T3/T4 from 84-85 manual T-Bird) very often anymore on the automatic search I have set up. I think you can get them new from Turbo City www.turbocity.com for around $600 each. That's where I got my rebuild kits ($90 each) and they also balanced the rotating assemblies for me ($35 each). So, I've got $615 in the pair... not too shabby

Along the lines of the air hat, did you notice the heat shields for the turbines? I made those from a stainless steel cooking pot that I bought at Value Village for 69 cents. It's not that I'm that cheap, but sometimes when I look at a piece of junk, I can see how to make it work in a different application.

 

[grumpyvette]

IVE used TONS of materials over the years for applications that they may never have been intended for as a starting point for fabricating components, and I sure have almost ZERO brand loyalty on small components, if I can get them to function correctly in a differant application that benefits my car.
example a large aluminum flat sheet cooking pan and a slightly smaller one over the air filter element can make a very satisfactory base with the addition of some closed cell foam and some contact cement for a dual carb air cleaner base that seals against a hoodscoop for a ramair air cleaner assembly

 

[dts300z]

love it! can't wait to see some videos...

 

[Grumpy]

yes videos of the car running, a few burn-outs would be great,
but any tips you might want to post on turbo selection,
tuning a turbo equiped car and examples of both what you did that worked out well, and things you would suggest were done differently,
or parts to seek out and those to avoid would be very useful from someone who gained experience building and driving that car!