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Turbo gurus?


Guest Anonymous

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The compressor is not what will cause the lag, it is the turbine side. A t3/t04 implies a t3 turbine side but it can be had with different wheels in the turbine housing. There is a tendency to throw the term LAG around without fulling understanding what it means or is. The stock t3 has instant spoolup and was at full boost by 2800RPMs and that is not necessarily a good thing.

 

When I ran my t3, it was almost impossible to launch the car without frying the tires. As impressive as it sounds and looks, it actually slowed me down as I could never get better than 2.0s in the 60' with 245 ZR-rated tires. I then upgraded to a t3/t04 and the car did not feel as strong off the line (some might say laggy) but the result was an effortless 1.74 60' and smoother acceleration through the lower gears.

 

My advice is to speak with the turbo manufacturer and tell them your setup and goals and let them configure the turbo for you.

 

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Scottie

71 240GN-Z

http://www.mindspring.com/~vscott911/gnz.html

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Guest Anonymous

I did. I ordered from the Birmingham place where walker morgan works. He suggested it to me. I just looked at compressor maps and to me it looks like an awfully big damn compressor. I don't mind a bit of lag and a whatnot, I'm tired or undersized t3 and t25 turbos anyhow smile.gif I'm just wondering if it's too big. Crunch a few numbers and look at the compressor maps, unless I don't know what to look for on compressor maps, that's a huge compressor. With a "high flow" something or the other t3 turbine I hope I don't have creep problems:

 

 

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Morgan

http://z31.com/~morgan/s30

http://carfiche.com

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Guest Anonymous

I got a spare borla muffler laying around(Got a deal on a pair of them from some guy with a z32 who never used them), one is on my 300zx, saved the other one for the 240 smile.gif 3 inches straight through. It'll need an entire new exhaust, the gimp stuff I have now has like 6 clamps on it and it hangs about 2 inches off the ground. It'll be 3 inches all the way for sure. I'd go larger, but no exhaust shops I know of work with anything over 3 inches.

I was gonna use 2.5 inch plumbing for the intercooler since my intercooler has 2.5 inch inlets. Probably just get it done at same time as the exhaust and then send it off to be jet-hotted if stainless is too $$$ for my blood.

 

 

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Morgan

http://z31.com/~morgan/s30

http://carfiche.com

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I would stick with a 2.25" pipe on the turbine side. The turbine outlet is only 2", so get a 2-2.25" hose at the turbo and blow out the pipe at the I/C end to 2.5" and use a straight 2.5" hose. This is what I am doing on the GNZ.

 

The 3" straight-thru Borla should be fine and you do not need larger than 3". Do not want to come off as a salesman, but you might want to consider one of my DPs. This is what I used and what Patrick is using for his almost 120mph ride. Below you see a pic of the DP compared to the stocker and a pic of the DP and 3" mandrel exhaust. I have the same exhaust modified to fit the GN DP.

 

DP-frontview.jpg

 

Exhfront.jpg

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Guest Anonymous

I don't have the stock turbo, nor do I have the stock turbine housing, ie. your downpipe won't fit. But it is quite nice anyhow smile.gif

I have the standard garrett housing/wastegate with the 3 bolt flange on it. It comes with a mating flange to weld the exhaust system onto.

I will get the biggest exhaust I can, I've seen 3.5 inch exhaust, but doubt I can find a shop to run it for me frown.gif

 

 

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Morgan

http://z31.com/~morgan/s30

http://carfiche.com

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Morgan, I don't think you need to worry about 3.5" exhaust, 3" is likely overkill for a 2.8, even with a turbo.

 

Yes, I know, backpressure ZERO is just perfect for a turbo engine, but you also have to concern yourself with exhaust gas velocity. Corky Bell suggests that you use an exhaust pipe 10% larger than the turbine outlet diameter. For a 400hp engine, his charts indicate that a single 2.5" exhaust should do. HOWEVER, Scottie has some real world experience here, heed his words. smile.gif If I were building an exhaust for my car right now, it'd be 3" all the way from the downpipe back.

 

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"Gimme Fuel,

Gimme Fire,

Gimme that which I desire"

-Metallica

 

Drax240z

1972 240z - L28TURBO transplant on the way!

http://members.xoom.com/r_lewis/datsun.html

http://members.home.net/drax77/newpage.html

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Guest Anonymous

Good idea Pauli, I would imagine those Ford and Dodge diesel performance aftermarket people probably work with that sort of tubing, if not them, the medium diesel service vans and such would definately have it, any major city would have a diesel garage that could do it. I know squat about turbo's with the exception of a book I had 15 yrs ago on it, but 3" pipe is pretty darn big, I looked at a piece this last weekend at a local speed shop and it would appear to be able to flow alot of exhaust. A unsolicited $.02.

 

Lone

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  • 3 weeks later...

I ran that combo and it is a real power maker. Even with a clipped P-trim it made 8-9psi of boost by 3Krpm. Walker was able to generate over 350hp@wheels with the turbo he proposes. The bigger turbos generally have more lag, but make up for it in brute power. I just upgraded my turbine a/r from .58 to .81 on my turbo and it spins the tires @45mph with 15psi of boost. I have a T64 w/a clipped P-trim turbine wheel. Don't kid yourself with these smaller wheels for L applications, they just don't make the power on most street motors. Use the 60-1 that Walker has suggested and you should be able to make full boost by 3200rpm or so.

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