MC tweaks

[JShadzi at aol.com]

Cody, a bigger turbo is definitely a good start, as is a cam to get the 
breathing up through the head.  Also, intercooling is critical, not sure what 
you're running now, but if its the stock dual pass then there is a lot to be gained 
there.  Ignition timing is very important once you start getting the boost up 
as others have mentioned.  These are some simple things you could do w/o any 
major fabrication, of course going with the Header is a big jump, the right 
turbo in conjunction, and IME, once you want to get much past 350 crank the 
ignition dist. has got to go.

Javad

In a message dated 12/2/2003 7:54:42 AM Pacific Standard Time, 
Cody at mail.craincorporated.com writes:
I have a few questions about simple tweaks for power on an MC engine in a '87 
5ktq. I'm not quite satisfied with the power I have in the EFI car (I highly 
doubt I EVER will be satisfied no matter how much it has), but I can't spend 
the cash for the T3/T4 and header right now, so I'm wondering what more I can 
do to get a bit more out of it with what I have. 

First thought is I remember somebody mentioning porting the collector of the 
stock header. Whats the full story there? As far as the rest of the exaust I'm 
running no cat and I removed the rear muffler. 

The biggest issue I see now with the stock turbo is that it just can't match 
the flow I'm requesting from it. With the boost set at 2.4bar absolute I get 
great mid range power, but after about 3000rpm the boost starts to drop until 
arround 4500rpm it levels off at 2.0bar. I have heard of people porting thier 
turbos, but my thoughts on that go with the compressor is supposed to have a 
very specific clearance at the inlet and porting would mess with that. I fully 
understand that my biggest restriction right now is the stock EM and turbo, but 
like I said I can't afford to change them right now. I was thinking of 
checking out the specs on 944 turbos, I have a bunch of them laying arround. I also 
have a k26/k27 hybrid, but last time I tried to fit it I found that it hits 
the alternator. Maybe I'll try that again with a smaller alt belt now that I 
think of it.

I plan on porting a head to put on it this week, and matching the intake 
manifold to the ports, but I don't expect much from that. I think I havfe an 
adjustable cam puley (it's for a 924, not sure if its the same, I'll look today) so 
I may tweak the cam a touch. Are there any other tricks for these motors, or 
any other suggestions?


-Cody Forbes
Black Forest Racing
2x '86 5ktq
'87 5ktq EFI
'88 80 4cyl