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Re: Corky Bell's Book[2]

Mp23cc@aol.com wrote:
> Before anyone thinks of installing a bigger turbo you should think about
> doing some head work. The bigger turbo with a stock flowing head and
> manifolds will not gain you much in the low end or the midrange. It willl
> only give you more lag. 

Which I think is why he was so hot on the VATN Aerocharger...it's supposed
to reduce the lag to the point that it's easier to do it first, and then
worry about porting, etc., later.

> You need to get more airflow into and out of the
> motor. Take the MM and FF test. they did not gain much power under 4000 rpms.
> We built a 2.3 with our exhaust, intercooler, ported and polished head and
> manifolds, our roller camshaft a stock turbo set to 17 psi and made almost
> 330 ft lbs of torque @ 3200.

Which is cool...;-)

> A test car that makes 300 plus hp with fuel
> pressure set at 50-60 psi will not work that good everyday on the street.

The only reason he raises the fuel pressure is to add adequate fuel for
the extra air, using a scheme similar to the stock SVO (fuel pressure
referenced to boost) since the computer on the previously NA motor is
not programmed for the extra air.  It's a bit of a patch, but he gets
good results, and tests with a good, wide range O2 sensor to get the
A/F ratios where he wants them.

> A big turbo on a stock motor may give you more topend power, but the turbo lag
> will be great.

Definitely true with conventional turbos, but VATN may solve that...