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Old 07-21-2012, 02:38 PM
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Take it to the track and get some time slips on it.
The MPH from the time slips tells you how much horsepower you are making.
Once you know the weight of the car+driver.

The casting number for the heads is under the valve cover.
Some of the 76cc heads are very restrictive. ( really restict the engine power)
The rest are lame in stock form but improve with porting.
Think of it likened to blowing air thru a straw.
Lots of back pressure, not much flow.

Turbo boost on the gauge is a measurement of back pressire.
What is not getting into the motor.
With a restrictive head you don;t get much (power increase) from
a indicated 5psi boost.

A restrictive exhaust system (stock ex manifolds, small exhaust, stock muffler) will really
restrict the torbo response and restrict engine power too.
A turbo motor needs free exhaust flow. A turbo does 4/8ths the job of a muffler in quieting the exhaust .
Often a turbo motor can run on the street with no muffler and be relatively quiet.
if the muffler is restrictive is will sure like the flow increase.

How would you rate the turbo's boost response time?
"turbo lag"

Last edited by F-BIRD'88; 07-21-2012 at 02:47 PM.
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