(Bit off topic) turbo lag...

[Axel Rietschin]

> >What kind of high CR are you planning to use? 9 - 9.5 to 1 is about as
high
> >as you can get if you use 102 octane race fuel. With 98 unleaded, 8.5 -
8.8
> >is probably very high. If you compress more, you'll reach the knock limit
> >really early under boost and you'll need to set your spark advance to a
> >(much) less than optimal point, negating most of the benefits of
> >turbocharging.
> >
> I have to disagree with the concept of CR and turbos. Yes a lower CR does
> allow you the ability to run higher boost numbers without retarding timing
> too much, but I know of at least 2 (there are plenty more) guys that are
> running 1.8L 4 cyl with a stock static CR of 10.0:1. The key is careful
> tuning and a good programmable system.

Definitely :)

> I know that they don't run higher
> then 102 octane fuel, and they are making some good power #'s.

I get 200hp per 1000cc on a 2000cc engine with 98 fuel and 8.8:1 CR. I reach
the knock limit well before MBT as the torque still increases when the
engine starts pinging. Some people get up to 275hp per 1000cc on the same
type of engine with 7.2:1 CR and the same fuel. What are your numbers with
the 10.0:1 engine?

> That being
> said it does require very careful tuning. I am building a turbo motor
right
> now (2035cc 4 cyl DOHC) and I plan on running a static CR of 9.0~9.2:1
> depending on how the head gasket spacer I am using turns out. Going to run
> this on 92 octane with ~10-14lbs of boost depending on what I can tune it
> too. Of course I am going for a full programmable (in my case an
> aftermarket) EFI system




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