Has anybody had experience with how much of a difference compression ratio makes on spool time. For example 2.0 LS VTEC with a T4/67 with 8.5 compared to same setup with 10.0 compression ratio. The car is a drag only car with air/water intercooler and will be running on 116 race gas.

 

Go to evans-tuning.com, I believe he has a 9:1 vs 10:1 c/r comparison there

 

i dont think your going to have any diff in spool time. your displacment is still the same.

i think the diff is going to be throttle response.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by advert &raquo;</TD></TR><TR><TD CLASS="quote">i dont think your going to have any diff in spool time. your displacment is still the same.

i think the diff is going to be throttle response. </TD></TR></TABLE>

True, but even the effect on throttle response is negligible. I am running 9:1 compression and the difference between 9:1 and 10:1 is basically unnoticeable on the street.

Since this is a race car running a T3/T67 and always race gas, I would run a flat top piston and whatever compression ratio that nets. An 84mm LS/VTEC with a B16 head and a flat top at zero deck will be anywhere from about 10.7:1 to 11.1:1, which is fine with race gas all the time, and might lead to a few more top end horsepower for a race car.