Loss of Power Before Blower w/GTP Pistons??

[cboney2000]

I know the GTP Pistons are forged and the rods too, and I'm going to have a blower in there eventually, just wondering how much slower the car is going to be when I put in the GTP pistons since they are lower compression and all and if it would create any problems without the blower installed with them immediately or tuning wise. Thanx again.

[slacker69]

I think it is something like 10 hp loss with that compression.

[BillyCobin]

Now, with GTP pistons, couldn't you mill the heads down, and regain the lost power?

I've been trying to find the numbers to run some calculations on this today. I think it would be a cheaper way to get forged pistons, while retaining the stock CR.

[cboney2000]

Ok, I can live with that for the cost effectiveness and the strength. However, are there ANY adverse effects that I will have to account for other than the lesser compression? Such as any tuning needed? Any fuel delivery changes? Do I have to balance the rotating assembly?? Do anything to the crankshaft? How about the rings and the blowby problems that people talk about with our stock piston rings?? And the GTP rods AND pistons are forged correct?

[ April 27, 2003: Message edited by: cboney2000 ]</p>

[Arctc Wolf]

uhhh, droping a full point of compression will result in more than a 10 hp decrease i think. The problem w/ balancing our rotating assemblies is that ours have a balance shaft and are externally balanced. I'd just save ur money and buy one of the race prepped blocks from ZZP or Intense that already come w/ all that stuff done.

[BillyCobin]

http://www.bgsoflex.com/crchange.html

Gives this result:

# Engine Horsepower (peak) is 200
# Old Compression Ratio is 9.4
# New Compression Ratio is 8.5
Computation Results:
# Computed New Engine HP is 194, a -3 percent change

So, taking into account inaccuracies in the equation, a 10 hp loss seems about right.