Pullying Down... guesstimate on boost/power?
Pullying Down... guesstimate on boost/power? I'm going to swap pulleys in the next couple of weeks and I was wondering if any of you guys have any idea how much more boost and possibly power the car may see?
As it sits the car is a 9.5:1 396ci with AFR 205's (66cc), D1-SC with a 3.70 pulley and makes just shy of 15psi (14.7 after converting kPa values, gauge shows 15). The car dyno's 654RWHP and 635RWTQ through a 4L60E.
If I went down to a 3.40" pulley is there a rough estimate of the boost (perhaps a range is best) and possibly the RWHP increase the car may see? Assuming similar run conditions of course, although I'm more interested in boost.
If it helps, perviously the car had a 4.75" pulley and made 10psi, no HP ratings from then.
I appreciate any input!
As it sits the car is a 9.5:1 396ci with AFR 205's (66cc), D1-SC with a 3.70 pulley and makes just shy of 15psi (14.7 after converting kPa values, gauge shows 15). The car dyno's 654RWHP and 635RWTQ through a 4L60E.
If I went down to a 3.40" pulley is there a rough estimate of the boost (perhaps a range is best) and possibly the RWHP increase the car may see? Assuming similar run conditions of course, although I'm more interested in boost.
If it helps, perviously the car had a 4.75" pulley and made 10psi, no HP ratings from then.
I appreciate any input!
The max boost we have seen at my shop out of an engine with a D-1SC has been 16 psi. http://www.exoticperformanceplus.com...Car.php?car=42 This was on a 402 with 225 heads, and normally a smaller engine with similar components would see more boost. Your 205 heads should help you to see a little more boost than what would be seen with larger 225 heads. It is somewhat of a guessing game, but I would imagine that you're within two pounds of what you'll see boost wise with the D-1SC. Bob
Thanks Bob, would you honestly say it would be worth switching? If so I'll be giving you guys a call in the morning to order the pulley.
EDIT: That is an impressive build!
EDIT: That is an impressive build!
Last edited by 'Trust'; Jan 18, 2009 at 10:43 PM.
I vote keep as is and enjoy it. You haven't even been able to run it all out yet and get the track times its capable of in its current configuration. Besides, if you make more power then we won't have a good race between us (we probably won't anyway as you'll probably get out on me and I won't be able to catch!) Keep it as it sits man, get it dialed in this Feb/March when the track opens and have it ready for the Pinks in Ennis at the end of March! If you go switchin things up now, you'll have to retune, and you may not have it ready for this spring season at the track when it'll be running its best.
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