PDA

View Full Version : ASP + 10% supercharger RPM? Max safe SC rpm?



suutari
01-13-2005, 01:52 PM
Hi!
What is the max safe limit for supercharger rpm? Does someone have the ASP underdrive kit + 10% overdrive pulley and what is the max SC Rpm with them? Im going to do some pulleys and would need to know the max safe rpm for the blower..
You with the monster 400hp/480nm engines should know ;). Impressive work you all with these cars! Nice!
Thanks, Sami

PS: searched the forum but had no luck..some info but not real assuring text for this problem...lot of talk with the pulley size etc.. but not actually the SC max RPM

specops_SC
01-13-2005, 02:48 PM
Hi!
What is the max safe limit for supercharger rpm? Does someone have the ASP underdrive kit + 10% overdrive pulley and what is the max SC Rpm with them? Im going to do some pulleys and would need to know the max safe rpm for the blower..
You with the monster 400hp/480nm engines should know ;). Impressive work you all with these cars! Nice!
Thanks, Sami

PS: searched the forum but had no luck..some info but not real assuring text for this problem...lot of talk with the pulley size etc.. but not actually the SC max RPM

well, do you want to spin the sc as fast as possible or make the most power out of it? you can spin the heck out of the sc itself. however, at a certain point, the act becomes so hot you actually begin to loose power, not to mention the amount of hp required to spin it so fast. the highest overdrive that i know of is david neibert. he's overdriving his 23%.

Moses

David Neibert
01-13-2005, 03:06 PM
Hi!
What is the max safe limit for supercharger rpm? Does someone have the ASP underdrive kit + 10% overdrive pulley and what is the max SC Rpm with them? Im going to do some pulleys and would need to know the max safe rpm for the blower..
You with the monster 400hp/480nm engines should know ;). Impressive work you all with these cars! Nice!
Thanks, Sami

PS: searched the forum but had no luck..some info but not real assuring text for this problem...lot of talk with the pulley size etc.. but not actually the SC max RPM

I think Eaton reccomends staying under 15,000 rpms or something close. IMO, it's not so much about how fast you spin it....it's more about how much of a load your putting on it while spinning it fast.

With stock heads, cam, exhaust and IC....spinning it any faster than it takes to make 14 pounds of boost is going to be counter productive. Meaning it will consume more power than the additional boost creates. I'm currently overdriving about 23% but only making around 17 pounds of boost. I haven't really had a chance to test it since changing cams at 26% overdrive, but do have the pulley to do it.

BTW, Using underdrive pulleys doesn't change the blower speed...it just slows down the accesories, so a 10% pulley will be fine.

David

XR7 Dave
01-13-2005, 05:43 PM
17-18000rpm would be considered typical. David is turning 21-22Krpm with his but I don't think that falls under the guidelines of "typical". ;)

A 10% pulley nets a 3:1 drive ratio.

Ryan A Harris
01-13-2005, 05:57 PM
I'm pretty sure about this, the ASP pulley is not the same size as stock for the drive diameter. There is a slight difference, not a big enough of one to change your boost level.

BT Motorsports
01-13-2005, 06:09 PM
Though not recommended, with the right bearings in the snout, you can buzz 28K RPM and the blower will hold together.

Paul

suutari
01-14-2005, 12:15 PM
So this is what Ive cathered..

about 15000-18000 max rpm and boost 14-17lbs is around efficient figures..All depending of the set up as intercoolers etc. but the main thing was that if you get say 17lbs and the sc is spinning 1800rpm thats about how far you can push the sc efficiently and safely...?(well as thumb rule..forged all the ice in the intercooler etc.. )
thanks for the fast info :)

XR7 Dave
01-14-2005, 12:20 PM
I would say that 15psi is max for anything that resembles efficient boost but that is just my opinion.

suutari
01-19-2005, 09:24 AM
Thanks for the info, this helps a lot alltough the charger is ported similar to magnaport II specs..Gives somekind of starting point.

ThunderDave
01-19-2005, 04:27 PM
I'm thinking of going from a 5% to a 10%. Will I need an ic fan to do that with my current mods?

Thanks!!!!