neverstop

what would you recommend? anyone in here over spinning their setup slightly?

reason I ask is because if I go down one size on blower pulley to 3.55" it puts my D1SC max impeller speed at 64.6k where as procharger says D1SC max speed should be 62k, so it would be ~4% too fast at the maximum redline my car would ever see, however, peak power with my new cam will be at about 6,500rpm at which blower speed is well below ProCharger's stated max, so my D1SC blower would only be spinning over its recommended max for a split second, very very rarely only right at red line.

Just wondering what you guys would recommend and how bad it is to over spin a blower by a tiny amount very rarely, or if the blower is likely to just break or if this is too much strain

would you pulley down to this setting or leave it where it is with 3.75" blower pulley? is the additional maybe 1-2psi worth the risk/trouble?

Blown06

iTrader: (32)

I used to spin mine 106% at the shift point. Didn't pick up a ton of power at the very top, but brought the power in a lot faster which improved my et's a lot.

SmokedOutZ28

iTrader: (35)

What would be more efficient or a better option.. Spinning the blower fast to bring power in sooner or changing rear gear setup?

Blown06

iTrader: (32)

Spinning the blower faster

hellbents10

iTrader: (10)

Take into account that you are calculating assuming absolutely zero belt slip too.

The Alchemist

iTrader: (19)

I've known guys who overspin the D1s and didn't go any faster. The max rating is based on the gears and bearings inside the blower, and not so much where it makes the most power, which very few actually know since Procharger doesn't release their maps. I know a lot of the F-series blowers continue to make more power above their stated max rpm, but with the D1s I don't think it's the case.

Just like stated above, spinning it faster helps to raise the overall hp average during a specific rpm range, which will in fact help you go faster, I would just make sure you keep an eye on the fluid, and fill/change more frequently.

neverstop

thanks guys, I still have found only one person who ran 3.55" blower pulley with 8" crank pulley on D1SC who didn't have belt slip issues so we'll see, my choice is 3.75" or 3.55" so still kind of torn but will likely just go with 3.55"

using 3.55" on the blower puts max D1SC rpm at 61,900 at 6,700 rpm which is right at Procharger stated max rpm of 62k on a D1SC, I imagine I won't be reving the car past 6,500 because of cam and blower side relative to motor (an LME built 427ci) so I doubt this is even an issue

if I rev it to 7k then I would theoretically be at 64.6k right at redline but I think my setup is going to nose over pretty hard at 6,500 rpm since it's a big flowing 427 so the more I think about this the more it seems I'll virtually never be at the rpm speeds necessary to over spin the blower and even if I do it would only be for a split second at red line before shifting.

I maintain my car to an absurd level also, to say I'm meticulous is a crazy understatement, basically the moment anything isn't in essentially perfect/new condition I jsut replace it without much regards for cost so I'll certainly be watching my blower health and changing oil super often, etc.

wish I could find a map on the D1SC so I could tell where it's maximum efficiency is.....


hopefully my 3.55" blower pulley won't cause too many belt slip issues on my 8 rib setup.

The Alchemist

iTrader: (19)

Good luck finding maps to the Prochargers... you'll find out who shot Kennedy first.

210guy

iTrader: (7)

good to know

Blown06

iTrader: (32)

I had near zero slip with a 3.55/8. Reichard blower pulley, HD tensioner and a green belt.

BLNLS1/RX7

iTrader: (2)

I ran a 3.25 pulley on my D1 for years with no belt slippage and was running 7100 RPM at the end of the track and never had any issues.

Blown06

iTrader: (32)

Doesn't really mean much if you don't tell us the crank pulley diameter.

ajrothm

3.55" is perfect with an 8" balancer on a D1. Lots of people run that combo.. It'll make 800-825 rwhp with a stick.

neverstop

thanks guys, appreciate the feedback. I'm going to slap on the 3.55" pulley and see how it goes. Hoping for >800whp on 427 with MAST heads, etc so should be a fun setup.

Been hearing so many nightmare stories on these forums about belt slip I'm probably just being paranoid.

I'll let you guys know how it goes.