MVP'S ZO6

I've heard that some people over spin the crap out of their blowers but how much are you guys really over spinning them? Like most things, I'm sure the manufacturer under rates the capabilities to keep down on warranty's Ect. What's the general concencus on over spinning say my YSi? By a little bit? What if I spin my YSi to 70.3K (which is 5,300 RPM's over what vortech recommends) am I asking for destruction?

c5mtl

! I would not hesitate over spinning a ysi by 5k

MVP'S ZO6

Are you over spinning yours buddy?

Milan

2.75" pulley, 8" OD balancer, 6,500 RPM is maxing it out

Anyone who has gone smaller pulley or revved their motor to 6.5k+ has overspun their Ysi, which from what I noticed has been a lot of people on this forum

jmuck

I ran a 8" crank and a 2.6" and shifted at 7,000-7,100. Pulled like a freight train.

MVP'S ZO6

Yes sir!!! I did the calculator from Vortech. I was just kind of wondering what the average they were overspinning.

MVP'S ZO6

That's sick!! :-)

MVP'S ZO6

I've been reading too that theres a little bit of room from what the manufacturer recommends and what the blower will take. Couple that with the fact that you have to account for belt slip (since they all slip a little unless your running a COG) and that your not holding the engine at the high RPM's for a long periods of time.

a/c man

IDK but I have a 3.33 with a 8" balancer went low! 9s @ 149mph what are u trying to achieve a big dyno! ###?? Mine hit 907rwhp but we all know it was more like 607rwhp!!

MVP'S ZO6

Nope I'm going to run an 8 second pass with a manual car and some suspension.

a/c man

I'm supporting this u deserve a 8s pass a
ll u been through bro!

69ls6

spin it to 80k impeller speed.I spin mine 75k

joshtownsend

always always over spin a blower...I see virtually no reason not too on any situation. 10-15% is a good round number.

easyvette

Personal experience. I was overspinning my procharger by 5/10k I forget right of hand. But when I had the car on the dyno the car stopped making power at 5.5K rpm. Whats the purpose of overspinnng something if it stops making power long before redline?

I moved to a larger blower. Less heat created and now curve continues all the way to redline. Just my opinion.

joshtownsend

The purpose of overspinng a blower is not to make more power on the top end, but to bring the power in sooner for the initial hit... more often the not, races are won or lost at the start.. not at the beggining.. Even if you are at peak hp at 5500... who cares... as long at it carries thur to wheverever radline is for you..

For instance...

A car making 1000hp at say 6600 rpm and shifts at 6600 rpm with a blower going to max rpm say at 7000rpms will get raped every single time by a 700 hp car that overspins a blower that is rated for max rpms at say 5800 rpm but spins it to say 7200 rpm.

Reason being.. is even thoght car A makes more power..it take so long to get there... where as the other car may make peak power at 600 which is 700 in this case.. it still pulling around 650-675 for an additional 1200 rpm and it has more power off the hit because its all ready in its efficiency range when the race gets started.

fyi, other things can be considered, gears, blower ranges and such.. but all things considered equal.

MVP'S ZO6

I get the principals behind overspinning. I was just curious how much I could really get away with.

69ls6 your a mad man. 75K eh?? That's awesome! Your not afraid of it being a ticking time bomb.

C6 Curtis

Not sure if its the same but ppl over spin the hell out of turbos all the time, so why not with a centrifugal.

-Curtis

Milan

Most people don't over spin their turbos they just boost them past compressor efficiency. Usually there isn't danger in the impeller touching down on a turbo.

Most turbos can spin way faster than a supercharger.

c5mtl

my overspun (r.i.p) t trim felt way faster than my ysi ...t trim would be at 15 psi almost as soon as got on the gas ....ysi only makes 11psi at 5k with my current pulley setup
Moral of the story .....pulley down!

69ls6

nope..Most is scared of 28psi too now that I've seen 30psi and looking for more