how much overdrive?

How much of an overdrive can the MPII be taken too before it is inefficiant?
I saw on another thread that someone was overdriving a MPIII like 20% or so.

Thanks
Chris

20-25%

Depending on your IC setup, I would imagine as much as 20-25%. Personally, I am going to drive mine 20%. I'm sure someone will post VE figures though to substantiate this (I don't have the figures handy).

How many cfms is a MPIII moving at 20% od?

I have a custom front mount IC, Dont remember the flow right off hand.I was thinkin about gettin the 10% MP crank pulley and the 10% jackshaft pulley along with my stock blower pulley(91 pulley) so that should get me a little over 20% overdrive and wasnt sure if that setup was going to be to much for it or not.

I ran a MPII with a 10% blower pulley and with a 10% jackshaft pulley.
The IC tube would get very warm. I ran the MP11 with a 10% blower
pulley all the time. I just tried the 20% overdrive for a test. I gained
a little power in the lower RPM range. But did not feel much gain in
the upper RPM range.

I have a MPIII that I ran with 10% OD on the blower. Then I switched
to running The MPIII with 20% overdrive .I made the switch with the
tuning help from XR7 Dave. It makes very nice power in every RPM range.
And at 20% OD the air is a lot cooler than the MPII was at 10% OD.

I would like to install a 10% od crankshaft pulley and try 25% and
30% OD's.

I detune for daily driving and only run 10% OD on the blower.

Pulley combinations that I use are.

Blower pulley 10%. (installed all the time.)

Jackshaft pullies. stock , 5%, 10%.

Crankshaft pulley, acc underdrive ,blower part has slight overdrive.(installed all the time.)

I think when running 15%,20%,25%, to 30%OD. It would be a good idea to run 94 or higher gas,or have an alky injection system.Both with 30% OD

Randy

Randy N Connie said:

I
I think when running 15%,20%,25%, to 30%OD. It would be a good idea to run 94 or higher gas,or have an alky injection system.Both with 30% OD

Randy

Click to expand...

Agreed. I'll be running a XX IC with alky while driving the MPII 20%.

Thanks for the info guys.I was thinkin of swappin pullies around to fit the driving i was goin to do, but dont plan on driving the car too much(just nice sunny days and to the track to get some practice for the shootout).
Here is a pic of the ic I used.

redtbirdsc said:

Thanks for the info guys.I was thinkin of swappin pullies around to fit the driving i was goin to do, but dont plan on driving the car too much(just nice sunny days and to the track to get some practice for the shootout).
Here is a pic of the ic I used.

Click to expand...

Nice FMIC pic.