Eaton M90 pulley size

Chedder · Post by **Chedder** » Wed Dec 05, 2007 7:21 pm

Hi chaps, just about to start a Supercharger installation on my Rover V8 engined TVR, will be using an Eaton M90 SC that is fitted with a 3" 8 ribbed pulley, the question is, what size crank pulley do I need to achieve 5-6psi.
The cranks will have a max of 5500 rpm and the SC has a max of 13500rpm and shifts 1.5l of air per revolution.
Any ideas who sells pulleys?

TIA
Chedder

kiwicar · Post by **kiwicar** » Fri Dec 07, 2007 12:58 pm

what capacity is the engine?

Mike

Chedder · Post by **Chedder** » Fri Dec 07, 2007 2:23 pm

kiwicar wrote:what capacity is the engine?
Mike

forgot that bit, it is a 3.5l.
Have been advised that a 5 3/4 diameter pulley will be correct for the application but want to be certain before I go on another spending spree!

kiwicar · Post by **kiwicar** » Sat Dec 08, 2007 2:46 pm

Hi
5.75 " pully would assume an 85% eficiency for the supercharger which is not unreasonable. Are you going to intercool it?
Mike

Chedder · Post by **Chedder** » Sat Dec 08, 2007 4:37 pm

kiwicar wrote:Hi
5.75 " pully would assume an 85% eficiency for the supercharger which is not unreasonable. Are you going to intercool it?
Mike

Hi Mike, will be fitting an air to air intercooler in the nosecone.
Chedder

kiwicar · Post by **kiwicar** » Sun Dec 09, 2007 11:01 am

If you intercool it you may need to spin the the supercharger a little bit faster, but I would think the 5.75" is a very good start. As with all engine tuning any one part effects all the others.
What is the supercharger off?
What is the engine going in, a seven?
What cam timing are you using? (especially how much overlap)
If you are only going for 5 to 6 psi and a max revs of 5500rpm it sounds like a mild tune (at a guess your going for about 275 bhp and a bucket of torque

)
Mike

Chedder · Post by **Chedder** » Sun Dec 09, 2007 1:06 pm

kiwicar wrote:If you intercool it you may need to spin the the supercharger a little bit faster, but I would think the 5.75" is a very good start. As with all engine tuning any one part effects all the others.
What is the supercharger off?
What is the engine going in, a seven?
What cam timing are you using? (especially how much overlap)
If you are only going for 5 to 6 psi and a max revs of 5500rpm it sounds like a mild tune (at a guess your going for about 275 bhp and a bucket of torque )
Mike

Thanks Mike, not sure what the SC came off originally, but it appears to have been rebuilt as the rotors are like new.
Cam will be the SC cam from Real Steel, engine has 9.75:1 compression but fitting composite gaskets to lower it a touch, along with stage 3 big valve heads, Microdynamics boost retard unit to take care of the ignition timing, JE modified Jag flapper unit and injectors along with a Vortech boost dependant FMU to manage the additional fueling.
Car is a 1980 TVR Tasmin orginally a V6 but now running a 3.5 efi TVR (Rover) V8. SS tubular manifolds and straight through exhausts, engine made 209hp at the flywheel on the Dyno this year.
Brakes, suspension and diff have been upgraded so now it's time for a few more ponies, aiming for 300 but will wait and see what it makes!
Just need to find a local engineering shop who can modify my crank pulley for the SC drived belt and make up a mounting bracket for the Eaton unit then its all systems go.

kiwicar · Post by **kiwicar** » Sun Dec 09, 2007 3:23 pm

Hi Chedder
I think to get 300 BHP you will need about 7 or 8 PSI, but it depends on alot of things, like the effeciency of the intercooler, the SC and the cam and heads. Sounds a fun project.
Mike