Has anyone ever used underdriver pullies and installed a supercharger ? If this is done, what negative effects occur ? Are the effects drasitc or minimal, etc. I currently have the Steeda UD Pullies and don't really want to have to remove them and I am hoping someone in here has tried this OR at least knows what might occur.

Thanks in advance.

-Bryan

 

As far I as know you cannot/should not run underdrive pullies w/ a blower of any kind. I am sure others know more and why. I believe you will have to take them off if you want the procharger.

 

Bryan,
You will not get the full benefit of your supercharger if you use the UD pullies. The pullies are design to slow all accessories by 25 %. Hence, you would slow your supercharger down reducing boost and horsepower. I suppose you could use the UD pulley and put a smaller pulley on the SC to gain back the rpm and boost lost. I guess it could be done. Probalby not worth it. You will never know you lost 8 hp from the loss of the UD pullies with a good SC'r.

Scott

 

The above statements are wrong for the Procharger as it does not run with the factory pulley and belt. It mounts a pulley to the factory(or underdrive) pulley and runs on it's own belt. The only concern is if the factory pulley and the steeda pulley are the same depth so the belt will be aligned. Other then that you will be good to go.

Also depending on the kit you can use a smaller blower pulley with the underdrives and still retain the boost level the kit is designed for. The only negative affect is belt wrap. Deepending on the size you have to use you may have some belt slip, but I feel at these low blower speeds it will be fine.

Thanks Mike

 

I stand corrected. Your car so I'd say go for it and see what happens.

 

Yes, you are right. I checked my kit, it does use its own pully. Great, now I do not have to remove them. Thanks Mike.

-Bryan

 

Just so people know if they see this thread, the Procharger pulley would not mount to the underdrive pulley, per Bryan.

Vortech,roots guys--I also did some checking and the size of the underdrive is too small and would require to small of a blower pulley to obtain the same boost levels. Belt slip would likely be a problem and you would not have any room to grow, so thats that.

So the theory was correct, but the real world said :nono:

Thanks Mike

 

Thanks Mike.

-Bryan

 

Actually I'm going to have to correct myself on the Vortech part. When Lidio (Alternative auto) and I were talking the other day about using the underdrive we were under the assumption the factory pulley was 7.5 inch in diameter. Anyway I just measured mine and it is 6.75. That being said a 2.9 pulley on the Vortech would allow you to make the same boost and run the underdrive.

Example : Crank pulley/ Blower pulley x rpm = blower speed

6.75 / 3.8 x 6000 = 10658 rpm's (impeller speed 38,475 at that rpm)

5 / 2.9 x 6000 = 10344 rpm's (impeller speed 37,448 at that rpm)

That should be real close in boost and performance and this is based on the Vortech V2 SQ.

The reason I wanted use the underdrive is,it is rated as a SFI unit and a few extra ponies couldn't hurt. I'll probably go ahead and try it and see how it turns out.

Thanks Mike

 

the ud pulley would work, and not change the rpm of the blower in relation of rpm of the crankshaft, BUT the procharger piggyback pulley wont work with a steeda piece, the pegs on the back of the pulley wont fit into the steeda or any other unit that i know of