YSI pulley combo suggestions

Hi everyone,

I am in the process of a rebuild on my 98 Cobra, balanced forged internals, stock stroke, teksid block, crower stage 2 blower cams, ported 01 cobra intake, heavily ported heads (320 cfm intake ports), FB performance 4r70w, long tubes with dual 3" exhaust, running a YSI with 8 rib conversion on e85 and meth. Controlled by AEM Infinity 5 series stand alone.

Looking for the suggested pulley combo to max out the blower - I can run it to 7300rpm or so if needed. My calculations came up with 15% OD crank pulley and 2.9 blower pulley to get me to 65k impeller speed. I'd like to keep my stock style water pump and not have belt slip - do you all think that is possible with my combo?

Do I need to worry about water pump, P/S pump or alternator spinning too fast?

shooting for 950 rwhp...

Thanks!

with that 15% overdrive you shouldn't have a belt slip issue with the 2.9.

Cool, if that's the consensus I'll go with it!

I run a 15% overdrive pulley as well. and I'm just fine. I plan on running a 3.0" pulley as well at some point. You'll need to adjust the alternator pulley I'm pretty sure. I run an electric water pump but I plan on spinning 8k rpm. I would recommend ditching that stock 01 intake and get a Sullivan.. I would also recommend a aftermarket ECU at that power level.

Cool, thanks for the input. What are your thoughts on alternator pulley size? Where can I get different sizes?

I am running an AEM Infinity standalone computer and I'll be running EGT sensor in each header tube so my tuner can set A/F for each cylinder. I am rebuilding because back 2 cylinders on passenger side had spark plug tips break off and damaged the walls. Previous owner went through 3 rebuilds. I'm going to do this one right. I checked out your build thread and see you have had similar experiences. In fact the guy who originally did the build on my car was in Northern California...

The AEM setup is legit. AED has it on a TT Coyote swap SN95 New Edge.. You're really like it.

I'm not to sure where I got mine from. I now run a alternator with a controller.

For the YSi. Make sure that you have a 8Rib, Thump R tensioner, and like we discussed a 15% O/D crank pulley. I would also highly consider a electric water pump. With the AEM setup you'll be able to spin high RPM, your water pump won't like that lol.

Got it. which electric water pump kit do you have? It looks like on your engine the belt still wraps around the water pump like a stock application?

I have a Meizere electric water pump. and yes the belt still wraps around it.

On my YSI I ran IW 18% OD balancer , and a 3.0 blower pulley for 26psi , with a Metco overdrive alternator pulley.

I'm in the process of finishing my YSI setup....around 8.5:1 compression, full exhaust, stock 03 aviator heads with fr500 cams, 99 cobra intake manifold, stock tb, procharger race intercooler, vortech mondo bov, 2.75 blower pulley, 15% IW OD balancer, e85....I'm really curious to see what boost it makes and rwhp....

That's a combo for like 28psi^^^ I hope you have a 8rib and a lot of other stuff to help with belt slip

One more question on this subject guys, belt length. How long of a belt would I need for the 2.9 blower pulley, 15% od balancer and all accessories? I can't find this info anywhere, I can do trial and error but I'm sure this info is available somewhere?

Thanks!

drhill said:

One more question on this subject guys, belt length. How long of a belt would I need for the 2.9 blower pulley, 15% od balancer and all accessories? I can't find this info anywhere, I can do trial and error but I'm sure this info is available somewhere?

Thanks!

Click to expand...

somewhere in the 114-115" range depending on alt, water pump etc..

great thanks!

I did some math based on the original belt length that comes with the vortech kit (113") and calculated my blower and crank pulley circumference differences from stock in that kit just to see if that was close and it puts me at about 114.75 inches. I know the belt doesn't completely wrap around either pulley but it's an estimate and it seems to pan out...