[Kev457]

Hello guys,
I'm going to get a whipple on my car soon, but one thing that confused me is which pulley size should get?

My current setup is tsp stg3 cam with 32% fuel lobe, ported heads,headers and cai. And I will upgrade to the lt4 fuel system with the whipple.

I can only 91 or 94(provided by chevron, no idea how close is it to 93 in US) octane here in Canada.

Whipple comes with the 3.625 pulley, but I believe I can run the smaller one to have more boost

Please help me out, thanks!

[JRS]

The biggest question is how much power are you looking to make? What is the boost suppose to be with the pulley you have now? This will help decide if you need a pulley change.

[Kev457]

Originally Posted by JRS

The biggest question is how much power are you looking to make? What is the boost suppose to be with the pulley you have now? This will help decide if you need a pulley change.

I haven't installed the supercharger yet, just trying to figure everything out first.
I'm looking for 650-700whp with the setup and I think the stock pulley comes with whipple is around 8psi?

[JRS]

It maybe fine with the pulley you have because the LT4 runs roughly 9-10 psi of boost but your increasing the CFM's 1750L vs. 2900L which effects the horse power. Whipple should have a chart of the different pulley sizes, I would guess you may need to install a 3.5'' to get closer to 650 whp though.

[JRS]

If you want some good advice as to what you should do to get the power level's your looking for you might want to talk to someone like PRAY Performance because you have some other obstacles to contend with.

[Joe's_cool_1le]

With no cam or LT4 HPFP... but had headers and Rotofab I was using the 3.375 pulley at about 11 PSI or so. Now I'm forged but dropped compression to handle more boost and a BTR cam, catless, meth, and LT4 fuel system running the 3.125 pulley at about 11-12 PSI with a bit of belt slip. Going with the bigger lower pulley and a larger TB next. Hopefully in August.

[Kev457]

Originally Posted by JRS

If you want some good advice as to what you should do to get the power level's your looking for you might want to talk to someone like PRAY Performance because you have some other obstacles to contend with.

Thanks for your advice.

[Kev457]

Originally Posted by Joe's_cool_1le

With no cam or LT4 HPFP... but had headers and Rotofab I was using the 3.375 pulley at about 11 PSI or so. Now I'm forged but dropped compression to handle more boost and a BTR cam, catless, meth, and LT4 fuel system running the 3.125 pulley at about 11-12 PSI with a bit of belt slip. Going with the bigger lower pulley and a larger TB next. Hopefully in August.

Do you think 3.125 or 3.25 will work on my setup without the forged stuffs?
What kind of hp are you getting with the current setup?

[Joe's_cool_1le]

Originally Posted by Kev457

Do you think 3.125 or 3.25 will work on my setup without the forged stuffs?
What kind of hp are you getting with the current setup?

I would think with your setup you could easily do the 3.25 but going any lower you will see belt slip so you will need to bump up that 7" to an 8". Might even see it with the 3.25.

Mine was low 600s with the stock setup with CAI, headers, and 3.375 pulley. Now dropping to 10:5:1 compression with a new RXT 1200 clutch with a heavier flywheel, LT4 HPFP, and meth I'm sitting around 700. Cars ATF is running pretty conservative at high 10's low 11s at WOT.

Fuel is the biggest issue with these cars. Meth distribution between cylinders is an issue with spraying before the TB. I know some now sell Whipples with port injection which would change the game.

[Kev457]

Originally Posted by Joe's_cool_1le

I would think with your setup you could easily do the 3.25 but going any lower you will see belt slip so you will need to bump up that 7" to an 8". Might even see it with the 3.25.

Mine was low 600s with the stock setup with CAI, headers, and 3.375 pulley. Now dropping to 10:5:1 compression with a new RXT 1200 clutch with a heavier flywheel, LT4 HPFP, and meth I'm sitting around 700. Cars ATF is running pretty conservative at high 10's low 11s at WOT.

Fuel is the biggest issue with these cars. Meth distribution between cylinders is an issue with spraying before the TB. I know some now sell Whipples with port injection which would change the game.

So should I go for the 8" to start since I will go with the 3.25 anyways.

[Joe's_cool_1le]

Originally Posted by Kev457

So should I go for the 8" to start since I will go with the 3.25 anyways.

In hindsight I would have but I think it comes down to how much boost your looking to put down with the stock pistons. I probably would still have done 8" and 103TB from the start if I had to do it all over again.

[Jhunsberger]

Originally Posted by Joe's_cool_1le

In hindsight I would have but I think it comes down to how much boost your looking to put down with the stock pistons. I probably would still have done 8" and 103TB from the start if I had to do it all over again.

Did you have to do anything special to your whipple setup to use the 103TB? Does the whipple accept the 103TB?

Without digging into the engine itself, a TB and headers might be my next step.

[JANNETTYRACING]

Originally Posted by Kev457

Hello guys,
I'm going to get a whipple on my car soon, but one thing that confused me is which pulley size should get?

My current setup is tsp stg3 cam with 32% fuel lobe, ported heads,headers and cai. And I will upgrade to the lt4 fuel system with the whipple.

I can only 91 or 94(provided by chevron, no idea how close is it to 93 in US) octane here in Canada.

Whipple comes with the 3.625 pulley, but I believe I can run the smaller one to have more boost

Please help me out, thanks!

The Chevron 94 is 94 octane and that is what I recommend you use, I would not exceed 10 psi boost on stock pistons on pump gas.

To get to 10 psi boost with your cam and mods you may need to move to a 3.5 or 3.375 only testing will say for sure as every combination responds differently.

Ted.

[Joe's_cool_1le]

Originally Posted by Jhunsberger

Did you have to do anything special to your whipple setup to use the 103TB? Does the whipple accept the 103TB?

Without digging into the engine itself, a TB and headers might be my next step.

My answer was a bit misleading. I have not done the TB and 8" yet but am scheduling it now to fix the belt slip and get more air in it with the TB. Yes the 103TB fits up to the Whipple but Whipple does sell an adapter plate but Ktech thought it didn't need it. /shrugs... shinysun on here has done it and I'm pretty sure Ted has too so maybe they could chime in.