[Whipplecamaro]

Hey guys i got a whipple 2.9 on my car now makes around 543whp and 565tq stock with supercharger.
-Doing a custom grind cam with a 32-38% fuel lobe.
- forged pistons
- rotofab cai
- and was looking change out the upper pulley to something smaller.

End goal is 700whp-750whp. Shop says it dueable. Im just wondering what size of pulley would help accomplish this goal? the stock one is a 3.625. Im new with FI. They havnt told me a size yet but was wondering if i could get a answer on what size might help

[shinysun]

How about CR? Are you gonna lower the ratio?

[Whipplecamaro]

From what ive been reading is i shouldnt have slippage till 3.125 upper but im not sure if ill need something that small or maybe i do? Try reading other guys builds but its hard to say what they all have to get it. E85 isnt really a option here so

[KingLT1]

These cars make 700whp on 9-10 psi with a cam. You can't compare old school methodology with these DI engines. They allow higher compression then port injection stuff from the past. The octane wall for the LT1 @ 11.5:1 on 93 octane is around 700whp. The LT4's can get away with upwards of 800whp on 93 because they are a point lower.

That being said the 3.25 pulley will probably get you there. I would still probably run some meth so you can run more timing. I like the idea of building a powerful and efficient engine NA then adding the least amount of boost required to reach the goal.

[Whipplecamaro]

Yeah website would br nice hahah. I know when they do forged drop ins they can lower compression abit too but i have no clue what pulley would take to get there. I thought rumour was 8-10 psi for the 3.625 pulley which is the stock one with whipple but sounds high. I know cams people are getting tons like 75whp+ so that will help tons. But im not sure what soze pulley would be needed after the additional 75hp from the cam

[Joe's_cool_1le]

I had slipping with 3.125 with the 7.0 lower. Now I am 3.500 upper and 8.0 lower and no longer slipping.

[KingLT1]

Originally Posted by Whipplecamaro

Yeah website would br nice hahah. I know when they do forged drop ins they can lower compression abit too but i have no clue what pulley would take to get there. I thought rumour was 8-10 psi for the 3.625 pulley which is the stock one with whipple but sounds high. I know cams people are getting tons like 75whp+ so that will help tons. But im not sure what soze pulley would be needed after the additional 75hp from the cam

3.625 pulley is generally 7 psi, but the thing is boost is a measure of restriction. So a car with headers and catless exhaust will have less boost then a stock exhaust car with the same size pulley. Ted Jenetty has provided some great information to learn from on this forum over the years.

Here is a couple threads that you might find useful.

https://www.camaro6.com/forums/showthread.php?t=502348

https://www.camaro6.com/forums/showthread.php?t=480537

[Whipplecamaro]

So 3.125 will slip good to know. So probably need a 3.25 or 3.375

[Whipplecamaro]

Also any word on if a cold air from roto fab is worth it? Like $ wise. Its 500 american so like 750+$ canadian after shipping and all. I have a drop in k&n right now in it and lethal camaro did a dyno test on it and its made 5whp more with a drop in but it was 60$ not 750$ lol. Worth it?

[wnta1ss]

Originally Posted by Whipplecamaro

Hey guys i got a whipple 2.9 on my car now makes around 543whp and 565tq stock with supercharger.
-Doing a custom grind cam with a 32-38% fuel lobe.
- forged pistons
- rotofab cai
- and was looking change out the upper pulley to something smaller.

End goal is 700whp-750whp. Shop says it dueable. Im just wondering what size of pulley would help accomplish this goal? the stock one is a 3.625. Im new with FI. They havnt told me a size yet but was wondering if i could get a answer on what size might help

The only fuel mod you're doing is a bigger fuel lobe on the cam? And you intend to make 750rwhp with an LT1? Think that you're going to need to do a better job on the fuel system to supply that much.

[Whipplecamaro]

I talked to 3 different performance shops and all said you can get away with it if you dont pass the 750 mark. With a 32-38% lash cap. Like other guys bang out 600-650 wheel even odd guy says stock everything and gets 700 wheel with stock everything so im not sure!

[wnta1ss]

Originally Posted by Whipplecamaro

I talked to 3 different performance shops and all said you can get away with it if you dont pass the 750 mark. With a 32-38% lash cap. Like other guys bang out 600-650 wheel even odd guy says stock everything and gets 700 wheel with stock everything so im not sure!

What altitude are these shops at? Need to know actual hp because that is what determines the load on the fuel system. If high altitude, an inflated corrected number is produced, which is misleading for this subject.

The fuel lobe helps, but the idea that it adds 200rwhp worth of fuel by itself is ludicrous. Are those guys using methanol injection and did not admit they're using a supplemental fuel system (not stock in other words)?

Suggest that you do some reading on the forum from somebody who knows what they are doing, like the Jannetty Super Street Brawler for example, and see what kind of work was really needed on the fuel system to make in the 700s with an LT1.

[Whipplecamaro]

Ive read like every forum for camaro and lots for the lt1 vettes too but they all bottleneck around 650 at low to 700 is what people are saying. Odd guy says hes got it to 750 but i think youd atleast need a new cam. Im not sure. I was gonna do injectors and pump before but they said if you stopping at that level then no need

[Whipplecamaro]

Im at 2300ft where i live