As usual, I am in search of more power as I see more and more guys running big numbers! I have seen several threads like this, but none really has a lot of useful info. Basically I am looking for anyone who is running the 2.87 pulley on a stock bottom end. Is this too much boost for the stock bottom end to handle reliably? Any thoughts on this topic are greatly appreciated.

I am currently running the 3.12 pulley and have gotten 367RWHP and 305RWTQ. Not bad, but not enough!!!

TIA,
Zach

 

I had the 2.87 before I built my engine (still do, will swap to the 2.62 when i'm no longer broke). 3 other cars in my area are running the 2.87 on a stock bottom end without any engine problems. The cars are driven hard. But there is always risk when you increase boost. Boost with stock cats was around 11.5psi at stock redline. When I added test pipes the boost went down to around 10psi.

What else do you want to know? Make sure your A/F is good and make sure you pull enough timing. I had to pull like 15 degrees of timing up top so it wouldn't detonate.

 

Thanks man. If I do go this route, I will have CP Racing do the install and tune. Anyone else out there running the 2.87 pulley?? I need more convincing before I drop the cash on this.

 

There is the option of adding a elec. boost controler and a external wastegate , to dump boost . It works and you can hold the boost at say , 9psi . But with the smaller pulley...reach it sooner . Then you dont have to pull as much timing out up top . Like Lou said he had to

 

If you go to a smaller pulley wouldn't you be then maxing out the SC, I mean how fast can it spin before it loses it's effiency to produce hp. Would it help to upgrade to an S trim or T trim and then go to a smaller pulley..? just thinking out aloud.

 

Read above. It's been done. No one has maxed out the SQ-trim blower yet.

 

The max rating on the blower is 50,000rpm . I think with the 2.87 , you would be over that rpm level . Any thing over that I think you would be taking it passed it's sweet spot . That doesn't meean you cant spin it faster though

 

Sorry that is what was refering to, the rated rpm for this SC.

Booger I am going the same route you did with forged internals and upgrading the trim and then whatever else needs to be one to make this safe.

 

You may want to look into the SGP VB for the AT5

 

Done so already

 

Ask Gspot35, Esemes and Timrod1011 about their experiences. They've all run the 2.87 for various amounts of time on stock bottom ends. Tim is the only one that still frequents this forum on a regular basis and he's a really nice/helpful guy to boot.