Hey Guys,

Sorry for the question that is probably posted on here atleast 5 times a month but, I am looking for a solid number on safely boosting the stock 4.6L 3V engine in my 06. I am upgrading to the Kenne and Bell 2.6L stage 1 intercooled and i have the option of what size pulley to get with the kit. 9 is the minimum and 19 the max, obviously i plan to stay on the low end near 9 with 91 octane. I have read that up to 12 is completly safe on the KB out of the box, and others claim dont go past 9. Anyone with info please chime in, i have done all of my homework but i cant find a good number to settle on. I am leaning toward an even 10psi but, if more is safely doable i may consider up to 12.

Thanks,
Sho

'06 Roush Stage 2

 

You are going to get different opinions. Mine is below 12 is fairly safe. If you are a little unsure about it and feel like you won't be confident in your decision, go with 10.

 

Yes - I would be conserative with stock motor but consider this a larger pulley more boost but safe tune with less timing....

 

Whipple sells their HO kit with the 12 lb pulley to get 500wheel, I'm sure their tune is not too aggressive. I'm running the whipple HO with the 10 lb pulley with a more aggressive dynotune making ~500wheel. Either option is probably just as safe as the other. It's really up to the tune you want. I'm sure KB's tune with the 12lb pulley will be pretty safe.

 

i agree with this but its a smaller pulley that will get you more boost, not a larger one. go with 12psi, and tell your tuner your motor is stock. he will get tune it so its safe for the mods you have, or dont have

 

The thing is with the KB stage 1 kit, it comes with a flash so you do not have to have a tuner. They claim it is good until you go past 12 psi i think ( will have to check that number). I am shooting for around 450 RWHP, any more than that i think would be damaging to no only the engine but drive train. Anyone that has this kit have some info on what set up they are running?

Thanks,
Sho

 

i have the same with the 2.6 k.b / with 10 lbs of boost my 2006 made 478/440 rwhp im upping boost to 12 lbs, but im installing a meth kit before i change pulleys, ill find out if motor holds together ???