Blk003GT

what psi until i start floating stock valve springs with a turbo?

teej281

Stock valvetrain?

Blk003GT

ya unfortunately for now

teej281

I wouldnt go past 10-12psi with the stock valvesprings. If you upgrade those you'll be golden.

Repzard

Isnt it based more on RPMs then boost.

teej281

Can be in high rpm n/a setups. But in f/i setups its very common if you run high boost on stock or not very stiff valve springs. Its not usually recommended to use stock valve springs in boosted applications but if you're using mild boost you should be fine up to like 12ish psi.

Sxynerd

The stock Valvetrain is good to 8k+ rpm. Anyone has anything to say that says otherwise is a noob and needs to go back to pushrod motors.

OP, clarify what you're talking about if you're not talking about valves & cam followers. The cast crank is good up til around 750hp maybe more but I don't know anyone that has went through all the trouble of building an engine and kept the cast crank. the Rods are good till about 450rw and the pistons are good right up until you detonate.

uberstang1

I dunno if thats true unless yor over revving, my friend is running 17psi ona turbo 98 4v with stock b heads and a buult shortblock no issues. Another is running 19 psi on a 02 2v with stock heads and a procharger f1.

ddmsgtr1

A blower is going to be a different scenario than a turbo. You shouldnt have as much of a problem with a blower as you would with a turbo. What the ops worry is about is the back pressure from the turbo floating the exhaust valves. I would talk to nick at mhs, he's got plenty of experience with turbo cars to tell you what he believes the safe level of boost is before this occurs.

mrtstang

Yeah, i agree this is probably a good question for Nick.