I was wondering why I never hear of anyone using relief valves. If you don't know what they are, you set them sort of like a blow off valve. They don't let you get past a certain boost level, as not too overboost or spike.

 

Save your motor, kill your turbo. (dumps all pressure, turbo spins with no resistance and turbo rpm skyrockets....)

 

But when you reach the certain boost level, you'll know it right? So you can just let off the throttle. Not like you'd be going around flooring it while the relief valve is opened. It just seems nice as a safety device, not a boost controller. I mean if your max boost level is like 11psi, you can set it for like 12 or 13 or whatever just so you don't blow your engine on those cold nights. I would be much happier replacing a turbo than having to get my engine rebuilt. Am I looking at these the right way?

 

Exactly.
But if you're going to monitor boost like that, why bother? Should it spike, you'll kill your turbo, as opposed to your motor.

Pick one to keep.

When you have a ball bearing turbo, you'll pick the motor to blow.

 

Well engines cost around $2k at least usually. I know some turbos are expensive, but that expensive? Plus I can change a turbo myself and wouldn't have to wait. For a rebuild I'd have to take it to a shop and wait for them to get done with it.

 

I'm sorry, what are the advantages to a relief valve?

Steve

 

Not blowing your engine.

 

Oh and I wouldn't monitor boost like that, I have gauges for that. I'd use strictly for a safety device. Its only like $100.

 

Lets say you ahve a turbo. A relief valve, or pop-off valve, will dump all the pressure at a certain boost level. Thus, you set your boost controller and set your pop-off valve two psi higher. Should you for some reason see a boost spike, the boost will be dumped and your engine will be saved from detonation. However, you turbo rpm will skyrocket and damage the turbo.


Running one is really a question of what you worry most about: With a boost spike, you may kill the motor. With a Pop-off valve you may over-rev the turbo. Pick what you want to risk damaging the most.

However, a well built system with a functioning wastegate shouldn't spike. Only if the wastegate line fell off or such would a pop-off valve be a nice accessory.

 

It's called a properly sized wastegate!


-Ted

 

The go for it. You know the gains and risks... you don't need someone to make this decision for you.

 

ditto

 

Thanks guys. Cleared that right up for me!

Steve

 

Like I said above... but if you wastegate line pops off, your boost will skyrocket.

 

Hose clamp that ****. During my rebuild I have put a hose clamp on every accesable hose on the whole car, and raplced at least 40ft. total of lines under the hood. Taking no chances nothing worse than a unreliable car.

 

Takeing no chances would be using braided lines and AN fittings.