I have read several threads about HSRs not sealing under boost but does anybody know how many lbs. of boost one will take before it leaks? I'm considering switching to an HSR on a supercharged 383 with Vortec heads. Right now at 5500 rpm, which is where I shift, it's at 7 lbs. of boost. Also does anyone know if welding on a couple more mounting points between the plenums will cure the issue? Thanks!

 

I am running 10 lbs with no serious problem. I do run RTV instead of the gaskets they send.

 

Great news thanks! I don't intend to go more than 9 lbs. so hopefully I'll be ok with RTV. If you don't mind me asking, what fuel rails, injector size and fuel pressure are you running on your setup? Thanks, Tom

 

Pics....?

 

Started with 24lb inj; Using Super FMU, the fuel pressure went from 41 to 75psi.

I have since switched to a Holley 950 Commander with 2 bar map sensor using 44 lb injectors at 43psi straight.

Gary
Kingston,NH

 

nitrous AND supercharger my kind of build up.


I would just use the gasket setup sealant on the gaskets and it shouldn't have an issue with blowout, perhaps torque the bolts slightly higher with a torque wrench as well.

 

I also run 10lbs of boost. I'm using homemade thicker gaskets and rtv. I made a pressure tester and the intake never leaked, though i found many other leaks that i need to fix. My biggest leak is the throttle body shaft o-rings. I blew intercooler hoses off the TB with the leak tester up to 30psi and the intake held it. I'm sure with T-bolt clamps it would hold even tighter even though it'll never see 30+psi.

 

T bolt clamps are really the only way to go IMO for a boosted motor.

 

I agree completely with that. When I originally superchaged the engine I had a problem with the hose blowing off of the throttle body above 5 lbs of boost and when I had to lift quickly on a hard pass. The throttle body on my original set up did not have much of a lip to clamp on to so I fabbed an extension, which also allowed me to step up a size on the hose, and I used a 3" banded t-bolt clamp. That completely solved the problem. Now I feel the intake is holding back some extra hp so I want to switch to a better setup and maybe even a couple lbs more boost.

 

I bought my HSR when it was released several years ago. Running same old gaskets it came with, plenty of removals, no RTV, no sealants and 16# of boost and it does not leak a bit.

 

No problems with 20 psi boost.