WS6HUMMER

iTrader: (19)

I have a boost bleed issue in 4K rpm region and have tried a number of things to rid myself of it but I just cant seem to stop it. I have pressure tested the system, found leaks, fixed them, and sitll have boost bleed. I was wondering if my 224 cam with a 112 LSA may be the cause, if not what about my valve springs, could I have valve float? My springs are 5 year old comp 918's. Any input would be appreciated.

MY99TAWS6

iTrader: (3)

I think I would be changing out springs to something stronger..dual patriot extremes seem popular. Then maybe try a different cam if you have found no more boost leaks.
Don't see many guys running a 112 with FI. Course if you are changing springs anyway good time to do a cam.

DeltaT

iTrader: (5)

Your cam is not at fault at those levels. A 112 is not a 'tight' lsa, especially at that duration. Something else is wrong and needs to be found.

And unless you damaged your valvesprings it is unlikely to be them at that rpm.

Can you explain what happens during your boost bleed? And what is your control system for boost?

Nice build, btw, I watched your slideshow. I respect anyone that does their own design and fab work...

Jim

ls1290

iTrader: (20)

5 year old springs would be a good thing to replace. With springs, you should not wait until one breaks to replace them. Like with any part, they do ware out in time/use.

Grr

iTrader: (2)

I ran a 283/293, 224/224-112 with .565" lift on my LQ4 build with no problems. That cam was perfect for boost and i even ran it on stock springs up to 16psi, so you have a problem somewhere else as you pretty much have the best cam you can get IMHO

WS6HUMMER

iTrader: (19)

Thanks guys for the input.

Thanks, during the boost bleed it feels normal, nothing out of the ordinary. I log speed along with RPM and look for wheel spin and there dosent seem to be any. If you use HP Tuners I can post the log, I posted a screenshot incase you dont. For boost control I have a Turbonetics manual boost controller. The only thing I have done that I'm not sure about is that I have the boost controller,wastegate, & the blow off valve all referenced off 1 -4 line that is plummed into the brake booster line. I do have a pin hole leak in the weld on a bung on 1 of the charge pipes after the intercooler but its so small that I dont see how that could affect anything.