Limit of internal wastegate?

[turbojimmy]

Hi all,

Happy Thanksgiving!

I've been working the bugs out of a new setup and found that I can't control my boost anymore. I have a CPT-70 BB turbo that was okay with my old setup. I could pretty much set the boost anywhere I want via a manual bleeder.

My new engine has a lot more head work and a pretty aggressive cam. I can still set what I'll call the 'initial' boost level with the bleeder, but it creeps substantially. On a recent log, I went from 17 psi 'initial' up to 23 PSI on a 5-second WOT run. I have the Precision housing ported as much as I can. I have a 3" RJC DP and 3" exhaust. It's an HD actuator and appears to be working fine. Have I simply reached the limit of an integral wastegate?

Thanks,
Jim

 

[Grumpy]

I don't think so BUT we don't use a HD one . if ya ever figure your fast system out just go with a boost controller .. guys are flying with them

 

[turbojimmy]

I don't think so BUT we don't use a HD one . if ya ever figure your fast system out just go with a boost controller .. guys are flying with them

I got the FAST sorted out. It actually wasn't the FAST, I'm pretty sure I was tuning around a leaky injector. I replaced the injectors last night and it's like a new car.

What kind of boost controller? My manual bleeder worked well until this new rebuild. I'll have to double check and make sure I didn't booger up the actuator when I put it back together. It looks like it's moving the full range, tho. If I put the stock solenoid back on FAST should be able to work it, but I need to figure out why it's creeping.

Jim

 

[Sinful6]

Jimmy, Long time! I don't browse these forums much anymore since I sold the Buick.

I always recommend putting a weaker spring in the wastegate, and using a ball and spring controller like the kind I used to sell on here to adjust boost. They're leaps and bounds better and more reliable than the bleeders. This worked great for me on DD's to 8-9sec cars. I have an ad running right now in the parts for sale section, let me know if you have any Q's.


http://www.turbobuick.com/forums/parts-sale/270231-car-quick-spool-boost-controller-blowout.html