Fixed the intake gasket and jumped on it today....Started breaking up about 5000 rpm,detonation i would suspect....65 psi on the fuel,showed in the "rich" on AF, and i'm only seeing 4.5 psi on the boost gauge.....I added another quarter turn on FP on the FMU, but i think i need to turn down my adj. FP regulator...I will check vacuum off, should be about 46-47 psi that way? PCMFORLESS tuning for this setup, so i'm ok there, but any tuning tips would be appreciated!
Where am i losing 4.5 psi? I'm pulley'd for 9 psi but i have never seen more than 4.5
Help please....
Thanks
John

 

Anyone?....Please?...

 

Tell me your complete engine specs & also the pulley size you are running, then I can try to help.

 

Thank you lonnie...
.030 over 9:5:1 forgings,balanced,4340 rods etc...LT1 heads 252cfm int 191 cfm ex, with Manley Race-flo's stock size.
Comp Cams XE 218-230 .528-.544 with 1.6's
52mm tb and the usual boltons, with PCMFORLESS tuning...
I went and jumped on it at my dinner break (i'm at work) and blew the SC'r outlet elbow off the SC'r!
Damn! I think i found my boost loss....That and a small tear at the stress point in the elbow...(it was used)...
P600b pulley'd for 9 psi, i don't know the exact Dia. of the pulley's...
Ah yes, all the little gremlins to work out....
Thanks for any help.
John

 

You may want to try running t-bolt clamps to help prevent your intercooler pipes from popping off during boost. Also make sure your belt is tightened properly. Good luck.

 

Agreed.

 

Ok....I replaced the elbow, now i'm seeing about 6 psi....
I'm puking oil out the breather on the pass. side again...
I had blown an intake gasket and i changed and then it ran fine....(it was blowing oil out the breather and dipstick tube then too)...Now it's doing it again! Damnit! This thing is really getting annoying....I don't know,maybe another intake gasket...The heads were cut at least .010 so i might need to cut the intake .005 so it will seal properly...
I'm not running a PCV, just had the small plastic elbow in the valvecover and a breather and it pukes oil out and hits the header...(embarassing)...
Am i missing some kind of venting?

 

A 9# pulley should be a 2.95"

A 2# loss is common with bigger cam & high flowing heads/exhaust.... so 7# should be within reason at 6000.

Your altitude, weather conditions & belt slippage can all contribute to the additional 1# boost loss.

Be careful with engine intake leaks, they can damage other seals as well & also the likelyhood of oil being drawn into the intake under vacuum conditions can contribute to detonation at full throttle.

You do have the t-body to valve cover line vent blocked off don't you?

 

Yes, i have the TB nipple blocked...I measured (on the car) approx. 3 inches across the face, so it sounds right...
I will route the pcv line and the line under the TB to the intake side of the blower and see if that helps, but i'm pretty sure the intake is coming off again....and i will check that thoroughly for the mating surfaces.
Thanks

 

You could also have the intercooler tubing beaded so there is something for the clamp to grab.

 

actually, all the metal ones ARE beaded...I will swap to some bettor clamps after i straighten out the oil pukin'....

 

Blew another intake gasket....I put a straight edge on the gasket face of the manifold and it has about a .005 warp...There's the problem.
I put it back together and no more oil pukin'....Just leaking!
I may have blown a rear main with that boost in the crankcase...
I just LOVE sorting out all these problems