mad boost creep with 38mm tial....

[j-z]

ok i just got my car running a few days ago. i have a iap mani (modified the wg outlet to make the wastegate sit parallel with the motor and dump straight down with a tube). im also running a greddy profec b ebc (old school original). ive got all my vacuum sources hooked up to a vacuum manifold i made out of sold aluminum.

heres how i have it hooked up. side port of wg goes directly to vacuum manifold (manifold is tapped into fpr source). top port goes to the in on the greddy solenoid, and the out goes to a nipple on the charge piping right out of the compressor housing. for the unit itself, im getting its vacuum source from the vacuum manifold as well.

right now i dont even have the boost controller on. i have a 3.5 psi spring in there (small yellow). i took the wg apart before i put everything in to change the spring. everything looked how it should. the first time i drove it was around my neighborhood. i eased into second and hit boost and the *** of the car just stepped out, and i let off. i didnt hear the dump at all (meaning the wg wasnt opening). i have no idea what i boosted to, but i know it was pretty high as it just broke loose not even WOT.

came around again for another spin, and turned the boost controller off. by the way, i have the boost controller knobs turned all the way down for high and low. that time it held at 3.5 psi like it should.

the next day when i went to drive to work it would creep up to like 9 psi. last night i got it on the highway for the first time and did a third gear pull and it went up to 15!!!!

today i went to a buddies house to show him, and it held steady right at 5-6 psi.

what in the hell do you think my problem is??

btw, a huge post with LOTS of pics will be up soon. im moving, so i dont have the time right now.

any input appreciated. this is my third 240, second kat, forth boosted car that i did. third time using the original profec b...

[WDRacing]

Manifold design seems to be an issue with that mani. So thats my first guess with no pictures.

WD

[ka-t 300]

Hey john how much boost were you running in your s 14 and what was your dyno #'s ect. track times. As far as the problem you have now maybe your ebc wiring is loose or bad solinoid ?

[j-z]

yeah WD, i agree with you on the design. reason i had to redo the wg outlet is because the mani was such poorly designed that if you bolted on the 38mm tial it could only bolt on one way and that was with the outlet facing towards the front of the car. if you tried to bolt it on facing the firewall, the outlet flange would hit the 4th runner not allowing you to bolt it up. so i made it how it shouldve been made from the get go. the collector is ****, but ill tell ya what i just got back from picking up some chillis and this car ****in flys! i could possibly get a high 12 out of it with the fmu on 9 lbs LOL (if i hooked up).

i still want this issue fixed though.

brian, i dont think its the solenoid because the kid i got it from came off his car and was working. not only that, when i have the ebc off its obsolete. on the way to chillis i turned the ebc on just to see what would happen, and same thing. the boost reacts in the same manner with the ebc off or on...

this was justins (florida240sx) old kit. he said he never had creep like this, although i did change the wg design which should make the exhaust gasses expel even quicker. i dont get it...

and brian... i was running 17 psi with a .63ar t3/t4 tuned by me via afc, itc, wideband, and the 417 LOL. never ran it at the track. never dynoed it. i would say i was maybe a lil over, or right at the 300 mark. mind you that was on the motor i fully built.

[480sx]

First things first, change your vac source. If you have an entire vacuum block run off of the 4mm vacuum line of the FPR, thats most likely going to be your issue. Garrett(Tial) says to have at least a 8mm(or 10 i cant remember) vac line running to the wastegate. T your vacuum block off your break booster line and try it again. The most common setup is to run the vac block inline on the Break booster vac line.

Also, your actually supposed to get your WG source from before your throttle plate. When your in light throttle boost situations, a cracked throttle plate creates air eddies that mess with your vac signal, causing you to get creep. Garrett recommends welding an 8mm ID pipe to your intercooler piping right before your throttle plate to fit your WG source on.

What is the manifold made of and how did you weld it back up when you redid the wg outlet?

[Florida240sx]

I had a 10psi spring in it. With mbc at set to make it 15psi it's spike to 17 then go back and hold, at 19psi it'd go to like 21 then settle. With the mbc out of the equation it never spiked ever. Try t'ing off just the fpr line for a day to see how it goes. Ignore your block for now.... actually how do you have your line in order on the t block? I'd put wastegate first bov 2nd and boost gauge 3rd.

[j-z]

well on all my other cars especially my s14 i ran the vacuum mani the exact same way. i do have the 8mm or whatever size hose is needed to fit on the tial wg. im also running bigger nipples (<----haha i said nipples) on the vacuum mani, and on the charge pipe too. when i saw all the diagrams that ive seen thus far for the profec b, everything is hooked up exactly how it should be.

on my s14 i was running the jgs mani with a 38mm tial as well and never ever had any boost issues. this thing is all over the damn place now.

im going to try and tap into the booster line for a source, but i dont think that will make a difference as vacuum is vacuum, and boost is boost. its going to see it the same no matter what. granted there will be a lil more volume, but the strength shall stay the same (atleast in my mind... i didnt take physics or none of that at school).

what i have running off the vacuum mani.... wg, fpr, boost gauge, bov, fmu, and profec b.

ill post pics after i try this if it doesnt help. im moving tomorrow, so it might be a while. i got sold out on my entire home theater system and puter for 2500 LOL.