Hey guys,

I posted this in the C5 FI section also, but would like as many suggestions as possible.

I have an APS TT kit on my 2002 corvette and am running a Eboost2 boost controller with one solenoid and its hooked up via "Method 1" per the instructions. It seems that no matter what setting I program the high boost too (SP 6), It won't reach over 11.x psi.....However, on cold nights, I've seen it reach in the 13's and settle in the high 12's. I first had a Greddy Profec boost controller and it did the same thing. I thought it was a controller problem so I switched.

I've done a boost leak check and fixed about 6 leaks, then tested again and the pressure held on my Eboost2 up to 28 psi.

I will say that my solenoid it mounted in my engine compartment near the front of the passanger side cylinder head, which is relatively far from the wastegates. This is the same mounting location that I had the Greddy solenoid mounted when it was tuned at 14 psi. I haven't seen 14 psi since I've had the car back.

Do you guys think I should continue to turn up the Boost controller? or maybe its a wastegate spring issue? or maybe more leaks that I've over-looked?

Today, I took both of the wastegates off and completely apart to clean the valve stems. I posted this on LS1Tech and some guys have had problems with these Tial 38mm gates sticking. They both had a lot of carbon build up on them and I sanded it all clean and put some hi temp anti-seize on the valve stems and reinstalled them.

NOW, the car wont reach over 9.5 psi. However, when I tested it today, it was almost 90* outside, but my issue still isnt fixed.

Im just kind of unsure on what to do next and would like to go to a speed density tune next month and want everything to go smoothly.

If I've left out any details or y'all would like to know what settings I have my Eboost2 set to, Ill post it up.

 

I had a problem awhile back with not being able to to hold boost and traced the problem to vacuum leaks at the BOV connections. The APS kit used vacuum lines that were to large for the bosch bov connections. The spring clamp that was supplied is not strong enough to compress the vacuum line. I ended up using a tie wrap to crank it down. There is also an inherit problem with the actuator rods flexing and hanging up when you go over about 10 psi.

BJK

 

Ill check that out on sunday or monday. Ive done a boost leak test and nothing indicated that there was any leak coming from the BOV connection.

Maybe the plastic bosch BOV's are leaking internally....who knows...

 

I got your texts chris, I think you need to pull the wastegates and make sure one isnt stuck open. I had a big spike problem on a recent car that came through, and one gate had stuck shut.

 

I pulled them both Friday and took them completely apart. Cleaned all the carbon build upp off the valve stems, cleaned the housings, sanded smooth the valve stems and put high temp anti seize on them. Still no go lol

 

take compressed air, and have a friend blow it into the bottom port, and make sure you can hear the gate working.

How bout new vac lines?

 

Ok, I'll see if I can get that done tomorrow.

I was thinking maybe I should just replace all the rubber hoses with some -3 an lines and fittings.

 

That would work well too, just a little bit of a pain in the ***, but at this point, you have nothing left to try, other than vac sources....

 

True. Their are so many places that are hard to get to and could have leaks in the hoses that I just can't see. I could just take care of it with a braided hose.

I'll prob check my BC vacuum routing one more time before I pull the hoses and start over

 

I just ordered some stainless steel braided hose, hose ends, and T fittings to replace the rubber hoses that go to and from the wastegates and boost controller solenoid. This will prevent any future chaffing and will hopefully be my fix. These hoses are in such compact places its very hard to check without just pulling them out, and since Id have to pull them out, Ill just replace with better hose.

I ordered -6AN hoses and ends to be big enough to go over the wastegate fittings. This will be roughly the size of my current rubber hoses.

 

Thanks for the update.

BJK

 

No problem!

Id like to publicly give Louis @ LG a HUGE shout-out and say thanks. Ever since I bought the Eboost2 off of one of the cars he has over there, he has been instrumental in helping me set it up and helping with various other technical questions/issues at all times throughout the day.

Two thumbs up bro

I should be able to route the lines and fittings on friday if they arrive.

 

hope the new lines solve your problems!

 

BTW, Do any of you think -6 AN is too big?

The vacuum hoses on it now are 3/8", I believe. -6 hose has an ID of .343". I went with -6 because I know -4 would not fit over the wastegate fittings.

 

Update guys:

I replaced the vacuum hoses that make The "circuit" from both ports on each of the wastegates to main boost source to the boost controller solenoid with SS braided hose and AN fittings with absolutely no change.

Tomorrow I may leak test the entire charge system again. Other than that, I'm kind of at a loss of things to do to make this little bastard reach over 9.8ish psi on a hot day (a little higher on a cooler night) !!!!

 

-6 is a little on the big side... I don't think it will hurt but it will take a little more "effort" to pressurize the line - you will loose some response. IE you don't want a -10 hose as it would take a lot of volume to fill the lines.

Can't believe you are having so many problems Chris, should be able to hit 15 psi pretty easily with that system.

At this point I would suggest putting in a heavy base spring, say a 1 bar spring and make a careful pull. Pull it to say 4500 RPM and see where you are first. Then, if possible with out overshooting your boost target, make a full pull to redline and see where you are.

That will tell you if you have a problem with your external boost control setup or if it is a mechanical issue with the turbo system (lack or airflow/leak/backpressure/etc).

 

Hey, thanks for the response Taylor!

Yeah, I knew -6 was a little on the bigger side for vacuum hoses but I was afraid -4 wouldnt have fit over the wastegate fittings. Nevertheless, I got it all on this afternoon and it didnt change. It looks good though and at least that rules out any problems I may have in the future with standard rubber hoses.

I am going to boost leak test it again tomorrow and just take my time searching. If all checks out OK, Ill change the springs to a 1 bar spring and see where Im at.

Im actually not all that frustrated. The car runs great under 10psi (give or take a lb. for air changes). I just want to be able to go faster. LOL

 

I just went a pressure tested the charge system again and found my problem (99.9% sure). At about 3.5-4 psi, the rubber coupler coming out of the passenger side intercooler starts blowing open. I would imagine at about 9.5psi, which is the pressure I can't ever get over, every bit of air my passenger side turbo is putting out, is escaping.....leaving only the drivers side turbo doing the work? or at least the boost from the passenger side is very negligible.

Ill pull the bumper either today or tomorrow and take a close look at a couple of the other clamps and fix the main problem.

 

I had the same problem with my APS..i changed ALL my cheap clamps to t-bolt and , never had a problem after that!

 

Ill see what i can find