Newly converted 6p turbo question.

3rd gear from around 2000 boost rises to up to 5, then stays solid. I was under the impression the with my exhaust I should be higher than stock, but now it seems I can't even get to stock levels. What potential issues could there be?

wastegate spring? I did dip the actuator in the parts washer to clean it up, any chance I damaged it?

bov leak? Aren't stock BOV's pretty decent?


What do you guys think??

I have a wideband it read low 12s high 11s once I get into boost

My mods:

s5 6p t2 (w/ japan2la LIM) (stock t2 UIM, TB w/ mod, intercooler)
stock turbo
ported wastegate
no emissions
ebay TID
stock BOV plumbed into TID
RB DP, Borla midpipe, RB duals
N370 ECU
HKS FCD
HKS FCON (setting 2, chip unknown) with GCC (untouched atm)

 

You have a ported wastegate.

 

it's that simple? Could you explain a little please? I'm new to turbo's so i'm not disagreeing, I just wasn't expecting that. so chances are nothing is wrong?

Also, I have a friend with a full t2 motor that was running 6 psi until he put a new exhaust on (apexi single) and also ported the wastegate and now he is running close to 10. stock otherwise.

 

Is the turbo pink?

 

You have an NA block with diffusers in the exhaust ports. These block a little of the airflow velocity to the turbos. I wouldnt be surprised if you only saw low boost without a controller.

Sometimes stock turbo cars will not build a lot of boost, and cannot hold it until redline. Other times cars with almost the same setup will boost insanely and out of control. Every setup is different. The only way to have excellent boost control is with an external wastegate on a full aftermarket turbo.

 

makes sense... I haven't gone to redline yet... we'll see

side question.

I am running premix as I put on new omp lines and they haven't filled yet.

One is full, while the others aren't 3/4 full, one hasn't moved in a while... how long should it take, and if something is wrong, like I think there is, bad omp maybe?

I do not have the vacuum spider and the omp tops are capped, could this be the cause??

bad omp nozzles??

 

uh, the injectors HAVE to have air routed to them via the 5 way splitter that they used stock. Assuming you are using a t2 UIM, this nipple is the fattest one of the 3 or 4 on the rear of the manifold, excluding the one for the brake booster.

 

ok, I can put those lines back on, I was debating whether or not to do it. but from what ive read, the lines only act as an air bleed and to keep the motor from sucking TOO much oil. Do I have this right or am I off?

After maybe 50 miles of driving only one has filled up, or at least to the point where it goes under the mani where I can't see it.

*The injectors tested ok from what I remember (blow/suck test). I'd be willing to replace them with known good ones just to be sure

* no noticeable leaks

* omp maybe? I have 2 spares i could try

 

It's not uncommon for the OMP lines to have some bubbles in them at all times. IF nothing at all is moving then I would worry about it. You could try another OMP, though they pretty much function the same unless you have a code/CEL.

 

if you are going to use the OMP you definitely need to take those caps off. the air lines help atomize the oil.

 

i'll be fixing the omp stuff later... premixing until then.

Landers knows the future. not only am I only boosting 5psi, between 5k and 6k I start losing boost... 7k yields about 2-3 psi. damn.

 

Do you have any intake or exhaust restrictions? Even with a stock catback, main cat, and air filter you should see 5psi across the board.

You must have a boost leak somewhere. Use an air compressor, turn your regulator down to 25psi, put a coupler on the front of the turbo, and rig up a plug/cap with an air fitting in it so you can pressurize the intake tract post-turbo. You'll find leaks this way. It's normal for a little air to hiss as it goes through the throttlebody.

 

I have a RB 2.5 DP, borla midpipe (see-thru), and what I assume is a "n/a" RB catback. no cats. I wouldn't expect the n/a catback to be restrictive for 5psi.

I made an adapter while I was at work today to seal up the intake and allow an air fitting to pressurize the intake. Whenever I get chance I will see if there are any boost leaks.

(if anyone cares the adapter is a 2 1/2 to 2 inch exhaust reducer with a rubber expansion plug in the small end, and a hose barb that I will braze into the pipe. The leak will happen around 5psi, but I will still take care in making sure the freeze plug doesn't shoot off and hit me in the junk or something)

 

Could be the turbo, too. The turbine blades looked a little chewed up. But the same turbo did do better in my car. Hmmm....

 

are you complaining because you are not getting boost creep? If so stop it.

 

umm, no?? I ported the wastegate, if I was getting boost I wouldn't have creep anyway. try reading the thread

the compressor side looked good, not chewed... the exhaust had one nick.

 

my apparatus for checking boost. apart from the hoses before the turbo blowing off because the pipes don't have beads and scaring the hell out of me, the only one I found was the nipple on the back of the bov pipe. I fixed it. Boost at second gear redline was 3-5 as the road was not ideal and I couldn't watch the gauge intently.

Earlier in the day I took the hose off the wastegate and drove CAREFULLY!!! Boost rose with no apprehension past 5 and went to 10 with no problem. So, apparently the wastegate is doing its job. Should the spring be that weak or is that normal pressure for it to open??

by the way, is there any way to get my sig on my first post but not the rest??

 

Uncheck the "show your signature" box before you post

Maybe its time for a helper spring on that waste gate.....or maybe a new waste gate.

 

I'm going to quote my initial post here, since everyone else seems to have ignored it.

If you want to raise boost, you need a boost controller. You proved this when you disconnected the wastegate line and thus saw 10 PSI.

 

i didn't want to believe you... I wanted to be able to fix something and boost 8-10

ok next one... what are the possibles for me losing boost at high rpms?? If i can't hold 5psi, then a boost controller would do no good

goods
*no more boost leaks
*can go past 5psi
*bov is working
*open exhaust (DP, no cats, straight thru borla, RB back)

bads
*losing psi at high rpms
*exhaust diffuzers still in
*stock turbo, a little play, not smoking
*running rich, 10s-11s at idle, 10s WOT (waiting to adjust FCON when everything else is fixed)

 

 

There's nothing to fix. The fact that its boosting close to stock pressure consistently is a good thing, means its working, and it also means your wastegate should flow enough once the boost is cranked up.

Its a stock turbo, thats the problem.

No, a boost controller would let you run 10psi for as long as the turbo will flow it. Thats helpful.

I don't know what you wanna know? Its working fine, if you want more boost adda boost controller? Good work on the Turbo'd/NA??

 

i am not holding 5psi at high rpm... thats the problem. I want to know what could cause 3-5 psi at high rpm, because if I turn boost up to say, 10, and still get 3-5 psi at high rpm, it defeats the purpose of turning it up to begin with.

before anyone says anything, I'm not complaining, i'm troubleshooting and learning. thanks for the compliment by the way. I have alot of hours in it.

 

Well, the fact that the boost bleeds down up high in the RPM's is a factor of the turbo istelf since it can't flow enough air. Admittedly, at 5psi, you should see near that to redline in the lower gears (ie. 3-4psi at 7K in 2nd)

However, upping to 10-11psi should net you 8 or so pounds by redline. There will be no correcting this until there is a different aftermarket or hrybrid turbo on there. But in short, upping the boost with either a manual or electronic boost conrollter will net more boost all around. However, the bleed off up top will stil lbe present, it will just be raised proportionally.

 

hmm.... interesting.

acceptable? possibly...

hell maybe the bleed off will help me not blow the motor... haha