Hey guys, I have an 88 t2 with 64k miles. I bought a 3inch dp, gutted cat, 3inch cat back, k&n air filter. The car has the stock turbo and wg, here is my problem. The most boost I get is in 3 gear and it is 8 psi, 1st and 2ng gear 5 psi. I have tried putting an mcb in and no change, I took off the wg vacume line out and no difference. Any suggestions?

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Isn't that normal on a stock t2 turbo?

every one of my friends, puts a free flow exhaust and it spikes to 10 or 12. with the wg line taking off the turbo should be boosting to its max and I dont think 8 psi is the max on the stocker.

Sorry I'm more of an internet database when it comes to TIIs, no real hands on experience ...



But according to This Post you should be getting about 7-8 close to stock.



I'm not sure how accurate that is, but anyways someone on here will give a better answer. Sorry I can't be of anymore help.

you r correct, 5 psi is stock boost level. but i am not compleatly stock, there are no real cats on the car (3 inch free flow exhaust) and cone filter. now the boost controler should alowme to boost over stock and that is where I am having the problem. I have gone to the point of taking the waste gate vacume line off, wich would translate into max boost on the turbo, but I am not getting anything more. BTW thanx you for you replys https://www.nopistons.com/forums/pub...IR#>/smile.png

Your ECU can trigger your twin scroll when it thinks there is a problem. It happend to me quite a few times. Mainly, it happend when I was at the track. I had a MBC set to 14 and it wouldnt boost more than 7.



This is my experience with this sort of problem. I would also check for a vac leak at a coupler, like on your turbo or intercooler.

Your ECU can trigger your twin scroll when it thinks there is a problem. It happend to me quite a few times. Mainly, it happend when I was at the track. I had a MBC set to 14 and it wouldnt boost more than 7.





Few questions.



How can you disable this twin scoll signal to the ecu?

You had this problem at 14 psi, did you have this problem at anything under that?





Thanx for the reply guys. I have also checked for vacume leaks on the turbo and intercooler.

Do you have a fuel cut defender yet?

I believe there is a vacuum soleniod under the intake manifolds in the rats nest that controls it. I just cut the arm out of the exhaust manifold. https://www.nopistons.com/forums/pub...DIR#>/wink.png

You need a fuel-cut defender before you even want to be running more than that 8psi.



My brother and I ghetto-rigged me a boost controller using a valve that cuts flow through the lines between the compressor housing and the waste-gate. The less air you let through, you trick the wastegate into thinking it's not getting enough air, so it pushes more..more boost. We've got me running at about 9-10psi on my setup, and it's pretty f*cking quick. https://www.nopistons.com/forums/pub...#>/biggrin.png



Do you have an aftermarket boost gauge that is hooked up correctly?

yes I do have an fcd, the boost guage is installed correctly, got the vacume line that is next to the one for the boost selenoid, I did a bleed off valve as a boost controler and when I didnt see the expected resolts I took the vacume line that goes to the waste gate off (this should have givin me a lot psi) but the resolt was the same 8psi max. I think I am just going to get a hybrid turbo and be done with this, I will try to see if I can find that vacume line for the twinscroll and if no luck turbo upgrade baby https://www.nopistons.com/forums/pub...O_DIR#>/11.gif

I'll sell you my motor setup. :P

check your wastegate...it may be stuck open! if without the line it only boosts 8psi max then you have a problem inside. you should be seeing a large boost spike!!! i was only running a dynomax turbo cat back (stock replacement basically) and hollowed out cats and i was seeing 13psi of spike sometimes. which is why my motor is a blown POS right now. there's something wrong with your wastegate period. pull your DP and check it out. i'll bet $20 its stuck/broke to stay open.



i have paypal and i might pay-up if i'm wrong. https://www.nopistons.com/forums/pub...DIR#>/cool.png



if its a vaccum leak in the manifolds or the cupplers its gonna have to be a very very noticeable hole to vent several psi of boost. also you car would idle like ass!

thats a tough call on that one. i'd have to agree with HP7 on that, somethin aint right. that turbo should have blown up your motor by now. im gonna go with wastegate for my final answer for 20$- even though i wont pay up on that one. lol

Well, I wont take your 20 bucks but saturday I will pull it out and see, if it's stuck open what should I do wd 40 with it? Thanx guys

if its open then you have a few possible answers....



1. your wastegate actuator is broken...the diaphragm with the rod attached.

2. the rod and pivot are seized up so it can't pivot to open the gate anymore.

3. its just broken...somewhere something is bent or broken.



see if your wastgate rod moves easily...you'll nkow then that the something is broken...wastegate actuator or the rod and such.



if its bound up...spray some lubricant (wd-40...be carefull of heat or flame!!!) and see if it can be worked free.



anything crazier than that and its beyond my shadetree knowledge. my wastegate on my 87 has been stuck closed a few times...talk about BOOST. whoa! 13-15 in nuetral, just free reving.

good luck

wow thanx guys for all the insight on this problem, I tried to get to the rod from the top of the car but no luck, so I will have to wait until saturday to work on this, hopefully it wont be anything too bad. https://www.nopistons.com/forums/pub...1047683473.gif