Zackb911

Hey guys I finally got around to installing my Autometer boost gauge and after replaceing my BOV as well I am still having some Boost issues. The car is a 86 with stock K26/6 100K+miles? Guru chip kit, stock UN-Shimmed WG, reliaboost, new 993 BOV, and new LR vaccum lines. The problem is it will build Boost upon initial accelleration to 12lbs or so and fall to about 5-6lbs and not come back up any higher. Usually It will be an acceration from 1st gear hit 12 fall quickly and stay steady at 5-6lbs as the rpm's climb and i upshift. The car pulls 22lbs of vaccum driving while warm and has all new vaccum lines, the reliaboost has not been adjusted so It should be set to 15. Does this seem like systems of the WG failing me or is it time to upgrade the Turbo?

Zack

Jake951

Hi Zack,

Didn't we meet at the Rennlist gathering last week? (I also have a B5 Passat).

What is your boost like in the higher gears, particular 4th and 5th? You ought to be able to pull 15 psi peak and drop maybe to 12-13 psi at redline with a healthy stock WG. If you can't hit 15 psi, then trying readjusting the Reliaboost to bring the boost up. If you still see a lot of boost dropoff at the high end, then your WG is probably due for replacement. Shimming may help to a degree but a new upgraded WG will help more.

Zackb911

Jake,
yes we did meet you have the car I want:-)
It seems to hit 12psi only on the initial accelleration with a quick drop off. I.E. if I start in first or do a roll on from 3K in second hit 12 and immediate drop. I do not seem to be able to make anything over 5-6 in any other gear 3rd, 4th, or 5th... I know the car should be able to hold alot more boost than that especially in higher gears?? I should note my Turbo does leak some oil as well not sure from where though... I am planning on doing some highway testing tonight if the roads are dry and will post if I can get it to do anything better... Any Thoughts?

Zack

Mike S

Well, the cheapest way I can think of to test is to go down to home depot and get some thick washers to shim the wastegate. If you don't see an improvement I would lean towards the turbo.

Jaak Lepson

Zack ... I would lean towards either an exhaust leak or a poor WG. I had my exhaust "gaskets" replaced and my boost came back up. Make sure all your intake pipes are sealed/tight, intake maniford is torqued down correctly, and your cycling valve is OK. They have plastic parts that crack and you would loose pressure. Just some thoughts.

Jaak Lepson

Zackb911

I will be shimming the WG tommorow to see if there is any improvement the CV is bypassed already with the reliaboost. I was able to get 12psi on the highway by downshifting to 4th, but in normal accelleration it doesnt build boost only if its a forced acceleration like downshifting to high rpms or an initial accelleration from 1st....

Zack

eclou

my bet is weak WG springs. You are only getting momentary peak boost

tjbreen

Zack:

We should have taken a ride in my '87. I had the same problem and the Guru wastegate solved it. I had put the chips in without shimming and that worked for a while but it seemed like the spring got weaker every day. I turned the Reliaboost up to the max and still got what you have.

My measure of performance was how scary a second gear pull was on anything but dry roads. Before the WG quit, I had to worry about breaking loose a wheel (no LSD). With a week spring, it feels lame. Now that I have the rebuilt WG, I have to watch second gear again and that is a good feeling.

When I tried to pull my WG for shimming I ended up breaking every bolt and stud. A rebuilt Guru WG was the most economical route and I am happy with the results. I would not try to pull it unless you can be without the car for a while. You might also contact Danno to see if he is in a quick shipping mood. It would be good to have the replacement ready when you take the old one out so you don't forget which combination of socket extensions and universal joints you used.

tjbreen

Oh, and get in line on Jake951's car. You can have the slot right behind me.

hosrom_951

If you have the Guru chips, they come with shims, the whole system wouldn't work properly without the shims. Try installing the shims and check out your boost.

daniel951

my bet is the wastegate. I finally just did away with mine and got a Tial

Zackb911

Well I tried taking off the WG today to shim it as I was doing a bunch of other things and Bolts started breaking.... So I think I'll look into the Guru WG and Tial.. I did however find an exhaust leak at a seam on the bottom of the downpipe, It looks like it scraped on a driveway and it definitly is leaking exhaust but should be an easy welding fix:-)

TJ- on a side note I installed the Weltmiester spacers today, Its ALOT better! no more crossing my fingers leaving the driveway! I did new 968 caster blocks as well and its a world of difference in ride quality:-)

Thanks Guys,
Zack

tjbreen

My spacers should be here on Tuesday and I already have the 968 caster blocks so I can't wait to try it out.

Jake951 mentioned upgrading from his Guru WG to a dual port with Apex controller. If he did that, he would have a spare Guru single port WG. Could be a deal out there for both of you if it worked.

I thought about the Tial but with the adapter plates and cost of purchase, I decided otherwise. The Guru was a simple bolt in and has no problems with fitting etc.

Did you ever figure out what was up with your sunroof?

Laust Pedersen

A serious exhaust restriction would show the same symptoms, by building up exhaust pressure with limited flow to adequately spool the turbine and pushing the wastegate valve open.

Laust

jimbo1111

As noted above. The waste gate spring is probably weak. But have your boost gauge checked out. Because 22 inch of vac. is a bit to much and could be an indication that it's off by 3 or 4 psi.