Rviscosi said:Anyone know how to do this on a BPU SupraTT? Thanks for any inputs.
Rob I wouldn't do it...I tried it for a week and had blue smoke at start-up. Not to mention someone's second turbo was having issues shortly after doing this mod.Rviscosi said:Anyone know how to do this on a BPU SupraTT? Thanks for any inputs.
Every car is different but my car actually felt terrible with the shimes. I never really got the chance to prove this b/c my clutch started slipping at the track. Also, I actually hit less boost with the shims...this was even with an open wastegate. Tony feels that his held boost longer but didn't hit higher boost. I definitely did not hit higher boost. Have you pressurized your intake? I would bet you have a boost leak somewhere. Have you pulled the hose to see if it isn't related to the boost controller?Rviscosi said:Matt, I was just thinking of doing it a little.But seriously, I'm not looking to get 25 psi of boost. My car has typically only ever held 16 to redline. Even before the fmic it was the same. I was trying to get it to maintain maybe 18-20 psi. I was thinking of just adding a couple of washers underneath the bracket held by the 2 bolts behind #2's VSV. Is that how you did it? How much boost did you get when you tried it?
Rviscosi said:Matt, I was just thinking of doing it a little.But seriously, I'm not looking to get 25 psi of boost. My car has typically only ever held 16 to redline. Even before the fmic it was the same. I was trying to get it to maintain maybe 18-20 psi. I was thinking of just adding a couple of washers underneath the bracket held by the 2 bolts behind #2's VSV. Is that how you did it? How much boost did you get when you tried it?
Blackbird,blackbird said:I shimmed my wastgate because I believed that it was leaking at high boost (18psi). I used the shims to increase the spring tension to prevent the wastegate door from opening too soon due to the increased exhaust pressure on the door. My car now holds the boost pressure better.
Me too!!!Andi said:
Blackbird,
Would you please post some details on how to do this? As long as I've had my car my boost has dropped from whatever it peaks at, to about 16psi by redline. Even if I run 100% on the DSBC and hit 23psi, it will still drop to 16 by redline. And I have no boost leaks.... so I'm thinking the same thing may be happening to me.
Also, did the shim mod cause any boost creep problems for you?
Thanks,
Andi
I guess pulling the hoses is no longer required when you do it this way. That might be why adding 3 washers behind each bolt won't do anything more than pulling the hoses?Grant said:I think you just put washers in with the wastagate spring to increase its stiffness, right? I thought about doing this for a while, and now that I don't really care how long my turbos last I guess I might as well, assuming its not too difficult.
It should be noted though, that the extreme backpressure which opens the wastegate early, can cause detonation... So it might not be such a bad thing on pump gas.
Wait, nevermind (google rules)
http://www.supras.com/sogi/techtips/1_engine/1023_MKIII_wastegate_shimming/
Problem with this is that you would probably get more boost creep, but its so easy to do its worth a try.
Rviscosi said:
I guess pulling the hoses is no longer required when you do it this way. That might be why adding 3 washers behind each bolt won't do anything more than pulling the hoses?
Euphoric said:So, what is the general rule for shims used? 3? And the shims are going behind the bolts of the brass actuator right?
Heres what the link had.Euphoric said:So, what is the general rule for shims used? 3? And the shims are going behind the bolts of the brass actuator right?
Rviscosi said:
Heres what the link had.
Shimming the wastegate is a very simple, very safe, very easy and very cheap way to increase
you boost pressure.
Materials: 8-14 washers (8mm)
Procedure:
1. Remove the pipe leading to the 3000 pipe (from the intercooler)
2. Remove the intake pipe disconnecting all the hoses from it (BOV, PCV, Cold start, and the
wee one on the bottom)
3. You should see a silver cylinder, the actuator (looks like the bottom of a pop can) undo the
bolts holding it on to the turbo (12mm socket)Pull this toward the from of the car, it is pretty hard
to move, and place 4-5 washers between the turbo and the actuator and replace the bolts.
4. Use a little super glue to attach the washers together so you have "1 big washer" so you are
dropping them through the car and finding all sorts of new curse word combinations.
5. 4 washers gave me about 9 psi, 5 gives about 10psi. Any more and you will need longer bolts
and if you want more than 10 psi and aftermarket exhaust is most definitely required.
6. Go for a ride and feel the benefits of 3 extra psi (remember 11hp for each psi!!)
I know a guy that did 3 washers first and didn't see any difference than pulling the hoses, then did 6 washers on each bolt and held 25 psi. He went to 100 mph or so about 3 times hitting high boost and then got the death whine and hardly any boost, so I would say 6 is to many. If I do it I will try 3 or 4 washers behind the bracket so 6 or 8 washers total since there are 2 bolts holding the bracket.