924Board.org

[JamesWilson]

So I was having problems with the 931 overboosting at around 4000rpm....I finally hooked up a boost pressure gauge this evening and drove home. Whoooooooosh, 5psi just rolling down the freeway and 20psi when I got on it!

Looks like the pressure line that runs to the wastegate is pretty cracked and old, I'm switching to a stainless steel -4 line to replace it. I am also going to replace the boost line that goes from the back of the intake manifold to the DITC box, as it doesn't look so good. New wastegate will arrive shortly as well, so if the line was not to blame I can swap out the wg as well.

As soon as I get measurements, I will have premade lines available if anyone else would like to replace these without fishing for hardware and fittings.

BTW-- got a new custom 3" exhaust system from the downpipe back (high-flow 3" cat, custom wg exhaust tube, 24"x3" resonator, no muffler) and boy is that great. Dropped 22lbs from the stainless steel system and stock cat/resonator that was on there before (pics soon, old ss system will be on the For Sale board). The only problem was it was kind of expensive, and the WG tubing was difficult to make work, but totally worth it!

-JamesW
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'82 924 Turbo (not stock) - soon returning home?
www.AffordableRacingData.com

[flosho]

That thing must have SCREEEAMED pushing 22psi and 3" exhaust! Lucky you didn't break anything!!


Although, if you're just cruising the car is usually in vacuum, so maybe your boost gauge is off? or is it partial throttle ~5psi and WOT 20psi?
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[This Space For Rent]

[JamesWilson]

Yes, correct, slight throttle at around 5psi. My speedo gear must have just popped out, because the needle used to be wonky and then it died. Need to pull it apart. I've been going by the tach the last couple weeks, its nice to have another gauge that moves Boost comes up immediately, very little time in vacuum when the loud pedal gets touched.

The car FLIES, I mix a little VP Motorsport 103 with California 91-octane pee pee water to help things along, exhaust is super-sweet. Feels like my old Merkur XR4Ti (24psi, no intercooler!), damn I love turbo cars.

I am still driving the car on the gentle side until the new wastegate comes in, still don't rev it beyond 3000rpm or so. There is a PCA autocross in a few weeks, hope to have it ready by then. I found a used set of Hoosier R3S03's in 215/60-15 (tall, but free) to help things along, will run them on my stock Mahle/BBS 15x8 and 15x9 wheels that came with the car.

-JamesW
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'82 924 Turbo (not stock) - soon returning home?
www.AffordableRacingData.com