2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

33mm wastegate madness! but fuel cut still in 2nd( or higher) gear!

Old Nov 3, 2008 | 07:36 PM
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33mm wastegate madness! but fuel cut still in 2nd( or higher) gear!

this past week i got my turbo back from a local machine shop and welding on my washer for my new 33mm waste gate.

it was cut 35 at the top, and 33 in the hole, similar to Aaroncakes writeup.

i have checked the vac line, and it is good, holds pressure from a 100psi-10 psi regulator. i can see it visually open and close with the pressure regulator so i know its opening.

MODs: 88 turbo II, 3 inch downpipe-streight pipe 2.5 inch exhaust. 3 inch turbo intake duct, and the largest K&N you can fit under the hood. Streetport with 1200 miles. AFTERMARKET TURBO MANIFOLD**

** Now i think the problem is the manifold, is large 1.5inch tube piping to an undivided turbo flange for the stock s4 TII. .. Is the problem here the fact i am using an undivided manifold with a divided( and knifed) turbo? i dont get fuel cut in 1st gear, but in sacond, immediatly after i shift.

sorry i was too lasy to take pics of the new goodies, i will next time.

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Old Nov 3, 2008 | 09:22 PM
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you made a custom manifold for the stock turbo? and all that heat blowing on the divider will increase the risk of a crack. You're much better off with a divided manifold and undivided turbine housing than vice versa.

And yeah, stock turbos suck for boost creep. They just suck. There's not much you can do about it if your wastegate is that big, you're sure you have a good vacuum source, and you don't have a boost controller installed. Have you bench tested the actuator?

I had boost creep with an HKS 40mm wastegate and 3" exhaust with 10psi spring. My new setup is a Tial 44mm with a manifold that is much better designed for boost control.
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Old Nov 3, 2008 | 11:16 PM
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yes i have benchtested it, before i installed it to make sure everything was going to clear, and i didnt make the manifold, it was an ebay special i got a few years ago. the bnr turbo go to a 35mm stock wastegate, and thats with a 60-1 turbo and alot more air, is there a better place to plumb the actuator, than right off the turbo as in stock? even then i am going to try and wire the waste gate as far open and see if i can redline with out hitting fuel cut in high rpms, i am betting i do.
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Old Nov 4, 2008 | 05:40 AM
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okay so have money to mod you car to pay a machine shop but you dont have the money to pay me,SCAMMER i hope that your car blow up.
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