Too much boost, not much control.

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Too much boost, not much control.

Postby Landon » Sat Feb 16, 2013 6:59 am

Ok I searched this, but can't seem to get much from that, so give me ideas if you have any, but here is the issue. Stock turbo, fuel, etc, only mods really engine wise are- 3in straight pipe exhaust, straight intake, no boost controller, 12psi -fuel cut. Basically I have to control boost with my throttle or I hit fuel cut. Is this boost creep or would you say I have some wastegate issues? I can hit fuel cut in 2nd with WOT, TVIS is still connected. I put vacuum on my wastegate diaphragm and it held vacuum on the compressor side, but didn't even build vacuum on the other side, I'm not sure if this is normal. I'd like to be able to experience full throttle but not sure what this might be, so if anyone has advice it'd be much appreciated.
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Re: Too much boost, not much control.

Postby gearhead313 » Sat Feb 16, 2013 12:28 pm

Sounds like the wastegate isnt opening? Did you mean you put a vacuum pump on the gate and watched it open? You could try running a dedicated vac line to the gate to see if it opened without the interruption of the other parts. Maybe one of those lines is leaking....
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Re: Too much boost, not much control.

Postby zero06 » Sat Feb 16, 2013 3:10 pm

It's the 3" exhaust. Check your WG preload & If your WG is opening properly if so your issue is that The stock wastegate cannot flow enough to bypass the turbine properly with that little turbine backpressure. I had the same issue. Options are bigger turbo setup, external WG, some people port the internal WG or have their turbines clipped? smaller zaust Would also fix the problem
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Re: Too much boost, not much control.

Postby Landon » Sat Feb 16, 2013 7:33 pm

Thanks for the response guys, I kinda thought it was the fact that the stock wg couldn't flow enough. I'll do a bit more testing and make sure everything is working right and then look into some other options. Thanks a lot!
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Re: Too much boost, not much control.

Postby brutekiller787 » Sun Feb 17, 2013 12:15 am

Ebay downpipe blocking the wastegate, or if you messed with the tvsv, you might have cracked a hose somewhere and you are leaking boost so the wastegate doesnt . Things to look for...
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Re: Too much boost, not much control.

Postby gearhead313 » Mon Feb 18, 2013 2:15 am

My last car started life with stock turbo and 3" turbo back, one muffler. Mine boosted fine.

I can see a cheap DP not allowing the flapper to open far enough? anything is possible when ebay is involved!
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#4598 - sold to Canada eh
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Re: Too much boost, not much control.

Postby phattyduck » Mon Feb 18, 2013 6:41 pm

gearhead313 wrote:I can see a cheap DP not allowing the flapper to open far enough? anything is possible when ebay is involved!
It has been well documented... Just needs like 1/16" ground off where the wastegate hits it. If you remove the downpipe, you should see the spot it is hitting.

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Re: Too much boost, not much control.

Postby Landon » Tue Feb 19, 2013 3:42 am

Sweet, thanks guys. Good to know, I'll look into it.
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