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Over boosting issues

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Old 05-30-10, 04:52 PM
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Over boosting issues

Well my car is finally back together tuned and on the road. I use a gt35 turbo not too sure which manifold i use but i run a turbo smart progate 48mm. Ive done a few things already to attack the problem. I ditched my boost controller and im just trying to run of the wastgate spring pressure. Still no good. Im using a 10lbs spring currently and it just spikes to about 13 and then creeps past to 15 even higher when cooler outside. I think my wg is large enough to run the turbo no problem. If i were to shorten the wastgate runner length do you guys think this could help resolve my issue. my worst case scenario is to go bigger but im tryin to be reasonable with cost. I think the way the manifold flows to the wg is just dumb it completley goes the opposite direction which gets alot less flow.
Old 05-30-10, 05:54 PM
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how did it run before? or is this a whole new setup? have you tried a weaker spring in the wastegate? what are you trying to get to boost wise? test the wastegate spring cracking an full open PSI with an air pump see exactly where it opens and is full open. sounds kinda like the spring is too much

z
Old 05-30-10, 06:21 PM
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Yes this is my first single setup on my fd. I want to achieve a steady 14psi. I began with the lowest rate spring which was 7psi and had my profec hooked to it. Thats when i got the car dyno tuned it was hot out that day the tuner got up to 13psi on it using the boost controller. He couldnt go past 13 cause he said the spring wanted to compress too much causing surges and could lead to a stuck open wg. I took the car out the following weekend it was alot cooler out. and started to get on it. (I run a massive intercooler v mount setup) the air temps drop and it started spiking past 13 to id have to say 15 and began surging. i turned off the profec to run 7psi and it still shot up. I decided to leave out the profec and just run a 10 psi spring for now and keep the vacuum lines simple and short. still boost beyond 10 unless im in fifth gear cruising around 3500 to 4000 and mat it then it holds at 10psi. Is a 48mm wastegate sufficent on a half bridge 35r setup with a un restrictive exhaust?
Old 05-30-10, 06:25 PM
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can you take a picture of your manifold at all?
Old 05-30-10, 06:30 PM
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im goona try to tonight the car is 20 miles away right now at my friends garage.
Old 05-30-10, 06:36 PM
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ya then i was gonna say if its new it sounds like the wastegate runner is not where it needs to be like you said get that pic up.

z
Old 05-30-10, 06:40 PM
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My friends fd has almost identical setups same port type and turbo i use a 1.06 housing he uses an .82 though i think. Same manifold though except he has a 60mm tial he doesnt have any issues though. but im still gettin that pic.
Old 05-30-10, 07:05 PM
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It would be easiest to just move to a bigger waste gate...
Old 05-30-10, 11:03 PM
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Originally Posted by 1Revvin7
It would be easiest to just move to a bigger waste gate...
very true but i have the ability and time to modify the manifold that will be the next step if i shorten the runner and i still get the same results. And a nice 60mm tial is gunna costs some good $$$ btw pics





Old 05-30-10, 11:04 PM
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Old 05-31-10, 06:19 PM
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Putting a weaker wastegate spring on a car with boost control issues is the one thing you DON'T want to do. It will make your boost even more sensitive to the weather. When it's really hot out you will overwhelm the spring a little bit, when it's really cold out you will overwhelm the spring a lot. When you put a boost controller on top of that it gets even more unpredictable.
Old 05-31-10, 08:03 PM
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Are you sure the WG is working properly? I would bench test it and make sure it's opening when it should and that it has no leaks.
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