Fighting boost creep - S4->S5 Turbo swap?
#26
Take the turbo off yourself, if the heatshields are gone it's not that hard at all, just the oil/coolant lines then unbolting the dp and manifold. Then all you have to do is have a friend or someone take you to a shop that can weld and bingo you've got it for a lot cheaper.
The only other thing you can do to lower boost is restrict the system; intake or exhuast side.
The only other thing you can do to lower boost is restrict the system; intake or exhuast side.
#29
Ok, I've decided upon either restricting the flow of the system.
Would reducing intake flow with a resticting plate between the filter and my 3" pipe be more effective in reducing the boost creep down to about 11psi, more so than say.. putting a 2.25" restricing plate in between the connections of one of the exhaust junctions?
Which would provide for better performance? And, which would have worse side effects?
Would reducing intake flow with a resticting plate between the filter and my 3" pipe be more effective in reducing the boost creep down to about 11psi, more so than say.. putting a 2.25" restricing plate in between the connections of one of the exhaust junctions?
Which would provide for better performance? And, which would have worse side effects?
#30
I'm a boost creep...
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If you've never done it before it can easily take that long, mainly from figuring out how to access all the nuts and bolts.
The first time I took the turbo off my Cosmo's 12AT it took many hours to get it off and back on. The third time took about an hour.
Besides, I'd assume that 6-8 hours includes modifying the turbo?
The first time I took the turbo off my Cosmo's 12AT it took many hours to get it off and back on. The third time took about an hour.
Besides, I'd assume that 6-8 hours includes modifying the turbo?
#31
Compression Tester Guy
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It took me quite a while to do the work myself, but I ran into trouble. Broke a couple bolts and had to hunt down replacements. I could do this mod again easily in 6-8 hours....someone more experienced/prepared would take even less time. Heh, easiest parts of the whole thing were the flapper (someone else welding it on) and the porting (30 mins with a die grinder and carbide bit).
#32
OH,YOU TOUCHED MY TRALALA
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try a diff cat back. do you still have your stock or a smaller cat back?try going up to a exsaust shop and ask them for a 2.5 inch two bolt flange. then take that and put it up betwen the cat and the cat back and see what that does. that should only be about 10 bucks. i have the stock cat back with a 2.5 down pipe and 2.5 cat replace ment pipe and hit 6-7at 28oo and 10 at 5ooo till my wast gate line came off then i hit 15 that was scarry. try what i mentioned and see what you get.
ej
ej
#33
Update!
I put a plate between my A'pexi Filter and my 3" TID pipe.
I cut a 2" circle in the middle of the plate - effectivly making the intake pipe only 2", and much more restricted.
It's about 50*F out right now - perfect element for major boost creep due to the cold, dense air.
Going WOT, about 5000rpms I hit 10.1 PSI and it started falling DOWN!.
I adjusted my wastegate on my Profec B Spec II, and I can hold 10.1 all the way to redline in second gear.
Continuing WOT in third gear, I hit 12.0 maximum at about 4000 rpms.
I'll go on the highway tomorrow and test to see what kind of boost I'll have at the end of third gear.
I put a plate between my A'pexi Filter and my 3" TID pipe.
I cut a 2" circle in the middle of the plate - effectivly making the intake pipe only 2", and much more restricted.
It's about 50*F out right now - perfect element for major boost creep due to the cold, dense air.
Going WOT, about 5000rpms I hit 10.1 PSI and it started falling DOWN!.
I adjusted my wastegate on my Profec B Spec II, and I can hold 10.1 all the way to redline in second gear.
Continuing WOT in third gear, I hit 12.0 maximum at about 4000 rpms.
I'll go on the highway tomorrow and test to see what kind of boost I'll have at the end of third gear.
#34
I'm a boost creep...
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I hope this is just a temporary fix. Adding restrictions to limit boost also reduces the engine's volumetric efficiency, so you just lose power. Improving the wastegate so it can hold boost means you can free up flow restrictions and make more power at the same boost.
Last edited by NZConvertible; 11-19-03 at 12:51 AM.
#35
Originally posted by NZConvertible
I hope this is just a temporary fix. Adding restrictions to limit boost also reduces the engine's volumetric efficiency, so you just lose power. Improving the wastegate so it can hold boost means you can free up flow restrictions and make more power at the same boost.
I hope this is just a temporary fix. Adding restrictions to limit boost also reduces the engine's volumetric efficiency, so you just lose power. Improving the wastegate so it can hold boost means you can free up flow restrictions and make more power at the same boost.
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