Intake and exhaust upgrades with stock ECU?
11-24-11, 06:13 PM
#1
20B/5 Speed/JC!
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Intake and exhaust upgrades with stock ECU?
First off, let me say sorry guys if this is a topic beaten to death, I've searched and haven't found an answer to my specific goal.
I have this that I'm looking install on my true '99 spec:
The downpipe looks to be a Knightsport dual pipe unit and the mid-section and cat-back is a Trust unit.
Neither the Trust cat or the muffler is ported or gutted out. I already have an ARC intake installed (might be switching to another cone set up later) and that's absolutely it for "power" mods.
I will not be turning up the boost, and I will not be doing any engine porting. I'm keeping it as stock as possible engine wise to hopefully prolong it's life.
I've been told I'd be ok running this set up with some kind of engine management. I just wanted to be super sure and see what you guys have to say about it. I read I may need to atleast install a boost controller, which I'm fine with.
What you guys think about it? Or if someone can link me an informative thread that'd be great too. Thanks fellas.
I have this that I'm looking install on my true '99 spec:
The downpipe looks to be a Knightsport dual pipe unit and the mid-section and cat-back is a Trust unit.
Neither the Trust cat or the muffler is ported or gutted out. I already have an ARC intake installed (might be switching to another cone set up later) and that's absolutely it for "power" mods.
I will not be turning up the boost, and I will not be doing any engine porting. I'm keeping it as stock as possible engine wise to hopefully prolong it's life.
I've been told I'd be ok running this set up with some kind of engine management. I just wanted to be super sure and see what you guys have to say about it. I read I may need to atleast install a boost controller, which I'm fine with.
What you guys think about it? Or if someone can link me an informative thread that'd be great too. Thanks fellas.
11-24-11, 09:15 PM
#2
Original Gangster/Rotary!
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I'm not sure how thoroughly you searched, because this topic has been beaten to death more than any around here 
Install the DP and CB and leave your stock main cat in place (bold for emphasis). Doing otherwise can lead to boost creep and a blown engine, irregardless of engine management. The factory internal wastegate is the limiting factor here.
Install the DP and CB and leave your stock main cat in place (bold for emphasis). Doing otherwise can lead to boost creep and a blown engine, irregardless of engine management. The factory internal wastegate is the limiting factor here.
11-24-11, 09:30 PM
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Sorry, I know it's been talked about a lot, but seemed like people were asking about straight pipe exhausts and more boost.
Would a manual boost controller keep it from spiking? I've read other than porting the wastegates, that's the other go to mod.
Would a manual boost controller keep it from spiking? I've read other than porting the wastegates, that's the other go to mod.
11-25-11, 08:25 AM
#4
Original Gangster/Rotary!
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No, search 'boost creep.' A manual or electronic BC will do nothing to help. Porting the WG is a huge PITA and involved removing your turbos. Your best bet is to leave your main cat in place for more backpressure. When you do step up to a PFC or other engine management which allows added fuel at 12-15 psi you can try the center section and hope the boost doesnt skyrocket.
11-25-11, 06:33 PM
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Ok gents, got it. No mid-section without tuning. I may just go with what I originally planned and what to afford a PFC.
I searched "stock exhaust diameter" and actually got better results than my original search phrase. I'll look into making a restrictor plate since I don't think the aftermarket exhaust will match up with the stock cat which if I read right is 2.5 inches in diameter correct? And the plate would go between the mid-section and cat-back, or the downpipe and cat, or does it even matter as long is it's in the system somewhere?
I searched "stock exhaust diameter" and actually got better results than my original search phrase. I'll look into making a restrictor plate since I don't think the aftermarket exhaust will match up with the stock cat which if I read right is 2.5 inches in diameter correct? And the plate would go between the mid-section and cat-back, or the downpipe and cat, or does it even matter as long is it's in the system somewhere?
11-25-11, 07:05 PM
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Lastly, can't I just not worry about porting or resctrictor plates if I have proper tuning that'll increase fuel in the higher RPMs, and a boost controller that'll catch the boost creep before it happens?
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11-25-11, 08:06 PM
#8
BOOST CONTROLLERS CANNOT REDUCE BOOST, THEY ONLY ALLOW YOU TO RAISE BOOST FROM THE LOWEST POSSIBLE BOOST LEVEL THAT THE CAR CAN PRODUCE.
emphasized.
but do keep in mind the restrictor pills do clamp down on the pressure that the wastegate does see, but you need to understand how the system works before attempting to redesign the whole system.
sorry if you meant that the cat was acting as a boost controller, it's merely a restriction to maintain lower boost levels.
11-25-11, 09:50 PM
#9
pffft, you should know better as it was already said earlier in this thread.
BOOST CONTROLLERS CANNOT REDUCE BOOST, THEY ONLY ALLOW YOU TO RAISE BOOST FROM THE LOWEST POSSIBLE BOOST LEVEL THAT THE CAR CAN PRODUCE.
emphasized.
but do keep in mind the restrictor pills do clamp down on the pressure that the wastegate does see, but you need to understand how the system works before attempting to redesign the whole system.
sorry if you meant that the cat was acting as a boost controller, it's merely a restriction to maintain lower boost levels.
BOOST CONTROLLERS CANNOT REDUCE BOOST, THEY ONLY ALLOW YOU TO RAISE BOOST FROM THE LOWEST POSSIBLE BOOST LEVEL THAT THE CAR CAN PRODUCE.
emphasized.
but do keep in mind the restrictor pills do clamp down on the pressure that the wastegate does see, but you need to understand how the system works before attempting to redesign the whole system.
sorry if you meant that the cat was acting as a boost controller, it's merely a restriction to maintain lower boost levels.