hooked up dual exhaust, engine chokes at WOT
03-11-2015, 01:42 PM
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hooked up dual exhaust, engine chokes at WOT I built my dual exhaust this last weekend and went to drive the car. Before this I just had a downpipe exiting out under the car.
The car is dramatically quieter now but at a WOT it bogs down and the A/F ratio shoots to 10:1.
I'm only running about 3-4psi right now and am wondering if there's too much backpressure or maybe my tune is just wrong or if I need more boost to even it out.
My tune came from my friend's engine and has worked flawlessly before the exhaust, but he was also running 15psi with a drastically more efficient turbo, so maybe my engine is just expecting more cfm when I floor it.
I'm also now having a warm idle issue, which I think is more due to the warmer air outside and just needs some tune adjustment.
Thoughts?
The car is dramatically quieter now but at a WOT it bogs down and the A/F ratio shoots to 10:1.
I'm only running about 3-4psi right now and am wondering if there's too much backpressure or maybe my tune is just wrong or if I need more boost to even it out.
My tune came from my friend's engine and has worked flawlessly before the exhaust, but he was also running 15psi with a drastically more efficient turbo, so maybe my engine is just expecting more cfm when I floor it.
I'm also now having a warm idle issue, which I think is more due to the warmer air outside and just needs some tune adjustment.
Thoughts?
03-11-2015, 07:17 PM
#2
So what does your exhaust consist of? How big is your downpipe, how long is it, and then what dual does it split to? When you say it ran fine before, did you have a downpipe hooked up then? Have you tried to change your A/F ratio to see if it stops laying down? At 10:1, it will lay down.
03-12-2015, 08:24 AM
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So what does your exhaust consist of? How big is your downpipe, how long is it, and then what dual does it split to? When you say it ran fine before, did you have a downpipe hooked up then? Have you tried to change your A/F ratio to see if it stops laying down? At 10:1, it will lay down.
Yes, the downpipe was hooked up before but it dumped out by the transmission with no spit.
I haven't done any tuning since the exhaust install, it just kind of took me off guard when it choked itself out.
03-12-2015, 08:48 AM
#4
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Changing from a cheap 2.5" dual exhaust to a mandrel bent dual 3" exhaust with Pyres Race mufflers made a huge performance gain on my 500HP motor-only car. (About .5 ET and 4 mph)
BTW - I love the Pyres Race mufflers - they are straight-through yet quieter at idle and low throttle than the Flowmasters I had on it. Of course at WOT they are louder.
BTW - I love the Pyres Race mufflers - they are straight-through yet quieter at idle and low throttle than the Flowmasters I had on it. Of course at WOT they are louder.
03-12-2015, 09:00 AM
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Changing from a cheap 2.5" dual exhaust to a mandrel bent dual 3" exhaust with Pyres Race mufflers made a huge performance gain on my 500HP motor-only car. (About .5 ET and 4 mph)
BTW - I love the Pyres Race mufflers - they are straight-through yet quieter at idle and low throttle than the Flowmasters I had on it. Of course at WOT they are louder.
BTW - I love the Pyres Race mufflers - they are straight-through yet quieter at idle and low throttle than the Flowmasters I had on it. Of course at WOT they are louder.
The kit I'm using is a mandrel bent 2.5" system from Summit.
I think the turbo mufflers are my main issue as far as restriction is concerned.
http://www.summitracing.com/parts/sum-680101