problem missfire
#13
11-01-2013, 05:04 PM
You have injectors for an 800cc? Is there anything a little larger you can install? Adding to the idle issue, have you inspected the fuel regulator? This MIGHT have an issue of rpm drop (misfire) at the higher rpm.
Last edited by Kevinkpk; 11-01-2013 at 05:08 PM. Reason: This MIGHT have an issue of rpm drop (misfire) at the higher rpm
#14
11-01-2013, 05:13 PM
Those injectors are huge I only needed 2.0 Protege injectors wich they are 300cc. And the rpm drop was when i was braking most of the times keep dropping until I stall. that missfire at 5700rpm I dont know what it is I dont feel anything out the ordinary. Yes the Fuel pressure regulator is working nicely.
#15
11-01-2013, 05:47 PM
I didn't realize this was a turbo unit with a ridiculously oversize exhaust.
The intercooler if it's front mounted especially could be sucking in air.
The exhaust is another issue. Seriously, 3" exhaust for a 1.6 ltr? That's way to big, especially since your down pipe is 2.5"
A small restrictive pipe would immediately fill with exhaust, and move at a considerable velocity, but excess gas would be left behind, which in the worst case scenario would actually remain in the combustion chamber and mix with the incoming fresh air, reducing power.
A large pipe would immediately absorb all the exhaust volume, but drop velocity. Exhaust would still flow out, but would not be as efficient as it could be.
Example; If anything, some of the catbacks are actually reducing overall power, because they're slowing down what little exhaust velocity there is, by the time it gets done going through the twists and honeycombs of doom."
Your exhaust is bigger than your downpipe which could be helping causing your misfire.
The 2.5" is more than adequate for a 1.6 ltr turbo. According to Garrett, your downpipe should be at least 1.25X the diameter of the turbine wheel.
The intercooler if it's front mounted especially could be sucking in air.
The exhaust is another issue. Seriously, 3" exhaust for a 1.6 ltr? That's way to big, especially since your down pipe is 2.5"
A small restrictive pipe would immediately fill with exhaust, and move at a considerable velocity, but excess gas would be left behind, which in the worst case scenario would actually remain in the combustion chamber and mix with the incoming fresh air, reducing power.
A large pipe would immediately absorb all the exhaust volume, but drop velocity. Exhaust would still flow out, but would not be as efficient as it could be.
Example; If anything, some of the catbacks are actually reducing overall power, because they're slowing down what little exhaust velocity there is, by the time it gets done going through the twists and honeycombs of doom."
Your exhaust is bigger than your downpipe which could be helping causing your misfire.
The 2.5" is more than adequate for a 1.6 ltr turbo. According to Garrett, your downpipe should be at least 1.25X the diameter of the turbine wheel.
Last edited by UseYourNoggin; 11-01-2013 at 06:57 PM.
#16
11-01-2013, 07:37 PM
The exhaust is another issue. Seriously, 3" exhaust for a 1.6 ltr? That's way to big, especially since your down pipe is 2.5"
A small restrictive pipe would immediately fill with exhaust, and move at a considerable velocity, but excess gas would be left behind, which in the worst case scenario would actually remain in the combustion chamber and mix with the incoming fresh air, reducing power.
A large pipe would immediately absorb all the exhaust volume, but drop velocity. Exhaust would still flow out, but would not be as efficient as it could be. This will cause pressure increase, thus the exhaust will be "backed up" The sizing you have is for something (less turbo) alot larger, as Noggin states the turbine diameter has to be included for exhaust sizing.
Example; If anything, some of the catbacks are actually reducing overall power, because they're slowing down what little exhaust velocity there is, by the time it gets done going through the twists and honeycombs of doom."
Your exhaust is bigger than your downpipe which could be helping causing your misfire.
The 2.5" is more than adequate for a 1.6 ltr turbo. According to Garrett, your downpipe should be at least 1.25X the diameter of the turbine wheel.
A small restrictive pipe would immediately fill with exhaust, and move at a considerable velocity, but excess gas would be left behind, which in the worst case scenario would actually remain in the combustion chamber and mix with the incoming fresh air, reducing power.
A large pipe would immediately absorb all the exhaust volume, but drop velocity. Exhaust would still flow out, but would not be as efficient as it could be. This will cause pressure increase, thus the exhaust will be "backed up" The sizing you have is for something (less turbo) alot larger, as Noggin states the turbine diameter has to be included for exhaust sizing.
Example; If anything, some of the catbacks are actually reducing overall power, because they're slowing down what little exhaust velocity there is, by the time it gets done going through the twists and honeycombs of doom."
Your exhaust is bigger than your downpipe which could be helping causing your misfire.
The 2.5" is more than adequate for a 1.6 ltr turbo. According to Garrett, your downpipe should be at least 1.25X the diameter of the turbine wheel.
#17
11-01-2013, 09:42 PM
Well my turbine is .63 AR 2.5 outlet for what is worth my previous exhaust setup was 2.5 DP with 2 1/4 custom exhaust since going 3 I spool my turbo 300rpm sooner and I fell the car with more power but to prove IF I lose or gain power I will dyno the car again and compare with the old graph
#18
11-01-2013, 10:11 PM
Well my turbine is .63 AR 2.5 outlet for what is worth my previous exhaust setup was 2.5 DP with 2 1/4 custom exhaust since going 3 I spool my turbo 300rpm sooner and I fell the car with more power but to prove IF I lose or gain power I will dyno the car again and compare with the old graph
#20
11-02-2013, 08:09 AM
Well my turbine is .63 AR 2.5 outlet for what is worth my previous exhaust setup was 2.5 DP with 2 1/4 custom exhaust since going 3 I spool my turbo 300rpm sooner and I fell the car with more power but to prove IF I lose or gain power I will dyno the car again and compare with the old graph
I know people with turbos go to 3" exhaust but they have bigger engines and a 3" downpipe. I've even read on the internet where they have 3" downpipes with 2.5" exhaust (not a fan of), but going the other way with a small engine like you are doing isn't a really good thing especially with low boost (I believe your boost was 6 as per dyno sheet).
Thanks for understanding and being calm!
Nov 3: "As for 2.5" vs. 3.0", the "best" turboback exhaust depends on the amount of flow, or horsepower. At 250 hp, 2.5" is fine. Going to 3" at this power level won't get you much, if anything, other than a louder exhaust note. 300 hp and you're definitely suboptimal with 2.5". For 400-450 hp, even 3" is on the small side.”
"Other things you can do (in addition to choosing an appropriate diameter) to minimize exhaust backpressure in a turboback exhaust are: avoid crush-bent tubes (use mandrel bends); avoid tight-radius turns (keep it as straight as possible); avoid step changes in diameter (especially rear cat further down); avoid "cheated" radii (cuts that are non-perpendicular); use a high flow cat; use a straight-thru perforated core muffler... etc.”
My .02: if you have a 2.5" downpipe, use a 2.5" mandrel bent exhaust with a 2.5" hi flow rear cat and straight-thru perforated core muffler.
If you have a 3" exhaust with a 2.5" rear main cat, you've done a bad thing because you go from 2.5" downpipe to 3" exhaust to 2.5" rear cat and back to 3"?
Last edited by UseYourNoggin; 11-03-2013 at 10:08 AM. Reason: Nov 3 @ bottom