Engine choking out at track
03-19-2013, 02:25 PM
#1
Engine choking out at track Hey guys,
A long while ago at a HPDE event at Road Atlanta I noticed the car was choking out at certain parts of the track. It ran fine for the greater part of the runs however there were several points where it just felt like the motor was skipping a beat.
Any idea as to what would cause that?
Couple specifics surrounding conditions:
1. Hot June day in Atlanta. Temp that day was roughly 95*. Temp gauge in the car was steady in the 190* - 200* range.
2. Car hadn't had any issues prior and didn't have any issues immediately thereafter.
3. 93 octane in the car.
4. The car was still on a N2O tune. Timing pulled for a 100 shot. Typically ran pretty rich on the street as a result.
5. There are a bunch of elevation changes on the track. Not sure if this is relevant however it seemed to occur when the car was lower in the power band and climbing up a hill.
The car has a new motor in it now. I'm heading back to the track and figured that I would try to understand why it was choking out the last time to determine if I need to do anything before heading out there this time. The current build has a N/A tune for the street.
A long while ago at a HPDE event at Road Atlanta I noticed the car was choking out at certain parts of the track. It ran fine for the greater part of the runs however there were several points where it just felt like the motor was skipping a beat.
Any idea as to what would cause that?
Couple specifics surrounding conditions:
1. Hot June day in Atlanta. Temp that day was roughly 95*. Temp gauge in the car was steady in the 190* - 200* range.
2. Car hadn't had any issues prior and didn't have any issues immediately thereafter.
3. 93 octane in the car.
4. The car was still on a N2O tune. Timing pulled for a 100 shot. Typically ran pretty rich on the street as a result.
5. There are a bunch of elevation changes on the track. Not sure if this is relevant however it seemed to occur when the car was lower in the power band and climbing up a hill.
The car has a new motor in it now. I'm heading back to the track and figured that I would try to understand why it was choking out the last time to determine if I need to do anything before heading out there this time. The current build has a N/A tune for the street.
03-20-2013, 06:20 AM
#4
How was the car rich on the street as a result of having a nitrous tune with less timing? It should be richer at wot, but certainly not driving around, but you probably mean that. Regardless, putting load on the engine in lower rpms going up hill, car could def be pulling timing. Hot day and lots of load and a hill fighting the car. Could be detonation. Your n/a tune might have better power under the curve to help the car accelerate quicker because of timing and it might not occur.
03-21-2013, 04:01 PM
#5
Is there a good fix for that?
I believe the issue is related to a combination of a bunch of factors: placing the enging under load at relatively low rpm climbing up a hill, less timing at WOT because of the N2O tune and the high temps at the track. That being said, I guess there's no harm in trying to eliminate the fuel pickup issue from possible causes.
I believe the issue is related to a combination of a bunch of factors: placing the enging under load at relatively low rpm climbing up a hill, less timing at WOT because of the N2O tune and the high temps at the track. That being said, I guess there's no harm in trying to eliminate the fuel pickup issue from possible causes.