A bit rich...but my buddy's CBR600 can't keep up!
08-11-2002, 05:16 AM
#16
Drifting
Ian,
Glad to have you back in town. Your A/F mixture that you're seeing is very normal for the setup you have. I'm really happy to see that your car is running as well as our racecar is. Lowell is a genius at engine tuning. We've been running the crap out of our racecar, with over 190 launches now on the clutch, multiple low 12 second passes, sixteen runs up the Knox Mountain Hillclimb and so many autocrosses that we can't keep count. Everytime that 1.4bar (pump gas) or 1.7bar (race gas) of boost hits, it amazes me that a 2.0L engine can pump that kind of power out. It keeps doing it weekend after weekend after weekend. We even placed 3rd at National Tour this year with the car, after driving to and from the event.
We finally lost our first race in the car a weekend ago at the BC Championship event. We were scratching our heads wondering what was wrong, it turned out that we corded our Kumhos in the morning
Lowell has set the 911 up now at 1.05bar and a mixture of 12:1. He'd like to go 12.5:1, but he felt that it was better to run it a bit richer due to it being air cooled and mechanically injected (can't believe Porsche used CIS on my car!)
fc-racer
Glad to have you back in town. Your A/F mixture that you're seeing is very normal for the setup you have. I'm really happy to see that your car is running as well as our racecar is. Lowell is a genius at engine tuning. We've been running the crap out of our racecar, with over 190 launches now on the clutch, multiple low 12 second passes, sixteen runs up the Knox Mountain Hillclimb and so many autocrosses that we can't keep count. Everytime that 1.4bar (pump gas) or 1.7bar (race gas) of boost hits, it amazes me that a 2.0L engine can pump that kind of power out. It keeps doing it weekend after weekend after weekend. We even placed 3rd at National Tour this year with the car, after driving to and from the event.
We finally lost our first race in the car a weekend ago at the BC Championship event. We were scratching our heads wondering what was wrong, it turned out that we corded our Kumhos in the morning
Lowell has set the 911 up now at 1.05bar and a mixture of 12:1. He'd like to go 12.5:1, but he felt that it was better to run it a bit richer due to it being air cooled and mechanically injected (can't believe Porsche used CIS on my car!)
fc-racer
08-11-2002, 10:59 PM
#17
Race Director
"But it certainly does lead me to question whether the next step is to chuck out the MAF. Could that fact that I repositioned my MAF sensor directly after the air filter (rather than after the 90 degree elbow) be contributing to these issues? I know it's not a big distance, but it sure helped remove my lift-throttle bucking problem."
Nah, that's a minimal difference in distances. A lot of people have had to move the MAF sensor away from the turbo, close to the air-filter, simply to avoid turbulence from the blades. This was especially bad on MAF-4 kits which had marginal low-flow capabilities. I've found that rotating my sensor so that the pick-up was at the outside radius of the elbow with higher-velocity helped idle stability. But others with the later MAF-4 kits using the 4-bolt Ford Lincoln MK-VIII sensors with 4-bolt flanges were simply out of luck.
Nah, that's a minimal difference in distances. A lot of people have had to move the MAF sensor away from the turbo, close to the air-filter, simply to avoid turbulence from the blades. This was especially bad on MAF-4 kits which had marginal low-flow capabilities. I've found that rotating my sensor so that the pick-up was at the outside radius of the elbow with higher-velocity helped idle stability. But others with the later MAF-4 kits using the 4-bolt Ford Lincoln MK-VIII sensors with 4-bolt flanges were simply out of luck.
