Lee5
31-01-2009, 03:29 PM
Hi,
I mapped a car the other month to 1.6 bar the car ran fine on the road and the fueling was 12.2ish falling 11.8 @7k, the owner then ran the car on the RR and it made 360bhp ATF.
But when the car was ran he was told the boost was dropping a bit in the mid range and did it have a boost leak???
After looking at the car it was found to have a leak round the throttle body due to the seals failing, when the car was pressure tested it was dropping 5psi from the seals which is a common problem I was told on the Evo 8.
So with new seals fitted and everything put back together the car was run up the road just to make sure all was fine. In doing this the car was very flat and didn't pull as well before which I thought was very odd at the time.
So next thing was to hook the LM1 back up and look at the fueling when under full load and peak boost the AFR's where now 10.1 dipping to 9.8 at the red line.....:eek:
The reason for this was due to the Maf being mapped with the leak and seeing more air when it has a leak due to the turbo having to work harder and also seeing different load cells as well in the map......
After an hour out mapping the car is now very close the std values that are in the fuel table and are around 0.4 out. And we also got some more timing in as well.
The affects of the boost leak as well, is very much the same as swapping an air filter after you have had your car mapped due to the way the maf reads so if you are going to map your car make sure your air filter is clean and don't swap to another brand with out looking at your map.:smile:
Here are the fueling maps and timing maps for you to see how much difference it can make.
Twin_maps is the old map and DS27-1-09-1 is the new map, I think they speak for them selfs.
Hope this helps shed some light on how a maf works and what effects a leak and changing the air filter have to the car.
Cheers
Lee
I mapped a car the other month to 1.6 bar the car ran fine on the road and the fueling was 12.2ish falling 11.8 @7k, the owner then ran the car on the RR and it made 360bhp ATF.
But when the car was ran he was told the boost was dropping a bit in the mid range and did it have a boost leak???
After looking at the car it was found to have a leak round the throttle body due to the seals failing, when the car was pressure tested it was dropping 5psi from the seals which is a common problem I was told on the Evo 8.
So with new seals fitted and everything put back together the car was run up the road just to make sure all was fine. In doing this the car was very flat and didn't pull as well before which I thought was very odd at the time.
So next thing was to hook the LM1 back up and look at the fueling when under full load and peak boost the AFR's where now 10.1 dipping to 9.8 at the red line.....:eek:
The reason for this was due to the Maf being mapped with the leak and seeing more air when it has a leak due to the turbo having to work harder and also seeing different load cells as well in the map......
After an hour out mapping the car is now very close the std values that are in the fuel table and are around 0.4 out. And we also got some more timing in as well.
The affects of the boost leak as well, is very much the same as swapping an air filter after you have had your car mapped due to the way the maf reads so if you are going to map your car make sure your air filter is clean and don't swap to another brand with out looking at your map.:smile:
Here are the fueling maps and timing maps for you to see how much difference it can make.
Twin_maps is the old map and DS27-1-09-1 is the new map, I think they speak for them selfs.
Hope this helps shed some light on how a maf works and what effects a leak and changing the air filter have to the car.
Cheers
Lee