2nd gear lean & Gear # malfunction

edomund · Post by **edomund** » Sat Oct 17, 2009 2:29 pm

Ser # 6948
Kmanager 1.3.7.0
2005 S2000
PRB Kpro ECU
Modified Greddy Turbo Kit

There're 3 problems in the one datalog I posted.
1. 2nd gear is always lean compared to all other gears by around 8%. I have the gear comp set to +8% fuel for 2nd gear.

2. During second gear pulls sometimes it will lean out during a pull.
In the datalog this occurs around 3:38 through 3:41.

3. When datalogging gear # it will jump between different gears when I know I'm not shifting between gears. This is a big issue because of the fuel correction for 2nd gear.
You can see this in the datalog throughout the datalog but especially between 0:46-1:01.

Thank you for your help,
Ed

edomund · Post by **edomund** » Sun Oct 18, 2009 11:13 am

Here's my wideband voltages.

Volts AFR

1.87 9.91
1.91 10.14
2.15 11.05
2.24 11.45
2.40 12.08
2.63 13.04
2.89 14.10
3.13 15.01
3.37 16.21
3.69 17.29
4.90 22.39

edomund · Post by **edomund** » Sun Oct 18, 2009 7:03 pm

Here's a 3rd gear WOT pull datalog for comparison. The AFR's are pretty flat.

Post by **Spunkster** » Mon Oct 19, 2009 4:48 pm

Have you changed your gearing at all?

edomund · Post by **edomund** » Mon Oct 19, 2009 5:08 pm

No, I have stock AP2 gearing. I selected the gear ratios in Kpro parameters to match my AP2 4.10 final drive.

edomund · Post by **edomund** » Wed Oct 21, 2009 6:32 pm

Any other ideas?

Post by **Spunkster** » Thu Oct 22, 2009 1:40 pm

Try using a final drive ratio of 4.95. The selections in the software are currently incorrect and will be updated. You cannot use the actual final drive ratio for for an S2000 as there is also a reduction gear ratio you must multiply the final ratio by.

AP1
6-speed, close-ratio
Primary Gear Reduction - 1.160
1st gear - 3.133 --- Est speed @ 9000rpm ~ 45mph
2nd gear - 2.045 --- Est speed @ 9000rpm ~ 60mph
3rd gear - 1.481 --- Est speed @ 9000rpm ~ 90mph
4th gear - 1.161 --- Est speed @ 9000rpm ~ 115mph
5th gear - 0.970 --- Est speed @ 9000rpm ~ 135mph
6th gear - 0.810 --- Est speed @ 9000rpm ~ 160mph
Reverse - 2.800
Final Drive - 4.10 with Torque-Sensing Limited-Slip

AP2
6-Speed Transmissions Gear Ratios:
Primary Gear Reduction - 1.208
1st gear - 3.133
2nd gear - 2.045 --- Est speed @ 8000rpm ~ 52mph
3rd gear - 1.481
4th gear - 1.161
5th gear - 0.942
6th gear - 0.763
Reverse - 2.800
Final Drive Ratio - 4.100

JustinC · Post by **JustinC** » Thu Oct 22, 2009 5:22 pm

Spunkster wrote:Try using a final drive ratio of 4.95. The selections in the software are currently incorrect and will be updated. You cannot use the actual final drive ratio for for an S2000 as there is also a reduction gear ratio you must multiply the final ratio by.

AP1
6-speed, close-ratio
Primary Gear Reduction - 1.160
1st gear - 3.133 --- Est speed @ 9000rpm ~ 45mph
2nd gear - 2.045 --- Est speed @ 9000rpm ~ 60mph
3rd gear - 1.481 --- Est speed @ 9000rpm ~ 90mph
4th gear - 1.161 --- Est speed @ 9000rpm ~ 115mph
5th gear - 0.970 --- Est speed @ 9000rpm ~ 135mph
6th gear - 0.810 --- Est speed @ 9000rpm ~ 160mph
Reverse - 2.800
Final Drive - 4.10 with Torque-Sensing Limited-Slip

AP2
6-Speed Transmissions Gear Ratios:
Primary Gear Reduction - 1.208
1st gear - 3.133
2nd gear - 2.045 --- Est speed @ 8000rpm ~ 52mph
3rd gear - 1.481
4th gear - 1.161
5th gear - 0.942
6th gear - 0.763
Reverse - 2.800
Final Drive Ratio - 4.100

Yeah, you should input these values for an AP2:

1st: 3.778
2nd: 2.466
3rd: 1.786
4th: 1.400
5th: 1.137
6th: 0.923

Final: 4.10

Post by **Hondata** » Fri Oct 23, 2009 8:44 am

We muliply the final drive by the secondary reduction ratio to give 4.756 for an AP1 and 4.953 for the AP2.

edomund · Post by **edomund** » Sun Oct 25, 2009 7:10 pm

These are the #'s that I found to work. I used the 1.208 multiplier on all gears exept on the final. You can't input the final as 4.953, it will show gears 3-5 as 1 gear higher than they actually are. If you input the final as 4.10 it seems to work.

1st 3.785
2nd 2.470
3rd 1.789
4th 1.402
5th 1.138
6th 0.922

Final 4.100

edomund · Post by **edomund** » Sun Oct 25, 2009 7:17 pm

1 problem solved 1 to go. I still can't figure out the 2nd gear issue.
Any ideas on why 2nd gear randomly goes lean & all other gears in boost are ok?

I did another pull in 2nd & it's odd because it's lean then goes back to around 10.5 AFR & then goes lean again. In 3rd gear on the same map it doesn't do this.

Post by **Spunkster** » Mon Oct 26, 2009 4:51 pm

What is your fuel pressure doing with this is happening?

edomund · Post by **edomund** » Tue Oct 27, 2009 8:39 am

That was my next thought that it could be a fuel delivery problem; injector, pump etc. Problem is I don't have a fuel pressure gauge, so it's hard to diagnose.

Is there any way I can diagnose this without a fuel pressure gauge?

Thanks,
Ed

Post by **Spunkster** » Tue Oct 27, 2009 9:49 am

At this point you really need a gauge so you cna see what is hapeneing. B&M makes an inexpensive one that should work for what you are doing.