2nd gear pull good, 3rd gear pull sucks.

[cfisher]

I can do a 2nd gear pull with a nearly perfect tune but a 3rd gear pull looks like crap. Anyone else have any ideas or run into the same problem. The only thing I can come up with is the engine is under more load on the 3rd gear pull and maybe running out of fuel up top? Main mods are RS60T, PTE 680cc inj, walbro 255, FMIC, 3" turboback, ect.. mods are in my profile. These were all WOT runs from 3K on.

SAFC Highs -25,-25,-25,-25,-28,-30,-30,-30

This was done on 20psi.

2nd gear log

RPM TIMING O2
3000 10 .92
3500 12 .92
4000 13 .92
4500 14 .92
5000 16 .92
5500 17 .92
6000 18 .92
6500 19 .92
7000 21 .92

3rd gear log

RPM TIMING O2
3000 10 .92
3500 11 .92
4000 12 .92
4500 12 .92
5000 14 .92
5500 14 .92
6000 14 .92
6500 14 .92
7000 14 .92

 

[CanadianTSi]

Your too lean. Although your just barely on the edge of knocking, try changing the -28 and everything there after to -27.

The taller gears put more load on the car and really bring out the weak spots in your tune.

This is why I do all my logging in 3rd and 4th

 

[GVR4592]

You should tune for no knock in 4th gear. It's pretty common to see what you're experiencing. It probably won't be as fast in the lower gears but it will be safe.

 

[cfisher]

That's exactly what I was thinking. Thanks guys. I'm going to be tuning all weekend so hopefully I can't get it dialed in better. I'll post up a new log. The reason this even came up was because I could tell 1st & 2nd gear were running good and screamed to redline. But when I did a 3rd gear pull it was definetly knocking past 5K. This brings up another issue then. How come my bumper gets a nice black carbon stain on it and I have to clean it off about once a week. That's from running to rich right but my logs say otherwise. I have no boost leaks and I held 20psi on the boost leak tester. Would this be caused from no cat?

 

[RavenX]

Honestly that 3rd gear log looks just fine. Don't base your tune looking at the o2 volts granted you should richen it up until you see around .94 volts but every car is different. There was no knock present there and 14 degrees of timing on pump gas is good. You could lean it out 1-2% and see if you get knock or you can turn up the boost 1-2psi. Also i think its time for you to invest in a wideband.

 

[dnhieu]

Honestly that 3rd gear log looks just fine. Don't base your tune looking at the o2 volts granted you should richen it up until you see around .94 volts but every car is different. There was no knock present there and 14 degrees of timing on pump gas is good. You could lean it out 1-2% and see if you get knock or you can turn up the boost 1-2psi. Also i think its time for you to invest in a wideband.

thats exactly what i was going to say. i dont see timing getting pulled...

 

[cfisher]

Honestly that 3rd gear log looks just fine. Don't base your tune looking at the o2 volts granted you should richen it up until you see around .94 volts but every car is different. There was no knock present there and 14 degrees of timing on pump gas is good. You could lean it out 1-2% and see if you get knock or you can turn up the boost 1-2psi. Also i think its time for you to invest in a wideband.

I'd like to get 16-18 deg timing by 7K in 3rd but I'm getting closer. I'm about to buy a wideband and hit the dyno so I'm trying to get as close as I can. I've really been thinking about just ditching the SAFC and going with link. I did change my high settings on the way home to -25,-25-,25-,25,-27,-27,-27-27 but didn't get a chance to log it. I'll be out tomorrow and post up what I find out. Thanks for you help guys.

 

[CanadianTSi]

You want your timing to steadily increase, if it stays the same that means you are knocking.

His timing stays the same for 2000rpms. The car is probably seeing 3-5 counts of knock which is not making it pull timing but not advancing it either.

As I said your right on the verge. Also pulling -30 you should be seeing around 19 degree's at the top of 3rd.

 

[RavenX]

Theres are just one of the reasons why i ditched the AFC. I do think its time for you to switch to dsmlink but am sure you can tweak with the afc a little bit more. Just post up another log.

 

[hellotbone]

If his timing isn't increasing he is knocking. I log 21* timing at WOT at 25psi on my 50 trim. He should get more timing with a richer tune.

 

[spyderturbo007]

Yep, I agree. With 680cc injectors and pulling 28% of airflow you should be getting between 19 nd 21 degrees up top. If you are maxing at 14 degrees you are knocking like crazy.

Go with CanadianTSi's suggestion and richen things up. Also, what is the gap and heat range of your plugs?

 

[cfisher]

Yep, I agree. With 680cc injectors and pulling 28% of airflow you should be getting between 19 nd 21 degrees up top. If you are maxing at 14 degrees you are knocking like crazy.

Go with CanadianTSi's suggestion and richen things up. Also, what is the gap and heat range of your plugs?

It's getting there and I'll post my new log up tonight when I get off work. I got 18 degrees timing at 7K with -27 on my highs with a 3rd gear pull so I was definetly lean up top. I'm using NGK BPR7ES plugs gapped at .28. I think my RS60T just blew the oil seal though.