Whats up everyone. I finally had a chance to do some WOT runs. It is a tad lean up top. I would love to here what the Gurus have to say. Good or bad please thats the only way I will learn more.
Both logs are done at 23 psi


thanks

 

I'm not a guru, but you could probably rid yourself of that little bit of knock by getting the AFRs back down below 12 in upper RPM range. You seem to like it around 11.5 - 11.6, so get it there all the way to redline and then add a little timing if you can. Other than that, you seem to be off to a good start.

Take what I write lightly please. I'm not a tuner. =)

 

You look good.

The only thing i would experiment with is running 22 psi with more timing after 5k, say 10* 5k, 11*5.5k, 13* 6k, 15*6.5k, 17* 7k.

 

do a Run in WOT in 4th gear.

 

any particular reason to log on 4th gear compared to 3rd besides safety?

 

I second that whats the reason

 

I was told to log on the gear closest I was told to log on the gear closest to 1:1 ratio. If 3rd gear is 1.44, the delta is -0.44. If 4rd gear is 1.09, the delta is -0.09. With that said, 4rd gear is the closest 1:1. Unless I’m missing something else….. I hope i'm not getting off the topic. sorry...

 

I've heard the 1:1 in reference to dyno's since a 1:1 ratio will give you the most accurate numbers.

I would suggest a 4th gear run for more load to see if you are really getting away with the leaner-than-usual AFR's with more load on the engine. I think you'll see more knock in 4th.

 

Essentially that is what we’re kinda doing but on the street which can be dangerous b/c max speed is around 120. YIKES! Yes, I agree that he will potentially hit higher load cells.

 

You have knocks on high RPM after 6000rpm. make sure those area gets more fuel. you are pulling timing up high and it is dangerous.
High rpm Area should have 0 knock counts. Our ECU is doesn't pick up knocks very well on that area, And if that is present on your log, Those are real and damaging your engine.
few knocks before 4000 rpm is way less serious than High rpm knocks.
Also, It seems generally too lean to me. Make sure as you approach the high RPM, A/F ratio becomes more richer.

 

The Engine is under the most load for the longest period of time in 4th gear. Thats your best bet to get your engine to knock due to higher temps and cylinder pressure. If your seeing knock in 3rd you will see more knock in 4th usually. Thus a log that shows 1-2 1-3 counts of knock in 3rd may show 4-7 counts in 4th.
It is harder to log in 4th due to the higher speeds, but its well worth it.

Tuning in 3rd is ok, but you should always finalize it with a log in 4th from 0-7000rpm.

Personally i Tune timing in 3rd and AFR's in 4th, but always finalize the tune with a run in 4th.

 

Do you have a fuel pump installed? If so, did you use the actual Walbro install kit?

 

Yes I have the walbro and the install kit

 

sense no one really addressed it here, the best reason you would tune in 4th over 3rd is that the the wideband sensor has a latency to it. basically, it is measuring exhaust gases that have already been burned a few revolutions earlier, and it also takes some time to process the signal and make it to your computer. this entire process can take up a significant amount of time, thats why you wont see people tuning in 1st or 2nd gear, you simple run through the revs so fast and the wideband readings will be behind what you are actually looking at. doing the runs in 3rd or even better in 4th extends the time it takes the car to run through the revs brining the actual a/f ratio recorded closer to the rpm value it would correspond to in your tables.

also, in higher gears you have more load on the engine because of the gear ratios. short gears like 1st and 2nd give a huge gear ratio thus the engine doesn't see a very high torque load, whereas in 3rd or 4th the gears are much taller and the engine will see higher loads (wind resistance, wheel inertias will also effect it) having a 1:1 doesn't mean anything.

 

Why do you ask? I have the Walbro and used the install kit, although in the WRX I re-used the stock sock/filter.