WAHUSKER

iTrader: (4)

This is the log file from yesterdays 2nd pass. The most obvious issue is the LTFTs cells along the bottom of the histogram chart. +14 the whole time I was WOT! Like I said earlier, Ellis & I had the car pretty much dialed in Saturday, so this just doesn't make sense. Unless it was the race gas. I had almost a full tank of premium with 6.25 gal of race gas. Could it change the a/f THAT much? (I have limited exp here)

The other thing that pops out at me is the MAF & MAP lines in the 2nd row. Both are maxed out. I've tried setting the chart to allow higher numnbers, so the sensors must not be enough for the air I'm flowing. Maybe it's time for the 2 bar MAP & an 85mm MAF.

The other change I'm thinking I should make is add an MSD (or equiv) Boost-a-pump & get rid of the ATI In-line pump. It seems to me the Walbro 255 with more voltage should be able to keep up with the small blower, and the ATI is likely as not limiting the flow in the high power bands. (Ellis - can we trade that fuel pump for a BAP?) The pressure stayed above 50, but the inj duty cycle is higher than I'd like it.

I also want to put my car on a lift & take a CLOSE look at the suspension. I'm convinced what I was hearing was something hitting something else at a high frequency. Anyone with an idea is more than welcome to chime in.

Ryan K

iTrader: (11)

Your log files don't really show much of a problem. Do you have a wide band yet? You O2 readins are in line with what I would expect for a FI car, mid .900 MV, being rich shouldn't hurt you that much at all. Hell I run pig rich between 10.90-11.50. Your timing looks good, what was the boost at?

As far as the MAP and MAF, you can tune around those... Hell, with my car I had the MAF pegged any thing over 4500rpm.

Ryan

WAHUSKER

iTrader: (4)

Really? That's interesting. Thanks Ryan.

The boost is only hitting 5-6 psi. Not like I'm pushing the limits. I do need to get my LM1 installed. That would tell me more about what's really going on I'm sure. But then like Ellis & I were discussing, the PCM gets it's info from the regular O2s, so what they read IS important.

The good news is the PCM is adjusting for what's going on since, like you pointed out, the O2s are over 900. It just bothers me when I go to the track thinking it's dialed in & then it all goes to ****......

Regarding the timing, I have it set to start at 24* at 2000rp, and then drop to 19 by 5000, so the solid 18* also puzzles me with no KR showing up. There must be a table somewhere that I missed.

Robert56

iTrader: (2)

The LTFT are really not that much of a problem like Ryan said. Mine also were out of wack, however, +10/15 in the lower regions. All this does is when going wot, if the ltft are positive they are froze and then added to your wot pe multiplier, so your just a little richer than normal. They would be better slightly negitive, as then they are dropped when going wot. Maybe it was the air, as I thought mine were dialed in too. Saturday I had it set for 11.25 a/f and then Sunday, at certain areas because of big positive trims it was richer than I wanted, so a slight loss of power, oh well. Remember, when going wot the O2 sensors are out of the picture for adjusting anything, only for part throttle. Yea, the LM1 is a great tuning tool, the farther you get from 14.7 the less accurate the stock O2s are. keep at it, you'll figure it out, tuning these cars can be a big long job.
Oh and thanks again for the trailer ride.
Robert

turbo50

Hey mark, you still thinking of coming down for the dyno day on sat.?

WAHUSKER

iTrader: (4)

That is funny EJ! And yes, now that I got my vibration figured out, I was thinking about dropping by IF you had room for my POS. I'd like some more tuning time now that the fuel pressure is stable, and I don't think the drivetrain is going to blow up, so I can focus on tuning it for max power.

Oh, Tranzor, yeeeaaah.....about that drive shaft you loaned me.....it was a spare, right? (in my best Office Space boss's voice) Because that's all it's good for now. Seems the balance was not quite right on it. And with the power I'm making, at 5500 rpm it flexed & wobbled enough to hit the DS Loop. But only on ~25% of 1 side (hence why we missed it when we jacked the car up at the track). At any rate, it has a nice galled trench in it now. I would not recommend using it for racing anymore. Let me know if you want me to find you a replacement, or give you $....

Now I know why Denny's makes such a big deal out of balancing theirs to 10,000 rpm!

Tranzor

Heh... yeah, it was a spare. That's why I have a Denny's as well. I was getting some significant vibration at high RPMs... I figured it was the stock driveshaft wobbling a bit under the high stress, not that anything was wrong with it. When I put my cam in, I was shifting at 6700 or 6800 rpms regularly, so I'm sure that was outside its normal operating range.