Frustrated, confused and out $240
Well, the morning started off when I missed my alarm. So I run out the door, laptop in hand, hop in my friend's car and make my way over to the dyno. Today, we were going to button up his tune along with another friend.
The first one up was an '00 A4 T/A with a freshly installed Torquer v.2 courtesy of Texas Speed. I had my LC1 in the other car, so we decided to use the shop's tail sniffer to make sure everything was ok (we stuck this in the true duals with a 3-foot tube). First run, it came up a whole AFR point leaner on their sniffer than my LC1 (which I recalibrate fairly frequently and matches the NBO2's in closed loop fairly well) and only made about 350 to the tire through the unlocked converter. I figured we'd trust that AFR reading and fattened up the fuel curve a tad before the next pull. We got 5 more hp. So, maybe a little more spark? I added in a degree and didn't see any better results. Disappointed, I advised my friend that there's not much use in adding in more spark if it won't make more power. So, we did one final run with the converter locked and gained 17 hp (373rwhp was the final number). The guy running the dyno suggested he look at his plugs while we loaded up the next car. (We later found the plugs had hair-line cracks and fine specs of metal - we guessed that was from when he hit the nitrous on the stock cam).
While he was going after his plugs, we loaded up the '99 SS A4 with the same cam plus a set of Patriot Stage 2 heads that were only shaved .006. His first pull was even lower than the T/A's first pull. Again, the shops sniffer read 13.6~14.0. This was through cats. But, my LC1 said all was well. So, I tried fattening up the fuel curve again for this car. Now, my LC1 was reading high 11's on the collector bung while the shop's sniffer looked more in line with where we wanted to be. There was a 2hp difference between the pulls (which I attribute to statistical error). Ok, so after several pulls with a little more timing, we realize we're not getting anywhere. So, I go back to the original fueling based on the LC1. More timing didn't help, so we thought less timing might help given it's a H/C car. Nothing. We ended up within 10hp of where we started after about 8 pulls and I was getting nervous about running the car too much on the dyno. We had fans and all, but still...
Then, I notice in the logs timing was identicle for EVERY run!!! I mean, for those 8 runs I had the high/low octane tables as high as 32* and as low as 18* in the WOT throttle cells and every run started off at 23* near 5,000rpm and ended at 26* when I shut down at 6,600rpm. I franticly searched through every spark table/adder and there was nothing that matched the operating ranges we were in to add or reduce timing. My next thought was "Optimal timing." I changed this and triple checked the high/low octane tables before making another pull. Still, the car started at 23* and ended at 26*. AAAAAAGGGGGGHHHHHH! Since we were there and strapped down, I made one final pull to give him some locked torque converter numbers. They were within 1hp and 8ft/lbs of the other non-H/C car! I was soooooo pissed! I not only didn't get my friend's cars where they need to be, I helped them blow $240 of their hard earned money!
Now, I need to know what went wrong. I have logs. I have a few saved tunes (but I started to get frustrated and made minor changes to the existing tune). I wish I would have saved each tune from the SS, but time was running out and I wasn't thinking. Is there a reason why my timing changes wouldn't take on the '99? Looking over the logs, it seems the timing changes only half took on the '00 as well.
I know the low rwhp numbers might be attributed to the weather (it was kinda muggy and MAP was only hitting 94kPa when it usually is 96~97kPa...intake temps were in the 80's...ECT's were in the 190~200's). But, why would these cars be this far down on power on a DynoJet?!?!? I need help as my friends are staring at me like they want answers!!!!
BTW - Both cars run on OS09381344 and I'm using Personal Scan&Tune V7.3.1 (Build 380).
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