Well, I went to the track last night. I had only made it out once before this season, and I had a terrible night then too. Last night wasn't as bad, but it was really disappointing.

Why you ask? Well, I added an ECU tune, intake manifolds, a supercooler, and a set of ET Streets and I'm going SLOWER than last season. WTF?!?

It's very frustrating. Last season, my best was 12.7 @ 110 mph. What was my best last night? 12.8 @ 109! I even had a couple 13 second runs!

Before Cruzin asks: the DA was between 2,000 and 2,500, which isn't bad, but isn't great either. The DA for my 12.7 last year was only 1500, which better, but not incredible.

 

Tom have you gained weight?.........................Just kidding buddy.

 

LMAO........

 

Maybe the track wasn't prepped as well as it was last time. Does it feel faster?

 

Need more to go on... Assuming there isn't something wrong with the car from the installation of the new parts.

The time slips from the before and after, and also how many runs. If the car has much more power from being modified it could be all traction related, even with the slicks. What size are the slicks, are they taller and you lost gear? How experienced of a driver are you at the track?

The MPH is rather low no matter what, which does point to me something is amiss with the car.

 

Are you data logging your runs? It will make you wince to see what the computer is doing. Im sure I'm making more power with my new mods because of the loss of traction over 5,000 rpm's in first and second. But because of traction loss the computer is pulling timing, closing the throttle body and shifting way before redline. Ugh. With the ET street radials I doubt your slipping, but the data logs will point you in the right direction as to why you slowed down. Perhaps your suffering knock retard throughout the rpm range? Does the computer need time to "adapt" to the new tune? Did the wife of girlfriend fill up with regular?

Les

 

Tom, we need to get together, maybe you should come up to my place and we'll go the 30th to US41 and see what's going on...trouble is getting the slicks to my house....pm me to see if something can be worked out buddy, this isn't right...

 

Thanks guys. I appreciate the feedback. I'm rather dismayed. I posted a couple weeks ago, when I had a terrible night at the track, but I can blame that all on traction. My Sumitomo street tires were spinning like crazy.

However, now that I've got the ET Streets on the car, I was getting no spin that I could tell at all. I wish I had someone at the track to video my runs, but I don't. Anyway, I logged 3 of my 4 runs. I'll upload the logs. Since the forum doesn't allow .CSV uploads, I renamed them .TXT. Rename them back so you can open them in Excel.

I left my slips out in the car, and I'm feeling too lazy to go get them right now. I'll post them up tomorrow.

To answer some of the questions:

• No, I'm not a very experienced drag racer. I raced last season, and even then I bailed out in August. It was just too hot and my allergies were kicking my butt.
• The parts might be installed wrong. I'm not professional mechanic, but I did have experienced mechanical people assist with all of the installs.
• I'm getting the P0505 check engine light almost every time I drive the car. So maybe my throttle is behaving.
• The slicks are almost exactly the same diameter as the stock tires. (Mickey Thompson ET Streets - non-radial version, 26" by 10.50" by 16" (26 diameter for 16" wheels, I don't know what the 10.50 is because the MT site says the tread is 8.4" wide)
• My tune is about 6 weeks old, with a trip to the Dragon and to Detroit under its belt. So I think the ECU has adapted.
• The track prep on Friday nights where I race is usually non-existent. But I wasn't feeling any tire spin - maybe a tiny bit on my last run, but I forgot to turn on the data logger on that run.
• Knock retard? I don't know how to tell that.
• Does it feel faster? Yes, it does, but I'm not seeing better numbers. It's strange.
• Did I gain weight? Yes, I've got too many socks in the trunk!

 

I only looked at the first log but your car is shifting from first to second gear at 5000 rpm. Second to third at 5500 rpm and third to fourth at 5975 rpm or 108 mph.
The 1-2 shift is real early. 2-3 is shifting early too. Why its shifting early I don't know, but you can't go faster if the car is shifting short of full power. Also the throttle position is 100% on the 1-2 shift but the computer is closing the throttle to 43% on the 2-3 and keeping it there for 10 mph. I'm seeing slightly more boost than you (Code 3) but your not reaching full boost because the car is shifting early.

My logs show a similar problem. My 1-2 is at 5500. 2-3 shifts early if the tires are loosing traction, 5500 rpm and with traction at 6050 rpm. I haven't been to the track so I don't have the 3-4 shift logged. I'm only seeing the closing of the throttle by the computer on the 1-2 shift (46%)

From what little I've seen, the car short shifts when the tires start loosing traction. I think your overpowering the tires somehow. Did they get wet? If they did and you didn't dry them during the burnout that could be the problem. AFR and spark advance on your log looks OK to me. The tune on your car has 3 to 4º more spark advance than my car. I'm going to do an experiment tomorrow. First, accelerate easy to redline to see where it shifts without full throttle. (take traction control out the scenario) Depending on what happens I'm thinking of pulling fuse 17 and 18 to see if the car goes to redline in first and second gear before shifting at full throttle. We are suffering (or benefiting against our will) from the computers self preservation programming.

Les

 

The last run your car shifted 1-2 at 4400 rpm. Shifted early 2-3 too. 3-4 was at redline. The computer is seeing something it doesn't like.

Les

 

Nice catch, yes it does look like your car is shifting early. Mine goes all the way to 6250 on each gear. Are you letting it shift by itself or you shifting? Also the DA of that much difference makes a huge difference. Post up both slips and I'll narrow it down to the tenth for you. At least you can see what both times averaged to and see the real gain or loss.

Edit: I guessed a few things to get you some numbers. Your first time out last year was around 6:50pm and corrected to 12.697 @ 111.25 (1500 DA). On friday I used the same time 6:50pm and it corrected your run to 12.696 @ 109.86 (2000 DA). Just ballparking with Thompson Raceway in Ohio? Used a base 12.80 with 109. That puts you about the same exact time but in 500' DA worst. Comparing splits between the 2 slips will give you more info where your gaining or losing. Splits are the time differences for each foot measurement, ex. 60', 330', 660', etc..

 

Bring her to IN Tom, we'll fix it or blow it up...but, like they said, if she is short shifting whether its you or the car, that is a big problem...my tune lets me go to 6200, maybe 6250...so take her out on a lonely road this evening, and do a few hole shots, just like we did in mine at the Dragon...just play with the burn outs to see if what the others are seeing is truely happening...if it is, that is a problem...we can work on your style, but the car has to cooperate...

 

Do as Doc suggests and do some runs in the boonies. I did some experiments already today. I accelerated calmly in first (manual mode of course) and the car shifted around 6000 rpm. A bit later I found myself in front on an on ramp and did the same up to 80mph and the 1-2 and 2-3 shifts occurred at 6000, or there about, just like it should. Then I went to my favorite on ramp where I can wait until no one is around and did a full throttle pull to 85. The tires broke loose in 1rst, the car short shifted to 2nd and then they lost traction again in 2nd and the car shifted early to 3rd. I logged all of this but it's not on the memory chip and neither are my other 20 logs. I don't know what could have happened.

Anyway Tom, traction control is intervening. No doubt at all in my mind. What has me puzzled is with the Micky Thompson's how can you be loosing traction? How much air are you running in them?

Les

 

Well, I didn't get any time to play with the car today - school work is a drag.

For each of those runs, I put the car in 1 and let it shift for me. I never shift on my own at the track. With these cars, there isn't much point to it, as you want it to run to redline anyway.

Nice catch on the short shifting. I didn't notice it while I was making those runs, but that would explain some of the problem. I really don't think I was slipping though. Those ET Streets seemed to stick like glue. I warmed them up until I saw smoke in the rear view, so they shouldn't have been wet from the water box. I was running 18 lbs of tire pressure on the first run, and then dropped to 16 lbs for the second and third. When I looked at the tires after the runs it seemed like I was riding on the centers of the tires (the edges of the tread weren't worn - a friend at the track caught that and recommended I drop a couple more lbs.)

 

are you driving through the water box or are you going around and backing up to it? if you run through it your dragging the water from the front tires all the way to the staging. which would create some crappy traction on your launch.

 

For those that asked, here's my time slips. As you can see, I was re-learning how to launch with the ET Streets. My first launch was mild and I was just testing it out. I got a little more aggressive each time. I don't know what happened to the third launch, as it was worse than the second. By the fourth I was starting to get back to 60' times that I'm used to. So I know there's more room to learn and improve here. If some of these guys can get 1.7 60' times on street tires, I should be able to get that on ET Streets.

The waterbox at this track is pretty unavoidable. You have to drive through it, so your front tires will pick up a small amount of water. Even so, that's been the case at this track and shouldn't make that much difference now.

 

Ok thanks for the slips. I used the 12.81 @ 109.02 for the DA and split comparison. Unfortunately at 9:45pm your DA was corrected to 1445'. Which is fantastic, only about 50' better than your other run. Before getting into detail of your splits, you ran at two different tracks with very similiar corrected DA. Quaker City Raceway will be the faster track for sure, depending on track prep. In the 12's with Mickey's tire slip is non existent. Your run corrected came to 12.751 @ 109.549. So you actually slowed down.
To understand your split times each with a negative is where you actually gained from your previous best run, the positives are where you slowed.

Splits 60' -.0151, 330' -.007, 1/8' + .0042, 1000' - .0403 1/4 mile + .0491
So you gained all the way to the 1/8th slowed there then gained at the 1000' then slowed at the quarter. I have to guess at the 1000' you were in 3rd shifting to 4th. I'm still waiting for a converter of .csv to .zto files so I can see your charts a little better. From your times it appears your car is letting up and then getting back in it. Possibly timing being pulled by your ecu? I don't see you spinning tires at that speed especially with drag radials. That's not possible and your not spinning off the line either. Another possible scenario is belt slip, maybe the pulley can't handle the extra power. Crank pullies don't slip much if any at all, so we don't even factor that in. My power is mid to top end and with that DA I'd be mid 11.8's. I would check the belt slip first. Good luck. BTW Quaker City is 955' above sea level and has a compulink system which is one of the most accurate timing systems around. Not sure what Thompson has.

 

I didn't consider belt slip. I always enjoy your analysis cruzinquick. Do you think belt slip would cause an early shift? Tom's car is shifting at the correct rpm from third to fourth. The early shifts are occurring on the 1-2 and 2-3 shifts. Are the faster climbing revs in the lower gears more prone to belt slippage? Would it empower the traction control to intervene if the belt started slipping badly? I ask because I'm seeing similar data logs as Tom's. I'm thinking of unplugging fuses 17 and 18 as an experiment to see if I can eliminate traction control as the cause.

Oh, I took my car out and leisurely accelerated in manual mode through the 1-2 and 2-3 and the car shifted at redline. So something is causing traction control to take over on the full throttle runs; for both Tom and myself. (I have a Code 3 too) How hot should the belt get? After a run I can't hold the belt, it's too hot. It never occurred to me to hold the stock belt so I don't know if its hot from slipping or if the temperature is normal for the belt on our cars. I don't see any obvious signs of slipping. Just thinking out loud. If we can trouble shoot for Tom it will possibly help others too. (like me!)

Les

 

I don't see the belt slip on the 1-2 shift or even mid 2nd gear because of his 60' and 330' times. He's actually pulling harder on those than his previous best time. If it is belt slip it seems to happen midrange and only for a split second. I also don't see traction control kicking in with mickey thompson drag radials at the 1/8th mile marker where he's slowing down, then picking back up. My traction control has only kicked in maybe once or twice with my hoosiers good or bad track conditions and that's only at launch. Once I felt a little tire spin shifting from 3rd to 4th but not enough to kick the traction control in. Just enough to put a little fear in me.

I'm sorry I can't help more on the code 3 pulley. I have never tested one. I replaced my belt at 1k miles and 4k later still looks new. The belt is going to be hot, but to accurately report if it's getting hotter than normal a heat gun reading would have to be done before and after your runs.

 

Honestly, I don't think the belt is slipping. But thinking and knowing are 2 different things. I'll keep thinking and trying new experiments to try and isolate the what and why. Discovery will come sooner or later. Sooner is better of course. Tom, get over to see Oledoc2u. I'll bet he can figure it out.

Les