DirtyDaveW

Environment:
Heavy storms all around but not raining in our immediate area at the time I arrived at the track.
Barometric pressure: 29.54
Humidity: 100%
Air temp underhood: 108degres.
Outside temp: 72degrees

The weather forecast strong thunderstorms so I rushed to the track with my tools in the trunk and a full 13 gallons of gas in the tank. The track is 7'ish miles from my house (<Napoleon Dynamite voice>"Luckee.."). There weren't too many cars or bikes there. Perhaps 50 or 60 in total? Fearing the rain could start at any moment and wanting to get at least one time trial, I didn't take my tools or the tub to hold them out of the car. I got out to check the air pressure in my Nitto DR's (275/45/17) and, at 40, I took them down to about 28 psi. Right then, a few sprinkles came down and I cursed, but then it stopped.

In the past, I've just dumped the clutch like I used to on M/T ET streets but these DR's don't like that and either spin or bog. I decided to 'drive' this time and feed the clutch out while keeping the RPM's up. Viola!! I got my first sub 2.0 (1.909) sixty foot since I put on the Turbo! But... shifted to second and it spun so hard, it made me lose my concentration so I tried to clumsily shift to 3rd but went into 5th, let out the clutch, realized my mistake, re-clutched and shifted to 3rd and got the rest of the race right.
I logged the passes. This pass had a lot of knock retard going on.

Results:
Left the line at 3,825 rpm.
Reaction time: .35377
sixty foot...: 1.909
330 foot.....: 5.309
660 foot.....: 8.37053
1/8th MPH....: 87.28
1000 foot ...: 10.696
1/4 mile ET..: 12.57353
1/4 mile MPH.: 121.89

The car felt fine on the way back. Running nice and cool, exhaust burbling. Oil pressure and all other gauges showing normal.

Went back and got in line(hot lapping) and talked to a nice young gent with a new blue GT500. We spoke a bit and he said he was spinning quite a bit tonight. He was there from Kingston area and had several buds with turbo Subarus and a Cobalt SS. Nice guys.

Time for the second pass. As I cleaned off the tires for the next pass, a check engine light came on. I made the pass anyway, deciding to check what it was after the pass since the car felt fine and all gauges were showing the normal readings. Rats... I let out the clutch too quick and I got my normal crap sixty foot, but a better MPH. My best to date with the current setup...

Results:
Left the line at 3,700 rpm.
Reaction time: .33675
sixty foot...: 2.107
330 foot.....: 5.553
660 foot.....: 8.08423
1/8th MPH....: 98.20
1000 foot ...: 10.212
1/4 mile ET..: 11.96798
1/4 mile MPH.: 128.96
Oddly, this pass, though still getting knock retard, only got it in 4th above 4,800 rpms.

Once again, I hotlapped it and went back in line. This time the GT500 guy wanted to race heads up. I said sure. Meanwhile, I checked the DTC and it said it was a low MAP reading. Odd... never had one of those before. I got out, checked the connectors and all and everything seemed to be in place. I cleared the DTC and started the car. No error right away. So the GT500 and myself line up and warm up the tires. Again comes the check engine light as I finish the burn out of the tires. We stage and the lights come down.

Results(GT500):
Reaction time: .53343
sixty foot...: 2.324
330 foot.....: 5.764
660 foot.....: 8.38338
1/8th MPH....: 95.04
1000 foot ...: 10.591
1/4 mile ET..: 12.45491
1/4 mile MPH.: 121.01

Results(ME):
Left the line at 4,775 rpm.
Reaction time: .34377
sixty foot...: 2.090
330 foot.....: 5.338
660 foot.....: 7.95996
1/8th MPH....: 98.94
1000 foot ...: 0.0000 (??!)
1/4 mile ET..: 11.95621
1/4 mile MPH.: 126.03

By the time I got back to the staging lane, a huge crack of lightning spanked the trees not to far away and the announcer told everyone to get out of the stands, "Show's over!"

I had a good time! Keven and Adam Martin from Twisted Synergy were there and they stopped by to say hello. It was great to see him again.

On the way home, though the gauges read normal, the car was running a tad lean and felt a bit weak. I gave her some gas and watched the boost gauge. Hmm... only gets about 2 or 3 psi. Sounds like a coupler has came nearly off or I have a split in one of them. I'll check tomorrow.

DirtyDaveW

Got up this morning and was reviewing my data logs from the 3 passes. I'd mentioned above that I got a DTC for "Low Map Reading". On the first pass, the MAP KPA was 44 at idle. At WOT, it was as high as 104 all the way from 1st gear till about the middle of 3rd gear, then it plummeted to 89, then down to as low as 11, all still at WOT, with the MAF max'd out at 471 and the RPM's at 6,000.

Reviewing the 2nd pass, MAP was ONLY 10 or 11 at WOT and idle. Going out here in a moment to see if the seal around the MAP crapped out. If that's not it, I'll look at the MAP sensor itself.

DirtyDaveW

Found it. The middle wire/pin in the MAP connector had backed out.


I plugged it back in and reinstalled it. Just about to go for a test drive.

DirtyDaveW

I just got back from a test drive (14 psi). I data logged it and found that the MAP KPA was pegged at 104 the whole time I was at WOT (100% TPS). Perfect. I had wondered why in all my past data logs (going back a month or two) the MAP KPA during WOT would vascillate between 104 and 8x and all points in-between. I can now suggest that the connector pin was making erratic contact. That probably also explains why my timing at WOT would go from the desired 2x advance to 41 (instantly introducing a ton of knock retard) for just a nanosecond, then go back to 2x advance.

Kevin Blown 95 TA

Aside from all your excuses and sh*t, 129 mph is really hauling the mail!

Also, with that kind of power, you need something better than a 17" Nitto on the rear if you want to hook up at all, but you probably already know that.

DirtyDaveW

Lol... thanks! A local bud with some fat's n skinnies is going to let me try his setup next week.

RealQuick

Dave, I knew something wasnt right... even your last track outing when you said you trapped 98mph in the 1/8th.

With your old ported stockers and the 4.10's you did 108mph in the 1/8th a couple years ago. With the new heads and 3.55's.... I was expecting 135-140mph traps.

RealQuick

Any plans to get it back out this week?

Kevin Blown 95 TA

no pressure, Dave...

RealQuick

Just to clarify... the 135-140mph is 1/4 mile mph

DirtyDaveW

The forecast is for thunderstorms tomorrow.

LT1-TA

Thing would be well in the tens with a auto!

Sounds like she hauls the mail.

This was on... 14#'s?

DirtyDaveW

THanks! I'm hoping for some much better numbers with the auto as well. I pulled the Vigilante 2800 off the TH350 last night and boxed it up. I'm driving to the UPS store here in an hour to drop it off. It's going to Precision industries for a restall to 4000. When it gets back, I'll swap the trannys and then we'll see how she does.

Yes, 14.x psi. I have a significant exhaust leak at the drivers side (if not both sides) header flange. I'm losing some pressure for the hot side there. It sounds like when I was Naturally Aspirated with long tube headers and part of the header gasket blew out. Embarrassing to drive in traffic. Sounds like a farm truck.

The rain and clouds stopped long enough that I could go back to the track last night. Right behind me in Tech line was a new GTR. I walked back and complemented him on the car. It was beautiful. I heard the tech guy ask him what the car turned. I snickered when he said "I don't know" and the tech guy said, "You need a helmet for anything quicker than a 14 second pass" and the guy shrugged. I was behind him in the staging lanes and saw him make a 10.xx pass at 130mph. They kicked him off the track after that. Lol... No helmet, no cage, no racing for you!

My exhaust leak was so bad, I couldn't get more than 11 psi so the best pass of the two was the first one(11.9 @ 126mph w/2.xx sixty foot). It felt rather weak thru 1st gear but the rest it felt decent. The exhaust leak was worse after that. On my second pass, just like last week, I rev'd up the RPM's then popped the clutch and the car/engine went into some kind of mode where it felt soooo sluggish. My wifes 11 year old beater Dodge Van performs better. It was so lethargic, I floored the gas pedal and pushed the clutch in to let it rev up and popped the clutch again. Still turtle slow... WTH? I shift to second and it's still taking it's time. Same with the 1st half of 3rd gear. Suddenly in the 2nd half of third gear, it was as if I'd hit a N20 button and the car took off strongly and all the way thru fourth gear.
To clarify the difference between pass 1 and pass 2's 1/8th MPH...
Pass one 1/8th mile MPH: 96
Pass two 1/8th mile MPH: 88


I was running only fresh VP race fuel so it's not experiencing 'real' knock but I suspect from my logs it's getting tons of frequent 'false knock' from exhaust or rockers or something. I'm going to get a second KS and hook it up to the harness connector but the other side that screws into the block? I'm going to just ground it via a wire and see what that does.

I'm going to replace the header gasket today too and pull my plugs for a visual.

RealQuick

Dave, you should see if you can make a few dyno pulls once you get the gasket leak fixed.

DirtyDaveW

Hey Jon. I would like to but I've been out of work for a little over 2 months. Been coasting on savings so far, so I don't have the $140 the local dyno shop is requesting.

Got the gasket fixed today. I bought a couple of long 3/8" bolts and was going to cut the head off them and use them on the front and rear bolt holes to keep the hotside aligned and, after removing all the other bolts, allow me to slide the hotside outward and swap the header gasket. Using my cutting wheel on my 4.5" angle grinder to cut the bolt heads off, I found that the cutting wheel cuts both bolt heads and thumbnails with equal efficiency. Lol... I now have a small bloody coin slot in the top of my left thumbnail. I had the bolt in a pair of vice grips but my thumb got a bit too close and it was getting ripped open before you know it. Ah well...

How's your car coming along? Hope you're making progress.

I'm going to program out all the knock tables since I'm using race gas and the Wideband shows I'm running 11.x to 12.x during WOT. I think my intermediate pipe is clanging on the second brace (the thin one after the trans X-member) since it's like this ' ' close and that's causing the false knock. If I hit WOT from a roll, I never get this anemic performace I get when I dump the clutch at high RPM's. And, in 3rd and 4th at WOT, it runs like a raped ape. If it were real knock, it would reveal itself there while the turbo load is the highest.

I pulled my plugs and they look perfect. A light tan. If the weather isn't vile tomorrow, I'll throw my hand held fuel pressure gauge on the schrader valve, tape it to my window, fire up the logger and take her for a couple of test passes on the highway.