Ok, armed with multiple passes, I have results that are...well...underwhelming.

Car: 2012 XKR, tune w/pulley on MT drag radials.

1st pass ever, all stock, Dunlop street tires. Weather was great, no correction factor.

60 1.871
330 5.257
1/8 7.975
mph 90.95
1000 10.291
1/4 12.253
mph 115.67

Eurocharged on Drag Radials, DA 1102

60 1.882
330 5.288
1/8 8.023
mph 90.34
1000 10.334
1/4 12.311
mph 114.74
Corrects to 12.278 @ 115.063

ETG on Drag Radials, DA 2402

60 1.761
330 5.179
1/8 7.933
mph 89.62
1000 10.268
1/4 12.254
mph 114.00
Corrects to 12.121 @ 115.21


I'm giving the ETG tune another shot in a week or so when it's not blazing hot and humid outside to be fair. But do I think it will pick up 5+mph like it should if it's making 60 real world rwhp? No, I don't.

A few things all this data means to me:

1) None of these tunes (so far) will top end like the car does stock, end of story.

2) The EC tune was dead repeatable, car would run 12.3x @ 114.7 - 114.9 back to back.

3) The ETG tune, is def hitting the tire harder. I launched the car exactly the same as all previous passes and it was belting out 1.75-1.76 60' back to back...but would just fall on its face on the big end. I can attribute that to heat soak and the awful weather. But even corrected, no dice. And I would be SHOCKED if it starts trapping 120mph when the weather is cooler.


A few interested things though:

Best launch is to just punch it off idle - NO brake torque.
On a sticky tire the car will 0-60 is 4.02-4.04sec.


I'm passing the baton on my friend Mr. BigCat09 who has seen dyno results...he should trap 117mph minimum if his car is seeing the gains all the way down the track.

I'll be back at the track in a week or so.

 

Bummer!

Still, thanks for the great info and descriptions. It would be interesting to see the dyno results back to back with the track results. I would definitely expect more, too, from a 60 RWHP increase. Something does not add up.

Albert

 

Those are good times, but I'm surprised you're not trapping in the 120's with the tune and drag radials. I've seen published 1/4 mi times for Xkr-s range from 11.8-12.2 with traps of 120-122. I wonder if they have this car way underrated at 550 hp. The only real world example I have with my car is a roll from 20mph to low 100's against my friends 2011 Porsche 997 turbo PDk - we were even. I think your car would do much better from a roll due to it's relative heavy weight and traction issues (and no launch control)

 

Do you know the environmentals (i.e. temp/pressure/humidity/elevation), also was there any difference in weight (i.e. full or empty tank)?
60 rwhp more should have shown, so something is odd here.

 

Let's assume for a moment that the ECUTG is in fact stronger than the first tune. The heat could cause a substantial drop in power if the ECU/TCU was responding by reducing boost and/or pulling timing, as opposed to the heat simply over-whelming the intercooler and reducing the air's density. I mention the TCU because I'm wondering if the combination of temps and the drag radial's much higher grip is putting enough extra load on the tranny to cause the TCU to trigger an ECU power cut.

The way to tell would be to data-log through the OBD port and monitor boost pressure and ignition advance during your runs. You could also monitor intake air temps to see if they're going crazy, but with an air to water intercooler that shouldn't be the case... unless it's stupid hot out again.

This may help determine what's happening, and hopefully lead to a solution.

Bruce

 

Yeah, I do know the environmentals, I used all of that when I added the "corrects to" ET and mph.

Don't get me wrong, the bone stock ET and trap were in perfect conditions. Great temps, low humidity. And the latest runs with the ETG tune was with the worst conditions.

Elevation (actual) was the same, same race track...even the same lane


Bruce - crap, excellent point. I threw in a correction factor based on the DA at the track each day. However, I'm sure the ECU/TCU were still having a field day with the awful weather conditions. That was most apparent in subsequent passes thursday night when the car was only trapping 112!! So, yeah, I suppose the ECU might be putting an end to the fun in 90F weather.

As for the TCU - well, that became apparent when I tried to brake torque the launch and got a worse 60' and ET. Best method was to simply floor it off idle and get a 1.75 60' - an animal for the first 330'

My logworks datalogger is giving me serious issues, but I'll try to sort that out and have it all logged next time at the track....when it's about 20deg cooler
out.

May have to work in methanol injection.

Jay

 

Jay: I will hit E-Town Tuesday evening as its the monthly free cruise night and we get a free pass down the track. If your able to come you shpuld check it out as it is a huge show with a burnout contest, rock crawlers, car and truck,bike show, and other good times. It is the first tuesday of each month. Then weather permiting I will return on wednesday but" hopefully" using your drag radials for a full comparision versus stock and drag radials.

AVOS/Bruce/All : I have a silly theory, For situations like highway pulls from a roll, dyno sessions, and things alike my car pulls like a raped ape. But from a dig/stop and any other impossing loads the car feels lugged down as the ECU/TCU sees this and invokes the TQ limiters.
So my guess is when the car has a drag wheel setup on it and you stomp it from a stop and it has 100% full traction the car will hold back power. But if the car has stock wheels that slip a bit it lets it run at full power. So no matter what the compensation is giving the same end results in the 1/4 mile times .

My plan this week coming is to get that 1 run in on street tires and log the pass and report back. Then the next day to make 3-4 passes on the drag radials and log each run with only the PID's Bruce and AVOS want to see and report back. This should give us lots of info for our comuninity to see if we are beating a dead horse or not.
For added cooling I was thinking of adding the Killer Chiller = There are 2 10 second Lightnings near me who have it and swear by it.

And for BLower mods I hear these guys have a simple upgrade to the stock unit that yeilds great power = Stiegemeier SnakeBite™ and StreetKing™

 

I have a ETG tune and Mina pulley on my XKR. We will verify it's making power when I race a stock XKR early this week. But the car does feel faster on the street with the mods. At least it feels a bit better.

Props to Jay for blazing a new trail at the drag strip!

 

Def interested in seeing how your car runs. I'm still waiting on new street tires, but shoot me a txt and we can discuss.

My old S65 had torque limiters to protect the transmission, but it had nothing to do with the amount of traction. And as of now, the S65 would absolutely rape my XKR...well, until it had to turn

 

Well, I went to my local tracks cruise night and they gave out 1 free pass to everyone. I decided to do it even knowing how hot it was. I was in S Auto mode with DSC all the way off. But DSC still kicked in when I spun on the launch and it bogged down and then came back to life in second gear. The ET was bad but the MPH showed the HP is there. Next is to go back when its cooler and the track is prepped with some sticky tires and then see what it does.

Click link for timeslip: http://imageshack.us/photo/my-images...190145775.jpg/
http://img208.imageshack.us/img208/6...0190145775.jpg


@:31 seconds you hear the tires break loose and then you hear the car fall on its face. Why is this so if the DSC is OFF ( Held for 11seconds).
A stock 2011 XKR vert went 12.6@113 with a 2.05 60"ft. He used TracDSC and S auto mode. He said he didnt spin at all. Maybe for the hole shot the TracDSC is a good thing to get that grip with less power.

 

Need a new host for that slip But 117mph is moving it out for a car 350ish pounds heavier than the XKR.

OK, so ETG tune is making power...so we can now conclude that one or a combo of the following is going on.

1) The extreme heat when I was there REALLY caused the ecu to pull significant timing.
2) Bill's theory of the car pulling power when it sees full traction & WOT is accurate.
3) My car just sucks and rejected the tune

 

All fixed and I added Vids. Youll notice I deep staged as to get that reaction time I knew I would be sleeping on the light. I also use the Ebrake to hold the car at the line versus using the foot brake so it gets the hit harder. Give it a try and see if you guys like that method. The footbrake leave just doesnt work as the TCU invokes the TQ limiters on the hole shot.

 

Wil try that, when I stage, will it move forwadr at all when i let go of teh brake while it grabs teh ebake?

Heading to NE Dragway on Sat. Morn. Have 200 miles on a fresh set of Hankook EVO12, Also kept teh 18K Dunlop stock incase i needed a pare set... From what i figure, 1st step DSC off sport mode let it shift even though it starts in 2nd? Wil post my slips again...

 

Man, my tires must suck. I can't launch the car from a stop by punching it without lighting up the rear tires. Or just one of the tires since I don't have a LSD.