Hello Jaguar family...

The local track here (Atco) opened up this past Friday night, so I took the f-type to see what's up.

Armed with a set of drag radials and a new tune, I went to hurt some feelings.

Lined up next to a new Camaro with a huge after market blower on it (guy said he was making 750rwhp and it was a stick car). Either he was WAY off on power bragging or (more likely) it can be attributed to trying to drag race a stick. But I walked him to the 1/8, then heard him next to me and for some reason hit the breaks....weird.

Anyway, the f-type went 11.44@124.09 - not bad and an improvement from my old best of 11.69@120. But I really expected a bit deeper into the 11s :/

The breakdown:
60' 1.788
330' 4.909
1/8 7.443 @ 97.67
1000' 9.618
1/4 11.44@124.09

Blew the tires off the next two passes, then hooked and backed that up with an 11.48

I compared this to my old runs and dissected the vbox data, some interesting things.

1) I pulled 1.196 G's - oddly enough that was about one second AFTER I launched the car and at ~14mph?! weird.

2) Check out the attached graph, for that first ~second, it looks like the car bogs and then wakes up. I've always preached that the best way to launch the f-type was to got WOT, just off idle - since the ecu would always seem to deny you ALL fun if you try to really brake torque the car to launch. Maybe I'll have to try and find a happy medium (if possible) - the car hooks hard, but it's making enough power to take advantage of it immediately.

3) My 65-110mph time at the track was SLOWER than my highway pulls!! Talk about a wtf moment. The only thing I can think of is that when manually shifting, I'm shifting 3-4 later than the car does when it's on it's own. I'll verify this Sunday and watch exactly when the car does the shift itself.
At the track 65-110 was 5.51 seconds. When doing a pull on the highway it was routinely 4.9-5.1 seconds.


Trying to go back again this week and try out a few different things....
Jay

 

Well that sends you to the top of the list then

EDIT

Oh wait, you were already there LOL https://www.jaguarforums.com/forum/m...andings-84783/

 

Great time and trap Philly!

It is interesting that I also have a "lag" in power from a dig running the same tune. It takes a while for the power to kick in and it has nothing to do with throttle response based on my logging.

 

Haha - Cambo, I'm everywhere Still shooting for that 10.99...sadly quite a way off though.

cbroth - Thanks brother. Yes, that is interesting, when you see that "lag" in your logs - is it when you basically hook from a launch and the car is playing catch up...so to speak?

I may have to spray it...just a little

Jay

 

Starting to think only you & I care about racing this car! haha.

So, a bit more research today. For the past 2yrs I've been an advocate of Dynamic / Sport mode from a dig and letting the car shift itself and only use the paddle shifters for highway pulls.

Well. Now that I have vbox data...AND assuming you can pull off the 1st two shifts w/o banging the rev limiters. From a dig or from a roll, we're better off manually shifting.

In Dynamic / Sport the car is still only shifting ~6500rpm. When I pull the gears myself, I'm shifting at 7000rpm and it's definitely a sharper / harder shift too.

I'm going back to the track Friday and assuming I can do the 2-3 shift w/o hitting the rev limiter we should see even better times!

Jay

 

Some great runs! Especially backing up your run with a 11.48. Nice.

I sense you've got another tenth or two--even without spray. For one, your 7.443 1/8-mi is suggestive of a strong top end. Since your 65-110 time is slower than your highway pulls, maybe there's something there, shifting-wise as you say. And though your 1.788 60-ft was impressive, there might be a little left there too. What brand of drag radials are your running? How tall, and at what pressure?

Good luck on Friday.

 

Hey, thanks man!

I think you about summed it up. Based on what I'm seeing, I think I can definitely pick up another 2/10 just by shifting myself the entire run. In theory or at least on paper - should pick up even more.

I'm running Mickey Thompson DR's 305/35/19 - 27.8", probably slightly less in reality. So far, I've found they like to be at 20psi cold. I tried 24psi and no dice.

Hope you're right about the 60' times. My plan of attack for Friday is to launch the as I have been (right off idle) and shift the entire pass myself. Once I get that straight, I'll start to play with the launch. At a certain rpm, the car puts an end to the fun when you let off the brake...but perhaps I can find a happy medium.

 

Not sure how many runs you made or how far down you've gone, pressure-wise. You might consider lowering to 18.5-19psi cold if you haven't already.

 

Ok. Dayumm....That is super impressive! Would like to put some DRs on my tank and see what it could do now...

 

Thanks for the info -- keep us posted ---and what tune are you running ? And are you running a pulley ?

 

I'm curious - are you guys power braking the car and getting into the torque converter at all at launch or are you launching at idle?


Also, if you move the shifter into manual mode but don't actually select a gear, won't the tranny manage the shifts itself until you start manually shifting? If so, that means you could launch the car, let the tranny do the first shift (or two) then take over. That'd be useful if you're finding you're hitting the limiter between 1 and 2 when manually shifting.

 

Hey Jay,

I think that the slower times on the Vbox at the track have more to do with heat soak kicking in the protection files than anything. The logs I've done support the dramatic difference in timing and AFR when the car is rolling fast on the road versus multiple runs from a dig. Cooling really seems to make a big difference in power. I would like to try a bit of pre-supercharger water/meth spray to lower IATs, but that won't help temps from a dig at the strip. Hot air is well, hot air, no matter how aggressive the tune, and hot oil/coolant doesn't help either.

I think that a race tune could be crafted to raise limits on protection when running race fuel (MS109) at the track, but the O2 molecules still need to get to the cylinders for the fuel to burn. With that in mind, perhaps a small dry shot of nitrous would help due to more oxygen and the cooling effect of the spray leading to a greater charge density....

 

Allen - def try to sort out some drag radials, it's night and day. I don't even goto the track on street tires.

Frank - I have a Vmax tune on the car. Supposedly I have a pulley on the car too - but based on a few things, I'm not 100% sure the shop actually did it 2yrs ago! ha.

Every pass I've ever made with this car, I'm launching at idle. Every time I've tried to brake torque the car up substantially - it'll let me rev, but then when I let off the brake the car just dies...like it's protecting itself from a hard launch. BUT - maybe I can find something at least a bit past idle.

Mr. cbroth - That could very well be, but either way, shifting manually at the track I'll be able to sqeeze an another 500rpm or so out of each gear. And that 11.44 pass with the 5.51 65-110 time was my very first pass at the track. And I let the car sit there for probably 45min's before that pass...I've been in the turbo world for a long time so I def get the heat soak thing for sure, just not sure it was the culprit this time.

I'd be game for trying some meth spray, I've used that with success racing Supras.

I do have a new thermostat and lower pulley from Vmax that I haven't installed yet. The new thermostat is supposed to help with heat soak and such.

 

Philly -- I too have the v max tune ( which I am very pleased with ) when I got it Bill said that were getting a thermostat which I was going to purchase - now I can't get ahold of him ? ---- would you keep us updated on your opinion about the thermostat ? And any information about it so maybe I can purchase elseware ----- also thanks for the launch info !!!! ------ I previously had a tuned Xfr that was also hard to get a good launch

 

Philly -- sorry 1 more question ? --- what have you found best to do with the traction control for launching ???

 

Yeah, I'm happy with the tune as well. Ever since the Vmax debacle here, they've been a bit (very) difficult to get ahold of. Last I spoke to them was a week ago. I'll absolutely keep you and everyone updated - hope to get it installed this coming weekend.

For me, I turn traction control completely off. As in, holding it down for 10 seconds to fully defeat it. Then I'll do the burnout and launch the car, it'll usually dead hook on drag radials

Jay

 

Hey Jay!
Nice to see a familiar face in this neck of the woods. I've been out of MKIV scene for awhile, other than visiting Frankie (franksupra) and his beast in MD not too long ago. I just recently picked up a 16' R Coupe. Should be interesting to see what I can squeeze out of this Jag . Hopefully a baseline dyno next week and then I'll be doing some R&D.
I moved down to Florida in December... I'm told there's a drag strip over in Gainesville. Looking forward to playing with this.

Ryan

 

Well, holy **** - look at this guy!! Welcome to the club Good luck with that R, these are definitely fun cars and as you know the RWD can be a handful, I need to take one of the new awd cars for a spin.

Funny you should, post...I was just about to update this thread.

I went to Atco again last night and was SURE it would be a bit quicker with me manually shifting and winding out the gears a bit more. No dice, I mean statistically speaking this f'ing thing ran exactly the same as last week with the car shifting.

Did a big burn out and nailed the 60' and nailed each shift - the results:

60' 1.752
330' 4.902
1/8 7.448 @ 97.31
1000' 9.630
1/4 11.462 @ 123.94

Essentially the same as my 11.446 @124.09 pass.

Then despite my better judgement, I tried to stall up the car and launch and it pull 1.82 60' and 11.53 - bleh.

I don't think this thing will go any faster until I get the new crank pulley installed...spray it...something.

Killing me.

 

Interesting on getting the same exact results. It certainly seems to substantiate, as all reviewers and many owners have commented, that the ZF-8 is perfectly programmed to get the most out of the engine.

For most drivers, the fastest way is to let the car do the work and concentrate on going straight. I'm impressed that you were able to nail the same results manually shifting.

 

Hmmm... Perhaps it might be worth looking into a re-stalled converter? If it's the PCM holding it back, maybe it's something locked down in the software? From what I understand, the V6 "S" PCMs (at least overseas) have Dynamic Launch Control as standard. I wonder if the SVR got it? I'll have to reach out to the software guru....

Ryan