We just got done installing the crank pulley and loaded a updated tune on it.
This weekend I was out and about doing some spirited driving with some friends (458 Italia, RS7 and a GTR) and we were doing some launches.

Came to a stop, mashed foot on brake and let the accelerator rip.

Now, in the past, it would stop itself in the 2500 RPM range and then we could just launch, but not this time.

Now as soon it crosses 2k, it starts to spin the rear tires.

The reason this concerns me is because I am AWD?

Is this something that I need to look in to it or is it because we are simply putting down more power than the car is expecting?

 

I've run into the same problem with my crank pulley/tune. ESC comes in and cuts power when I start to get wheelspin. Happened to me on 2 of 4 runs on a prepped dragstrip also. It's simply just not enough traction with the additional power.

I assume youre running the stock pirellis? I'm going to upgrade to the PS4S eventually to solve this problem, they should add more grip to all four wheels.

Short term, if you turn ESC to TracESC mode, the vehicle will let you spin the tires and won't cut power immediately like when ESC is on full.

 

Also keep in mind the quickest way to launch this car is off idle. The brake torque method just trips the torque limiters in the PCM and cuts power back.

 

Punisher, do you have a V6S, which has Dynamic Launch? Or are you just talking about general launching?

Think the AWD system normally sends most of the power to the rear, until it detect slip.

 

It does this with ESC fully off (long press).
I have upgraded wheels and tires to 20x10 front and 20x12 rear with 275/30 and 305/30 Nitto 555 Gen 2's so I feel like this should not be happening.

I understand more power going down there, but let's just pretend the crank pulley and the tune bumps us to stock V8 AWD Power levels, how come they don't have this issue?

So were slower when we use launch control with TCS off and get the RPM to ~2k on launch? That does not seem right at all.

AWD S with the Dynamic Launch Control.
I know it send power to the rear until it slips, but for a AWD car to do a burn out while trying to launch seems a bit silly.

 

I'd guess that Dynamic Launch is programmed for 380HP, and doesn't work right with more power/torque. I don't use it much, but it's fun when I do.

 

I assumed you had a V8R. Disregard all of my comments as they don't apply to a V6S.

I have no idea why you're getting wheelspin then. That doesn't make a ton of sense.

 

This applies to V8 only I believe. But yes, that is the case on a V8 based on those of us who have done extensive drag racing.

 

Haha!

So, do you think this is a problem to be addressed with the dealer or with the tuner?

 

I don't believe the PCM has any control over the transfercase assembly and clutch actuation, but I don't know jaguar's system well enough to say for sure. I know the AWD Giulia which uses the same transmission doesn't get any requests from the PCM, so based on that I would say this is either a transmission issue or something as a result of the added power not being recognized by the trans. However, I'm not having this problem with ~100 hp over stock, so who knows.

 

You wouldn't. With the V8, you don't have the ability to raise the torque converter lockup speed.



I'm guessing that the fastest way for launching any of these cars is to turn off the DSC entirely and rely on driver skills to sense the limit of traction. That means not using full throttle when using Dynamic Launch on a tuned/pullied V6S.

 

Note under the 'Dynamic Launch' section of this document, all it mentions is that the PCM doesn't drop the torque to do rev matching during shifts, with Dynamic Launch. I've always assumed that it's doing something with the torque converter too, but I've never actually seen documentation that mentions that.
https://www.dropbox.com/s/wskjex70o2...ntrol.pdf?dl=0