Hi all, new here and looking for a little advice. Just picked up a 2020 SVR and I’m finding it struggles a bit traction wise in the dry, 1st 2nd gear 70-80 degrees temperature. I’m no stranger to the F Type had a 2014 V8S and 2017 R and I don’t recall the R having traction issues at all, am I missing something? I’m also used to high horsepower cars (2 Hellcats, 2 RedEyes and multiple others) so I don’t think it’s user error. Any thoughts appreciated.

 

Is it running Pirelli P-Zeros? If so that could be the problem, especially if they are half worn or more.

 

Yup, running P Zeros but less than 3,000 miles on them. I know on the RedEyes the P Zeros were junk but they were trying to cope with 800 bhp and over 700 lbs/ft of torque through 2 275s or 305s. My recollection of my R was no traction issues at all, the TC seems to kick in a lot on the SVR.

 

C an you describe what is happening in more detail. Are you getting slip from standing starts when launching at full pedal depression or something else? 31 degrees here this morning so testing at your temperatures today..

 

I had the same problem. I switched the P-Zeros to other tires and the problem went away entirely. The P-Zeros only had 2,400 miles on them.

 

Car rolling, rolling on tho accelerator quickly, not standing on it in first or second gear I get immediate response followed in a slit second by TC light and power being reduced until traction regained (typical TC intervention) I can live with it, I just remember my R being so much better. Point taken on Pirellis I was thinking this might be the problem, just wanted to see what others were experiencing before Intake it to the dealer to get TC looked or change tyres or lessen traction expectations and drive accordingly.

 

I think I may have jumped to a conclusion too quickly. I never experienced that particular issue.

 

I'll ditto the guess (hard with limited data) to concur on the P (for poopy) Zeros as your cause!

 

Am I correct in thinking that the SVR has a more rear biased awd than the R? If so, coupled with Pirellis Inthink that could be what I’m experiencing. Thanks for the help so far.

 

I thought all F-Types were predominantly rear wheel biased until the car decides it needs a bit of front power to keep it on the road.

 

Yes, it's rear wheel biased, I've seen numerous publications that state 20% of the output can go to each front wheel (i.e. 40% front/60% rear), but I've also seen where they can actually split 50% front/rear (go figure - consistence on the internet?!). If I had to guess the splits are then proportional to the output. So much depends on the actuator authority (e.g. the limited slip rear differential has an 'actuator' that determines the split left to right). How much can the actuator vary the output and are the clutch packs actually limited on how much they will actually transmit per wheel? I've not studied the front to rear bias system - I think it's somehow managed by other actuated clutch packs for each front wheel.

So... my guess (again - not studied) - is that the outputs are proportional.

 

It's WAY rear biased compared to my Audi TT. The TT (quattro) is front biased and shifts power to the rear when slip is detected. I put in WaveTrac diffs front and rear, and can stomp on the power at any time and retain traction. Never a hint of over steer.

With the R, I have now spun three times, all accidently. All three in the wet. All three the rear end power sliding around. I need to get some track time to learn the car and get a feel for the driving dynamics. As it is now, I am actually scared to put the power down!

 

There's a hint there. Huge torque exceeds tire traction in the wet.

As a side note, as I understand the traction control defaults to all torque to the rear tires UNTIL it senses other inputs (like tire spin, yaw, etc.)

 

All AWD F-Types, whether they are Rs, SVRs, or any other models, are biased to 100% RWD. Power is added to the front only when traction is compromised.

 

Here's straight from Jaguar:

"Operating on the torque-on-demand principle, the AWD system sends 100 per cent of the engine's torque to the rear wheels under normal driving conditions. This maintains the F-TYPE's rear-wheel drive handling characteristics and also reduces parasitic losses in the drivetrain.If the system determines that the rear wheels are approaching the limit of available grip the electronically-controlled centre coupling transfers torque to the front axle, improving traction."

https://media.jaguar.com/en-gb/news/...l-transmission

 

Fixed that for them...

Doesn't seem predictive at all to me, all reaction and "too late". But I do have to get the car on the track soon to test that out for sure. I will say my incidents have been in the wet, so harder to control and earlier onset than in the dry.

 

My experience at the track was that when I got past the body roll and started to hit some traction issues, I could feel the car start to pull through. I didn't test it very far as my car is my daily driver and I had to interest in finding the absolute limit.

Like you, though, I have experienced the car completely lose the rear on tight corners at lower speeds with moderate throttle. My instinct was to let off the throttle and steer through it. It may be that adding throttle would pull the car through, but I'm just not that comfortable with the AWD system to try it out. I have not experienced the loss of the rear since switching out the P-Zeros.

 

Couple weeks ago on a dry track, the R understeered, pronounced from corner entry to apex and exacerbated by trail braking however slight, and will still understeer from apex to exit under throttle. It needs to be driven more in a slow, point, then shoot fashion than carry appreciable speed into and through turns. When the track was wet (downpour), understeer was horrible and surprisingly weather mode (50/50 torque split) understeered more than in either normal or dynamic mode. On MPS4. Now looking to pull together a set of 275 and 315 in 19s, and later maybe KW HAS.

 

That Jaguar statement is interesting and I would love it to be true. However, in all AWD F-type dyno videos, front wheels seem to spin as well. That seems contrary to the statement from Jaguar. Maybe there is something else in the play?

 

Maybe it senses the fronts aren't spinning so sends a bit of power forward to get 'em rolling? It doesn't know it's on a dyno!