2015 F Type R Handling Issues

[oilydan]

Hi all.

After a couple of years in an XFR back in 2010 I find myself back to a Jaag, of the F Type R variety.

Under hard accelleration I found the rear a little squirmy. Not due to traction issues, but felt like one side diving on gearchanges and if finding little bumps causing side to side wobble that warrants backing off to stabilise and avoid ending up shiny side down.

My recent service ended up costing a fortune in 'bushes', which meant changing a whole load of parts as the bushes are integral. I'm just out of warranty period so went to my trusted indy.

Rear lower control arms.
Upper control arms.
Lower big arm
Lower control arm straight
Lower arm bushes RH
Rear stabilser link
Wheel Balancing
Transaxle Mount

To the tune of around 3k GBP (inc service).

The problem is that it still feels a little unstable, not as much, but still a little. Not as much on gear changes, but cats eyes cause a little wobble at motorway speeds.

The garage tells me that the rear tyres fitted may be iffy (fitted 305 30 20 rather than the standard 295 30 20). Would this cause a wobble?

I dont want to change the tyres with 50% life still in them and not solve the issue, I'm doing my best to wear them out quickly but fear that it will put me into a hedge if I keep pressing it.

If it makes any diffence I'm in the UAE so fuel is cheap enough to warrant lairy activity to force a change in rubber. I guess it is the heat here that has ruined the bushes?

Anyone else found themselves in a twerking Jag?

[anonymous-user]

I wouldn’t have thought a 10mm wider tyre would make much difference but are they a decent make, do they match with the fronts?

I would have thought that if the suspension’s been sorted, it’s a tyre issue of some sort.

[The Bodyman]

REALIST123 said:

I wouldn’t have thought a 10mm wider tyre would make much difference but are they a decent make, do they match with the fronts?

I would have thought that if the suspension’s been sorted, it’s a tyre issue of some sort.

Agree with this.

What brand of tyres do you have?

[oilydan]

P-Zeros all-round.

With a decent amount of tread left on them.

[Summit_Detailing]

4-wheel alignment done after all your recent work?

Cheers,

Chris

[oilydan]

Summit_Detailing said:

4-wheel alignment done after all your recent work?

Cheers,

Chris

Yes, alignment and balancing.

[The Bodyman]

oilydan said:

P-Zeros all-round.

With a decent amount of tread left on them.

I changed mine on my F type R (don't have it now) for Michelin's sport 4 S. Got a set of Michelin's for £900 fitted. Sold the stock P-Zeros for £250. Made such a big difference to the car.

[anonymous-user]

The Bodyman said:

oilydan said:

P-Zeros all-round.

With a decent amount of tread left on them.

I changed mine on my F type R (don't have it now) for Michelin's sport 4 S. Got a set of Michelin's for £900 fitted. Sold the stock P-Zeros for £250. Made such a big difference to the car.

I can well imagine that to be a solution. I had a 911 which came on P Zero Rosso. They were all changed when the rears were worn, at about 10k, for Michelins which were much more grippy.

[fatboy b]

oilydan said:

P-Zeros all-round.

With a decent amount of tread left on them.

P-zeros on Jags are excellent tyres - for the first 1mm of tread wear. Then they become a fking liability. As above, MPS4Ss are your friend. I have them on the Jag, and I recently ditched half-worn Primacys on the Cooper S for MPS4S too. They transform a car’s handling.

[oilydan]

fatboy b said:

...Then they become a fking liability...

In what way? A wibbly wobbly world of their own, or just in terms of grip?

I dont lose traction, just has a load of sideways movement over bumps, like tramlining.

[Stedman]

Tyres may have worn in a funny way due to bushes. After fk loads of similar work to my XJR over the last 18 months it still wasn't right. Managed to try it with another set of wheels and brand new tyres and it was much much better (although now bang on the money...sigh).

Are you able to swap wheels and see how it is after that?

[The Bodyman]

oilydan said:

In what way? A wibbly wobbly world of their own, or just in terms of grip?

I dont lose traction, just has a load of sideways movement over bumps, like tramlining.

That could be yours tyres. They will do that even with tread.

[fatboy b]

oilydan said:

fatboy b said:

...Then they become a fking liability...

In what way? A wibbly wobbly world of their own, or just in terms of grip?

I dont lose traction, just has a load of sideways movement over bumps, like tramlining.

Grip, or lack of it.

The road camber can make the car feel weird under hard acceleration too. I’ve just replaced my rears after 20k miles. The old ones were on about 3mm. While they were still way better then part-worn p-zeros, the new ones are amazing again. The old ones used to squirm a bit under hard acceleration this time of year in the uk in the dry. But in the warm they’re great. The p-zeros never really felt right.