FAO Emma & other wide rear Ro's

[mikeyb1987]

Quite a specific audience this!

Basically, I'm curious as to what other peoples thoughts are (who have wider rear tyres on Monaros) as to how it has changed the handling balance. I seem to have picked up a bit of understeer when swapping to VXR8 wheels.

My fronts (Michelin Pilot Sport 2) need changing as the tread depth is low. The rears are 265 MPSS, with loads of tread. I'm trying to work out whether new tyres would cure all of the understeer, or whether a stiffer rear ARB is necessary. Pre-R8 wheels, the balance was more neutral.

The reason for FAO Emma is she has wider rears and is a fast and competent driver- I'm unsure of who has wider rears and pushes it in the corners

TIA

[SturdyHSV]

PS2s are crap compared to PSS, so I'd get some decent tyres up front before deciding.

It's something that has played on my mind a bit too going to wider rears, the old lump has a nice balance at the moment, and would prefer a grippy nose to a grippy rear in the corners...

[Xpuffin]

I'm running Bridgestone Potenza R050A (99Y) 285/35/19.
The car handles superbly on fast sweeping corners. Grip wise though not the best unless they are warm.

[007 VXR]

245(front) 285(rears)
VXR Monaro on MPSS no issues, and grip like S***

[S800VXR]

MPSSwill solve yr issues. Run them on the R8 now and they stick like st to stick, best handling upgrade I've done really..... After the Pedders kit.

[bigunit00]

S800VXR said:

MPSSwill solve yr issues. Run them on the R8 now and they stick like st to stick, best handling upgrade I've done really..... After the Pedders kit.

How much for a set out of interest?

[007 VXR]

bigunit00 said:

How much for a set out of interest?

about £900 but well worth it

[mikeyb1987]

Spot on, cheers guys- I'll get the MPSS fronts and see if that re-dresses the balance

[mikeyb1987]

SturdyHSV said:

PS2s are crap compared to PSS, so I'd get some decent tyres up front before deciding.

It's something that has played on my mind a bit too going to wider rears, the old lump has a nice balance at the moment, and would prefer a grippy nose to a grippy rear in the corners...

It was something that played on my mind too, but (assuming I can resolve the understeer issue) I wouldn't look back.

I went for a drive up Hartside, which is a Mecca for bikes up here. Rear grip is absolute unless provoked. I had a quick play with a Yam R6 and could hit the power hard in 2nd, mid corner, and not be fearful of waywardness.

The only thing wrong with R8 wheels is the weight

[EmmaJ]

Still find my pushes wide first even with MPSS on the front if I progressively feed in the power coming out of 1st or 2nd gear corners unless I'm lairy with the loud pedal in which case you can have it as sideways as you like

FYI I've switched back to stock VXR rears and 245 MPSS tyres and still have a understeer bias when cornering hard with a neutral throttle. That's with RRP, REP and pedder dampers on standard springs. I'm toying with the idea of switching out the standard springs and putting on the the low pedder springs (not the ultra low) and having a bit more camber dialled in to offer up a bit more traction. Hopefully as well as putting more rubber on the road under WOT it will also further sharpen up the handling but I'm not expecting miracles ....

Unfortunately given the offset on my OZ wheels it's not possible to lower the car and continue to use them without a major rework of the rear arches and if I'm going to do that I'd want more than a 265 tyre....

[Black VXR]

Understeer is normal with a road based setup. You could consider having the car set up more aggressively for track use and it would change this bias round, however your tyres would last half as long on the front

[mikeyb1987]

Thanks for the insight Emma. It appears that I should look to change the rear ARB too, as well as fitting MPSS' to the fronts.

For info, I'm running pedders dampers and springs, with the RRP.

[Xpuffin]

mikeyb1987 said:

Thanks for the insight Emma. It appears that I should look to change the rear ARB too, as well as fitting MPSS' to the fronts.

For info, I'm running pedders dampers and springs, with the RRP.

Change one thing at a time. The ro's are very sensitive to both tyre and suspension changes.
If you dial out the under steer you may very well end up with an unforgiving car on the limits.
Of course it's all very dependant on your level of skill but for me its desirable to have that under steer. There's always trail braking, cheaper.

Edited by Xpuffin on Sunday 6th July 13:39

[mikeyb1987]

Naturally, I will change the tyres first, and go from there.

I agree with you- understeer at the limit is more forgiving and probably reflective of my level of driving skill, but it's more the level at which the understeer occurs, which is too low at the moment

[SturdyHSV]

mikeyb1987 said:

Thanks for the insight Emma. It appears that I should look to change the rear ARB too, as well as fitting MPSS' to the fronts.

For info, I'm running pedders dampers and springs, with the RRP.

I'm running the following:

245/35 PSS all round
RRP
REP
Quick rack
Upgraded dampers (from the 'fish)
Stock springs
Thicker rear anti roll bar (standard up front)
TrueTrac w/ harrop diff cover

Weight distribution with a full tank and no driver was about 52:48

I'm very happy with how the car handles, the ride is suitable for our crap roads, although can be a bit jiggly side to side at low speeds over really crap sections (hardly surprising!)

I'm not one to regularly push the car nearer the limits at high speed, but as and when the situation arises, I find it's reasonably neutral, it's fairly easy to balance on the point of understeer / neutrality with steering input, whether it's just my small wheel but I think the 'understeer' in my case is often just perhaps me 'over steering' a bit and then asking too much of the fronts, and that a little less lock allows them to work better...

It would require a bit more commitment from me to get a decent understanding of though I'd say, but so far from my experience the 'on limit' (by which I probably mean 'near limit') handling the car tends to sit itself in a position whereby more lock gives you understeer and more right foot gives you oversteer.

Overall I think I drive it accepting that it's not a 'darty' car, so no finger tip flicking it into a corner, but trying to give it smooth inputs to keep it settled and I find it a pleasingly good natured beasty

EDIT:

Just to add, I'd assume I'm by no means an exceptional driver, I've just played driving sims for probably 15 years, and I'm quite analytical, so I like to try and think about what it's doing etc. and understand it as best I can