Eagle F1 vs SO3's

[stu]

Thought that'd get you attention. 8)

Well, after an amazing piece of good fortune, I've now been able to back to back test the above.

The new tyres (F1's) are 255/30ZR18 Rear and 235/35ZR18 Front and the SO3's were 225/45ZR17 Front and 245/40ZR17 Rear.

Initial impressions are that the F1's have a much softer sidewall, as the tyres felt like they were rolling over more and the car was more stable/slower/less edgy responding to the throttle mid corner. The SO3's definitely have a stronger initial turn in as a result, though the F1's are more stable.

Outright grip? Weather/roads not really good enough to tell, but the rears let go with 3,000 on the tacho from a standing start, so I doubt there's more outright grip.

Ride comfort - considering the reduction in sidewall profile was a revelation on the F1's. Really surprised me and they felt very nice on bumps roads (though again, less 'dynamic' than the SO3's). For the lakes/meanders type roads, the F1's would be my choice as there's less chance to get the best from the SO3's. For the track/next Yorks cruise the SO3 would probably the nod.

Only caveat so far is that I haven't checked the pressures on the F1's yet, so if I find (as I suspect) they're a bit low, I'll report back.

Biggest difference I've noted with the new tyres/wheels was in the reduction of the wheel/tyre weight (second moment of inertia to any engineering types), the car feels about half a second quicker to 60!

So the wheels then, thanks Gary, mate I'm so chuffed. They're amazing;y gorgeous on the silver car. Will post a link to some pictures V soon.

Tip for anyone getting Alipna's with centre cap - use fairy liquid on the rubber seals when re-fitting the centre cap- goes back on a treat. 8)

[stu]

http://www.photobox.co.uk/public/detail ... bum=469049

[garyw]

AWESOME

Check them tyre pressures

[stu]

So the fronts were about 22 and the left rear was 25. Only 1 tyre with a reasonable 30 psi.

Gone for 30 front and 32 rear and that's answered the sloppy sidewall issue, though it still aint nowhere near the same stiffness as the SO3.

Eveything feels better with these pressures and the tramlining compared to the SO3's is amazingly good, especially as the widths have gone up.

Got to admit it, I like them F1's, but I couldn't say they were superior in the dry to the SO3's (feels like they're an intermediate tyre to the SO3's advanced), just loads easier to live with on a big tyred Z!

So, you pays your money and takes your choice.

[bmwstuff]

Will probably get some SO3's next and see what they are like compared to the pilots. I hear its a great difference.

Dan
________
IOLITE VAPORIZER

[stu]

New Pilot is rated by some Journo's as is Pirelli as well as the venerable SO3 & F1, plus Simon S also liked his Toyo Proxes!

Shop around for best deal matey and have fun!

[JohnM]

Does this mean that you're going to be pulling away from me next time Stu

Maybe I'll stand a chance as the extra width will be a little extra wind resistance.

I'm still on those lousy Dunlop 8080s - god knows what I'll be like on the F1s. I'm assuming that it's be like going from the wet to dry

John.

[Jon Miller]

whilst they are a massive improvement over the original pilots as far as handling and traction are concerned one thing really bugs me - Tramlining in a straight line on a less than perfect road (which means most of them in this country!) the car feels like it has a mind of its own, which is unnerving. I have read elsewhere that this is common for brand new SO3s but after 800miles I would have expected them to be settling in by now and they don't seem to be.

Just my experience

Oh 225/50/16s on standard rims BTW

[stu]

As I said, I think the SO3 is a much stiffer construction, so it's not going to get softer and less tramliney with age, but if you run your pressures a little lower (2 or 3 psi) I'd guess you'd see an improvement.

This area is the biggest difference between them and the F1's though, so if you're not enjoying fighting the car, go for F1's, they really did impress with stability (particularly as I went down in profile (255/30ZR18 rear))

If you haven't got a strut brace - get one - it's a revelation

Johm M on sticky tyres? Scary

[easyrider]

Stu, I can't help but set you straight on this!
I am an automotive design engineer and currently design car engines (V8) and I can assure you that there is absolutely NO WAY that you would have any noticable gain in performance (especially 0.5secs) or significant increase in inertia from different tyre/rubber makes/grades whatever..
I think it is all very phsycological!!!
The M produces enough torque and power to rotate lead wheels!
The energy losses in the drive train especially frictional are massive comparred to the tyes!!!

[Nick]

Stu, I can't help but set you straight on this!
I can assure you that there is absolutely NO WAY that you would have any noticable gain in performance from different tyre/rubber

I have seen different tyres run up on a rolling road dynamometer and can assure you there <b>is </b>a difference in BHP produced at the wheels.

[c_w]

Stu, I can't help but set you straight on this!
I am an automotive design engineer and currently design car engines (V8) and I can assure you that there is absolutely NO WAY that you would have any noticable gain in performance (especially 0.5secs) or significant increase in inertia from different tyre/rubber makes/grades whatever..
I think it is all very phsycological!!!
The M produces enough torque and power to rotate lead wheels!
The energy losses in the drive train especially frictional are massive comparred to the tyes!!!

Generally, rotational mass can affect the cars acceleration quite a lot, not to mention the benefits of less unsprung weight.

[stu]

I knew this and couldn't be ar$ed to respond.

['MC' MarkC]

Twas a bit like suggesting a lightweight flywheel doesn't allow the engine speed to rise & fall more quickly:?: