Going in for camber adjustment tomorrow

techathy said:
With air temps at just above freezing, surface temp in the 1-2c range & cold tyres times were never going to good.
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If the tyres were cold (especially the RFT) then it's probably better than expected- probably a lot of wheel spin then?
 
Garvin said:
Stuart, reading through your last post again I would make some further comments:

Heavy footed : No matter what the tyres/road surface, a car of this weight and torque will spin the rear wheels if you just put pedal to the metal from the off in first gear!

Road surface: With surfaces as you describe (slippery under foot) then the above comment is accentuated and will easily extend to gears two and three.

LSD : This can make a difference in straight line acceleration but it can't redefine the laws of physics and create more grip where none exists - it will though stabilise the car more if one wheel gives up before the other and maximise the grip available. It can, and should, make a significant difference in cornering ability where it will stabilise the car when the lighter loaded inner wheel gives up traction. It should prevent the inner wheel spinning all the drive away resulting in a drop of drive to the loaded outer wheel, deceleration, weight transfer back to front and the resulting reduction in grip of the outer wheel and the usual lift off oversteer scenario (even if you haven't lifted off the throttle) which the stability control then has to intervene in order to prevent an unscheduled visit to the scenery. However, if the stability electrickery is too intrusive it can 'trigger' early even with the LSD fitted. I would contend though that with the ESP switched off things should be much better. It is always best to take advice first from someone like Birds who will have tested and, hopefully, matched their LSD dynamics to the car.

35is over-engined for chassis : I have some sympathy with your dad's view as I think it is marginal which is why I always advise against mapping a 35is for more power before first making mechanical (LSD, suspension etc.) changes. In stock trim I just can't see the extra power being remotely useable.

Finally, if the road surfaces are as dire as you state then perhaps some road legal track oriented rubber is the way to go - expensive and they can wear out very, very quickly!
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Yes you are right, I probably need to re-adjust my expectations because the only way to get a truely clean getaway is in ideal situations, which most normal roads are not. Birds have the LSD for the 35iS, you've sold me on it now :thumbsup:

You may like this article: http://www.birdsauto.com/editorial/editorial-bmwcar-sharpening-zed-e89-z4-35is-dec-2012
 
Did you see Birds are offering Alpina maps for our cars too?

http://www.birdsauto.com/parts/L8912895400

B4-3.5s Engine Management, 400ps

Bit expensive considering what I can do with MHD, but interesting nonetheless !
 
Garvin, The RS3 are going up against the likes of the Pirelli Cinturato P7, Michelin PS2, Conti Premium Contact. Uniroyal don't do a VHP tyre.

stuartinzg, I'd say about where I'd expect them to be, the surface was clean & dry.

I thought the B4-3.5s included uprated engine internals?
 
techathy said:
Garvin, The RS3 are going up against the likes of the Pirelli Cinturato P7, Michelin PS2, Conti Premium Contact. Uniroyal don't do a VHP tyre.

stuartinzg, I'd say about where I'd expect them to be, the surface was clean & dry.

I thought the B4-3.5s included uprated engine internals?
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I'm not sure what internals you'd need, the N54 can put out a lot more than 400 - but bolt on bits perhaps. It's on their site, so not sure what they offer as part of that, just a flash I would expect.
 
All this over some tyres I agree with Garvin somewhere between 34f-38r will be perfect u need to adjust to your needs as each brand tyre reacts and feels different to another ruuning with say the same psi.

also u replied to my suggestion about using a box setup something ive used on my e46's past 10yrs and now the z4 running 8.5j all round all cars handled perfect, one stock, one on coilovers and 2 with eibach suspension setup. Running alloys same width will give more stability and less tramlining from having narrower fronts. The reason a box setup is used for some track use is for those reasons. Im not sure where your getting you will have less traction. Not all bmw's come with wider rears infact in bad weather wider rears will cause u more problems than narrower or box setup. Another thing to consider is think about some of the best handleing cars new or old they never have massive wide wheels they have narrower wheels for quicker turn in and better handleing. Having wider rears is mainly for grip on straights putting the power down that's all. As soon as we have any bad weather you see all m3,m5 with too much power and stupid 10j wide wheels struggling and not going anywhere whilst mr 7j wide alloy cruises past you whilst your sliding everywhere because there too wide.
 
goldbcfc said:
All this over some tyres
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Isn't that a little bit patronising? :wink:

I don't see Porsche, AM, Ferrari, Bugatti, Maserati, DTM cars, GT series - running box? Or am I missing something?

Box is cheaper if you track because you can use the same tyres all round, swap front/back, etc. I can't see grip being better with 360 hp going through even narrower rear tyres.

I would not talk about it and actually try it and see for myself because I like to test and improve things, but I can't, because I'd need to spend an extra £1700 on new rear wheels and tyres, plus spacers, unless someone will lend me some?! :thumbsup:
 
stuartinzg said:
goldbcfc said:
All this over some tyres
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Isn't that a little bit patronising? :wink:

I don't see Porsche, AM, Ferrari, Bugatti, Maserati, DTM cars, GT series - running box? Or am I missing something?

Box is cheaper if you track because you can use the same tyres all round, swap front/back, etc. I can't see grip being better with 360 hp going through even narrower rear tyres.

I would not talk about it and actually try it and see for myself because I like to test and improve things, but I can't, because I'd need to spend an extra £1700 on new rear wheels and tyres, plus spacers, unless someone will lend me some?! :thumbsup:
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So many variables to consider. I went for 265 instead of 255 at the rear because in standing water up to 1/2 the tread depth the wider tyre is more resistant to aquaplaning as void to contact ratio is higher.

Certainly my 35iS completely overwhelmed the OE 225/40R18 front tyres.
 
You going to Pilot Sport Cup 2? :o

One thing to remember with the Z4 is the high neg camber actually makes the car less prone to aquaplaning at the rear up to moderate cornering loads
 
From what I remember MPSS come in at 255/35R18 & 275/35R18 but no 265/35R18 but there is a cup 2 in that size.
 
Opps... you're running on 19" rims :slaphead: ignore me.

That'll not be helping your straight line traction issues ;)
 
Interesting post..

I am planning in purchasing some new summer tyres, I dont have the same issues as I have an wee 4 Pot.

But reading in other forums - there is an consensus of having upgrading the front tyres from 225 to 255?

Whats everyone thoughts on this?
 
stuartinzg said:
My dad is of the opinion (and being around a long time, having driven many many cars over the years, from e-types, dino's, RS200, you name it ) he thinks the chassis is "hair dresser" and not as sorted as it could be, over engined in the 35iS and thinks the 30i would be a better drive - he may be right !
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From my experience the the 28i handles better than the 3.0is
 
Twin Turbo said:
Interesting post..

I am planning in purchasing some new summer tyres, I dont have the same issues as I have an wee 4 Pot.

But reading in other forums - there is an consensus of having upgrading the front tyres from 225 to 255?

Whats everyone thoughts on this?
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If you want unpleasant handling but a lot of mid-corner grip knock your self out. That said if you want a track car why in gods name did you buy a E89 Z4? It's setup for 4-6/10ths GT fast road driving.
 
Twin Turbo said:
Interesting post..

I am planning in purchasing some new summer tyres, I dont have the same issues as I have an wee 4 Pot.

But reading in other forums - there is an consensus of having upgrading the front tyres from 225 to 255?

Whats everyone thoughts on this?
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Please don't do that - plus, I don't think it would even fit under the arch. My BBS are 0.5" wider front/rear, and it was "just" flush at the front, the tyre fitter was concerned it would rub. The front could take 235 (one size up), but I won't bother.
 
techathy said:
Opps... you're running on 19" rims :slaphead: ignore me.

That'll not be helping your straight line traction issues ;)
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True, some more rubber to wobble around would probably help :wink:
 
stuartinzg said:
Twin Turbo said:
Interesting post..

I am planning in purchasing some new summer tyres, I dont have the same issues as I have an wee 4 Pot.

But reading in other forums - there is an consensus of having upgrading the front tyres from 225 to 255?

Whats everyone thoughts on this?
Click to expand...

Please don't do that - plus, I don't think it would even fit under the arch. My BBS are 0.5" wider front/rear, and it was "just" flush at the front, the tyre fitter was concerned it would rub. The front could take 235 (one size up), but I won't bother.
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For an experiment I swapped the front & rear wheels on my car, 255/35R18 on an 8.5j rim. It did fit just, there was no scrubbing after a fairly hard 15min drive. However the wide tyres at the front resulted in needing exaggerated steering input and also introduced turn-in understeer, this was exaggerated on direction changes. However, once settled into a corner there was a lot more grip at the front end. As 245/40R18 tyres produced even more turn-in understeer than 255/35R18, I'm thinking that 245/35R18 with 10mm lower springs at the front will dial this out.

The fronts are 245/40R18 on 8j rims:
2ahejx5.jpg
 
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