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Col.Evan.Mil 
Newbie
Joined: 17-August-2003
Location: United Kingdom
Status: Offline
Points: 5
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 Posted: 17-August-2003 at 21:29 |
Hi newbie here, Just a quick note,
My e36 coupe tramlines all the time.
Tyres at the rear are 235 x 40 x 18
After chatting to many other BM owners, I am informed that most rear wheel drive car with wide back tyres tramline..
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Ian M
Newbie
Joined: 18-August-2003
Location: United Kingdom
Status: Offline
Points: 13
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Posted: 18-August-2003 at 09:59 |
I've now had an 02 320d Touring for a whole week (std 16" wheels) and am finding I feel indentations in the road etc - not sure I'd quite go so far as to call it tramlining as such - much more than in my previous Audi A3. I suspect it may be just that the Audi didn't have steering feel, but any thoughts?
Ian
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jolf
Newbie
Joined: 19-August-2003
Location: United Kingdom
Status: Offline
Points: 36
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Posted: 21-August-2003 at 01:34 |
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i maybe wrong i'm just going by what my brother in law told me, but he works for pirelli and has done for donkeys years and says that my tramlining was caused by my front tyres Bridgestone SO3s, he maybe biased i don't know but my friend had the same problem with the same tyres, i have now changed to pirelli p7000 drago's and they are the best tyres ive ever had in wet and in the dry, really nice to drive with shoes that reliable, pricey tyres but you get what you pay for sometimes.....
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b318isp
Moderator Group
Joined: 10-October-2002
Location: Ireland
Status: Offline
Points: 2057
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Posted: 21-August-2003 at 10:12 |
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I don't think tyres are the deciding factor - more their width.
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Ian M
Newbie
Joined: 18-August-2003
Location: United Kingdom
Status: Offline
Points: 13
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Posted: 22-August-2003 at 10:12 |
Having done a bit more driving now, it definitely seems a bit funny - twitches noticeably over lumps and indentations, follows ruts and pulls slightly but definitely to whichever side the camber is running down on.
Any views on if this is normal and/or whether there's anything to be done to correct it?
Ian
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b318isp
Moderator Group
Joined: 10-October-2002
Location: Ireland
Status: Offline
Points: 2057
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Posted: 22-August-2003 at 15:41 |
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Check you tyre pressures too. Should be around 35-37psi on 16". What width are they?
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thepits
Moderator Group
Joined: 09-July-2003
Location: far far away
Status: Offline
Points: 10000473
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Posted: 22-August-2003 at 22:25 |
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Gosh - this is all getting a bit technical isn't it?
Sure there is meant to be a proper / optimun tyre pressure for front and rear which depends on the size of wheel/Tyre, but it finally comes down to how you want the car to feel.
If it understeers too much, increase the rears a bit and drop the fronts - ok not too much otherwise the tyre wear will screw up, but you don't need much.
Play with the pressures until the car FEELS better. Then keep an eye on the wear rate.
Why do you think pressures are so critical on Racing Cars? Even with their tricky suspension!?
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Cats know your every thought.
But don't care.
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b318isp
Moderator Group
Joined: 10-October-2002
Location: Ireland
Status: Offline
Points: 2057
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Posted: 25-August-2003 at 12:40 |
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No. If you have understeer you need to INCREASE the front pressure. For most road tyres, the sidewalls are deforming too much under side load. This is corrected by increasing their pressure to have more of the load supported by the centre of the thread.
The best way to optimise tyre pressures is to measure the wear across the threads and compensate from there (use a vernier). Race cars use temperature to do the same. I run 38psi front and 33 psi rear on 205/55/15 - but this is only valid for my car and type of driving. With 16's with a similar width I would recommend starting with similar figures.
You are right about experimenting - I would suggest 2psi steps.
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paul325i
Really Senior Member II
Joined: 23-January-2003
Location: United Kingdom
Status: Offline
Points: 666
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Posted: 25-August-2003 at 13:24 |
Can anybody remember what the claimed optimum was for the E30 325i on 15s?
It was in the newsletter a while ago, something like 37 for the rear and 32 for the front. If thats right, thats set up for more understeer than over?
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b318isp
Moderator Group
Joined: 10-October-2002
Location: Ireland
Status: Offline
Points: 2057
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Posted: 25-August-2003 at 14:03 |
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That's not a bad setting. With the slightly heavier front you could go a little higher up front. There is no such thing as an optimum as it is down to driving style and personal preferance. As I say, checking wear with a vernier will determine the best pressure for YOU!
That pressure will reduce understeer from the stock BMW figures.
If it is still understeering too much then try 2 psi more up front - after that consider a 14.5mm rear anti-roll bar if not already fitted! If it is oversteering (cornering not power) try 2 psi extra in the rear.
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paul325i
Really Senior Member II
Joined: 23-January-2003
Location: United Kingdom
Status: Offline
Points: 666
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Posted: 25-August-2003 at 18:08 |
I'll have to experiment with them once i've fixed the subframe boshes, its a bloody death trap at high speeds, been out to much recently haven't had a chance.
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paul325i
Really Senior Member II
Joined: 23-January-2003
Location: United Kingdom
Status: Offline
Points: 666
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Posted: 25-August-2003 at 18:09 |
ooo boshes is a new one 
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thepits
Moderator Group
Joined: 09-July-2003
Location: far far away
Status: Offline
Points: 10000473
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Posted: 25-August-2003 at 19:21 |
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Cats know your every thought.
But don't care.
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PikeyM3
Really Senior Member I
E30 M3
Joined: 31-May-2003
Location: Cheltenham - Uk
Status: Offline
Points: 438
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Posted: 25-August-2003 at 20:02 |
What the hell are you lot going an about!
If you manage to notice the difference between 2 psi here and 2 psi there on a uk road then your'e a genious.
I think you'll find that because of the average uk road surface you could probably run with flat tyres and still experience tramlining or whatever.
Pikey
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Old enough to know better, too young to care!
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skull
Really Senior Member II
Joined: 20-April-2003
Location: United Kingdom
Status: Offline
Points: 640
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Posted: 25-August-2003 at 20:24 |
at the end of the day we are useing wider tyres all the time and our roads get worse, and driving a car with sports everything is not going to feel like a family saloon on skinny tyres. sports in not about comfort its about feel , and if you feel the road you know what your tyres are doing and if you dont ,well how do you know whats happening, if you dont like the feel then buy smaller wheels and tyres.
there is a difference between people that drive there car and realy drive there car 
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just a little crazy.
My drive
E46 M3 COUPE [MAN]CARBON BLACK GREY LEATHER H/K 19"s LED REARS S/B.
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thepits
Moderator Group
Joined: 09-July-2003
Location: far far away
Status: Offline
Points: 10000473
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Posted: 25-August-2003 at 21:15 |
 skull wrote:
at the end of the day we are useing wider tyres all the time and our roads get worse, and driving a car with sports everything is not going to feel like a family saloon on skinny tyres. sports in not about comfort its about feel , and if you feel the road you know what your tyres are doing and if you dont ,well how do you know whats happening, if you dont like the feel then buy smaller wheels and tyres.
there is a difference between people that drive there car and realy drive there car |
So there! - that told 'em!
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Cats know your every thought.
But don't care.
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b318isp
Moderator Group
Joined: 10-October-2002
Location: Ireland
Status: Offline
Points: 2057
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Posted: 26-August-2003 at 09:49 |
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Huh? I think you guys might be generalising a bit about the roads. Anyway, you can always tweak to improve things.
Optimising your tyre pressures is always good - in maximises grip and minimises wear. In the wet you don't have to run quite as high a pressure as the tyre won't generate as much load - but you don't know what the ideal pressure is (wet or dry) at any point in time (unless you use temperature measurements). So measuring wear over time will give an averagely correct figure.
Pikey, you misunderstood my comments about 2 psi steps. I am saying that if you are tweaking tyre pressures, then do it in 2 psi steps until you are satisfied.
I agree that tramlining is fact of life with wide tyres though.
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Guests
Guest
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Posted: 26-August-2003 at 23:10 |
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Try tramlining with front wheel drive!!
I had an Audi which tramlined bad. Had 225 40 17 Falken tyres all round ran at 42psi!. It helped a bit. Had front wheel bearings replaced, it helped a lot more. But never totaly trusted it not to do something silly.
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PikeyM3
Really Senior Member I
E30 M3
Joined: 31-May-2003
Location: Cheltenham - Uk
Status: Offline
Points: 438
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Posted: 27-August-2003 at 19:42 |
B318sp - oh I see. I think it becomes more difficult to calculate the correct tyre pressure on aftermarket alloys (thats is different size ones).
with a 195/55R 15 the correct tyre pressure by the manufacturer could be, say, 32 psi. But with a 205/40R 17 is the tyre pressure the same? Does the tyre contain the same area for air to be in?
It all gets a bit complicated and best left to track tinckering, but I agree with b318sp try it and see, until you get the best result for you.
Good Luck,
Pikey
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Old enough to know better, too young to care!
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Sohlman
Really Senior Member II
Coupe Chairman
Joined: 19-August-2003
Location: Surrey
Status: Offline
Points: 1259
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Posted: 27-August-2003 at 19:51 |
I was on another forum on the internet recently and a similar debate was discussed regarding tramlining with reference to the new 330. From the opinions that were exspressed different tyres seriously affect tramlining as modern low profile tyres usually have very hard side walls which don't deviate on bumps and thus tramlining occours as well as those discussed regarding wheel width.
My exsperience is that pirelli's and Dunlops can suffer badly from this, whilst other companies like Michelins and Uniroyles and Bridgestones are less prone. I have a six which runs of seventeens and have found Uniroyles to be excellent, and have not exsperiences any problems with tramlining so would recomend these.
Worn suspension componentry can be another factor, and if your car has done more than 60k suspension will be begining to get a little tired and a change of dampers will make a big difference.
Anyway hope this helps
Regards
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Tramlining
