Tramlining. How to reduce it?

[ChasR]

My 944 handles quite nicely, and there are no clonks or bangs from the suspension, but it does tramline quite a bit. I am used to it, but my dad thought it was awful. As for telling him not to drive it, that won't be possible with his car off the road. It does have a minimal amount of play in the balljoint (unless moved in a certain way, the wear can't be detected), but I'll be getting a new arm from Hartech for it, which should hopefully reduce it.

What do you think is responsible for the tramlining? It's on 225/45R17s up front and 255/40R17s on the rear, all Pirelli P6000s. I think they have around 37PSi in all of them.

Here's a couple of pics of the wheels:

 

[mik_ok]

My experience > CLICK

In summary I'd suggest :
- 968 castor mounts
- geometry
- may need new front boots to take advantage of the latter

 

[stjohnsmythe]

I've got the same wheels on my 944. I've checked various sources and I'm pretty certain you should be running 29psi front and 36 psi rear....

 

[GC8]

968 castor mounts.

 

[edh]

I recommend 16" wheels

I have fitted 17's recently & the car is much more prone to tramlining now - it never really did before (just read mik's thread, my 16's are on T1-R's, the 17's are Goodyear F1's - don't know if that is significant)

I have the 968 castor mounts

 

[zcacogp]

ORIGINAL: GC8

968 castor mounts.

Ding and verily Dong.

Best £100 I've spent on my S2.


Oli.

 

[sawood12]

I think tyre pressures, tyre sizes and wheel sizes are a red herring. Across everyone on this forum you have a massive variation as to what people run across those three variables with no evidence of tramlining being directly attributable. I guess all you can do is to methodically sure all your bushes are OK, your alignment and geometry is OK, nothing is bent or loose. If there is a camber on the road then any car will tend to follow it, so all cars will tramline to some extent.

 

[mik_ok]

ORIGINAL: stjohnsmythe

I've got the same wheels on my 944. I've checked various sources and I'm pretty certain you should be running 29psi front and 36 psi rear....

Only if you want an understeer biased balance.

944's prefer much closer numbers ~ I liked 33F, 34R but many folks like them to be the same front & back.

 

[edh]

ORIGINAL: sawood12

I think tyre pressures, tyre sizes and wheel sizes are a red herring. Across everyone on this forum you have a massive variation as to what people run across those three variables with no evidence of tramlining being directly attributable. I guess all you can do is to methodically sure all your bushes are OK, your alignment and geometry is OK, nothing is bent or loose. If there is a camber on the road then any car will tend to follow it, so all cars will tramline to some extent.

Not true Scott - come round one day & drive my car on 17's - then swap to 16's. It will take you about 1 minute (the drive down my road) to see a huge difference.

 

[stjohnsmythe]

ORIGINAL: mik_ok

ORIGINAL: stjohnsmythe

I've got the same wheels on my 944. I've checked various sources and I'm pretty certain you should be running 29psi front and 36 psi rear....

Only if you want an understeer biased balance.

944's prefer much closer numbers ~ I liked 33F, 34R but many folks like them to be the same front & back.

I'll give those pressures a try!

 

[pauljmcnulty]

I'll give those pressures a try!

Back to tyre pressures then! As I posted just before going away for a week I never got a definitive answer to the S2 tyre pressure thing. [8|]

My handbook says:

944S2/turbo with or without sports chassis, F36 R44

Plainly we all think this is rubbish [&:], but what is everyone else using?

BTW, Lux on standard wheels is 29F/36R as StJohn said earlier. I used to run VJ with a little less at the back, but it never made a huge difference. They are all very sensitive to pressure being out on one side or the other, though.

 

[edh]

I'd go around 34F / 36R on 16's

 

[craig2105]

I'm running 36 psi all round, on 17" Cup 2's with 215/45 front and 245/45 rear. There is some tramlining at lower pressures on the front - I tried 32F and it was much worse, plus it understeered like a bugger too. At 36 the tramlining is fine unless on really rutted roads, but then it's no worse than anything else.

 

[944Turbo]

32 front and rear on mine 17" tramlining is also geometry dependent, and tyres can have an effect especially if part worn. Offset will affect it. Anything that allows geometry to change will also have an effect - worn dampers, worn top mounts, worn steering arms/ racks and wishbone mounts. Lower profile tyres will increase the loads on these components, as will increased unsprung weight.

 

[zcacogp]

>Yawn< We've done this very recently.

38/38 for my S2 on D90's.


Oli.

 

[dlknight]

I was getting paranoid about mine tramlining, had the geo checked twice and have now gone with slightly more aggresive camber settings which has helped alot. I'm running D90 16" wheels by the way.

I think it is just the sorry state of Britains roads that is to blame for tramlining, a recent episode of fifth gear highlighted how the councils now deal with road maintenance. Potholes are now only repaired if it is economical e.g. cost of damages to vehicles > cost of repairing. It stinks especially as fuel and road tax keep climbing, I imagine alot of "wear" that is done to our suspension is from the shoddy roads []

Rant over [] but I'm sure you all agree?

Dave K

 

[ChasR]

Cheers chaps. When the arms are ordered I'll get some new 968 castor mounts too and see if that reduces it, and probably tone down the pressures a little. But I had a nasty suspicion that it will be down to the tyres eventually as a few postees have said...[8|]

Regarding pressures, my driver's manual says 36PSI all round for the D90s, regardless of what suspension (Sports or none-Sports) the S2 has.

 

[GC8]

In my opinion/experience; the only argument against 16"s centres on tyre choice. I moved back to 16"s on my hillclimber because it drove better, but in the early nineteen nineties 16" wheels were becomming popluar again, this time on more mundane vehicles, so tyre choice was increasing. This is no longer the case, of course.


Simon

 

[944Turbo]

ORIGINAL: GC8

In my opinion/experience; the only argument against 16"s centres on tyre choice. I moved back to 16"s on my hillclimber because it drove better, but in the early nineteen nineties 16" wheels were becomming popluar again, this time on more mundane vehicles, so tyre choice was increasing. This is no longer the case, of course.


Simon

16's dont fit over my brakes which is another fair reason for not using them [] though it could be argued big brakes are not required.
Tony

 

[Hilux]

I was getting paranoid about mine tramlining, had the geo checked twice and have now gone with slightly more aggresive camber settings which has helped alot. I'm running D90 16" wheels by the way.

I think it is just the sorry state of Britains roads that is to blame for tramlining, a recent episode of fifth gear highlighted how the councils now deal with road maintenance. Potholes are now only repaired if it is economical e.g. cost of damages to vehicles > cost of repairing. It stinks especially as fuel and road tax keep climbing, I imagine alot of "wear" that is done to our suspension is from the shoddy roads []

Nowt t`do with roads in my book................

I had 16`s on worn Mo30 - no tramlining on 33 f/r

I had 17`s (with 968 castor mounts) - no tramlining on 33 f/r

Its a geometry thing IMO and well set up there`s no reason why it should happen. I`m inclined to agree that slighty more aggressive camber settings may help dial it out but wrong toe/poor tracking is normally the cause especially under braking.

I`d suggest these cars are probably sensitive to geometry settings and knackered suspension as I never heard much discussion about it on other forums and with other cars I`ve owned/built over the years.