Tyre Pressure advice needed

[Guest]

Decided to upgrade to 17" wheels on my 1986 Lux. Going with 225/45/17 tyres on the front and 255/40/17 on the rear. Anyone know what sort of pressures I should be running ? [8|]

 

[Fen]

Something like 34-36psi all round is what most people with 17" wheels run I think.

 

[944turboS]

I run 36psi after checking with some 968 owners what pressure they run their 17s at.

 

[Guest]

Used to use 29F and 36R on my old BBSs, same size as yours, maybe thats too soft at the front. Used to tramline, and if you caught a puddle at the edge of the road at any speed sheld take the steering wheel out of your hands! Gone back to Teledials. Anyone want a set of BBS splitrims in need of recon?

 

[Diver944]

What do they look like Keith? I don't think I've ever seen any 17" BBS wheels on a 944 [&:]

 

[John Sims]

ORIGINAL: poulton

Decided to upgrade to 17" wheels on my 1986 Lux. Going with 225/45/17 tyres on the front and 255/40/17 on the rear. Anyone know what sort of pressures I should be running ? [8|]

What size are your front rims? I've just gone from 205's to 215's of a 7" rim, I was a bit dubious of going wider on that size rim.

 

[Fen]

I've got 225's on 7" fronts. That's about as big as you can go but it's fine.

 

[Guest]

Thanks for the advice. My Rims are 7.5J from & 9J. Wondering now whether to drop down to 215 front & 245 rear if tramlining is an issue ?

 

[Fen]

Do you have 968 castor mounts? I doubt 215 would make tramlining any less and 225 is the correct size for the 7.5" fronts. 255 is correct for the 9" rears also and they make no difference to tramlining. If you have the correct offset wheels, 968 castor mounts and the alignment is close to correct you should not have tramlining.

 

[Guest]

Fen, Just checked workshop, BBS are 16s 225/45 F 245/50 R. They look great, particularly at night with their shiny criss-cross pattern, but really noisy.

Remember a year old thread from a lux guy losing loads of water? I suggested the pipes coming from the intercooler!!! Just checked Brooklands pg 16, Motor mag Oct.17 1981, theres a diagram of what old lux chaps refer to as the intercooler. There was much derision at the time from Turbot chaps about luxs having "intercoolers". Maybe a difference in terminology but I just knew the info came from somewhere!

Will try to find piccy of SCZ wearing BBS.

 

[John Sims]

ORIGINAL: scz
.......Remember a year old thread from a lux guy losing loads of water? I suggested the pipes coming from the intercooler!!! Just checked Brooklands pg 16, Motor mag Oct.17 1981, theres a diagram of what old lux chaps refer to as the intercooler. There was much derision at the time from Turbot chaps about luxs having "intercoolers". Maybe a difference in terminology but I just knew the info came from somewhere!

That'll perhaps be the heat exchanger then. Luxes have a heat exchanger which IIRC comprises a water matrix which kind of sits in the sump; it helps to speed up getting the oil to operating temperature. The seals for this matrix were found to be faulty on early cars and were subsequently changed for a revised seal which was green in colour (Not that Porsche ever produce seals with a history of failure though). If these seals are the old type, or have failed through age, you can get water in your oil.

Don't take all of this as gospel as it is a few years ago I had them replaced on my Lux. I haven't looked to see if the heat exchanger was continued into Turbots and S2's.

 

[Fen]

No, it wasn't. The holes are there with a blanking plate over them I believe.

 

[Guest]

Offsets are correct with ET23 front & ET15 rear (Pre ABS hub car). Alignment is good but not so sure about the 968 castor mount bit. Standard 1986 944 as far as I know. What does the 968 castor mount do & is it easy to upgrade to rom standard ? Thanks

 

[mik_ok]

ORIGINAL: poulton
What does the 968 castor mount do & is it easy to upgrade to rom standard ?  Thanks

Have a quick look at this thread (I've sent you straight to page 3 as there is a huge amount of waffly banter on pages 1 & 2 [&:] CLICK HERE

They make a big difference to the tramlining.

The only thing I'm not sure of is whether they will suit your car? I know early cars had different wishbones..... but I'm afraid I don't know enough to advise you.

 

[Fen]

I think he's OK to use them mik - the alloy arms were developed for the Turbo which launched in '86 but as I recall they were so much better that they went on the Lux immediately too (do you have alloy arms, poulton?) I'm also pretty sure the '86 alloy arms are a direct swap for the earlier pressed steel arms (possibly on Mk1 and maybe Mk2 Golf GTi's also) so the castor mount should be Ok even with steel arms. Problem with steel arms is that they might be contributing to the tramlining themselves through being slightly flexible.

 

[Guest]

[] OK, understand now. I have alloy wishbones so I will try the car with the new wheels & upgrade to the 968 castor mount if I find problems with the standard 944 item. Thanks for all the help and advice...so much easier than learning through trial and error !