Tyre pressure help?

Northwestern · Post by **Northwestern** » Fri Aug 29, 2008 7:38 pm

Can anyone clear up what is the correct tyre pressure when running Pirelli P4000 205/70 ZR 15 on MWS comp. size wire wheels. The car is a S1 4.2 roadster. The initial pressure was just 20 lbs which seems and felt very low! I've seem and read so many different pressure ratings on the net, so I'd prefer to hear from other members with the same package and how they get on. Car is run up to "normal" road speeds and is not a track car. Thanks Paul

S1 Coupe 1961 HSK 138
S1 Coupe "pile of parts"
S1 Roadster 1968 XKE 32

Car-Nut · Post by **Car-Nut** » Sat Aug 30, 2008 8:40 am

Paul, have you done a search on the forum I think there has been a tyre pressure question before.......

Or otherwise when David (Heuer) gets on today he'll know

Post by **Heuer** » Sat Aug 30, 2008 9:57 am

Paul

I would recommend 32 psi front and rear. I ran my S1 on P6000's (similar tyre to the P4000) for a few years and experimented with various tyre pressures on the Pirelli's. I once tried upping the pressure to 38psi in expectation of a high speed trip to France and the handling was abysmal so I quickly reverted to 32psi. Managed 18,000 fast miles through Europe and the Rallye des Alpes running at that pressure.

Currently running on Michelin XVS 185's and again I have found 32 psi to be the sweet spot for the S1.

Moeregaard · Post by **Moeregaard** » Sat Aug 30, 2008 2:24 pm

When running on 185-15 Avons, 32 PSI front and rear felt right. I would not run below 30 PSI.

falcon3 · Post by **falcon3** » Sun Aug 31, 2008 5:00 pm

Denis Jenkinson who used E-Types for years doing a high milerage all over Europe wrote in his Motor Sport article in April 1967 (by which time he had covered over 50,000 miles in the S1 E-Type that I now own) "I am happily motoring on Goodyear G800 tyres with 30 lb./sq.in in the front ones and 35 lb./sq. in in the back ones. An E-Type on equal pressures front and rear is a rather dangerous joke, no mattter what make of tyre."

I leave that thought with you all....!!

Roger

Post by **Heuer** » Sun Aug 31, 2008 5:16 pm

Roger

I will give it a go and report back although pressure choice does depend on driving style. Perhaps Jerry can let us know what he uses for both road and track. I wonder if Jenks set his car up like that as he was used to a Porsche 356 and 'wischening' it around corners?

Moeregaard · Post by **Moeregaard** » Sun Aug 31, 2008 5:59 pm

I played around with higher pressures in the rear and didn't notice any improvement in handling, with my aforementioned 185-15 Avons. At 32 PSI, with two people aboard and all the cr*p necessary for a weekend road trip in back, the car just felt right. I never autocrossed my E-Types, so Jerry's thoughts on this are certainly welcome.

Jenks may have utilized higher pressures to gain additional sidewall stiffness with the bias-ply rubber--just my guess.

Post by **Heuer** » Mon Sep 01, 2008 2:50 pm

Just been out for a short run with 30psi front and 35psi rear and the handling feels promising with a touch more weight to the steering. Rain stopped play as the roads became greasy but at the moment I am prepared to give Jenks the benefit of the doubt.

Northwestern · Post by **Northwestern** » Mon Sep 01, 2008 9:31 pm

Thanks very much for all the info. Much appreciated. Just back after a long and hectic weekend away at a family wedding with the car loaded with E-Type suitcases (very heavy but wonderfully made) and one wife (reason for cases). Roads is Northern Ireland were wet but at 32lbs the car seems much better, certainly the handling on corners is improved. I'm going to try her again with 30lbs front and 35lbs rear as Roger quotes from Jenks but with the car unloaded. At least the roads here are like those in England 40 years ago (lack of cars), so I should be able to get in some good high speed testing. I'll report back. Thanks again to you all. Paul

S1 Coupe 1961 HSK 138
S1 Coupe "pile of parts"
S1 Roadster 1968 XKE 32

Post by **Heuer** » Tue Sep 02, 2008 9:48 am

Michelin recommend 33/35 psi f/r for the XVS 185's on my car but when I tried it I did not like the handling and went to 32/32. Could have been because the tyres were brand new. Now, with 2,000 miles on them, the side walls are slightly softer and the higher rear pressure works.

Paul - remember Jenks was using period tyres (as indeed am I with the XVS's) so the 30/35 psi might not be appropriate on the modern P4000's. When the time comes to replace your current tyres I would avoid the P4000's as they are really not up to the handling of an E-Type - they are designed for small hatchbacks and vans. A better tyre would be the Vredestein 185 or one of the other 'period' tyres (Dunlop SP Sport, Michelin XVS etc). Give Longstone Tyres a call for further advice as they certainly helped transform the handling of my car.

Northwestern · Post by **Northwestern** » Wed Sep 03, 2008 9:48 am

David, thank you for the info, road test cancelled due to torrential rain in Co. Fermanagh. May I ask what size of XVS you're using/used on the MWS comp size wheels? I like the larger wheel, but don't like the heavy steering and juddering at slow speeds with this set up. The stainless steel MWS wheels are great, used well and cleaned periodically, they still look as good as new. The Dayton (American Dunlop) wheels they replaced were rubbish and after a few hundred miles and several stone chips the chrome started to peel and rust. I read with interest you're experiments with Borrani wheels and will purchase a set of these and use the MWS on my track car. What type of spinner are you using?

Post by **Heuer** » Wed Sep 03, 2008 10:16 am

Paul

The Michelin XVS 185 VR15 will fit on 5", 5.5" or 6" wheels and the ride will become firmer as the width increases. I went for 5" Borrani's on the recommendation of Dougal Cawley at Longstone. Basically I wanted the wider wheels with XVS's - he thought I was mad. In the end he put a set of Borrani's shod with Michelin on the car and we went out for a test drive to prove the point. I was convinced within 10 miles - superb ride, perfectly weighted steering and fantastic handling - and I bought the complete set there and then. Sold the 6" MWS/P6000 combo.

The lighter construction of the Borrani's reduces unsprung weight and adds to the delicate feel of the car. They also look fantastic. I use the standard Jaguar eared spinners although you can get Borrani ones if you want. Dougal can supply a complete Borrani XVS set by post but there is a 6-8 week order time on the wheels I believe. Give him a call 01302 711 123 - great character who will put a smile on your face! Happy for you to mention my name.

Northwestern · Post by **Northwestern** » Wed Sep 03, 2008 10:55 am

Thanks again David, will do.

Paul

S1 Coupe 1961 HSK 138
S1 Coupe "pile of parts"
S1 Roadster 1968 XKE 32

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

The 'E' Type Forum

Tyre pressure help?

#1 Tyre pressure help?

#2

#3

#4

#5

#6

#7

#8

#9 Tyre pressure on XKE 32

#10

#11 XKE 32's cancelled test

#12

#13 XKE 32