The 'E' Type Forum

On the subject of tyres my ser 3 is running on Pirrelli 205 x 70 x 15 p4000 tyres (wire wheels)
I am forever catching the rear exhaust boxes on ridges and I have heard that these tyres will actually decrease the clearence height by 1" compared to Dunlop Aquas
True or False ????
Suspension is all correct and I am not to keen on spending best part of a grand on 4 new tyres but then again a new stainless exhaust isn't that cheap either

jon

The 205/70's were standard on the S3 - the earlier cars had higher profile tyres and fitting the 205/70's on those will reduce ride height. Have you checked the ride height as per the service manual?

Car is within 3mm of specs in manual, perhaps its the exhaust although it looks pretty snug under the car, I have noticed the rear box rubbers require changing and I have a new set ready to fit. It well may be that it will pull it up.
As I am new to E type ownership (and enjoying every minute of it) I am avoiding speed humps like the plague as Im pretty sure I would leave the exhaust behind if I went over one ! How does this compare with other ser 3 coupes ?
I also am about to fit new carb diaphrams as after giving car the full monty service it is still revving at idle and warm at 1000 to 1500 rpm and I want to change them before adjusting the carbs. Service included new HT leads, plugs, dizzy cap and rotor, condensor plus all the normal service items. Breather pipes clear and carb dashpots topped up (dashpot topping up cured problem for about half an hour then it started to increase in revs again) No doubt if I fit new carb rubbers and it does not work I think its time to adjust and balance out the carbs
jon

Take care messing with those Stromberg's - lots of guidance here: http://etypeuk.com/forum/viewtopic.php?t=1664 Basically you can balance them with the slow running screws and that's about it. Going deeper requires a fair amount of knowledge!

Hi all,

Following this thread I have a couple of comments, firstly, I too have the same tyres and the car looks fine to me for clearance and although I didn't take measurements, the tyres replaced an original set of Dunlop tyres - and I do mean original, including the VR rating which they originally lost years ago (I heard rumours this had been changed again as German rules allow fitment only of the correct speed rating tyres, whilst UK rules did allow the fit of the Dunlop SP Sport ER70HR15 Tyre because it was original fit, despite being de-rated from VR to HR rating in the 1990s. Having checked, it appears this is true and the tyres once again are rated as VR). Replacing these tyres, which had marking indicating they were manufactured in the 1970s or 1980s (Tyre markings back then only indicated the final digit of the year of manufacture and the tyres were de-rated in the early '90s), led to no noticable difference in ride height.

I fitted these tyres after a lot of research and although some don't like them for being too modern, they came up as the best combination of speed rating vs price, size and ability. Longstone Tyres, who know their stuff, list the rolling diameter of the Dunlop ER70VR15 (original fit tyre - back to VR rating as discussed above) as 669mm. They also list the rolling diameter of the Pirelli P4000 20/ZR15 as..... 669mm, so I guess the tyres are the saame size. They have identical section too: 202mm. Pretty conclusive to me.

I think Dunlop Aquas are often quoted as original fit and this may be true in some markets, however, all my research made me believe the SP Sport ER70/VR15 is the original UK fit (ER means 205 in some Tyre marking schemes).

Unfortunately, as my car is still not road legal I can't comment on speed bump clearance. However, are the springs/shock absorbers in good condition, are the tyres at the right pressure and are the exhaust hangers all there and in good condition? They might hold the exhaust in the right place when stationary, but be rather too flexible when in motion.

Incidently, David, when I followed the link to the Stromberg tuning, I was reminded that there is no link on that page for a Series III wiring Diagram, try this one:

http://www.xkedata.com/resources/read/?id=11

I found and downloaded this, then printed it on four sheets of A3, taped together as a massive poster. It was an enormous help. It is basically the original, but the key has been removed and the items named on the diagram, the colour codes are as per the workshop manual (generally standard Lucas wire colour convention).

Regards,

The Dunlop ER70VR15 tyre (sometimes badged Aquajet) is a fabric radial whereas the Dunlop 205 70VR15 tyre is a steel belt radial. When I bought my car in 1982 it had both fitted - same rolling diameter but the width must have been slightly less with the fabric radial. Then the tank was full the steels would rub on the rear inner guards but the fabrics were clear.

I still actually have these worn out tyres.

Thanks Simon! I have added it. Pete Crespin mentioned the lack of S3 material so if anyone has any links or access to digital manuals please PM me.

I had very similar problems - interesting reading about tyres as mine are on edge of perishing and have decide the Pirellis due to the exact same spec will be the way I'll go. technically they are a better fitment for modern driving than teh original Dunlops - anyway back to the exhaust issue, having exact same prob when the welding was done underneatth and back end dropped I got them to change bushes and springs as matter of course and problem sorted! Was only I recon 5-10mm tops and still looks low to me but enough that it doesnt clobber speedbumps any more!