Tyre pressures

[Rodger H]

Hi,
Just bought a brilliant lotus éclat excel 1984
It has minimum service history and no manuals - could anyone tell me what the tyre pressures should be ? I can't find any info for this online
It us fitted with. 215 50 15 ( has later excel wheels not original éclat wheels )
Thanks
Rodger

[alanmoss]

Congratulations on your purchase and welcome to the forum.
I run at about 25psi all round.
Enjoy, enjoy!

[Rodger H]

Thanks, much appreciated - gonna do that now !!

[Lotus-e-Clan]

24 psi is the factory recommend tyre pressure for the original Goodyear NCTs 215/50-15.

You may have to take into account the more modern construction for newer non-Goodyear NCTs however...and your driver preferences.

Some have stiffer sidewalls to account for the increase in loads from moderns (heavier cars and a lot more 4X4 saloons these days) and they may feel uncomfortable and bounce on bumpy B roads on a relatively lighter Lotus if pressures are higher than 24 but may wear the outside tread more at these lower pressures as the side walls are less compliant...especially if you use the full cornering potential of the Excel!

[KevW]

Welcome to the forum Rodger. I also run 25psi on my Dunlop 215/50X15 and am happy with how they feel.

How about showing some pics of your car ? Most photos are being posted on this thread at the moment :

http://www.lotusexcel.net/phpbb/viewtop ... =12&t=3722

[alanmoss]

Should have said, sorry, like Kev running on Dunlop SP9000 which are good; right size right specification, but not the cheapest option if you change size.
Available here http://www.mytyres.co.uk/

[Lotus-e-Clan]

I also run Dunlop SP9000 with lowish pressures on the rear of my Clan (ie 24 psi at the heavy engine end) and they suit this kind of pressure, so I can see 25 psi (all round) would be in the zone too for Dunlops on the Excel.

However having ran Toyo T1Rs at 22- 24 psi (for 4 or 5 years) to account for the hard ride due to reinforced side walls, the outside edges are wearing much more than the centres (particularly on the rears possibly indicating under inflation for my particular driving style where I like to use the throttle to adjust the cars attitude in corners. ie I very rarely lift off in corners, if ever in fact. The predecessor to the T1Rs, the T1S, don't have the extra sidewall reinforcement which was brought about due to "modern" demands.

I've upped the pressures to 28 psi JUST to get more mileage out of the T1Rs to wear the centre of the tyres more but the ride is harsh and bouncy on the B roads I tend to travel up here in the Dales and frankly I don't like it...but needs must or I'll have to chuck away the tyres prematurely.
If you travel smooth flowing A roads /motorways most of the time then you probably would get on with 28 psi IF the tyre construction demands it.

So my current thinking is Toyo T1Rs are very good and worth their money, but Dunlop Sp9000s perform better at the lower pressure that suits the Excel suspension / dampers but unfortunately the Dunlops are much more expensive...so as ever, you get what you pay for I suppose.

[Ozzy_UK]

i ran 24psi all round on my R888s for winter track days, and 26psi all round on the road.

on my newer R1Rs i was running 27psi all round.

[hodders]

the outside edges are wearing much more than the centres (particularly on the rears possibly indicating under inflation for my particular driving style where I like to use the throttle to adjust the cars attitude in corners. ie I very rarely lift off in corners, if ever in fact.

Snap, my tyres always wear at the edges, so run the pressures harder than you might think ie minimum 24psi and even higher.

[Ozzy_UK]

mine wore nicely on the inside

then i did go very low with the front ride hight, and agressive on the GEO (3mm toe out front, 2mm toe in rear...)
the rears wear evenly, the fronts... well...



thats the result of low right height, and Toe Out, after 3 track days...

[Lotus-e-Clan]

A slight adjustment needed for next time then oz!

That's the sort of wear we get with lowered Clans/Imps etc and too much negative camber..ie 5 degrees or so!. With little weight in the front of a Clan, you also get no front-end grip in the wet and scary understeer when there's too much negative camber. I run mine with 1/2 a degree of negative at the front and zero toe out which actually results in some toe out on the move (due to movement in the track rod bushes).

[Ozzy_UK]

A slight adjustment needed for next time then oz!

That's the sort of wear we get with lowered Clans/Imps etc and too much negative camber..ie 5 degrees or so!. With little weight in the front of a Clan, you also get no front-end grip in the wet and scary understeer when there's too much negative camber. I run mine with 1/2 a degree of negative at the front and zero toe out which actually results in some toe out on the move (due to movement in the track rod bushes).

That set up was pretty much spot on for brands hatch indy circuit (all 3 of the track days on that set)...
Car felt fantastic... and was quicker than an elise trophy race car which was 152bhp at the wheels, and 750kgs!
(i admit this was in the wet, where the excel seems to have the edge over the elise in terms of braking and turn in... straight line the elise's were leaving me for dust...)

[Rodger H]

Thanks, what a great forum, lots of replies cheers
I have tried both and settled on 25 psi for round the B roads, dies seem less jumpy than 28 which I also tried.
Will take advice and opt for 28 when the wee car takes it's first trip to sciand in a few weeks.
Thanks again guys.
Rodger