+2 Roadholding

PostPost by: iain.hamlton » Wed Sep 20, 2006 8:53 am

The handbook talks about braking of 0.9g and roadholding of 0.8g which is pretty impressive, even by modern standards. As good as the handling is, I would be surprised if the roadholding is close to 0.8g. Does anyone know what the roadholding is? has it ever been measured?

best regards, iain
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PostPost by: rgh0 » Wed Sep 20, 2006 9:37 am

Iain
When I had to get a road worthy certificate for my plus 2 a few years ago the road tester measured over 1g braking using an accelerometer on the road and I doubt he got it to the limit. I use very sticky road legal racing compound tyres. On the orginal tyres 0.9 g braking and 0.8 g cornering sounds doable and should be easily achievable on todays tyres.

An early 70's Road and Track test of a +2S 130 gave a 0.757 lateral acceleration. A Sports car Graphics test of a +2S verified the Lotus claims of the .8g lateral and .9g braking numbers based on their tests

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PostPost by: MintSprint » Wed Sep 20, 2006 11:30 am

Pretty much a meaningless question (or, rather, one to which there is no accurate answer).

As Rohan says, some of the US magazines published Tapley meter readings as part of their period road tests, but actual figures are more dependent on road surface and tyre grip than anything else, both of which are extremely variable.

The Plus 2 has inherent advantages over most cars, due to its low centre of gravity and relatively wide track (hence low weight transfer, so the tyres all get a chance to do their fair share of the work), but the actual figures would vary dramatically depending on whether you are on 35 year old badly inflated remoulds or the latest track day Yokahamas and whether the car is cornering on smooth, dry ShellGrip or wet tarmac liberally smeared with cowsh1t from the nearest farmyard access!
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PostPost by: iain.hamlton » Wed Sep 20, 2006 12:43 pm

I accept the variability. I am still surprised by the claim - I have never seen G quoted in a handbook before. Subjectively, my +2 does not feel as "grippy" as my everyday VW golf (with modern tyres) but on the same roads as I uses the +2. Presumably, the claim referred to a good surface and standard tyres of the time, rather than modern trackday tyres.

Do you think the tyres on +2 now - 1998 Firestone 165 x 13s are comparable with the Dunlops, or whatever, fitted by the factory?

best regards, iain
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PostPost by: MintSprint » Wed Sep 20, 2006 4:23 pm

One factor that you need to bear in mind with Elans of any sort is that the tall profile tyres they use operate at much higher slip angles than modern, low profile rubber.

Wide, low profile tyres grip very well, at relatively low slip angles, up to close to their ultimate limit, but when they do 'let go' the grip falls away very suddenly. Tall, narrow profile tyres (such as used by the Elan) function at much higher slip angles throughout the envelope and break away much more progressively.

What this means in practice is that you will feel the Elan start to drift or slide long before it reaches its ultimate level of grip.

Put simply, you might be able to corner your Golf at 0.75g (say) with no drama at all, but at 0.8g it would wash out really quite suddenly, to the point that you would need quick, correct reactions to catch it.

The tyres on the Plus 2 would probably be howling in protest at 0.75g and there would be a definite feeling that the car was drifting, balanced on the steering and throttle. At 0.8g, when the Golf would have fallen off its grip curve and washed out (or thrown you into a monumental tank-slapper, if you reacted incorrectly), the Plus 2 would just be squealing its tyres a little more loudly, drifting a little more, and requiring just a little more steering and throttle input to keep it balanced.

If you are used to modern cars like the Golf, you have to acclimatise to the very different grip envelope offered by cars like the Elan if you are to exploit them properly.
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PostPost by: thor » Wed Sep 20, 2006 5:50 pm

hmm, Ian this is a very interesing debate which I'll test at he weekend, as my everyday car also is a Golf, with 165/13 on the +2, even if they're from this year...
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PostPost by: thor » Wed Sep 20, 2006 5:53 pm

and completely agree with MintSprint in that I feel much safer on the limit in the +2, as I actually feel and know what it's doing, rather than the very comfy numb feeling of the Golf....Though living in Norway I know what to do when things get out of hand on slippery bits.A wash out is the rule..
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PostPost by: tower of strength » Wed Sep 20, 2006 10:44 pm

iain.hamlton wrote:
Do you think the tyres on +2 now - 1998 Firestone 165 x 13s are comparable with the Dunlops, or whatever, fitted by the factory?

best regards, iain


No way!! I had Firestones on my S130/5, the dry grip was poor and wet grip was apalling!! The reason being: most tyres of this size were for saloon cars, i.e. heavy and as such are too hard wearing for the Elan, I was massively disapointed in the reduction of grip and feel with these over the old, perished and flat spotted Goodyear G800 (fabric radials) that I replaced.

I'm led to believe that the classic SP Sport from Dunlop is the only way to go on these cars in the standard sizes,(I stand to be corrected on this!!)

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PostPost by: iain.hamlton » Thu Sep 21, 2006 9:03 am

Fascinating!


do you mean "wet grip was appalling" like this?


Does anyone else have opinions or data on different types of tyre? I know Steve WW favours Michelin.

best regards, iain
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PostPost by: peterako » Thu Sep 21, 2006 9:21 am

My t'pence....

I have been very fortunate to have driven a huge variety of cars.
(More a reflection of my age then anything else!!)

Some cars feel fast and 'racey' but are not. Others feel soggy
and slow....but are not!

When I first drove my Elan +2 I was a bit dissapointed at
the handling etc. That is until I started to notice that the car
was in fact quicker from A to B then most of my previous cars....
even though it felt slower. (OK, on BAD surfaces it is
much slower...partly due to fear of damage slowing me down)

I don't think I've come even close to the cars limits.

The Elan +2 just seems to do what it's supposed to, and without any
fuss. This can be deceptive as the car remains pretty comfortable
at most times.
Most 'modern' sportscars arive at their 'fantastic' handling
by using stiffer suspension....extremely wide tyres etc. that
can make use of modern smoother roads (available
everywhere it seems other than Ireland!!).
This also rattles your bones a bit.....

Lotus, on the other hand, developed a fantastic Chassis and
comfortable car that does the same thing. It feels soggy and
'slow'. But, from my experience on back roads for trips I
do on a regular basis.....its a bloody quick car!!!

And Stops well too....very important!

Regarding tyres.....I have new 'noname' 165/80's on the
front and old Dunlop 175/80's on the back. Will be changing the back
ones soon. Wet and drip handling and grip is good.
Can be a little tail happy in the wet on round-abouts.

Sorry for the long email.

Take care,
Peter (1973 +2S 130/5)
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PostPost by: thor » Thu Sep 21, 2006 11:16 am

hmmm, completely agree with the last post about the good handling and comfort. But I put on my Firestone 165/80R13 this summer and I'm completely happy with them, once they got a bit driven in, and I got the right pressures (24/26).
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PostPost by: lotuselan2 » Thu Sep 21, 2006 2:00 pm

I'm completely happy with my Michelin XAS 185/80 x 13's on my +2. I think they are the Series 3 of this out of production tire that I found. I replace Yoko Avid's which I did not like in spite of being a Yoko fan on my Europa and SVX's.
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PostPost by: tower of strength » Sun Sep 24, 2006 9:28 pm

I "terrorised" a guy on his GPZ750RRXXYYYZ( or what ever green thing) on a twisty B road in my 130/5 a couple of years back, he was doing the knee down thing and got in my way on the bends, but left me on the straight bits (I know its irresponsible, but we are a long time dead and it was i the middle of no where with great visibility), he was gutted when he saw that the carbs were bigger than the engine!! He was expecting a big lump or a turbo nutter device under the bonnet of what he thought may have been a Ferrari!!! (1550 ford lump mate, and a sickly one at that!)

He waited for me at a layby and flagged me down, we have become firm friends!!!

(Good job he's a strong lad, got a body shell to lift off soon)

This was on naff Firestones, with fairly low pressures, 24 psi all round from memory

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PostPost by: types26/36 » Sun Sep 24, 2006 9:48 pm

tower of strength wrote:I "terrorised" a guy on his GPZ750RRXXYYYZ( or (I know its irresponsible, but we are a long time dead Mark


Hmm! Mark, just checked your profile and quote:
Your Interests: ...sniffing resin fumes.......
Well things are starting to make sense :lol: :lol: :lol:
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PostPost by: tower of strength » Sun Sep 24, 2006 10:21 pm

types26/36/74 wrote:
tower of strength wrote:I "terrorised" a guy on his GPZ750RRXXYYYZ( or (I know its irresponsible, but we are a long time dead Mark


Hmm! Mark, just checked your profile and quote:
Your Interests: ...sniffing resin fumes.......
Well things are starting to make sense :lol: :lol: :lol:


have a gander at the delight that I "exhumed " from my back garden today, in the gallery!!! I have plenty of resin fumes to sniff!!! My neigbours rekon I'm on drugs, or if not , I need to be!!! I'm trying something socially acceptable and legal at the moment from California, its white and slips down the gullet a treat!!

The guy on the bike was V impressed with the cornering ability of the Elan, all Joking aside!! (another 500bhp on the straights would have been usefull though!)

A couple of my bike riding pals cant get thier heads around 165 tyres and 120(on a good day) BHP cornering ability when strapped to one of Colins finest backbones! In fairness, a modern hot hatch will waste an Elan on outright grip, but they totally lack feel and the average driver couldnt extract the performance without losing it any way! Just my humble opinion!

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