Tyres Again!!

[msd1107]

I don't know what brand of tire dsly1 is running, but tirerack.com has them in Hoosier A6 and R6. UTQG of 40, though!

David
1968 36/7988

[dsly1]

They are the older model Hoosier Street TD. The Street TD and Track TD was replaced by the R6 and A6

Lemme know if you still wanna see pics of the rim or tire

My question still stands.......................... opinions on if a 205/60-13 would be too large for my application. I am running the Lotus TC with about 150-165 HP


me

[msd1107]

Will 205/60-13 fit?

The general answer is that the section width is too wide to fit under the wheel arches of either the earlier S1-S3 or the S4-Sprint bodies, even if you have relieved the inside of the wheel arches and flattened the spring collars.

However:

If you have small diameter rear springs and wheels that move the tires in toward the center of the body, they might fit. I know 185s are a struggle, even on a S4. The other thing to consider is the front wheel lock. You just can't crank the steering wheel as much as the tires interfer with the arb.

On a quantitive basis:

155-13 is 912 rev/mile, 22.8 in diameter.
165-13 is 887 rev/mile, 23.4".
175/70-13 is 917, 22.6".
185/70-13 is 893, 23.2".
185/60-13 is 956, 21.7".
205/60-13 is 916, 22.7"
225/45-13 is 990, 21.0".
185/60-14 (Spyder) is 915, 22.7".
185/55-15 is 904, 23.0".

In speed terms, if you have 6500 rpm and 3.77 this gives

155-13 113
165-13 117
175/70-13 113
185/70-13 116
185/60-13 108
205/60-13 113
225/45-13 104
185/60-14 113
185/55-15 114

If you are relatively sensitive, you can tell the difference between tires that differ by 2mph or even less. A good percentage of the population is not that sensitive, and will happily motor about with even a 10 mph difference.

So your 205/60-13 is practically the same diameter as the standard 155-13, although almost 2 inches wider. However, the wider profile will be more sensitive to camber changes while cornering and braking. So you will have to adjust initial camber settings (if you can) and use different roll bar thicknesses. There is a substantial amount of opinion on this site that the Elan does not handle as well with these wider tires, and you get the best handling with the old 80 series tires. You can be sceptical about this, or accept their arguments as you see fit.

However, the Elan with original tires was a .7g cornering machine. If you go with sticky modern tires, whether Michelin XAS FF 80 series, or a more modern 60 series tire, you can be getting 1g, more or less. This has implications through the car. Bearings, bushings, dampers, roll bars (and rear roll bars) are all impacted, as is the engine sump. The rear suspension suffers the most, since a strut suspension does not have as favorable geometry as a wishbone suspension. To alleviate this, you can go with the Spyder chassis, their wishbone rear suspension, adjustable upper front and lower rear wishbones, and test equipment to properly set up your car. It is not simple, that is why so many of us stay with relatively standard tires.

You ask a simple question, do you get a simple answer?

David
1968 36/7988

[dsly1]

Tell me if these wheel arches look standard or altered. They are wearing 225-50-13

What threadwear are the Michelins you are recommending ?

What tire do you recommend that is available in the US ?

I see what you are saying and it is not going to be my race car, so a nice tidy setup tobe able to daily drive it if I wish would be desireable.

Thanks
Shane

[dsly1]

Based on what is available at tire race for my 6" wide minilites.

My choces are:

185/60-13
Sumitomo HTR 200
(High Performance Summer)
or
Hoosier R6
(Competition)


175/70-13
Yokohama AVID T4
(Performance All-Season)
OR
Sumitomo HTR 200
(High Performance Summer)
OR
Yokohama AVID Touring
(Standard Touring All-Season)

185/70-13
Yokohama AVID T4
(Performance All-Season)
OR
Yokohama AVID Touring
(Standard Touring All-Season)


Any suggestions ? CAR will be driven occationally/weekly and hopefully spirited. NOT TRACK

[msd1107]

You could try to enter each of the prospective tires in the search box and see what has appeared on LotusElan.net previously. Tires have been a popular topic, due to the decreasing availability of high performance rubber in the desired Elan sizes. But there is a considerable amount of discussion.

Rohan has mentoned that the Hoosier 185/60-13 is actually the diameter of a 185/50-13 tire, so it is quite small.

The tire companies have code words to outline the basic level of performance you can expect from a tire. Standard Touring is basically for sedans. High performance is not, at least in an Elan perspective. Look at the tread wear rating. Anything over 200 is going to be too hard and not offer the cornering you want (I hope), anyway. DOT treadwear of 60 may be useable for Elans, since the treadwear rating is based on the rated weight, and Elans are typically half that.

Difficult subject, good luck.

David
1968 36/7988

[dsly1]

Only tire I am finding with treadwear above 60 and below 150 is the TOYO RA1 I might be able to locate this in a 185-60-13.

Any votes of confidence here ?


Thanks

[msd1107]

Look at this site

http://archive.mirafiori.com/show.php?f ... 137613#top

David