FIA papers for S1 - period wheels

[jkatthehelm]

I am working on obtaining and FIA HTP for my S1 Elan, and have hit a problem with wheels.
According to the homologation papers I have the option of the std bolt on steel, converting to knock on steels, or to 6" 26R mag alloys.
I have eliminated the bolt in steeels owing to their known weekness, and am not convinced either by the strength of the knock on steels. The 6" mags would require modification of the body, which I'd like to avoid.

I am told by a scrutineer that if I can show that an Elan raced in period in an international event with minilites I may obtain papers with those wheels.
Can anyone help me to establish whether this ever happened?
Any info/photos/precedents would be a great help!
Thanks
JK

[batfish]

In Appendix K 2008 under the item homologation for Lotus Elans 26 and 26R it states on page 153?Minilite?-style alloy wheels of 41⁄2 or 51⁄2 inches are accetable for use. Therefore you should not have any problem with these type of wheels

Regards

Andy

[jkatthehelm]

Thanks Andy, the scrutineer is now happy!!
J

[msd1107]

JK,

Multiple questions here.

There is nothing inherently wrong with the steel wheels. They are quite light, for steel wheels. But 45 years of sometimes running into kerbs or into potholes gives ample opportunity to over stress the wheel. Good inspection practices allow then to be used safely.

But if you are going racing, the 4 1/2" rim is going to leave you with less cornering than a wider rim. The standard steel wheel is ~12.5 lbs. The 5 1/2" steel wheel is ~12.8 lbs. A period style Minilite wheel is under 10 lbs and a magnesium wheel even lighter.

If you think a 6" rim is going to be too wide, superlite wheels (http://www.superlite-wheels.com/wheelpage.asp?cat=5) makes period style magnesium wheels in a range of rim widths. Tony Thompson may be able to supply other than 6" rims also.

Probably, update from the Spitfire spindles and uprights to the GT-6 ones. They are stronger, and probably an undetectable change.

If possible, use aluminum hubs for weight savings (and if you can afford it, aluminum calipers). Use 7/16-20 studs and lug nuts (available through the Dave Bean catalog and others) torqued to 40 ftlbs instead of the weaker 3/8-24. Use a torque wrench to mount the wheels to the recommended dry torque specifications for the stud. The smaller studs probably failed because they were either under tightened or over tightened. Properly torqued, the wheels should not loosen or fail, but it never hurts to check regularly.

Center lock wheels and hubs are heavier, and are torqued to 200 ft-lbs. Not many people have a torque wrench of this capacity. Long distance racers used center lock wheels to speed tire changes. Vintage races do not need this.

Tire clearance is going to be a problem, and you may not be able to use 6" rims. (A 6" rim is going to extend out 1/8" further or more than a 5 1/2" rim) In any case, remove material from the inside of the fender, carefully and incrementally, until you get satisfactory wheel clearance or until you can see the paint layer (I ran my car this way for more than a decade, but it was the only way 185/70 tires would fit on bounce). At the front, there is no way to keep the tire away under all conditions. Make sure the tire fits while straight ahead on bump, and turns satisfactorily without bumps.

A 6" rim is the widest recommended for a 155 size tire. If you are forced to use a 145 to fit your fenders, a 5 1/2" rim is the maximum recommended.

Lots of options, but others have faced the same decision matrix. Good luck and have fun.

David
1968 36/7988

[jkatthehelm]

Thanks for the advice!
We're sorted - 155's on 5" minilites, clearance all round on the car, scrutineer happy.
Cheers
J

[Dag-Henning]

- bet your scrutineer will not be happy for alu hubs and/or calippers....They are, - unfortunately -, not homologated for S1 Elan.

Dag

[batfish]

Dag

Something that might interest you, I have just been talking to one of the UK eligability scrutineers regarding parts on race Elans that are not on the FIA forms.
He is just back from a meeting in Paris where it has been agreed to drop the item that specifically bans rose jointed suspension for Elans although this may take some time to be deleted from Appendix K.
He also told me that adjustable spring platforms are OK as long as they are inoperable ie with a blob of weld, brass alloy hubs are acceptable as are Girling AR front calipers.

Interesting as most race Elans run with these parts anyway but they are not specified in the homologation papers.

Regards

Andy

[Dag-Henning]

Andy, that was good news !! Let's hope this comes out in a written form. Too many of the scruteneers "rule" according to their own minds, which is very unsatisfactory ! I will discuss this with my other scandinavian Elan friends when me meet for racing in the "Scandinavian Historic Masters" last weekend in August, and try to get it commented by the FIA delegates.

Dag

[sebring]

i too am building an FIA S1 so am having the same problems with wheels -how did you manage to get 5" rims approved? - appendix K states only 5.5" or 4.5" minilites

[Dag-Henning]

- I doubt you will have difficulties with 5", as long as 5,5 is OK. Are you building a narrow body S1 ? Even 6" is homologated, but requires a wide body.

Dag

[sebring]

in reply to Dag - i am building a narrow bodied S1 - refer also to query re. seats

[toomspj]

I too am rebuilding an S1. Plan is for it to be narrow bodied and suitable for HSCC roadsports as well as GTS.
I'm not really sure why I've taken this on as I already have a '72 Sprint DHC that just never quite seems to be fit to go on the road - that's probably because i keep borrowing parts from it for my S4 racer.
I'll happily share stories with you guys. I am planning to fit a dual cylinder brake pedal box with balance bar etc but I really don't need to hand over 500 -600 pounds for one. Does anyone have a drawing, photo or sketch of one that they're proud of?

[batfish]

Hi

I fitted a Pat Thomas pedal box. It was quite alot of work as had to cut out the inner wing to make room for the extra cylinder and then shorten the steering column outer tube to clear the clutch pedal. Only got a photo of the engine bay at the moment but will take one of the pedal box if you want.

regards

Andy

[cabc26b]

how about this for the dual amster set up -

My s1 narrow arch project is stalled at moment so a bit envious the you are moving forward, I put 26R inner fenders to accommodate the wider wheels and think the I should be able to fit 5.5 in there but have not gotten there ...

[toomspj]

thanks for the photos - it would be good to be able to adjust the bias while seated.