Shaun_E

I drive to all events and had the soft Kumhos fitted for most of last season - for track days and road I used CR500s. This year I have bought some hard compound Kumhos for track days and general road use and will fit the softs for sprint events (including the drive there). That way I can get the car set up once for road, track and sprint.

Yellow SL #32 - member of Drowned Rat Racing

Yes. Mine are fitted on 13" race wingstays but they will fit on the normal 13" stays just a bit further from the tyre.

Yellow SL #32 - member of Drowned Rat Racing

Thanks folks. will get some from local supplier.

Rob - Barbie has already offered me the use of her air rivetter!

Yellow SL #32 - member of Drowned Rat Racing

Correct. You will either need CSR style wings or, as I have done, fit some RiF wider wings.

Yellow SL #32 - member of Drowned Rat Racing

Some of the rivets have pulled through the drivers side floor pan so I need to re-rivet the floor.

1. What size rivet do I need? (length and diameter please).

2. Are steel rivets the best bet?

3. Can you get rivets with a wider head as the holes in the aluminum floor have become enlarged where the old rivets pulled through?

4. Is there an easier way than drilling of removing the old rivets? I don't really want to use a chisel as that might damage the powder coat.

Thanks,

Shaun

Yellow SL #32 - member of Drowned Rat Racing

*arrowup*No throttle bodies and unlikely to have the ECU either.

Yellow SL #32 - member of Drowned Rat Racing

Robin - fit them inverted, i.e. with the damping adjusters at the bottom.

Be thankful you didn't find a sheared damper mount bolt! That was a real pain.

Yellow SL #32 - member of Drowned Rat Racing

I got mine from Cromwell but they are a bit pricey. Looks like they are £5.01 each now!

Yellow SL #32 - member of Drowned Rat Racing

The Caterham 8 spokes are 6" front and 8" rear. IIRC the offset is ET24. If you go for wider wheels then that offset may not work.

The lightweight wheels are 6.5" and 8.5".

The critical dimension is the backdepth - how far the wheels extend into the car from the hub face. On the fronts this is limited by the wing stay and should be around 113mm. On the rears it should be around 140mm.

Yellow SL #32 - member of Drowned Rat Racing

Edited by - Shaun_E on 2 Mar 2009 09:47:49

As Adrian says I have run 235 Kunhos on Caterhan 8" rears for the last season with no issues but have now changed to split rims.

My new rears are 8.5" with the backdepth the same as the Caterham ones (I have an overslung ARB) and the outside of the tyres are very close to the outside of the wheel arches. The offsets to run wide fronts are different to the rears - if you try to run with the same front and rear wheels you will either end up with the rears sticking out or the fronts fouling the wingstays.

Yellow SL #32 - member of Drowned Rat Racing

You won't get over 200bhp for much less than that.

Think about the cost of the following:

Throttle bodies

Programmable ECU

Forged pistons

MS2 or VVC head ported

Decent bottom end (Scholar maybe?)

Camshafts

New bolts, gaskets, etc.

4-2-1 exhaust

Assembly by someone who knows what they are doing

rolling road session

Yellow SL #32 - member of Drowned Rat Racing

My cutoff switch operated when I put a wheel on a large curb at Angelsey last year during the club sprint there. It left me sat on the racing line while the next car approached at 100mph . I am not the only sprinter it has happened to and many actually bypass the cut off completely.

For racing I would definitely do it.

Yellow SL #32 - member of Drowned Rat Racing

In CXRs I was looking at 8" fronts and 9" rears but with standard width wings and an overslung ARB. It was the fronts that were a real problem with the offsets but even the rears would likely have been an issue with the range of offsets available.

The wheels I have bought are 7.5" fronts and 8.5" rears as that is what the other Carlos Fandangos 😬 have and I knew they would fit if I kept the standard Caterham backdepth. Image could build wheels with the correct backdepths so I went for them. With the 235 rear Kumhos the clearance from the rear wing looks a bit tight but should be OK.

Yellow SL #32 - member of Drowned Rat Racing

I had them specially coloured "brake dust black" so that you can't tell they are dirty until you pick them up and put them in the back of your car 😬.

Yellow SL #32 - member of Drowned Rat Racing

I have to say I am a little bit disappointed but it's not a bad weight.

I wanted to get CXRs but couldn't get the offsets I required. Split rims were the only way to get the size and offset I wanted and I wasn't keen on having magnesium wheels with all the maintenance required.

The Image wheels look fine and I have had the centres powdercoated and the rims anodized (all in black) - hopefully they will stay in a reasonable condition without having to be polished all the time.

Yellow SL #32 - member of Drowned Rat Racing

I know everyone is interested in what things weigh so, for the record, I thought I'd stick my new Image wheels on the scales.

They are 13" Billet 4 style 3-piece wheels with billet aluminium centres and spun outers.

7.5" = 5.0kg

8.5" = 5.2kg

I guess not amazingly impressive for split rims but lighter than many wheels and the centres are pretty solid.

Image do an extra light weight wheel - Billet 93p - which did tempt me but, given the abuse my car gets, I decided against it.

Yellow SL #32 - member of Drowned Rat Racing

Entries in the post today from the Elwells.

Yellow SL #32 - member of Drowned Rat Racing

On the road, R888 SG compound (soft) will be fine although you won't get many miles out of them. A single trackday would destroy them.

I used them for a season of sprinting and probably covered about 2000 road miles on them as well.

Yellow SL #32 - member of Drowned Rat Racing

Yellow SL #32 - member of Drowned Rat Racing

I've only recently bought a complete set of the soft compound

I just can't keep up in the class 5 arms race ☹️

Yellow SL #32 - member of Drowned Rat Racing

Thanks everyone. I'll take a hacksaw/dremel/angle grinder (whatever fits!) to cut through the spacer and bolt and see what I am left with.

I think Michael has some spare spacers but if not then Mark or Darren I'll give you a shout thanks. If the wishbone is toast then a spare would be great Simon - it's the driver's side - annoyingly the only new one on the car!

Yellow SL #32 - member of Drowned Rat Racing

The lower wishbone damper mount bolt has sheared on my car. The breakpoint is about half way inside the damper sleeve, so the damper won't come away from the wishbone.

I believe I have 2 options:

1) cut through the bolt between the damper and the wishbone

2) sacrifice the wishbone - take an angle grinder to it either side of the mounting point

Which would you do or is there another solution?

An added complication is that the damper is a Nitron with spherical bearings instead of rubber bushes.

Solution 1 looks tricky as there is very little room - maybe a thin hacksaw blade would fit?

Solution 2 is easy enough but will cost me a new wishbone. If I can't get the bolt stub out I'll need a new one anyway.

Help please!

Yellow SL #32 - member of Drowned Rat Racing

Edited by - Shaun_E on 15 Feb 2009 16:22:49

A 2000 reg car needs a Cat for sprinting.

Yellow SL #32 - member of Drowned Rat Racing

Careful - it is possible that silicone can foul the catalytic converter and can affect the lambda sensor.

If it's on'y fitted for the MOT then I guess not such a big deal but it could end up failing the emissions test.

Yellow SL #32 - member of Drowned Rat Racing

Edited by - Shaun_E on 13 Feb 2009 16:15:45

Change to Avon CR500 tyres - this is the biggest step as they are much lighter than Yokos or similar.

Caterham 8 spoke 13" wheels would then be the second step.

The difference between an 8 spoke with CR500 and a minilight with Yoko is massive.

Yellow SL #32 - member of Drowned Rat Racing