Castle Combe

[Mad Mart]

A bit late I know, but I'm off to Castle Combe in a mo. It's the classic & sportscar action day. £10 entry. I'm only spectating unfortunately.

[Mad Mart]

If anyone has next Monday off (not tomorrow), I'm taking part (hopefully) in a Track day at CC with MGoT & CT. The only downside is that the MGs will be in different sessions to the Triumphs......wooses!

Anyway, it's free to get in afaik & I shall have an empty passenger seat for those who dare!

[Mad Mart]

If anyone wants to take part in their Dolly on Monday, I beleive there are a couple of spaces left.

[knightrider150]

if only i didnt have to give a weeks notice for giving holiday.

hope the weather holds for you mate!

[Nick C]

Is there a link somewhere for how to get to the circuit? I've got Monday off so might pop up to watch/try and blag some passenger rides...

(tho presumably you need a lid for anything on track? damn...)

[Mad Mart]

Here's a link to the CCC website:-

http://www.castlecombecircuit.co.uk/findus.htm

I'm pretty sure there will be helmet hire, not sure how much, give 'em a ring.

[Mad Mart]

Well we had a great day & no rain to boot (except for a couple of spots).

There were only 12 cars in our sessions, all Triumphs unfortunately. It would have been nice to mix it up a bit with the MGs as it was at Silverstone in March. Ah! well. The sessions lasted for 15 minutes and we had 4 in the morning & 3 in the afternoon.

Near the end of the second session I was just going round Quarry, I lost all power & the rear wheels locked up for a second. Pulled it over onto the grass and tried to start it again but it wasn't going to. It was then I noticed the green light on my dash wasn't working (leccy fan) so I immediately thought "fuse blown". Anyway, after the session had finished I got towed back to the pits, opened the bonnet & sure enough a fuse had blown. For some unknown reason I had brought the kitchen sink but not any fuses Plenty of people with spares though. So I replaced the fuse & moved the leccy fan & leccy water pump to a different one, thinking it may have been over-loaded. Off I go for the next session, did about 2 laps then coming past the pits it did the same thing again. Of course I now have to wait for 10 minutes for the session to end to be towed back in again. Once is annoying, twice is embarrassing.

Bonnet up, same fuse blown. It must be a short somewhere me thinks. Only the leccy fuel pump & leccy ignition left on that one. So I traced the lead for the fuel pump & found the cause in about 5 seconds, the lead had wedged itself under my seat mounts, chafed & then shorted. I was both pleased & annoyed at the same time. Pleased 'cause I wasn't going back out 'til I found the cause of the problem but annoyed that I let something so trivial spoil one of my sessions.

Anyway, that was about the only problem that any of the Triumphs had all day I think, except for a Spit driver who had to purchase a silencer as his car was too noisy.

Myself & "Sierra brake" Jon had some great tussles, his Sprint was quicker in the corners but mine was quicker down the straights. I think his Sierra front ARB helps but in truth I think he's just plain better than me (he has done a lot more track days than me). Mine is a lot quicker than his out of the corners but that will be down to the 4.1:1 final ratio, he's running standard ratio. Both cars are pretty even on power.

I was just touching 130 mph at the top of Avon Rise so all you clever bods out there, what was my actual (approx.) speed, running on 185/60 13s ?

Here are some pics taken by professional photographers kindly nicked from Chris (2Toledos) from the CT forum. Hopefully some videos to follow.

Robin is in the Yellow Sprint, Chris (2Toledos) in the Toledo & Fred (a very nice young lady) in the 2000.


Chris again, me & Jon (Trackerjack) in front.

[DavePoth]

Was that 2000 standard? it looks like it might scrape the door handles on a hairpin. Top effort though.

[Mad Mart]

Was that 2000 standard?

Absolutely, I don't think they come any more standard than that.

[tinweevil]

I was just touching 130 mph at the top of Avon Rise so all you clever bods out there, what was my actual (approx.) speed, running on 185/60 13s

105 I make it.

[tinweevil]

Arghhhh can't do it! Can't just state stuff without working or reasoning.

Accounting for diff:
130 / 4.1 * 3.45 = 109.4mph

Circumference of standard tyre:
Sidewall = 170 * 0.7 = 119mm
Rim = 330mm
Circumference = pi * d = pi * 2xSidewall + Rim = 1784.4mm

Circumference of fitted tyre=
Sidewall = 180 * 0.6 = 108mm
Rim = 330mm
Circumference = pi * d = pi * 2xSidewall + Rim = 1715.3mm

Difference beween standard and fitted:
1715.3 / 1784.4 = 0.961

So correct for tyres:
109mph * 0.961 = 105.1mph

Took a bloody site longer to write that than the original calculation took!


Overall correction factor to remember is:
1 / 4.1 * 3.45 * 0.961 = 0.8086

80% indicated speed near enough.

Tin

[Sprint36]

I make it 103.5 mph as the standard tyre width is 175 not 170.

David

[Mad Mart]

Some more pics, half inched from the CT forum:-

[tinweevil]

Ta. Fitted tyre is 185 too.

Accounting for diff:
130 / 4.1 * 3.45 = 109.4mph

Circumference of standard tyre:
Sidewall = 175 * 0.7 = 122.5mm
Rim = 330mm
Circumference = pi * d = pi * (2 x Sidewall + Rim) = 1806.4mm

Circumference of fitted tyre=
Sidewall = 185 * 0.6 = 111mm
Rim = 330mm
Circumference = pi * d = pi * (2 x Sidewall + Rim) = 1734.1mm

Difference beween standard and fitted:
1734.1 / 1806.4 = 0.959

So correct for tyres:
109mph * 0.959 = 104.5mph

Overall correction factor to remember is:
1 / 4.1 * 3.45 * 0.959 = 0.8069

Still 80% indicated speed near enough.

[Mad Mart]

Thanks Tin & David. I've now saved your calcs so that I can refer to them in future.