Hello and Diff Advice

[Paul999]

Hello all

New to the forum so introducing myself along with a quick question. I'm currently on an enforced break from racing for medical grounds. I should be back out next season so keeping myself busy converting an FIA rally car into an FIA race car. Hoping to be out with HSCC in Historic Touring Cars.

Can anyone give me a steer as to what CWP ratio is best for a circuit car? Mine is currently far too low...

Cheers, Paul

[pad4]

have a look on swifty site - the most expensive is certainly what you need - lol

Pad

[Pete]

3.9 is usually the way for circuits.

Going Class D or Appendix K and a half?

[rich@minispares.com]

I found a 3.9 to be too high geared and dropped down to a 4.1 which is far better

You really need to combine your choice of final drive with the drop ratio, so you can nudge it back and forth a little to suit what ever circuit your at, you also need to look at cam choice and gearkit choice as both of these will have some impact on what is correct for you.

[Paul999]

Thanks all, much appreciated. The plan is to go App K, but HSCC App K!

Cheers, Paul

[YMJ]

Thanks all, much appreciated. The plan is to go App K, but HSCC App K!

Cheers, Paul

App K but with Lumenition or the like, then?

[Paul999]

Exactly. It's running points at the moment but if you can't beat them, join them!

[YMJ]

Can't say I agree with all this Appendix K-except-you-can-do-this nonsense. Either it's Appendix K or it's not, e.g. Class D (HSCC) or "Ron's Rules" (Masters), etc.

The whole idea of building and running an App K car is that IT'S MORE DIFFICULT TO DO. That's the challenge!

It's takes a more than a good few hours (i.e. all winter) to....set up the suspension geometry, balance your SUs and make the ignition work at 8000rpm+ which is the whole point of having similar cars racing against each other.

However, at the end of the day, race organisers get more entries if they are lax with the regs. They're red hot on the continent, it's more black and white and your HTP is actually worth the paper it's written on. It's getting so anyone who goes to the extreme bother of running an AppK is now in a minority in the UK.

[Tim Harber]

3.9 it is . Rich has a small motor so needs shorter legs

Interestingly, one of our HSCC Mini mob came in yesterday and confirmed what I suspected. He built the car with an ATB diff years ago as it was percieved as being state of the art at the time

He changed to a Minispares Trannexy type one and was over 3 seconds a lap quicker on the Silverstone GP track

[rich@minispares.com]

my car is quicker with an atb than a plate diff, but I think the power the plate diff saps is more telling as I have less to start with.

[Paul999]

Can't say I agree with all this Appendix K-except-you-can-do-this nonsense. Either it's Appendix K or it's not, e.g. Class D (HSCC) or "Ron's Rules" (Masters), etc.

The whole idea of building and running an App K car is that IT'S MORE DIFFICULT TO DO. That's the challenge!

It's takes a more than a good few hours (i.e. all winter) to....set up the suspension geometry, balance your SUs and make the ignition work at 8000rpm+ which is the whole point of having similar cars racing against each other.

However, at the end of the day, race organisers get more entries if they are lax with the regs. They're red hot on the continent, it's more black and white and your HTP is actually worth the paper it's written on. It's getting so anyone who goes to the extreme bother of running an AppK is now in a minority in the UK.

I do take your point. The two series I'm intending to run in the UK, HSCC and Classic K, both allow electronic ignition within the App K structure. Its not strictly App K but I do want to be a bit competitive. I think the problem with App K as it stands is that given the recent increase in costs, the delay in obtaining papers, and the lifing of the papers, more series will see it as pointless (pun not intended!) and set their own rules to the spirit of App K. I've never raced with Masters but I hear they take a fairly pragmatic, sensible approach.

Thanks again to everyone for their advice - much appreciated. My background's in single seaters and sports cars, people are much less helpful with advice there than here!

Rich - do you mind if I drop you an email? I need to order a few bits and pieces and would appreciate a bit of a steer.

Cheers, Paul

[YMJ]

Tell you what, we'll meet halfway.....I've got absolutely no problem with competing with fellas (even if they beat me!) who are starting out and taking a few shortcuts, for example running with HiLos until the suspension settles down.

As I mentioned earlier, setting up AppK is really hard to do and if you go straight in with a fully legal but not-functioning car then its no fun for anyone and no one wants that.

Tim Harber blew me away when he told me what he built his car for....and I thought I'd done mine on the cheap!

[Paul999]

I think there's not much chance of beating you, I've never raced a FWD car before!

Unfortunately when I stripped the engine to check the diff today, there's damage to the flywheel and the crank. A few late nights ahead...