Re: Just to add fuel to the fire ........

[Dick Roberts (Web admin)]

Posted by Terry Collier on June 01, 2004 at 11:27:20:

In Reply to: Just to add fuel to the fire ........ posted by Derek Harnett on May 27, 2004 at 18:28:44:

Hi

Sorry I have been away and have missed the fun(?)

This is just a point about the Club Cam which seems to have been ignored in the general furore. The basis for the implementation of the club cam was very simple.

It was impossible to police the existing cam. The cams available were not consistent with either the official Citroen figures, the Club regulations or each other. This meant that all cams used were technically illegal although they were from 2CV engines. My report to the Club made this clear. Again because of this it was possible for people to gain an advantage by checking large numbers of cams to find an optimal one.

The new cam meant that everyone was starting from the same base as far as the bottom end of the engine was concerned. Engineering expertise was limited to the top end -- valve train, heads and ignition timing. Also not to be forgotten was suspension, drive train and weight. This should help maintain the interest and motivation of the non glory boys.

The new cam was also designed not to be too hot. This was to avoid extra stress on other components which would have created more problems for the less technical amongst us and increased costs. It was designed to help improve car performance at all levels. It significantly improved the rpm range of the effective torque band which helps everyone with the horrible third to fourth gear change which tended to lose power. It had increased duration to help people with less good head designs to increase cylinder fill. The conclusion was that poor engines would perform better whilst the impact upon the top designs would not be as great. In this way we had a chance of closing more of the grid creating clusters of close racing cars. However, this assumes set up and driving skills are equal.In general from the feed back this is what we are getting -- a great deal of close racing -- more thrills -- for a cost of 25 to 40 GB£ -- small bills.

It is very difficult to compare different tracks in terms of evaluating performance. Mallory, Pembury, Oulton and Snetterton require quite different characteristics. Snetterton needs very little in way of low rev grunt but a lot in terms of mid to high range plus a well set up suspension unit. To reduce lap times by a second in the first three tracks takes some doing whilst at Snet and Donnington less so, it is all to do with the straight corner mix. Last year we retuned our car to each track in order to maximise the profile.

The vernier guage issue is just a red herring. With the Vernier you can alter cam timing by either plus or minus 3 degrees or I suppose up to six in one direction. You can also use to teeth setting to achieve six degrees. This engine does not really respond to such slight variations as three degrees -- moving from 0.5 degrees to 3.5 BTDC will not generate anything in the way of HP, but 0.5 to 6.5 might just. I do not use a Vernier!

Regards

Terry