Steve Heath - 520 body mods
Discussion
steve, enjoyed your talk about the racer at rockingham on saturday, very interested in the aerodynamic mods, would you be able to post a few pics and a bit of an explanation of the front end etc, my 350i seems to get very light above about 70 mph (obviously not a problem on public roads then)thought the tyre for an air damn seemed a good idea but couldnt see where it was situated, also is there any benifit to plating the bottom of the car with aluminium sheet or similar, they do resemble an upside down bath, wasnt sure if that helped matters either.
any help would be greatfully recieved, even better if you could use your experience to design some aesthetically pleasing bolt on mods we could buy from your engineering company.
regards
and thanks to every one for a cracking day out.
jon.
any help would be greatfully recieved, even better if you could use your experience to design some aesthetically pleasing bolt on mods we could buy from your engineering company.
regards
and thanks to every one for a cracking day out.
jon.
There are some piccies in this month's sprint which show the position of the air dam.
Plating the underneath with ally is not worth it as the ground effect doesn't really start working with the ride height that a road car has and as a result air starts leaking into the undernaeth from the side etc. End result is a lot of effort for little return. There is also the issue of practicality vs performance. For a road car it is not practical to lower the suspension like the 520 to exploit some of the ground effect/aero mods because it destroys the car's road manners. The ride is harsh and uncomfortable and speed humps are a real nightmare. However without this. the mods do not work as well - if at all - so it is a compromise. The 520's mods do work well but it is not simply a question of replicating the body mods but the whole car set up.
If the car is getting light above 70 then check the obvious things like tyre pressures (quite common for these to be too high), front wheel bearings/suspension play and rake angles. Toe can also be quite critical as well and can make the car unstable at speed. I would check these first.
Plating the underneath with ally is not worth it as the ground effect doesn't really start working with the ride height that a road car has and as a result air starts leaking into the undernaeth from the side etc. End result is a lot of effort for little return. There is also the issue of practicality vs performance. For a road car it is not practical to lower the suspension like the 520 to exploit some of the ground effect/aero mods because it destroys the car's road manners. The ride is harsh and uncomfortable and speed humps are a real nightmare. However without this. the mods do not work as well - if at all - so it is a compromise. The 520's mods do work well but it is not simply a question of replicating the body mods but the whole car set up.
If the car is getting light above 70 then check the obvious things like tyre pressures (quite common for these to be too high), front wheel bearings/suspension play and rake angles. Toe can also be quite critical as well and can make the car unstable at speed. I would check these first.
I would second this .. if it feel light at 'just' 70 mph then you have a set-up problem or something is not working .. as wedges are pretty stable up to .. well double that figure (on a race track of course..).
Lower the car and you just have a night mare with speed bumps.. Just jacked mine up 3/4 inch at the rear as my exhaust was suffering.
Lower the car and you just have a night mare with speed bumps.. Just jacked mine up 3/4 inch at the rear as my exhaust was suffering.
IIRC the guy at the 2006 BBWF said the back should be slightly higher than the front.
The front spliter can help on the SE's but only at 140+ as had mine on a autobarn at 155 and was ok I have the front splitter and no rear boot spoiler, Where other without the splitter have said there's have felt light at 140+ but at 70 you sould not bet getting these problems.
The front spliter can help on the SE's but only at 140+ as had mine on a autobarn at 155 and was ok I have the front splitter and no rear boot spoiler, Where other without the splitter have said there's have felt light at 140+ but at 70 you sould not bet getting these problems.
rev-erend said:
I would second this .. if it feel light at 'just' 70 mph then you have a set-up problem or something is not working .. as wedges are pretty stable up to .. well double that figure (on a race track of course..).
Lower the car and you just have a night mare with speed bumps.. Just jacked mine up 3/4 inch at the rear as my exhaust was suffering.
Yep.Lower the car and you just have a night mare with speed bumps.. Just jacked mine up 3/4 inch at the rear as my exhaust was suffering.
Definitely sounds like somethings not working to spec.
Check out all the suspension. Something could be past its sell by date. And only then get a proper four wheel alignment done!
All manner of faults could cause this behaviour but if I were to have a wild stab in the dark I'd say a duff bush or too much toe out (front or rear!)
Just noticed the time. Now where's that "... Days to go" thread
Check out all the suspension. Something could be past its sell by date. And only then get a proper four wheel alignment done!
All manner of faults could cause this behaviour but if I were to have a wild stab in the dark I'd say a duff bush or too much toe out (front or rear!)
Just noticed the time. Now where's that "... Days to go" thread
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