Trackday Zandvoort 13-4-2007

[Wally]

Originally Posted by Steve C

Hi Wally

Have you always had the rear wing on the car? Did you notice any improvement with it?

Steve

No,only recently. I am quite confident it gives better downforce and/or aerodynamics as I had a better top speed, but not more hp
It does really feel more stable at high speeds tho, that really is noticeble.

Dyno testing did give very interesting results, especially the timing advance differences were remarkeble. No higher hp however, even a few less, but tuning was off as lambda values were too high as it turned out and no time ($$) to correct it.

[oasis]

That really looks like fun! I hope I get some similar opportunity some day. The pics were fantastic. I liked how the lead grew over the blue Porsche from Pic 1 to Pic 2. Thanks for sharing.

[Wally]

You're very welcome.
I all honesty I must also mention that after about 6 laps he got the hang of it how we drove the circuit lines and passed us with his 300 hp on the straight
The porsche boys were nice about it though and we chatted about brakes, tires and gearboxes some afterwards. They were surprised to see my EFI-ECU behind the front seat and sort-of gave me the 'aha!' comment

[trevorbrady]

how much wider are those rear wings/fenders? they are obviously flared on the outside, but are they widened on the inside too?

car looks great BTW!

[Wally]

Rear 3cm inner and 4 cm outside
Front only +3cm outside (lip)

[trevorbrady]

thanks!

[Chris Percival]

Originally Posted by Wally

No,only recently. I am quite confident it gives better downforce and/or aerodynamics as I had a better top speed, but not more hp
It does really feel more stable at high speeds tho, that really is noticeble.

I have the same rear spoiler and can confirm this..

[Wally]

Thanks for the confirmation Chris!
Did you also have to make your own middle pedastal? I had to add that one as the horizontal plane vibrated badly above 70 mph and I just noticed it in my rear view mirror.. Now its rock stable.

[Chris Percival]

No, i didn't notice any vibration, but then the rear edge is folded up a little, so I can't see it flexing much, maybe yours is a little different?

[oasis]

Do you think the rear spoiler is more effective for stability than a Kamei front spoiler?

[Wally]

Originally Posted by oasis

Do you think the rear spoiler is more effective for stability than a Kamei front spoiler?

No idea really, but I believe the front you will notice more directly. The rear is more tricky when you brake at high speed and the rear suspension is lifted some extra because of this. Also lifting throttle after strong acceleration (i.e turbo'd cars) at high speed can cause an imbalance you really don't like. The rear wing will help counter this to some extent. And you will want all the help you can get at some point

@Chris: you will need to look in the rear view mirror for this you know LOL
yes, mine has the folded-up rear lip as well, but still it happenend. John didn't believe me either tho. Adjusting the mounting points somewhat didn't help either, so I made an extra support.

[oasis]

Originally Posted by Wally

... I believe the front you will notice more directly. The rear is more tricky when you brake at high speed and the rear suspension is lifted some extra because of this. Also lifting throttle after strong acceleration (i.e turbo'd cars) at high speed can cause an imbalance you really don't like. The rear wing will help counter this to some extent. And you will want all the help you can get at some point ...

Good info. Thanks.

[Steve C]

Hi

Does the wing have any affect on engine temps?

I used to help a friend with a beetle race car in the 80s, he was persuaded to fit a whale tail to his car and he found it a great help at Sydney track called Amaroo Park, at the end of the straight there was an uphill section, just after cresting the hill there was long right hander, he found the car much more settled after fitting the tail.

Steve

[Wally]

Originally Posted by Steve C

Hi

Does the wing have any affect on engine temps?

I had all 4 CHT's still in place at the track, but couldn't notice any difference in head temps. As the Porsche fan draws mostly from the back side of the license plate opening, its not conclusive for a type 1 style shrouds that draws from under the rear windscreen, but I doubt it would make a difference as there is quit some opening between the body and the wing (unlike the picture at the acn website).
Oil temp stayed well at or below 90 degrees Celcius (190F?) all the time, but the dry-sump gives a much more stable (and a bit lower) oil temp anyways, so I am cheating a bit in that respect also

[Chris Percival]

Originally Posted by Wally

@Chris: you will need to look in the rear view mirror for this you know LOL
yes, mine has the folded-up rear lip as well, but still it happenend. John didn't believe me either tho. Adjusting the mounting points somewhat didn't help either, so I made an extra support.

Haha! Ah thats why I didn't notice.. Hmm, its exactly the same, I have no idea why I didn't get the problem. Most odd.