Corner speed and thin aluminum

[supersportsp]

They are great most of the time, especially on a car like a Se7en. However, they can also bite you in the ass.

 

Short Summary: Car is very fast on Avon ZZR r-comps. Don't leave crap in your trunk at a track day.

 

A few weeks back I did another track day at Pacific GP. It is our rather big, local kart track. But they do lapping days, drift events, time attacks and super moto events there as well. It is pretty fun, relatively low risk as you never hit triple digits and very, very turny. Nearly a mile in length.

 

http://www.pacificgp.com/images/stories/trackmaps/PGPAerialMap.png

 

I was out on the new 13" wheel and Avon ZZR set-up that I bought from Karl. No other mods from the last time I was there.

 

With my 15" Prisoner wheel and Toyo T1-R combo, I was running in the high 1:17s to low 1:18s. I knew the car had way more in it, it was just that I didn't have the grip. S2000's on R-comps were running 1:15s and a well driven Exige S260 on R-comps was dropping in the low 1:14s.

 

The first session out I was immediately made aware that my car was in a new league. I was easily in the low 1:15s in the first session without even trying. The grip was a huge difference, especially in the rear, which seemed to be a weak point with the T1-Rs. Where as I could drift the rear with ease on the Toyo's, I couldn't break the rear end loose at all with the Avons.

 

Session 2 had me dipping into the low 1:14s as I got more confident in the tires and just how hard I could push them. Still could do no better than a very subtle drift of the rear, even on the fastest corner at what seemed to be full throttle. By now I had apparently impressed the guy running the track that day and he wanted to put a transponder on the car to get accurate lap times. I obliged as I didn't have a lap timer set-up as I got there late.

 

Session 3 I decided to really see what these new tires could do. The corner speeds I was hitting were pretty stellar. I was comfortably into the 1:13s in this session and started to actually be able to break traction at the rear. The grip was awesome. Even on 180 degree turns I could almost be at full throttle at the apex and just hold on from there (my car has a 180hp Zetec). I had to recalibrate braking points and what I thought was acceptable entry speed. I was also going too hard in some areas and driving a little ham fisted. Very fun, but not necessarily fast.

 

I had heard some knocking/thunking in this session coming from the back of the car, but I thought it was just the diff trying to cope with the massively increased loads from the grip. It was only occurring under maximum cornering which seemed to jive with that hypothesis.

 

Session 4 I decided to smooth it out, drive more precisely and focus on hitting apexs and getting the braking maximized. Again, I heard the thunking, which was a bit distracting, but I was having so much fun I didn't care. The car was ripping. I came in and checked with the scoring system and I had done a 1:12.75. That put me on par with a super charged Ariel Atom on R-comps and just behind a 350+ hp turbo Miata with huge wings and a 400+ hp turbo S2000 also with huge wings. I was elated with the new pace.

 

Then, I pulled into my little pit area to load up my stuff and head home. I opened the rear cover to load up my tool kit and other stuff and it hit me. The source of my thunking noise became readily apparent. Even though I had removed my spare to save some weight for the outing, I had brought my little Caterham jack kit just in case I needed to use it at the track. Even though I swear I had checked several times that the trunk area was empty, my jack kit had avoided detection. The little, but heavy, lug wrench had gotten out of the kit bag and cause all sorts of havoc with the paper thin aluminum in the trunk. Luckily, most of it was confined to the areas hidden by the wheel wells, but the left rear corner took some real abuse, and was quite visible on the outside of the car.

 

http://img.photobucket.com/albums/v715/tgodbout/Caterhamdamage.jpg

 

So, now I have to figure out if it is repairable. Luckily it didn't actually pierce the aluminum. I might see if my paintless dent guy (whom is very good) can take it on, but I will at a minimum need to repaint this area as it has flaked off.

 

Has anyone taken dents out of their aluminum successfully? If so, how did you do it?

[scannon]

I've had several dents successfully removed from the aluminum skin of my Caterham by the PRD guy. He was also able to remove a large number of hail dents from the aluminum hood of my Miata.

 

I'm guessing your PDR guy can get most of yours out except perhaps the really pointy ones which he can make less noticeable but not disappear.

[bball7754]

Did the same thing at an Autocross about 4 years ago. Was in the process of emptying the boot when someone came up and started a conversation. I got distracted, and didn't remove my jack kit.

 

I already had a few dents in that same area, but added a few more. I've come to accept them as providing my Seven more character.

 

Misery loves company?

 

Steve

[MHKflyer52]

I had to fix my hood which is aluminum after someone sat on it and dented it. You use a slapping bar and a little heat and lots of patients to work the stretched aluminum back into shape and even then I had to use a surface file and then sand the large scratches out and then used a scotch brite green pad to polish the aluminum to a burnished look. The dents are in front of the driver and behind the air filter which is flush with the hood.

See this post http://usa7s.com/vb/showthread.php?t=5634 and the ninth reply has a photo of what the car looks like after lots of work to smooth out the dents.

You will have a much easier time as you can get it very close and then use a thin layer of bondo to smooth out the little imperfections that will occur and then repaint the rear body section to match the color.

I would think the paintless dent guy should be able to get a lot of the dents out so I would start their and ask him or a good body shop to fix it for you.

Edited July 29, 2011 by MHKflyer52
Added location of another photo that shows finished hood.

[Jon W.]

You can probably remove the worst dents yourself with a steel dolly inside and by using a wooden or rubber hammer outside. The metal is already stretched. Don't use a steel hammer on the outside you risk stretching it more.

 

Put some painter's tape over it first. You might get it 80% the above method and by just touching up the peeled areas.

 

I'm afraid to get it 100% you might have to use heat to shrink it back (or at least aneal it to make it more workable) , or push the dents in and use filler as Martin said. If using heat, you'd need to remove the rear wing and repaint a larger area.

 

I'd live with it until I got tired of it and then replace the entire panel. That panel is not that difficult to make.

[Hank]

Good luck on getting it fixed. Where did you purchase your Avon tires?