What sort of tooling resin can I use to make a press tool?

One of my customers wants to retrofit a vent in the front fender of a Porsche. This is to relieve air pressure that builds up in the wheel well at high speed. This mod is worth 40 lbs of front downforce. So cutting the hole and rolling the edge is no big deal on 1 or 2 sets of fenders but my customer thinks we could be doing up to 50 sets of fenders. The material I need to form is steel .028 thick. Of course this is not flat, the opening is irregular shaped about 18" long and varies between 2" and 8" wide. I need a 3/16 or so flange in all around the opening. I can form the first one by hand and use it to make the tooling. But what to use?

Whats wrong with Kirksite? Its been used for decades.

I haven't tried it , and .028 steel might be a bit much,

But I have shaped aluminum over fairing molds made from the "gorrilla hair" glass reinforced auto body filler (bondo)

It;s certainly cheap and easy to come by. (NB, not the glass bead light weight stuff)

If you have all the time in the world to let it cure, glass filled cement would be an option. I think it's sold as patching material.

gbent said:

Whats wrong with Kirksite? Its been used for decades.

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I don't know anything about it, I have always made hard tooling in the past.

so you want to put louvers on the front fenders? usually plastic parts are used. or are talking about shaping the hole?

dian said:

so you want to put louvers on the front fenders? usually plastic parts are used. or are talking about shaping the hole?

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Using standard porsche louvers from a 991 GT3RS. I am wanting to make tooling to roll the edge of the opening. A 1/8" or so flange around the opening will do the job.

Something like these fender vents? 520 HP and 9000 RPM redline, no turbos. I had this beast on the local road course race tracks about 14 days last summer. Only got passed a few times by drivers with race rubber. My street tires are good, but not as good as race rubber.
But cutting open the front fenders of newer GT3s may not be as popular as you think. Resale value of the car may suffer.

Scruffy887 said:

Something like these fender vents? 520 HP and 9000 RPM redline, no turbos. I had this beast on the local road course race tracks about 14 days last summer. Only got passed a few times by drivers with race rubber. My street tires are good, but not as good as race rubber.
But cutting open the front fenders of newer GT3s may not be as popular as you think. Resale value of the car may suffer.
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Wow! That's beautiful!

Joe Miranda said:

Wow! That's beautiful!

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Sounds good too.
GAME ON - YouTube

Scruffy887 said:

Something like these fender vents? 520 HP and 9000 RPM redline, no turbos. I had this beast on the local road course race tracks about 14 days last summer. Only got passed a few times by drivers with race rubber. My street tires are good, but not as good as race rubber.
But cutting open the front fenders of newer GT3s may not be as popular as you think. Resale value of the car may suffer.
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No big deal, the Porsche dealer only gets 680.00 each for the fenders. Hell Chev charges 550.00 each for the front fenders on my dually!

What track is that Scruffy - I don't recognize that one.

As for tooling resin - I'll observe that people are having some success making press brake tooling with 3d printers (there's a member here whose done it, some other folks on the web) - so that might give a hind about what would work for this project.

bryan_machine said:

What track is that Scruffy - I don't recognize that one.

As for tooling resin - I'll observe that people are having some success making press brake tooling with 3d printers (there's a member here whose done it, some other folks on the web) - so that might give a hind about what would work for this project.

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Club Motorsports in Tamworth NH. Beautiful track, good elevation changes, and better runoff than most. Considering it is partially carved into a mountain. We have another "local" track at Palmer, Ma that is also carved into a mountain. Lots of Armco and tire walls, and little runoff.
The Vette I chased down had an instructor in the car with him. He tried to keep up after I passed him. His instructor told him to back off.

Brake tooling could be carved from Delrin maybe?

So the underside is going to be kirksite/bondo etc. how about the punch ?
Rubber in a containment box ?

digger doug said:

So the underside is going to be kirksite/bondo etc. how about the punch ?
Rubber in a containment box ?

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Or maybe an oak dowel, just lean on it and roll it. As long as there is something behind it it should work.

Scruffy887 said:

Sounds good too.
GAME ON - YouTube

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That ain't just cool. That's waaay cool!

Scruffy887 said:

Something like these fender vents? 520 HP and 9000 RPM redline, no turbos. I had this beast on the local road course race tracks about 14 days last summer. Only got passed a few times by drivers with race rubber. My street tires are good, but not as good as race rubber.
But cutting open the front fenders of newer GT3s may not be as popular as you think. Resale value of the car may suffer.
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That must have set you back a few clams!

Rapid_Tech said:

That must have set you back a few clams!

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Hey, it's Massachusetts - lobstahs, not clams...

That's a sweet track, I'd imagine NHMS loses it's charm after being at a place like Club Motorsports.

And yet Lime Rock Park is apparently still on the IMSA calendar while some of these much nicer new tracks generally aren't (at least the schedules I've seen - I pay stunningly little attention anymore....)

Milland said:

Hey, it's Massachusetts - lobstahs, not clams...

That's a sweet track, I'd imagine NHMS loses it's charm after being at a place like Club Motorsports.

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NHMS is an OK track and they also have a NASCAR oval. Ran the road course there a few times.

bryan_machine said:

And yet Lime Rock Park is apparently still on the IMSA calendar while some of these much nicer new tracks generally aren't (at least the schedules I've seen - I pay stunningly little attention anymore....)

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Club Motorsports is a private track and they also rent it out to different clubs. LRP does have members too and has a lot of history. I was there last year the day after IMSA cleared out. Temps in the high 90s. 2 days with Empire State Ferrari Club. Crazy event. 20 minute sessions that started 20 minutes past the hour. I ran 8 sessions the first day and 6 the second day. The Ferrari guys did not want a Porsche to pass them at first. But so much Lizard Green filling up their mirrors and they finally pointed me by. I left all of them in the dust. After that first session where I passed all of them I was respected and they got me by right away. Ferrari club is the only club I know of that allows passengers. Near the end of day one a Ferrari novice (novices not allowed passengers other than instructor)asked me to give his 16 year old daughter a ride. Sure. When the time came she is wearing a full fire suit and full helmet. The fire suit was brown and a bit large. She looked like she was wearing Lion King pajamas. I asked her if it was OK to put my camera on her, OK. Camera shows her face and all sorts of data like Gs, track position, SPEED. I backed off a bit because most novice passengers will not do well with any drift or sliding. I still passed everybody and she looks perfectly calm in the passengers seat. But you could see her lean over to see the speedo at the end of every straight. Usually 135+. I uploaded it on youtube, but made it private because she is a minor. Sent the link to her father. But I wonder if the father ever shared the link with her mom.

In about 2003 the race team I owned and drove with had a sponsor deal where people could buy a square on the car, and people who bought enough squares could get a ride at a party at the end of the year - at the road course at Las Vegas speedway. This was an LMP675 car - think formula car with fenders and a funny weight balance.

So various passengers went for rides, and not a one could hold their heads up under braking or in the corners. What was funnier was the fit but small women who could just get their heads back up after braking, then when the driver stood on the gas out of the corner their heads were pinned hard against the headrest for some time.

After that they all understood why we did neck exercises....