So with the tutelage of you guys over the past few years I got a chance to prep a car for a gentleman making his first run for the SCCA Majors (formerly National Runoffs). This is our first weekend and with a fraction of the budget of the big boys in P2, so far we qualified 3rd for this afternoons race. If we finish well enough today and tomorrow, we only need to run Sebring next weekend and Road Atlanta to be in for Daytona in September. Already avoided a catastrophe yesterday when I spotted a control arm bolt nearly ground off by the curbs during my final check.[
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Even cooler is that I've had two different team owners ask me to come crew for them next year. Anyhow, thanks for helping me get a foot in the door!

How did it go?

Pretty good Shane. These cars are really finicky, and this one being a home-built chassis has it's own quirks. Everything is hard to get to and I'm still trying to get a handle on what's over-built and what isn't engineered well enough.

We finished 6th on Saturday and 5th on Sunday out of 8 cars entered in class. Personally, I don't think it's setup right yet and the driver isn't doing quite what it's capable of.

Right now, the fronts are wearing out the inside shoulders of the tires over the weekend and since he always complains about not having enough front end grip, I'm positive that it's just got too much camber for as soft as the suspension is - i.e., he can't transfer enough weight to the corner to get it to get a full contact patch on the ground, so most of the time the inner portion of the tire is doing the majority of the work.

I suggested we add some positive camber to get a little more contact patch for him... but he is adamant it's setup correctly. We have to qualify again for Sebring on this Friday, so we'll see what happens. Still have to change the oil, tires, chain and sprocket before Friday anyways.

If it's home-built who did the design work? Can you post a picture of the suspension?

Yeah I can get pics this weekend. The owner dropped the car off at Sebring on the way back to town so he didn't have to tow twice.

The car is built on an 85 Van Diemen Formula Ford chassis, which is simple enough, and being steel, should last for a very long time. Typical double wishbone, outboard brakes. Suzuki GSXR 1000cc linked to a "locked" rear shaft. The aero bits are all homemade fiberglass by the guy who built in, which is a local dude- don't recall his name. Even being 150 lbs overweight, it's pretty quick at least in a straight line - keeps up with most of the other cars in the class.

Nice; can't wait to see them. I'm just wondering what the kinematics look like. If it has very long arms like some modern DSR's it's kinematics are likely very roll insensitive so it very well might have too much camber like you're thinking. It might also have too little weight on the front and not be stiff enough in roll in the rear. With a spool (locked diff) or solid axle you often need to lift one rear wheel or you'll get a push.

Motor choice is great; Suzuki builds fantastic motors. Does it have a drysump or fancy pickup in the flat pan? If it doesn't and he's not killing motors from oil starvation on a regular basis he's definitely not driving hard enough!

Does he have any data logging? There are some great books out there (Jorge Seeger's stands out to me) which have lots of great data processing formulas and tips so you can analytically look at car performance and have concrete data justifying changes.

Thanks Jim!

I'm positive that these are stock Van Diemen control arms, which seem pretty long to me, but not *as* long as the more modern chassis with the inboard spring plate setup in front of the driver's feet. I already had to replace the RF when he hit a curb or something and parts are only available from Van Diemen.

I also know that the front is far too light, or at least for the way he is driving it. The motorcycle engine thew the balance of the chassis a bit out of whack, not to mention he's driven front engine cars his whole career. On top of that, the rear bar had to be removed for the spool setup (thanks, sorry, couldn't remember the name). I've suggested that we look into a rear bar, which wouldn't be all that hard to do, but he's a cheapskate - which is why we don't have datalogging or a radio either.

George Dean out of WA built the motor, and though it's not a dry sump, he builds his own custom pans, windage trays and pickups as far as I know. It's about the only decision the owner has made that spared no expense, and so far, the only thing I haven't had to touch!

For this weekend, I'm going to try to convince the owner to soften up the front end and add some positive camber. Then we'll look into a rear bar for later in the season.

So the car understeers and the owner says the setup is good? Have y'all been taking tire temps? That's data that you could present to him and set up the camber from there. That's how I go about it.

I think he knows that there are obviously problems with the setup, but he's afraid to tinker with it. I explained that dialing out the camber is a five minute deal. But he's stubborn, like most drivers who aren't really mechanics. He doesn't own a pyrometer, so I'm at least going to bring my digital thermometer with me this weekend and get a baseline.

What he REALLY needs to do is come off the $100 and actually run a test day, usually held on Thursdays before the race weekend. I can't ever get any good temp or pressure readings anyways because he only runs qualifying and races. This is why I'll probably consider moving on to a bigger team next year, not to mention I think I'd learn a lot more.

I had the same problem crewing on a catamaran. Owner was happy with last place. I wasn't so I left the team. You can't go forward if the owner can't figure which way that is.

Kind of interesting this thread! I have tuned several IMSA prototype lights cars over the years, and had good success, winning two. IMSA Championships.

Tire wear is not always indicator of an issue, but understeer AND tire wear is. So, a bit more detail is needed here. Radials? And let's remember that VD's of that era were designed to run on bias ply's... Is the understeer all the time (mechanical) or at speed (aero). The front of the car is frankly speaking a mess, with the NACA ducts being in one of the worst locations or best of you want to reduce front downforce bias.

I imagine this is a non tunnel car? Please Add some tire temp and tire details and it should be easy to determine

Eric - Wow! Blast from the past. How are you? Mark

Yeah, blast from the past! Eric, if you're ever at IMSA races, look for me (usually with Ganassi or Multimatic). We need to catch up.

BYW I was really surprised the owner didn't have anything to test tire temperatures.

In any event looks like your having fun!

I'm sure looking forward to running a DSR on a hill climb, but as preparation will be doing a couple of track days to get comfortable with the car prior to running on a hill. And trust me I'll be doing temperatures every couple laps!

Also wondering how down force works (or doesn't) on crowned roads, like we find on BLM land where we run the events.

Hello Guys,


Great to hear you guys are still at it. I spent a few years in Grand Am and IMSA, Grand Am was good competition, but too much circus, hard to put together a string of wins.... IMSA was better, and a lot of test driving. LMPC cars are a little different than the an EP 914.... Kevin, I hope the family is good, since I last saw you, I had a daughter as well, and she is 9....... I know, it has been some time....

I am looking for fly in crew work for the season, let me know if anything is out there.


Erik

I remember about your daughter. I have one of those now, too.... she's 7. Zach is 9, too. Time flies.

The crew guys I works with are all full time. They may know of some opportunities.

I haven't raced the 914 in quite a while. And with the IMSA season, there isn't much opportunity.

Totally forgot to update this when the Runoffs were over. It was a great season, but was a ton of work. Something to be said about running a sorted, purpose-designed chassis versus the homebuilt car that Ed ran this season. But all in all, it was a success running a 20 year old 20k homebuilt car versus 125k+ Stohrs and Radicals.

We finished 14th at Daytona, which was mostly due to just staying on track. The guys at the front, Chris and Jeff are truly in a league of their own.

http://cdn.growassets.net/user_files/scca/....pdf?1443221791

But the cool part is Ed ran the Turkey Trot (regional race) just after Thanksgiving at Sebring and won! I don't think he's won a race since he was racing in ITB in the early nineties, so it was nice to get him a good result with all the headaches we had over the past 2 years.

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The goal for next year, in my mind, is to get another 50 lbs off of the car (and the driver). I finally have a couple of setups for Sebring and Daytona that I'm happy with, but the rest remains in getting the car closer to weight and having Ed drive it more aggressively. I've got some other tricks up my sleeve like getting it to flat-shift and some aero tweaks, but those are more fine tuning.

Ed has also insisted that I get my SCCA license this year, and (apparently) already registered me for drivers school in June. Not sure how I feel about that, since I'd be doing it in this car and it's by far the fastest thing I'll ever have driven. But it does look fun...

I've never driven a DSR, but coming from many FSAE autocross cars, flat shifting is awesome! Obviously our drivers were much less experienced, but flat shifting was worth ~.18 seconds per shift minimum (nominal was probably nearer to 0.4-0.6 s) and with good ignition cut and fuel trim likely easier on the motor than clutching in the heat of the moment.