Is it reasonable to think a WCM Ultralite could win D Mod at Nats?

[teamking]

Hi all,

 

It's been a while since I've been on this board. I had a haybusa/birkin but ended up selling it as I don't do track days any more.

 

But I've gone all-in on autocross and am a reasonable shoe at the National level in my CStreet ND2 Miata, where I've earned a couple of trophies at Nats.

 

That said, I'm thinking about D Mod. And if I go that route, I'd like the car (perhaps with a "reasonable" amount of work) to be nationally competitive since my daughter and my son-in-law are both fully capable of winning in the right car (both finished 2nd in CSL/CS last year).

 

In addition to Birkin, I've also owned a couple of S2000's.

 

So, a WCM Ultralite has some appeal to me... and I wonder if it is a good platform for building a nationally competitive D Mod car. The advertised wait of 1240 is perfect for me and my son-in-law, and we'd actually have to add some ballast for my daughter to get up to the 1400lb minimum weight (with driver). But I see these cars in lots of configurations and I wonder how many of them actually tip this scales at 1240 with enough gas to avoid starvation.

 

Also, is the outboard front suspension a non-starter at Nats. And it's hard to know what track width and wheelbase the top cars are running (and how the WCM compares).

 

So, I'm very naive about all this and looking for input from those that know more than me about building a competitive D Mod car.

 

Thanks in advance!

[BirkinBernie]

"I'd like the car (perhaps with a "reasonable" amount of work) to be nationally competitive"

 

That kind of depends on what you mean by "competitive".  I *think* you will find that the DM cars that are winning nationally are all hand built, zero compromise specials.  Their index is something like .90 of AM.  Getting there with any car resembling a standard issue Seven is, IMHO, impossible.  (FWIW, I autocrossed from 1972 till 1998, in cars ranging from AM to HS.  So I have some background....).

 

But you can have bags of fun trying, and I'd love to see you prove me wrong!  I say go for it!

[panamericano]

Check the SCCA website for the car that usually wins DM at Nationals and see what is running at other national tour stops.  From the few photos I recall, I would bet you are up against 200 HP (bike) and 900 pounds.  Like Bernie said, the cars are custom built race cars.  A WCM should be able to hold its own in Region, Division and no idea about Pro and Tour stuff.  Just depends on who shows up.  I wouldn't let all that be too big a concern in buying a good WCM.

[11Budlite]

I have no experience with autocross, but I agree with what's been said previously. Looking at the results from last year, it looks like an Ultralite would be a good starting point to build a competitive D-mod car. I think you'd have to modify it to the limit of the rules, and then develop the suspension, drivetrain, and aero to gain every advantage of the platform. It should be a fun endeavor. Here's a photo of what I believe is last year's winner. 

 

Edited June 27 by 11Budlite

[Davemk1]

I have a friend who used a Ultralite for autocross for a number of years and after seeing it run countless times I'd say that one could make it nationally competitive but that it will take a lot of work. I think there are a few challenges -

 

 - like my Westfield the Ultralite is powered by a Honda S2000 engine. It's a wonderful powerplant that revs to 9000 rpms and that's good. The downside is that it makes very little low end grunt to pull out of tight corners. My S2000 engine makes 250 hp and 150 ft/lbs but peak torque is at nearly 7000 rpms. At 3000 rpm's it makes only 118 ft/lbs, which given the weight of the car isn't bad but I doubt this would be nationally competitive. My S2000 has ITB's, a tubular exhaust, and light pulleys and flywheel to get these numbers.

 - the two Ultralites I've personally seen did not have an provision to use sway bars front or rear so it can be hard to really fine tune the handling. One can add a bar but it's not a straight forward "bolt-on" proposition.

 

 - Looking at the build of the Ultralite makes me think it would be a real job to get it down to min weight of 1400 lbs with the driver. One issue is that the S2000 engine and trans are very heavy compared to a Duratech or other engines out there. I wonder if there are any Ultralite owners out here with actual real world weights of their cars?

 - I think to compete at a national level I think that one would need to do a lot of work on the aerodynamics. Much of the underside of the car is open and it would need a full width nose so that you could run an effective front splitter. Last year's DM winner looks to have he winning recipe when it comes to aero and I'm sure it wasn't easy to get that to happen while staying close to min weight.


I've been competing in the Northwest for many years in a Westfield and I think if I had a VERY good day I could make the top 5 in my car nationally...or should I say that I think the car is up to the task. I think that the Westfield, Caterham or Birkin would be better platforms to start with....particularly if they used a small engine/turbo/supercharger to boost low end torque. I suspect that these cars are lighter to start with and that the suspensions are easier to adjust and fine tune.

Just my 2 cents.

 

dave