SU with minimal aero

[brakesareforquitters]

Hello all, I'm a new member, I joined to glean whatever knowledge I could before starting the build for my first 4 wheeled track toy. I don't have any 4 wheeled track experience other than a ride along at the BMW Performance Center in SC back when I ran a BMW motorcycle dealer. My plan is to build, buy, or some mixture of the two an asphalt late model based track car and run HPDEs in order to earn my license and eventually run ST1 or SU.  I'm happy to have the conversation about why I'm choosing that platform but my question is if they can be competitive without any aero elements outside of a wicker bill spoiler and possibly a front splitter. My understanding is that they split SU between full bodied cars and sports racers/prototypes but most of the full bodied SU cars I have seen had higher downforce setups. I did see that a car of this type took 3rd in class at the Championships recently but I'm not sure the field was very big. I'd appreciate any insight into this as I am still undecided on if I'll run a motor in a lower state of tune so it can fit into ST1. 

Edited June 19 by brakesareforquitters

[Brett B.]

We have lots of old Cup cars in our Southeast Region. People pick them up at reasonable prices from teams in the Mooresville, N.C., area offloading them. 

If you go into Super Unlimited, you'll be classed with open- and closed-cockpit prototypes, which are in almost all cases quicker than a late model chassis on a road course. Because you have the ability to detune, and tune precisely to maximize the car to the ST1 rules, that seems like the better bet. 

Super Touring 1 (ST1) = “Adjusted Wt/HP Ratio” equal to, or greater than, 6.00:1

I would like to see what people who actually race in ST1 think. 

[brakesareforquitters]

Thank you for the reply, my gut tells me you're right, that's probably the best choice. I will say the late model will be much lighter than a cup car though. These cars are 2800lbs ready to race (including driver) with an iron block when they're setup for short track racing but with an Aluminum block and no weight requirement the car  should be close to 2650 including driver whereas a cup car weighs 3400lbs w/ driver. The Late Model also has a lower coefficient of drag. It's probably still not enough to overcome the cornering/braking advantages of the downforce cars but a slick car with a bunch of tire and a power to weigh ratio around 4.5:1 would be a hoot. 

[Tansar_Motorsports]

you're essentially talking about turning a super late model into a trans-am TA2 car.

I've had the same thought many times over the years.
speed/$ ratio is pretty unbeatable.

But can it win against fully optimized corvettes?  --> Probably not

First problem is the solid axle rear suspension, which will hold back your ultimate cornering potential.  No great way to overcome this, unfortunately.

Second problem would be aero.  You need it.  Big wing, big splitter, rear diffuser, hood venting, all of it.  Without it you'll be giving away a lot of cornering speed.

Third problem is you'll take a 0.4 "non-production" modifier to your pwr/wt ratio.  So all else equal, you'd still have less HP than a corvette.

 

That doesn't mean you shouldn't do it.  Its still a great solution to a fun, fast, affordable track car.

 

(I'm looking forward to the current Cup cars trickling out into the used market.  Independent suspension, center lock wheels, sequential trans...  Throw some aero on those and you'd have an absolute weapon) 

[brakesareforquitters]

You're talking about running it in ST1 correct? I was under the impression SU didn't have any restriction on power to weight but I also just started looking at the rules. However, you're right it will essentially be a TA2 car without much of a rear wing and with 100-150 or so more HP. To your point the speed per dollar is very high plus spares are fairly ubiquitous so you can pick up a lot of quality stuff second hand from circle track racers with bigger budgets. 

I feel the same way about the modern cup cars, all you have to do is look at the Garage 56 car from LeMans last year to see what they will be capable of with a little more aero.