This is Thomas Hamilton's number 19 D-Sports Racer, a 750lb D Sports Racer. This thing is tiny; it looks to me like a shrunk down version of a Can-Am car Jim Hall might have come up with in the 60s! This car is actually an A-Mac chassis built in the 90s by Art McQueary in California.
The A-Mac AM-6 was built specifically to compete in the popular D-Sports class in SCCA. DSR is known as one of the most open class allowing almost unlimited aerodynamics and suspension designs, with regulation on engine size, engine type, and overall vehicle size.
In the 90s, this car was very successful in the SCCA Club Racing scene, winning championships and races across USA and Canada.
This AM-6 runs a 1 litre 4 cylinder Suzuki GSX-R engine. 1000cc is the largest size allowable for a 4 stroke DOHC engine, with 1300cc allowed for a pushrod engine, and 850cc allowed for 2-stroke engines. From what I understand the Suzuki GSX-R engine is one of the most popular choices in the class with its power output and reliability.
One of the first things I noticed about the cars racing in DSR was the vast differences in setup. Some looking like classic Can-Am cars, others like open cockpit prototypes from the mid 90s, and some similar to LMP cars running in their low drag setups.
This cars runs with a full width rear wing with a massive chord and endplates. Running those full length solid endplates increases the effectiveness of the rear wing just as much as adding extra span to the wing would. If you're a nerd like me, check out this article written by Michael Fuller here.
You can see there have been some diagonal struts added to help increase the stiffness of the wing and stop it from buffeting. A large Gurney Flap is run as well and helps to fine tune the aero balance.
I would imagine in a class with very little aero restrictions that the roll hoop and supports would be faired in' but that might just be me being picky.
A good sized splitter is mounted with a detachable front steel subframe, and you can see the small diffusers ahead of the front wheels which helps to provide a little extra downforce.
This car definitely looks seasoned. I wonder how many track miles it has seen over the years?
Central hard mounted steering rack which I imagine makes this thing feel like the palms of your hands are connected directly to each piece of aggregate in the asphalt. You can just see the tips of foot pedals here, which are just behind the front axle centerline to provide a better margin for safety. You can also spot the small dry cell battery which is mounted between the driver's legs.
Typical mounting of the double adjustable Konis keep the bumps in check and 4130 chromoly A-arms top and bottom keep the suspension, strong, stiff, and light.
Rear propulsion is via a chain-drive setup, using some custom parts and a high performance motorcycle chain. You can see the steel detachable wing support that lives under the bodywork to help transmit the downforce efficiently into the chassis.
13" wheels and 9" slicks in the rear, and 7" slicks in the front provide the grip. I just love how compact this car is. It would be a blast to drive one of these.
Next time there is a Regional or National SCCA event near you, be sure to check out the DSRs; they often run with the faster Formula cars on track and are just awesome to watch.
OFFICIAL SPEEDHUNTERS SUPPLIERS
Stohr WF1 is the DSR to beat at the moment. Some are under 900lb packing over 200hp, tunnel aerodynamics producing 2.5G corner speeds and amazing braking. I have one on my shopping list for the future!
Any info on the wheels? Ronals?
Compomotive 13" three piece wheels.
fantastic article and glad you looked at the technical aspects of the car. if possible could you cover the next dsr race in full.
Thank you for doing more extensive coverage on other types of cars such as Can-Am racers! Great post!
That is rad! Gotta find some video of these DSR's racing! Wow!
Wow, thanks for opening my eyes to the world of DSR, now I really want to find some way to get one of these machines
Cool car.
I nerd at Mulsanne's Corner too.
Cool and I'm glad you guys are showing this but pretty heavy though. I bet a modern Formula SAE car could beat it on an autocross course... 600cc but 300lb lighter at least. FSAE cars have moved away from rod ends in bending on the a-arms, 6 ball CVs, carbs, direct acting shocks, car mufflers, and a lot of them run carbon chassis'.
Nice one. A feature about the famous Osella PA20s would be nice. They are used for Hillclimb and Trackuse all over Europe for years and are fast as Hell!!
Thanks Mr.Jarrett. A new aspect of car culutre i would have other wise not been exposed to. Keep it up!!
Great article, I want one.
Downforce nerds unite!
Maximum respect
This is awesome. I didnt even know there was this type of racing. Seems like an awesome way to get into racing,
I spent one afternoon drawing out side illustrations of cars I wanted to build, and one concept I sketched up was a "Mini Le-Mans Prototype" type of car. Like most of my sketches or ideas, Speedhunters comes up with a feature of something similar and better, and fuels my drive even more. Man, this just makes me wanna build a car like this. You know, when I get the money and such.
Article written by someone who isn't an idiot. Very impressed, love it!
Looks like an absolute blast to drive. Is it quick in its class?
More articles like this!
M - Formula SAE would of course be faster around a tight autocross course if you just took a DSR in circuit trim and did an autocross. FSAE have extremely short gearing and are designed around the restrictor to produce maximum hp and torque.
Conversely, put a FSAE car on a full size track and it would get swallowed alive by all of the DSR's. Don't think for a second this A-Mac is fast in DSR these days either. They've come a long way!
http://youtu.be/MfoQ01ZoxcY
Tell me a FSAE car would beat that...
Australia is a very large country and driving distances can be long. Don't spend all day driving just to keep to an unrealistic itinerary. You will see and enjoy it more with a relaxed schedule. Either plan to travel a shorter distance or allow more time. There may be many local attractions that you will miss if traveling to a tight schedule.
Awesome article. It's nice to see an article on here cover some technical aspects of the car being featured, as opposed to the typical 'Here's the engine, here's the wheels, here's how low it is'. Kudos.
this looks much the same as a racing-sereis we have here in Norway called "Shortcar"
http://shortcar.com/en/
very cool, lets have more like this please! i enjo seeing form following function in all motorsport.
Because Race Car!!!
Awesome post, nice and technical !! Its great to see speedhunters covering other forms of grassroots racing, you guys rock!! Please continue to show the many ways to terrorize local track... Maybe even make it to Solo Nationals next years, i promise you wont be disappointed with the quality of cars.
hey! an article that touches on technical material! more of this, less of hardparking stance coverage!
Hey folks.
This car has any kind of a diferential?
Since its chain driven.
This car does not have a diff, though there are other Amacs that do.
great post love looking at these types off things been going to some local hill climbs here in aus seeing all the custom single seaters with all kinds off engines and suspension set-ups. just the right amount off technical information
This article is awesome, more of this style please
yes indeed, DSR is the bomba!
now show us a feature on a modern DSR with ground effect tunnels and full on aero
still nice to know that grasroots racing with older chassis is alive and kickin
I think the allure of these race cars is the fact that there's so little to them. I mean, it's primal, ya know.. There's the light weight chassis, race components (susp, brake, tire...), light and FAST engine, and light weight shell. Only the essentials, and to top it off, you're flying down the track as low to the ground as possible.. In the end, I believe it's about 'you' and speed. The more you get, the more alive you feel and these types of motorsports bring you as close to that addiction as possible. It's a great feeling
Awesome. Thanks for responding to my answers in your survey. I asked you to make articles with mulsannes corner and you did something like that. Thanks a lot. More articles like this.
that rear shot is just the best, you gotta post up more stuff like this.
Arctiels like these put the consumer in the driver seat-very important.
Great post, so glad this isn't just another loser's ill-conceived, poorly executed money pit.
Is Carl Jarret still working for Speedhunters? I really miss his grass roots coverage!!
Is Carl Jarret still working for Speedhunters? I really miss his grass roots coverage!!
This was a nice article by Carl providing a view of our club level sports racers. You can see more of these same A-Mac cars here :: https://sportsracernet.smugmug.com/Cars/A-MAC
The whole world of club sports racers can be explored throughout our entire archive site :: https://sportsracer.net
Cheer,
Tom Clayton
Just ran across this story, very cool, though there are a few inaccuracies. This particular car was not actually built by Art McQueary. Art is the owner of Amac Fabrication, originally in Santa Clara Ca. I'm the original builder and owner of this car. I was an employee at Amac when this car was originally built in 1993. It originally had a dry sumped kawasaki zx10 of 1980-1982 vintage, and was only converted when Tom bought it about ten years ago. It did not have many events on it when Tom bought it. I actually finished, raced, and sold it over the course of one weekend in August 1993!