After I promised you guys to make a car feature of the Denstsport 240RS, here it is. I have been in contact with Bill Washburn from Denstsport about this car who drove the car during the GT Live Red Line Time Attack event.
It seems that more and more car builders are giving more attention to how the air flows around the car. Same goes for Dentsport, the rear quarters are cut in half to let the air pass as smooth as possible. In the opening picture you can see the diffuser they used during a time attack event. Before the entire build started, Dentsport stripped the car bare and welded all the seams for more rigidity. They also went to extremes to make this car as light as possible.
I like the Lamborghini style air vents on the sides of the car, they are there to feed air to the radiator at the rear of the car.
The story of Bill when he went for the third number one finish on Virginia International Raceway (VIR), note the following was written by Bill Washburn from Dentsport.
“I consider the event a success for me only because I was able to squeeze onto the podium with only 4 complete laps around the track the whole weekend and with 5 year old Hoosier R3s. The car handled so well and once the suspension has been tuned a bit it can definitely do 2:00 laps at VIR. I was able to do a 2:08 (besting last years 2:13) before something on the engine let go after two laps of the timed session. (note: It looks like coolant contaminated the oil at some point and the 4th rod bearing spun.)
The weekend started with a cylinder misfire under boost. This was happening at idle once in a while over the past two months and it seemed to fix itself so I forgot about it. After three sessions missed because of that I took out the Autronic and MSD ignition and tracked it down to one of the pins in the 12 pin Deutsch connector. I think something got in there connecting the plug at one point and the pin for the #4 spark into the MSD had backed out, just enough for intermittent spark.
Another problem was the coolant spewing out of the overflow which sucked because it is in the back of the car and shoots forward into the cockpit when it relieves. The surgetank cap ended up not being completely tight. Every practice session was wasted because of these two things. I figured out the coolant problem during the practice session Sunday morning. The remainder of the session was cancelled due to a heavy shunt of the Takata car. So I went into the timed session with no practice besides laps cruising the track after realizing the car was still not running right.
I lowered the boost to 19psi and drove the car without worrying about anything. It ran awesome, handled well and by the middle of the second lap the tires gripped better than any I have ever had (note; get good tires next year). Both my competitors had brand new autocross tires (super sticky but only will last about 5 laps on a circuit) for the timed session so I was happy with the car.
I didn’t even care that my engine failed during the third timed lap(especially since the flat bottom and diffuser created a giant, smooth, 50 ft long rooster tail behind the car with the oil smoke). I have little to work on over the winter, mainly a new engine. I am mainly excited because the suspension was mapped out on paper by an engineer and actually having it work was a relief. The engine ran so well when it wasn’t misfiring or shooting coolant and these issues are already fixed (now I just need to find the funds for a new motor!). The downforce with the flat bottom is incredible as well.
Overall it was successful”
Maybe you recognized the frontbumper, it’s made by DRFT a division run by C-West. To accommodate the rear tires Bill used 50mm overfenders in the rear. The rest of the body consists of custom made parts. For extra downforce Bill decided to put a tried and tested Voltex wing on the back using extended wing stands.
The interior is as Spartan as it gets, but then again what more do you need? The vital signs can be tracked via the various meters. We have a Tachometer and a boost meter right in front of the driver, the others are for oil pressure and water temperature. The three lights in the middle are from top to bottom Shift Light, Low Oil Pressure and Alternator Low Charge light. You can see there’s not much left of the standard dashboard, everything is made from carbon and weighs around 1lb. Talking about weight savings.
The gear shifter connects to a custom DSG/G-force T5 5 speed Dogbox to ensure the fastest gear changes while pushing hard.
After a crash at Summit point last year Bill was forced to rebuild his front end. It resulted in the contraption you see before you. Bill rebuild the entire front end with a Chromoly and titanium to attach the front splitter. With this entire structure finished it is easy to remove the front end for easier access.
This reminds me of the S14 I posted a few days ago, where the owner also made sure that the splitter was attached to the chassis and not to the bumper.
Here we see the underside of the car seen from behind. This goes to show how much work went into the aerodynamics of the car. I really see an uprising of car builders that are building more and more extreme cars to compete in Time Attack series all around the world. I think it is just a matter of time that we will see a World Championship Time Attack just like the Red Bull Drifting World Championship.
The SR20 engine has been heavily modified with JE pistons, Eagle rods, Peak Performance racesprings and so on. The Garrett GT3076R twin scroll turbocharger is mated to a HKS 60mm wastegate. All the intake and exhaust plumbing has been custom made by Dent Sport Garage. The electronics are handled by the Autronic ECU.
The poweroutput lies between 400 and 550bhp depending on the boost level, torque is around 450ft/lbs at the wheels. For a more refined spec list you can check out Dentsport own page here.
One of the most important things on a Time Attack car is the suspension. When it is dialed in correctly you can win seconds. Dentsport turned to TIP Engineering to make them a custom suspension system. Ohlins dampers together with Custom Eibach springs are the preferred choice.
So there you have it, the Dentsport 240RS Maxi E2