Car Feature>> Dentsport 240rs Maxi E2

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

-Jeroen Willemsen


pictures are made by Budski Photography and Karen Snyder Photography



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great car ....saw it in an auto mag when they first entered the time attack, they've improved a lot since then. the mag article was total BS however, comparing the this car to a NA s2000 on street tires.


To be fair, it was the Super Autobacs team car, with much higher budget, and the "Street tires" were Yokohama A048 in their super soft compound (which we can't get in the states), versus our 3-year old used Avon tires.


Oh, and talking about world championship time attack...

the 2009">World Time Attack Championship


I've still never really heard this car I don't think.

Nice write-up.


Dentsports performance was excellent especially considering the low budget and the used tires however the autobacs car was a street machine with low horsepower and the article was misleading. they made a big deal out of the comparison as if the autobacs car somehow lost an epic battle between the two cars. I'm not trying to discount Dentsports hard work.


Yeah, I remember the article in the mag on this car too. This car is cool! I like how its taken a number of years to dial in and build this thing, making it faster and faster every year.


This feature is sooooo dope!



you can hear her first startup earlier this year here:


The car is so F'ing RAD!


Awesome car. It proves that aerodynamics are important at any level of the sport. Great build, and definitively a benchmark/inspiration for my own S13 grip machine.


I have a lot of respect for Bill, Alex and the rest of the crew. Those folks know what they're doing. And the car is a very simple piece of art.

I remember seeing this car in the early stages 3 years ago or so. I kept browsing dentsport website to see more pics and how the project was turning. Maybe some of you might not know, but Bill went so far to cut the A pillar, the B pillar and the C pillar and lift the whole roof to access to the cage and build a proper roll cage.

I also remember seeing the pics of the car on the Longacre scale (19XX lbs.....!!!!), that's what I call, shaving some

How about the water injectors in the plenum?

Again, my hat off to those peeps, Great job. Keep up the good work.

...and thanks to Jeroen for posting a car that trully deserves a spot light :)



you are right about comparing the two cars with one being a street car (with a stereo and navigation!) and one a race car. It was a good battle regardless. On the other hand, the ASM car did have the same Toda 2.2 motor found in their super light Tsukuba racecar. ASM also hired a top running Formula Atlantic driver and Bill had a handful of track days to his name.

Here is a hillclimb the car competed in 2007

and a video from VIR a couple weeks ago


if they were really thinking about the aerodynamics of the car and not only copiying some higher team does(even tought its a good thing to do when you know nothing in aerodynamics)they wouldnt have put those enormous air intake at the rear and alot of other stuff would hae been done in other way.

For the huge air intake,the problem is that they will cause alot of drag and mess up the air.Instead they could have designed some naca air duct which wont mess up the flow of air over the body and will still be able to draw some air to the radiator.another issue is the hood vent hole that will cause the air to be messed even tought it will give a bit of downforce.I am sure this is not the purpose that hood,so for a vented hood,they should have designed one with louver instead instead of this one like what you can see on LeMans racer at the wheel arches on LMP.There is alot more of issue like those for aerodynamics.


snoro, you should email bill about this ASAP.



There are already large naca ducts being made at the moment. The original intent of the car was to run hillclimbs but it has moved more toward a dedicated circuit car. The aerodynamic defaults of the car are slowly being addressed but the hood, rear end and side pods are all areas that are currently being changed in one way or another (with the side inlets a #1 concern)


Has this car and the BC/CWest S2000 ever gone head to head?



They did last weekend at GT Live.


I know the first prototype S2000/ C-West and now Gary Castillo/ Brian Crower car pushed some 1.35G force in steady turns at Button Willow (it was featured on Sport Compact Cars a while ago) that's definitely a good battle to see.

Then again, the C-West S2000 has dry carbon fiber body, which is a lot of $$$.



another thing that you could do is to redesign the front splitter so it would a shaoe like this __-----__ to take a part of the air go to the nuder tray and the rear diffuser and make it work even better to generate more downforce and less drag.


nuder=under and also if you can lower your side skirts,you ill be able to create ground effect which will give you alot of downforce with less than a big gt wing.But check first if its not illegal in your serie to have ground effect and also make sure that you use ground effect on clean track and not some bumpy one like Nordschleife cause if you car bottom out and you have some ground effect and you are in a curve,the flow under the car will be all disrupted and will lose instantly downforce from the bottom of the car


Global Time Attack has one goal in mind, setting records at tracks around the United States. That is


I'd like to see a tire company sponsor this car.  This guy enjoys what he does.


I'd like to see a tire company sponsor this car.  This guy enjoys what he does.


I'd like to see a tire company sponsor this car.  This guy enjoys what he does.