Chat with Mike Dunn
Moderator (9:08 PM)
Mike will be here any second!
Mike Dunn (9:09 PM)
I am here and ready to answer your questions!
Mike, how come the throttle blades dont open during the burnout?
Mike Dunn (9:10 PM)
Since they do the burnout in water, it doesn't require much horsepower to get the wheels to spin. They just open the throttle blades, about one-eighth to one-quarter at the most to get the tires to spin for the burnout.
Scott, Long Beach,CA.
HI Mike, Have any of the teams talked to about returning as a driver?
Mike Dunn (9:12 PM)
I spent last year trying to put a deal together. I was working for a top team and was not able to do that even though I had an opportunity to possibly drive. When the opportuntiy to do TV came up, I went with it because even though it is not as good as driving a good racecar, I like it better than driving a bad racecar!
Art Yonkers NY
Hi Mike, Since Ron Capps prefers that his body not be lifted after the burnout, how is the second mag turned on and final adjustments made/ Thanks
Mike Dunn (9:14 PM)
Not all teams do the burnout on one mag. Some do it with both mags so if they are not raising the body to switch on the other mag, I asssume they are doing the burnout with both.
Tyson, Marble Hill, MO
I know that you probably are not supposed to be biased towards any driver, but who would you like to see win the top fuel and funny car championships this year?
Mike Dunn (9:15 PM)
Hell, if I can't win the championship, I don't care WHO does!
Billy Concord CA
Mike whats that little button in the middle of the steering wheel on the fuel cars?
Mike Dunn (9:16 PM)
More than likely it is a parachute release. Some drivers have a radio and a switch to activate it. It was probably one or the other.
Bradley McKenzie Tn
Mike what was your favoritw race car? See ya in Brainerd.
Mike Dunn (9:18 PM)
Hey Bradley, I didn't know you knew how to use the internet! I'm impressed! My favorite car was the Joe Pisano Oldsmobile's I drove from 1986 to 1989. They were the last cars I drove with a transmission and you activated the clutch manually. You had to do a lot in the car in a short time. It was a blast.
Paul Ft. Myers, Fl.
Is Big Jim Dunn your father? If so, why aren't you driving for him?
Mike Dunn (9:19 PM)
Yes he is my father. He doesn't pay enough!
Duane Wilson Upper Sandusky Ohio
Mike , I have a top fuel question for you that has been troubling me for some time. After they do the burn out and back up the crew chief will go to the motor and make a adjustment or two but I always see them pull something out of the air scoop and then show it to the driver . What is he doing when this goes on ? Mike I really like what you bring to the booth but I really liked you behind the wheel , any plans in the works ?? Thanks , Duane.
Mike Dunn (9:21 PM)
Normally the thing they pull form an injecotor will be a plug on the side to adjust the idle. Normally they will raise th idle a little bit before the car goes into stage.
Have you given any thoghts to being a crew chief?
Mike Dunn (9:22 PM)
I did when I found out how much they made! But I have a general knowledge of the sport but I do not have the techincal knowlegdge of a top crew chief. I think I'll keep my day job.
wil (salt lake city , utah)
hey Mike , are "hats" on fuelers aluminium or some thing else?
Mike Dunn (9:23 PM)
For those who don't know, the hat is basically the fuel injector on top of the supercharger. The majority of those are made out of carbon fiber these days.
What is going to happen when guys like Richards,Coil,Kalitta and Beard retire? Do they teach all the secrets to the younger crowds?
Mike Dunn (9:25 PM)
Yes, they do. There are some young guys coming up like Dickie Venebles, Mike Neff and Jimmy Prock and Jim Oberhofer all how have been trained by the guys you mention.
Paul Ft. Myers, Fl.
John Force once said in the beginning of the year that it is Tony's turn to win and he will using his car for testing. Do you think that is why John is not doing good?
Mike Dunn (9:28 PM)
Even though John won the championship last year, towards the end of the season they did not have a dominant race car. They knew they would have to make changes to stay ahead and win. Obviously they have struggled doing that. In my opinion, it's just a natural thing that happens in racing. Sometimes to move ahead you have to take a step or two back.
Explain how the reverse works in a nitro car that does not have a transmission. Thanks
Mike Dunn (9:31 PM)
Even when the cars had a transmission, the reverse was still bolted to the back of it. Now that they don't have one, it is bolted to the back of the clutch management system which is bolted to the back of the bell housing system. The reverser just has a planetary in there that when you move the handle, it moves a dog gear over the planetary gears which allow the output shaft to spin in the reverse direction which allows the car to back up.
Jason - Weatherford, TX
Mike, What is the white stripe that is on the rear tires on some of the Fuel Dragsters, and Funny Cars.
Mike Dunn (9:33 PM)
They paint a white stripe around the circumfrance of the tire and they also paint a white patch from the wheel to the outside of the tire normally about 4-5 inches wide. They do this because when they videotape the car running, it's easier to see what the tire is doing in the video .. how much it squats and how much it is spinning.
Hi Mike, When we see the "sparklers" coming out of the fuel cars towards the end of the runs,what kind of engine parts are being used up??
Mike Dunn (9:35 PM)
Normally when we see the sparklers, it is pieces of the exhaust valve. When the engine if running to leane at the other end, it burns the cylinder heads. The exhaust valve takes the majority of that heat.
how much boost are the superchargers putting out?
Mike Dunn (9:36 PM)
Normally about 40-45 lbs. of boost. Up here in Denver with the thinner air, they have to spin the supercharger faster to achieve that boost and even then they are still lower than what they see at sea level.
Mark Wright, St Petersburg, FL
How much fuel is expended during a top fuel run? Thanks
Mike Dunn (9:38 PM)
Normally they will use about 12 gallons to make the run .. that includes the burnout, backing up and making the actual run. The run itself burns probably 4-5 gallons.
wow, the question actually went through, internet has been acting up. how do the engines stand up to having no cooling system? a crew member up here told me it was from the aluminum sleeved block, and then the rest is absorbed in oil. however, a normal aluminum sleeved motor like an LS1 would seize up, whats special about the top fuel motor?
Mike Dunn (9:41 PM)
That's a good question. The blocks are aluminum but the sleeves are steel which helps. With the volume of fuel that the cars run, they can regulate the heat in the engine. The engine only runs for about two minutes, maybe two and a half, from the time they start the car until they are finished in the rundown. They also take the cars apart after every run. That helps cool the car down.
Jeff Derencin(Mission Viejo, CA)
How long do fuel drivers keep the clutch pedal pushed in from starting the car to staging?
Mike Dunn (9:43 PM)
The drivers keep the pedal pushed in the entire time except when they let it up to make the car move. Once the car is moving, they push it back in to keep the clutch from getting too hot.
is there a reason why we see the funny cars launching the blower off more than top fuel?
Mike Dunn (9:45 PM)
Actually I don't think the Funny Cars launch blowers any more than the Dragsters. It's just that Funny Cars have those bodies over the top of the engine and when they do blow the supercharger, it either blows the burst panel at th front of the body off or sometimes the entire body. It's just more noticeable. Just my opinion.
Tony: (Balto. MD)
Mike, what is the purpose of the the third beam on the starting line? Does the ET Clock start when the wheels leaves the second beam or when they cross the third beam, Thanks
Mike Dunn (9:48 PM)
They don't use the third beam anymore. It used to be there so in case something was dragging under the car, they wouldn't get an excessive amount of rollout and they would hit the third beam and it would start the clock. Nowadays, they have other ways of being able to tell if that is happening. The elapsed time clock starts when the wheels break the second beam which is a staged beam.
Joe, Puerto Rico
How much is the compression ratio of top fuel cars
Mike Dunn (9:50 PM)
The fuel cars run from 6 1/2 to 7 1/2 to one compression. The reason it is so low is because they run such a large volume of fuel in the cylinder that they are able to create the cylinder pressure with the fuel and air and thus they don't need the high compression. It's one reason why they make so much horsepower.
Brian Garden Grove CA
what was the purpose of changing to the led, and why are some of the drivers having so much trouble with it?
Mike Dunn (9:54 PM)
There are a couple reasons. 1) With the old incadesent bulbs, a lot of them burnt out. With the LEDs you don't have that problem so you don't have as many reruns which normally happen in the Sportsman categories. 2) You are able to see the light more consistently. In other words, your reaction times will be pretty close in the nighttime to what they are in the daytime. That wasn't the case with the incandesent bulbs.
Brian Garden Grove CA
if it more consistent, why so many redlights?
Mike Dunn (9:57 PM)
The reason is you can see the LED about three-hundreths of a second faster than an incandesent light. So for the categories that were close to redlighting before like Pro Stock and Pro Stock Bikes, they have had to adjust their linkages to slow the car's reaction time down so the driver can still react when he seems amber and still not redlight. Obviously there has been a learning curve and that explains why you have seen so many redlights.
imaracingmom - Murray Racing, Brainerd, MN
Are you doing your own typing tonight?
Mike Dunn (9:58 PM)
Hell no ... I'd still be on the first question if I was!
Mike, Dublin CA
Hi Mike, glad to see you in the booth giving the fans good tech info!! I was in Atlanta last year watching Del Worsham's Team prepare the car. I watched one guy measuring the compression height and saw that each piston was down in the hole different from front to rear. Why do they use different heights from front to rear? See you in Sonoma!
Mike Dunn (10:00 PM)
The way the manifolds are designed on the fuel car, the air doesn't get to each cylinder equally which causes some cylinders to run hotter and some colder. The crew chiefs will lower or raise that compression to make the cylinder run at the proper temp. The cylinder that run colder will have higher compression. The cylinder that run hot will have lower compression.
imaracingmom - Murray Racing, Brainerd, MN
How do you think the new track surface in Brainerd is going to be? Will the drivers like having more more concrete before it switches to asphalt?
Mike Dunn (10:04 PM)
Good to hear from you Skip. I think the increased concrete will be better because before where the concrete ended was where you were trying to apply the most clutch and horsepower. Concrete is a better surface for the fuel cars so I think it will definitely be better once they get some rubber down on it.
Jesse (McKenzie TN)
what is the average cost of a top fuel run?
Mike Dunn (10:09 PM)
Average cost for a 1/4 mile run is between $3,500 and $4,500. That takes into account all the parts used, plus fuel, etc. Thanks for all your support and for all the great questions. You can email me off my website www.mikedunnracing.com. I don't get to respond to all of them but I do read them all so keep them coming! Keep watching the show! Drag racing fans are the greatest!