My name is Danny Thompson. Last week I set a 400mph speed record in a car my dad originally built in 1968. Ask me anything!

Did the weight of your huge balls play a factor?

They were only big at the starting line. By the finish I had trouble finding them.

How do you feel about tacos?

They are my favorite food. This should not be down voted.

What sorts of modifications did you have to make to the car since your dad built it to get it to break the record?

The first thing we changed was the engines. Today's units make way more horsepower than the original Ford SOHCs. The modern iteration of the car has dual dry block hemis, each generating around 2500 horsepower at an 80% nitro load.

Once we changed the engines we had to upgrade the transmissions, rear ends, and the drivetrain to handle the additional power. We basically upped the material specifications wherever possible.

We made fewer external/aerodynamic modifications. The original car was a slippery beast.

I was at Booneville this year, ( I was the guy who rode 5000km just to see it) you inspired me to do it Question- Are you going to attempt to up the record? What's your best guess? & when?

This is the last year the C2 will run. We're going for a higher speed record during the September FIA meet, but we'll let the SCTA record we set stand. Edit: I'm really glad you made it! It's a special place.

how much fuel per mile would you be using at that speed (400mph) in that car?

During our last set of runs, we were using about 6 gallons per mile of a 72% nitro 28% methanol blend.

How did you first start getting into racing? Was your mom against it? And also, could you see anything while going that fast? The tunnel vision must've been pretty insane...

I started at age 10. My dad stopped me at age 12. By that time, eight of the ten friends he'd originally started racing with had died while doing so. He actually wanted me to be a lawyer instead. I didn't care for that. My mom was basically always fine with it (and still is).

You can definitely see while driving, and its very important to be aware of your specific location. I had roughly five miles to accelerate (at the most recent event) and the surface conditions changed enormously along that length.

Hello Danny

First thank you for during this AMA. I have a couple of questions. I hope that's alright.

When you crashed, when did you know something was wrong and what did it feel like?

Also what's your process for getting ready to do the fast run?

Lastly what's something funny or weird that people normally wouldn't think about the speed record?

Once again thanks!

1. With the Mustang, it was when everything got really quiet. I knew I was sliding, but the silence meant that I'd gone into the air. The car flew more than 1000 feet then landed upside-down on the roof. The hood (which was not attached) went through the speed traps at around 248mph. Not sure how fast I was going. Hell of a ride though.

2. I don't really have any pre-race superstitions, but I do like the time I have alone after the crew closes the canopy. It gives me a few seconds to get my thoughts in order.

3. That you don't need to steer. We put a GoPro on the wheel this time, and I think the amount of motion is pretty telling.

Danny, Could you tell a big difference in the handling of the car from the first 400+ pass to the runs this year with the updated exhaust and diffuser / splitter upgrades?

Good question. It's hard to make a direct comparison because the track conditions were so different, but I think the new diffuser and spoiler worked a little bit too good, and probably generated excess downforce. They are currently being modified.

I've been 170 mph (speedo registered) on a superbike and it felt the same as 150. Was there a point where you no longer noticed the additional speed?

Hmm. Not really. I've always had a pretty general awareness of the increases in speed. The way I handle the car changes. Hope that makes sense.

Any pointers for anyone dumb enough to decided they want to get started in land speed racing and have to do it on a budget? First class suggestion maybe?

The good news is that between the SCTA and the USFRA there are classes for almost any sort of vehicle, including lawnmowers. Most of the 200+ cars are an expensive proposition, but I genuinely think there's glory in just making it out there and doing it, no matter what you're driving. If you build from scratch, I'd encourage you to design around safety from the get go.

What is the strangest "can't explain this at all" moment you've experienced while in the driver's seat?

Probably when the fire extinguishers went off during a 390mph test run of the C2. I had no idea what was happening and I couldn't see a thing. We fixed that problem.

Congratulations Danny. Some of the latest photos on your website show the car without a lot of the sponsorship livery, whereas previous pics show a lot of sponsorship. Is there a story there (that you can talk about)?

Sure. Following the 2014 runs, the project was stuck for two years without a track. A lot of those sponsors, reasonably, didn't want to keep paying for a car that wasn't able to run. It would have been nice to keep them on there, but the fact of racing is that you need fresh money all the time. We are, of course, always looking for more sponsors (even though we only have one event left). We actually had all of the logos hand painted on this time by Dennis Jones. They look killer.

Wow I did not expect to read about Challenger II being dusted off and setting records in 2016! So happy to see this.

A couple of questions....

First, checking out your website, it looks like you made the run on a Saturday and the return the next day. I always thought for speed records there was generally something like a 1 or 2 hour limit to turn around? Is there an official window?

Also, I remember reading many years ago (in the 80's or 90's) in one of the car mags that Bonneville was drying up, which was causing the salt to be more of a loose powder instead of hard packed, and that it might not be possible to race on someday. Do you know if this trend is continuing or did that turn out not to be the case?

SCTA records require a run, a night in impound, and then a backup run the next morning. FIA records, which we'll attempt in September, work as you described (with a one hour window).

I'm not sure about drying up, but the track is definitely in trouble. Check out Save The Salt for more info. They're leading the effort to reverse the changes.

Do you have any experience with motorcycles? What's more exhilarating, a redline launch on a liter-bike or travelling 400 MPH in a car?

400mph in a car, unquestionably. That said, a bunch of people are currently trying to break the 400 barrier on a bike. They're braver than me.

Hi Danny! Thanks for doing this AMA.

What, if anything, did you eat before you drove?

Oatmeal and protein powder. I didn't want to be hungry, but I didn't want to risk an upset stomach. [edited]

Hi Danny! What do you consider the ultimate record?

I think the ultimate piston record would be the 500mph mark. You'd need a perfect car and better salt than we've had over the last few years to get it.

Did you do any wind tunnel testing for aerodynamics?

We did not. All the original tunnel work on the car was done in 1967 by Ford and Kar Kraft. Tim Gibson, our aero engineer, reran the numbers and was pleased with the result.

Can you please break down the total costs to build a vehicle of this caliber?

I can't answer that succinctly, but a new vehicle that competes at a similar level from scratch would probably be a three million plus project.

First off, congratulations! My question is; what kind of physical preparation did you have to do before trying to set the record? I can only imagine what kind of strain that much force puts on your body.

I do train a lot, but that's mostly because the cockpit is so small. I can't gain weight and still fit inside. It's a good motivator.

I'm not sure how much physical preparation is necessary, but my philosophy has always been that the physical and mental aspects of racing are closely related, and neglecting one imperils the other.

Would you rather fight one horse-sized duck or 100 duck-sized horses?

This feels like a good question to end on. One horse sized duck. Less work to hit with a car. Thanks for making this a pleasant AMA!

Which one of the new cars do you feel has the most potential going forward? In my mind, the Carbinite car will be very hard to beat when they get the systems lined out.

The Carbinite car looks great, but George and the new Speed Demon are still the big dogs until someone goes faster. We're giving the new stuff a run for its money though!

Hey Danny! This is so awesome. What was the first car you took to Bonneville?

It was called the Pumpkin Seed. It was a streamliner built in the 1960s by Bill Burke. My dad bought it at some point, and I gave it to Jim Travis, who restored it. He was nice enough to give me a ride. I set a record around 253mph.

What type of tires did you use and what was special about them that allows for extreme speeds over such long distances compared to just 1/4 mile?

We use custom Mickey Thompson tires. They're a prototype nylon weave backed with banded steel. There's not much rubber on them, about 1/32 of an inch. They're built to avoid head expansion, and are pretty activity specific. You would't want to use them on the street. M/T makes a lot of other great tires for that (had to get in a sponsor plug somewhere).

First congrats. I was there Last weekend when you set the record and was looking at your car and noticed the rear engine has a different setup than the front engine. May I ask why?

The fore engine is actually mounted in the car backwards (because it drives the front wheels in the four-wheel drive system). I need to see over it, so the throttle bodies were placed in front of it instead of on top. That keeps the profile low. We don't have to worry about that with the rear engine, so the setup is more conventional. Good question!

What's the technique behind driving a car like that at an optimal level?

Technique varies as the course changes, but you do need to make much more smooth and gradual movements than in other forms of racing, even when you're panicked or in trouble. Jerky adjustments will get you hurt.

Fine reddit I'll ask a question: Did you drive the hauler all the way home by yourself? If so, was it peaceful?

I did drive it, but to California to have the C2's engines taken apart rather than back home to Colorado. Driving the rig in traffic is, sadly, never peaceful.

Hi Danny! :)

What was your first car?

I got one of the 1963 Corvette test units GM gave my dad (not sure if GM knew that). I traded it in for a pickup truck because I was an idiot.

Challenger 2 was obviously state of the art when it was created, but technology has changed quite a bit in the last half-century. You've already mentioned that most of the internals were upgraded to modern standards and you tried to keep the essence of the car the same otherwise, but if you had to do it again and had nearly unlimited resources what would challenger 3 look like and what would it have under the hood?

Interesting. It would definitely be four-wheel drive. Probably single engine (the double engine is a killer during the FIA turn-around). Supercharged for sure. I'd keep the long wheel base, and might borrow some of the shape. Carbon fiber body with a lower total weight. Much larger driver compartment. I hate to say it, but probably traction control too. Still blue though!

Hey Danny! Congratulations on your record! Im a big fan of you and your dad. I have M/Ts on my offroad rig and I've raced at Bonneville myself. I've been following your Challenger 2 efforts the past couple years and picked up some great stuff from you when you were fund raising. I have 2 questions #1 Would you consider racing at the Ohio Mile or Loring AFB where the courses are shorter but the traction and air density are much better? And #2 What can you tell me about the belt buckles from Mickeys personal belongings? Just gifts from sponsors? Do you think he ever actually wore them?

Pics: http://imgur.com/0ILve56 http://imgur.com/rMAAfVb

Thanks for supporting. I have that poster by my desk. I'd guess it was probably a sponsor gift, but as with all that stuff, there's no way to be sure.

First off, congrats on the record. It's quite an achievement!

How good/bad was the course? I scheduled a trip and visited Bonneville last year only to learn that Speedweek was cancelled for the second year in a row, this time for poor salt conditions (IIRC it was quite thin in areas). I've been following some of the efforts of the "Save the salt" group and it seems as though they are finally making some progress. The salt flats are a national treasure and they deserve to be preserved.

The course varied from day to day, but I would say that it was marginal. The SCTA did great with what they had, but conditions were far from ideal for high speed runs.

What's your daily driver?

I have an F-450. Brought it to California, have yet to find a parking place.

Do you have any pictures of the engine/drivetrain for us gearheads? The car is insanely cool but I want to see the magic underneath.

They aren't 100% up-to-day, but check out these galleries. We have sections for both.

Thanks for doing this AMA and congratulations!

What are your top 5 favorite cars of all time?

1. The Challenger 2
2. The Ongais M/T Funny Car (1969)
3. The Ongais Interscope Bat Mobile
4. The Mario Andretti John Player Special F1 Car (Lotus 78?)
5. 1954 VW Pickup

What was your very first car? What is your dream car?

This was the dream car.

Why are AN fittings so expensive?

Because it's all aircraft quality? Thank god we have a sponsor for those (BMRS--the stuff is killer).

What motor? I saw you went from 0-300 in two miles then just another 100+ in the next three miles, can you expand on how that feels to accelerate so quickly then just kind of cruise up up up? How's the over-steer at 400mph?

Edit: what's your alignment like for these runs? Negative camber, positive caster?

I talked about the engines a bit above. You always hope for no over-steer, and we've managed to avoid it so far. It would be a deal killer in this car.

Straight up camber, 6 degrees caster, 11 degrees king pin angle.

Would you ever consider trying to break the land speed record on a motorcycle as your next project? If not are there any other records you want to break?

No to the motorcycle. Not enough tire on the salt for me at this point. I'd still like to break 500 in a piston car.