Bill Ball

231+ MPH on salt? That would scare the hell out of me!

Imo000

I have a feeling, witht hat much HP, keeping the tires from loosing traction will be the biggest challange.
Very nice numbers by the way.

mark kibort

yep, double the speed, 8x the HP required.

toofast928

Awesome HP Carl>>>>>>>> Congratulations!

IcemanG17

I wonder what the friction coefficent of salt is compared to asphalt....since asphalt typically is in the .7 range up to .8 for really nice tracks.....

My guess is under .4 or so....or worse than wet asphalt :>(

Sounds pretty wicked.....

James Bailey

Which is one reason all rookies must do a moderate speed run on the short course..followed by a 175 MPH plus to qualify to run on the long course. If when on the long course you have a record breaking speed run you must follow up the next day with a run the opposite direction and make the speed in the same measured mile as the day before. That is how you set an official record. So looks like it is a minimum of four runs that are needed. Should be very interesting.

Imo000

I always thought the opposite run must be completed withing an hour. So much for watching TV.

Carl Fausett

The opposite run is only for those trying to set a FIA-sanctioned World record. An Opposite-direction run means you are driving towards the spectators and the starting queue, so they dont like to do it much.

The Bonneville land speed records are as Jim Bailey said - mostly. The 2nd run does not have to be the next day, it can be the same day, but they must be two back-to-back runs and then they average your two into the one time.

Should your first run break a current record, your car will be impounded so you cannot touch it. When you are ready for your second run, you can check the oil level and tire pressure and repack the parachute - very little else, and then its "go time"

Carl Fausett

I was very surprised to see black burnout marks on the slat, but they are everywhere. Its very hard with a slight sprinkling of table salt on top.

This may be the only motorsport where weight is not a penalty... its an advantage. (I know, it impedes acceleration, but you get 5 miles to accelerate...) We are adding about 600 pounds of ballast to the vehicle to help traction, maintain steerage, and avoid flight.

Also, the negative pressure beneath the car caused by ground effect is increased as the speeds go up, so with proper skirting and belly panning to prevent air from going under the car, we get some suction to the ground.

I know these things from book-learning, and my visit to Bonneville in 2010. But I will remind you, I haven't DONE it (ever) so I do not know if I will have wheel spin at the top end with this car until I try. Many do, however.

The build is a lot more technical than I thought it would be at first, that's for sure.

Carl Fausett

Jim is right - we have to do at least 4 runs before the engines pops. My bet is more than that. Given nobody knows how much the 928 block will take and for how long, "this is going ot be interesting".

hacker-pschorr

Looking at the chute, I cannot help but think what hilarity would ensue if it were only attached to the bumper cover.

I know yours is not, but I can only imagine how often they see stuff like that in tech inspection.

Anyone interested in this thread / project must see the movie "The Worlds Fastest Indian".

SeanR

Just please have lots of cameras taking shots of this run.

Can you mount a camera on the lower cross member so we can see the oil pan during the run?

mark kibort

as long as you are not accelerating faster than the traction, which is still pretty decent at the start of a run (ive heard it is like a rainy day at the track on slicks) , you should have no problem gettting to top speed. this is where weight and downforce will help a little (but you dont want down force as that can imbalance the car and cause major problems at speed. you want it neutral and to have as little air go under the car as possible . the venturi effect under the car will pale to the low pressure over the hood and top of the car, but even that pales to the weight of the car even at 180mph, that "lifting force" , or "negative pressure" will only be .36psi. that goes to near double at 225mph so where it can cause issues. for example, 2ft x 2ft section could have 400lbs of lifting force. (take the square" of the hood for example that sees low pressure, and figure out the lifting force) . you could have this on the roof too. under the car is near ambient for the most part. you just dont want it to go positive, due to the nose of the car lifting up for some reason. you saw the RX7 flip, it wasnt from being unbalanced, it was from the driver not feeling the wheel spin. might not hurt to have some big vertical stabilizers to help with straightline stability. weld a couple of big fins in the rear on each side of the rear spoiler .

sounds exiting. have fun and be safe!

when will it be??

mk

PS, as a side note, because HP is fixed, (for the most part) you cant make anymore HP than you got, so best case, is that your ability to accelerate goes down directly inversely proportioal to speed. so, whatever you could do at 50-60mph in 1st gear at max HP as far as acceleration, would go down as the speed increases. The net net of that, is that you have a 4x or 5x reduction of acceleration forces to the rear wheels at over 200mph to the rear tires on the salt. in otherwords, if you can accelerate with 1/4 throttle in 1st gear, that might be the type of force on the salt at 200mph in 5th.

blown 87

Great movie

928mac

Carl, you need to do a wind tunnel test before you run.
Better to not wreck the car due to not enough wing and or splitter