V8Rumble

iTrader: (2)

Yeah, I know that the Subj./Title line probably sounds kind of odd, but I have a good reason for asking. The big thing that I'm building my car for is to get into the 130 - or maybe even the 150! - Club on the Bonneville salt flats.

The challenge with that is that you begin from a standing start, like a drag race, & you have to be able to get up to the speed specified (130 or 150) within one mile. No problem, right?

The difficulty lies in the fact that there's very little traction to be had - here are a couple of quotes I've gotten when I started investigating this from people who've been there for years...

Now, I'm currently trying to learn which tires will work the best for me, as well as any aero tricks that might help - but I figure that you guys can probably give me some really good advice regarding what I can do to get the best possible "hook" all the way down the mile...

(Or, alternatively, what tricks have worked for you when the track was really bad?? Besides VHT! )

Thanks in advance!!

Mcdamit

I have never run it but I heard and from watching some of the cars that it maybe a good idea to run smaller tires

V8Rumble

iTrader: (2)

Yeah, I've already figured out that I'm probably going to have to have special tires shipped to me (not that big a deal, I guess).

I guess what I'm really hoping to learn is what kinds of "chassis setup tricks" work well for slick tracks when drag racing? New LCAs, changing pinion angle or the angle of the torque arm, or...? (Yes, I'm pretty new to this ) What kinds of things can help you to really hook well?

It's really a "different" form of racing in that a lot of people add weight in an attempt to find traction!

It's also interesting to see how racing is changed when you take away the traction part of the equation...

Thanks for the reply!

84406

A often used size for the 130 would be a 185-195/??/15. You could also use front runners of about 6" wide tread. Other classes are using the front runners to well over 200.

1983Fbody

I posted a reply in your other thread about possibly using nascar tires, now that I've seen this thread and what you plan to do... A big wing might be helpful by putting more downforce onto the back end, it will slow you down a bit as well from aerodynamics the traction payoff may be better than the aero drag tho! Look at funny cars, they have huge wings and still manage to crack 300 can't get the power down might as well have ten thousand horsepower its useless w/o traction and at 130 a lot of drag isn't that harmful. It's at a point of about 150mph that aero drag really starts to come into play, a boxy car like a chevelle needs something close to 8or9 hundred horsepower to reach 200 versus a similarly geared thirdgen only needs about 500 horses. That's with all the basic aero mods, slight body rake, low front spoiler, mirrors removed, ductape covering the body seams, etc. Just about any vehicle with enough power can reach up to 150 without any of those aero mods on good traction surface, worrying about Coefficient drag (sp?) should only come into play after the magic 150 number. you either need more power or less drag to go faster after 150 so I really think a wing may help you more than hurt.
-Ben

V8Rumble

iTrader: (2)

Thanks for the reply. I'm checking the rules to see whether or not an add-on wing is allowed in the classes I'll be running. I've already got the GTA aerowing which is supposed to be pretty good, but I agree with you - one of the biggest factors in whether or not I'm successful will be traction, & more downforce is likely to be a big help.

Been studying a LOT on aerodynamics lately, from all of the research I've been doing (reading and empirical data from those who've been there), it seems that aerodynamics first start to come into play at around 35 mph, but the real "wall" that people run into is right around the 170-175 mph mark. (Interestingly, this seems to be regardless of the platform that people are using - my buddy/coworker is building his WRX for the salt also, so I'm getting some data from his side as well).

It's also interesting how people come out of the woodwork when they find out that you're getting ready to run B'ville - the guy who runs the body shop that's fixing my wife's car (long story) pulled out a half-dozen pictures of the time he went as a crewmember to help wrench on a stretched-wheelbase Infiniti that had an Infiniti Indy-car engine in it! Sucker did 230 without even working too hard... He said that they captured the record for their street-car class, then bolted on an airdam & a fairly decent-sized aluminum wing using Dzus fasteners, then went out & got the record for the 'modified' class the same day. (He also had a pic of a motorcycle that had a 426 Hemi - complete with Roots blower and Hilborn scoop - that had made the trip there! )

Anyway, thanks again for the reply. If anyone else can think of anything that might help me plant the power to the ground, I'd sure like to hear it...

unknown_host

iTrader: (1)

If it were me, I would look into an ignition box with a mutliple retard feature or multiple customizable timing curves. Build a stout motor, pull a bunch of timing in your lower gears and slowly start adding it back in as you pick up speed (and hopefully downforce).

rx7speed

one mag was trying to do a top speed run. think what they ended up using was y or z rated snow tires.
said it helped out a lot. still wasn't that great but better then what it was.
might want to give it a shot

Anvil

I think I read an article on that Trans Am at Bonneville in 1989.As I remember, they had a problem with the door glass popping out at the top(not sure what speed this happened at).The fix was a small clip at the top.Just an observation, but Formula 1 cars pay a lot of attention to the amount and route of air under the car.
Ross