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-   -   Epic quest to hit 200 MPH at bonneville (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/epic-quest-hit-200-mph-bonneville-810225/)

TIIFC3S 08-17-11 11:15 AM

Interesting thread. Good luck with the entire project! It'd be nice to have a pic or two of your car so we have some visual reference as to what you're working with...

SpeedOfLife 08-17-11 12:16 PM


Originally Posted by mrehrhar (Post 10750652)
Not to be a Dick but you could just buy a litre bike and do some minor mods n hit 200 on the road for a lot less cash

He wants to do it the right way.

Rob XX 7 08-17-11 12:16 PM


Originally Posted by mrehrhar (Post 10750652)
Not to be a Dick but you could just buy a litre bike and do some minor mods n hit 200 on the road for a lot less cash

he could just ride in a airplane and go even faster!

patman 08-17-11 12:31 PM

200 on the salt is also a lot different than 200 on pavement

StevenL5975 08-17-11 03:12 PM

Very nice project.

I did 140 mph (225 kmh) with my stock 86 NA S4 (145000 km). Had a GPS, passenger and trunk full of baggage with me.

It was relatively easy to reach 140 mph, its not a rocket of course but it wasn't struggeling or whatever. Just make sure not to pull out the headlights =) :lol:

Was a 350 km trip and my friend who was taking a nap at 140 mph did not even woke up.
Maybe a minute in total @ 140, letting of the throttle for a few mins between the passes.

Me: "Hey, we're at 225 kmh"
He: "What ? Oh really. Feels comfortable..."

That being said I think 200 mph is realistic/doable without to much hazzle.

Steven

PS
Any details about those undertray/aero parts from mazda ?? - Potential interest here ...

Rob XX 7 08-17-11 03:22 PM

Im sure you have all read the car and driver article on the RB FC that still holds the record for its class, but read it again- it aint that easy on salt- traction and stability become a issue

http://www.racingbeat.com/gallery/Car-Driver-Dec-86.pdf

StevenL5975 08-17-11 03:31 PM


Originally Posted by Rob XX 7 (Post 10751138)
Im sure you have all read the car and driver article on the RB FC that still holds the record for its class, but read it again- it aint that easy on salt- traction and stability become a issue

http://www.racingbeat.com/gallery/Car-Driver-Dec-86.pdf

Thanks for that great document

For the rest ... Yes, salt is the problem.
Personally I wouldn't try it on salt.

BLUE TII 08-18-11 12:25 PM

PS
Any details about those undertray/aero parts from mazda ?? - Potential interest here ...


Last time I checked you could still get the factory "Aero kit" pieces which decreased drag coefficient from .30 to .29 AND decreased lift (read adds downforce) a result of the FCs development in Mazda's wind tunnel.

It was around $1,000 with MazdaComp pricing for 3 piece front lip, aluminum undertray, rear gurney flaps, and rear spoiler.

SirCygnus 08-18-11 05:57 PM

dont you mean aluminum belly pan? all under trays are plastic.

BLUE TII 08-19-11 01:28 PM

To do a little bench racing...

I see some advantages the Racing Beat 1985 effort had over the Dandy 2009 effort.

Racing Beat used the FUNCTIONAL rear lip spoiler from the wind tunnel designed factory aero kit that HALVES the rear coefficient of lift.

Dandy used the aesthetic "wing" and tried to add weight to the rear to overcome the rear lift.

Racing Beat car appears lower keeping more air from going under the car while the Dandy car seems to have exhaust hanging too low to lower the car properly for the very flat surface.

Racing Beat used a front side exit exhaust enhancing the already factory designed airflow out of the rear of the car to decrease lift. Dandy's rear exit exhaust used wider round mufflers and larger less tucked in piping than stock decreasing airflow out the rear of the car.

Racing Beat used smooth wheel covers to reduce drag.

Racing Beat used no hood pins as opposed to Dandy's four standard hood pins.

Racing Beat used a turbo bridgeport engine with possibly a less abrupt change in engine VE with rpm increase than the peripheral port turbo engine that may have helped keep the rear tires from spinning. Note that Racing Beats relatively failed FD attempt (double the HP, out of stock body class and 5mph faster) also used peripheral intake port timing and had a hard time not spinning the rear tires. It is hard to regulate the power of a peripheral port turbo motor with throttle, perhaps adding a exhaust restricting "throttle" would help.

If only building a car was as easy as tearing one apart in internet bench racing. I still admire, applaud and covet the Dandy FC.

j9fd3s 08-19-11 02:19 PM

the racing beat FC also has a totally custom rear suspension, its using porsche parts. if you go to the library and go find the article in car and a driver, there are actually some good pics.

having see the RB car in person a few times, its LOW. maybe its got 2" of clearance from the ground. there is no pretension of it being anything other than a salt flats car

the other thing that's impressive is how stock the car is, on the exterior they pulled the wipers off. in the interior they added some safety stuff.

the wheel covers also are probably really functional, and easy to do

the RB car also has ballast in the rear, although its the ice for the water to air IC system, 25 gallons.

the engine used in the bonneville FC is actually straight from mazda, in 1981 mazda started development work on a turbo rotary, and they settled on the bridgeport + 2 separate turbo configuration. the engine program never really worked very well, and they ended up going NA 3 rotor instead. RB got 4 engines for bonneville effort.

so the engines were bridgeport, unknown timing, although the factory template we have is conservative timing, big area. 7.5:1 rotors. turbos were iconel HT-20's running 1 bar boost@2100F egts (!). it used a DISTRIBUTOR + MECHANICAL fuel injection, and the slide throttle style throttle like the NA race engines. dry sump

they quote 530hp@8500rpm@1 bar.

these days EFI would probably make this easier....


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