Flexicoker

Sorry if this doesn't flow well, I just got my wisdom teeth pulled... and for some reason, this medicine is making it hard to concentrate. We have a CNG truck that was converted back in... '93 I think. It has raised compression, different cam... and a Reher-Morrison ported head, haha. There is so much torqre that you can spin the tires so slowly that you can still read the words on the side on them while they're going. Its awesome! The range on it is not very good, but I'm not sure how big the tank is. Also, finding fuel for it is an issue, we have to go ~15 miles to get to the station. I have no idea how much fuel costs. I might be able to get my hands on a report that was written on this if there's interest. E85 is sort of a pain in the ass. But has some real nice benefits that were already mentioned here. We ran a Honda CBR250, thats a 250cc 4 cyl, 20,000rpm redline, that we turbocharged and and ran on the stuff. Stock the engine made ~45hp, and afterwards made 72 which is where we choked our restrictor. That was non-intercooled with 11.5 static compression ratio. It has such a great latent heat of vaporization that depending on the amount of boost you're running, and how efficiently you're compressing it, you can probably get away without an intercooler if you're going forced induction and place your injectors right. I saw an article a little while ago where they ran a flex fuel Tahoe on gasonline and then E85, and with E85 it got worse gas mileage of course, BUT, the 0-60 improved. I didn't think you would be making more power without raising compression first. But I was wrong. Here's the article: http://autos.msn.com/advice/CRArt.aspx?contentid=4024242 Also E85 is corrosive, so everything thats going to be in contace with it needs to be stainless steel, hard anodized aluminum, alcohol compatable rubber, etc. JB Weld is NOT compatable. Here's some compatability information that was collected off the internet and condensed for our Turbo250 project. No gaurantees are made to its accuracy. A √ indicates compatability. Aluminum Most Rubber* Teflon √ Stainless Steel √ Natural Rubber √ Latex √ Brass Cast Iron √ Tin √ Copper Steel Nickel √ Glass √ Fiberglass** √ Most Plastics*** √ Flex Pipe √ Anodized Aluminum Hardcoat √ Anodized Aluminum √ Zinc Cork Lead Silicone √ Butyl √ Nitrile Latex √ Neoprene √ Titanium √ Carbon Steel √ Galvanized Steel √ PVC √ Fuel filters may clog because ethanol will break apart sediment in the tank. It also will pick up more water which stays suspended in the alcohol. There are fewer problems with higher concentrations of ethanol. *O-rings and seals in some standard dispensers are affected by E85. Equipment must be specialized. Nitrile has been successfully used. **Problems exist with single-walled fiberglass tanks. Double-walled tanks and piping are completely compatible. ***See next page Plastic Durability Type of Plastic Extent of Durability Conventional Polyethylene Good High-Density Polythylene Excellent Teflon Excellent Tefzel Excellent Polypropylene Good Polymethylpentene Good Polycarbonate Good Polyvinyl Chloride Good Excellent: Will tolerate years of exposure Good: No damage after 30 days, should tolerate years of exposure

Moving the wing up or backwards is going to move the aero balance rearwards. You're correct about the wing lifting the front wheels. There is also a drag force pushing backwards on the wing, that is going to want rotate the car and lift the front end, so the higher the wing is, the greater your 'lever arm' is. The lift at the front wheels from the drag force is going to be a much lower magnitude than that from the downforce. So while tuning, if you're experience oversteer thats worse the faster you go. You'd probably see alot more difference by moving the wing backwards some more rather than adjusting the angle of attack. Most racecars are designed with aero-push. ie. the aerodynamic center of pressure is behind the center of gravity, and causes them to understeer slightly the faster they go.

I could maybe go for a patch panel or two. How is the rear of the passenger side fenderwell... under the battery? And the left side of the... uh... whatever you call the area right above the tailights... covered up when the hatch is closed. I'm having a brain fart. Thanks!

I've been using a Miller for over a year that I like pretty well. It was $220 if I remember correctly. When I get another I'd go for the next model up with 4 arc sensors as opposed to 2, and 5 amp sensitivity instead of 15. I've never had to replace the battery or 'let it charge.' However, I did have to replace the headstrap ratchet deal ~$30 after about a year once it wore out and stopped ratcheting. And I've had a couple of times when it just decided to not darken when I struck an arc. The 'low battery' light wouldn't be on, and it would turn on normally. Trying again after an hour fixed it?!? My only qualms.

I've been using a Synchrowave 250 for a few years, and the only things I wish it had were a pulser, and frequency control. The DX has frequency control, both have pulsers. I never use all of the amperage. It's never let us down except for breaking/exploding torches(watercooled), and its been pretty well raped on.

Wow! That looks really cool! What size endmill did you have to use for finishing? What did you do the programming with?

I only have these pics from the ebay ad when I bought it... It looks like its just scooted forwards a few inches the bumper guard guys are a little closer together. Those are coming off soon anyways. Switching to the earlier bumpers is Plan B, but I'd really like it to be as easy as switching out the brackets.

Hey guys. I don't like how the bumper on my '73 sticks out a few inches, and I'd like it to sit against the body like the '72 and earlier cars. Does anybody know if the difference is soley in the brackets that mount the bumper to the frame? ie. could I just replace mine with those off of a '72? Or is there a difference with the bumper and/or the mounting location on the frame? Thanks, Eric

Any book by Carroll Smith. If you want to get really advanced there's: http://www.amazon.com/Race-Car-Vehicle-Dynamics-R146/dp/1560915269

Whats shakin? Do you guys like Intros here? I hope you so... You get your ass reamed elsewhere for not doing one. I'm Eric, 21 yr old mechanical engineering major at University of Texas - Arlington. I'm on the Formula SAE team, we build badass little racecars with motorcycle engines. 610cc limit. 20mm restrictor. Last years car had a Honda CBR250. 250cc 4cyl, 20,000 rpm redline (yeah, 4 zeroes), turbocharged, and drank E85 that smelt like bad tequila. Made about 75 hp between 'spontaneous crankcase ventilations'. In a car that weighs 450lbs without driver and can pull over 2 lateral G's. We also build our own carbon fiber wheels. My specialities include delivering hot passion with a TIG torch, running a CNC 4-axis mill, and your mom jokes. I don't actually have a 240Z yet, but I will... soon. It'll be my daily driver, so nothing too radical, but I'd like to slowly build a 3.1L while I'm still driving it. Oh, and a Torsen. That would rule. I find it pretty awesome that you guys are discussing roll center heights and ackerman and the like. Hopefully I'm smart enough to contribute something useful there. I'm usually smart enough to contribute in the 'don't do that you're going to die' welding/fabrication arena. This is becoming borderline novel length, so... pictures here: http://smg.photobucket.com/albums/v237/Flexicoker/Formula%20SAE/ http://smg.photobucket.com/albums/v237/Flexicoker/F06/ Movies here: Later!