starting the tube V8 car, no turning back now Options

[byndbad914]

No, Otto still has his yellow 914 with the 6cyl AFAIK. I swing by there every once in a while for parts and look it over periodically...

This was a stocker 72 I bought about 10yrs ago, drove for a few, then tore it down for the V8 project. Then it sat for about 7 yrs while I finished school, went back to school, had a business, etc etc.

[Brett W]

Hey Tim, if you are looking for Chromoly, check out The Chassis Shop. They have 2x1 Chromoly tubing for 7.44 per foot. And round is 3.36. Other than ease of fit up why square tubing for anything other than the rockers and perimeter floor and why Chromoly. Steel can be had cheaper and is easier to weld. Plus it is just as stong if you are using the same size tubing.

[GTPatrick]

Brett, . . . Which " Chassis Shop " ? (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif) Google showed up more than one Chassis Shop. (IMG:http://www.914world.com/bbs2/html/emoticons/idea.gif)

[914_1.8t]

QUOTE (Brett W @ Feb 17 2006, 09:46 PM)

Hey Tim, if you are looking for Chromoly, check out The Chassis Shop. They have 2x1 Chromoly tubing for 7.44 per foot. And round is 3.36. Other than ease of fit up why square tubing for anything other than the rockers and perimeter floor and why Chromoly. Steel can be had cheaper and is easier to weld. Plus it is just as stong if you are using the same size tubing.

They don't have every thing in their catalog in stock....I was trying to get some 1.5" tubing.
But they can order it if they don't have it. They mentioned anywhere from 2 weeks or longer to get in orders.

Their address is chassisshop.com

[Brett W]

I called yesterday to see if the prices on steel change daily and the guy I talked to said, "no". If I had a 2005 catalog then those were the prices on their materials.

[byndbad914]

1x2 would be too small... can't find 2x3 so I may just have to go round.

Chromoly is stronger than mild steel... so I can use a thinner wall on chromoly for the same strength, decreasing the weight about 30%.

I wanted to build a "frame" car so that technically, you could run the car without any cage. Then the additional cage would just be for safety not rigidity. For rigidity on a round tube car, you have to run a lot of overhead structure to tie everything together (or use large diam tube which would just look wierd) which means for the same rigidity in a 1-3/4" perimeter chassis v. 2x3 box frame I would have a bunch of bars in the interior to crawl around and get in the way, which I am trying to get away from.

Was a good idea on paper (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) Now that nobody seems to stock it, and I don't need a factory order qty, I will probably be caging the hell out of it.

[Brett W]

Why 2X3 tubing. I build your perimeter out of 2x4 .065 mild steel then build the rest with 2x2 x.045 chromoly. Your "cage will have to be built of at least 1 3/8 .095 or 1.5 .095 wall alloy tubing. That means main roll hoops, halo bars, rear down bars, etc. Since your car is built to Super Production rules it must meet all GT spec safety rules to be legal to play in SCCA or at SCCA events.

What is the predicted weight? There is nothing wrong with combining mild steel and chromoly. Take a look at how the Trans AM cars are built the chassis is all square tubing and the main hoops are all round.

Check out http://www.racefabinc.com/gt-1_page_2.htm

[byndbad914]

the chassis builder wants to steer completely clear of DOM. That stuff cracks over time. Also, .065" wall would be way too thin for my taste. If I used DOM, it would be .120" wall minimum. Chromoly would crack too if over stressed, but in terms of fatigue, alloy equivalent cross sections (thinner wall to match strength) seem to hold up much better.

I don't have a weight prediction. I am not that concerned with it surprisingly - I just like to beat the (IMG:http://www.914world.com/bbs2/html/emoticons/stromberg.gif) out of the car and have fun, but I am not looking to be the lightest, fastest guy out there. I want the car to be rigid and last a long time (not fatigue crack), be safe in the event of a mishap, but not be so "barred-up" I look like Bo Duke just trying to run down to the burger joint for a cruise night or need to take the top off to make getting in easier.

I can be dead last in class track time and have fun. In fact, at club events I usually let everyone go ahead of me entering the track and stick back a bit and then just beat the crap out of it and catch up so I can run as fast as I can and not deal with anybody being slower, or blocking anybody that is faster. If anyone comes up behind me, I wave them by as soon as is safe and slow down as they go around.

If the car turns out to be 2300lbs again, I won't sweat it. Heck 2500lbs I wouldn't sweat. 1800lbs would be sweet, but not my priority.

Oh yeah, why 2x3 -- basically that was thought to be the largest size available in chromoly and I wanted 2x4. Apparently anything over 1x2 doesn't seem to exist in chromoly though. We are still looking, but are going to give up by the end of the week and go with plan B if we don't find it.

[byndbad914]

couple updated pics as of last week - threw them on the bird board while the club was down, so a couple of you have already seen them. AJ will hopefully have the interior cage framed out this week - we will see Wed night. He leaves for the San Felipe 250 Thursday (running his insane tube chassis Ranger this weekend) so I will be on hold until next week (IMG:http://www.914world.com/bbs2/html/emoticons/mad.gif) No biggie.

Current idea is to cut the trailing arms down to just hubs then build uprights from them. Then there will be 5 links going to each hub for a nice independent rear end (2 forward links, 2 perp links, one more for toe) so I have a complete array of options (rear caster adjustment (though I don't know if that would really matter since the wheels don't turn??), rear camber and toe will be independent of each other, wheelbase could be changed, track width could be changed (within reason w/o screwing up camber gain), so forth... Getting rather excited about the project!

Put the dry sump pan on the engine over the weekend, so it is ready to set into the car. He might have the engine in place as early as next Friday - hope so.

[byndbad914]

The rear taillight panel will be easily removed, so the engine/trans will come out from the top... that under-the-car crap is for the birds! (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif) And it was a real beotch to get the car high enough to clear the hi-rise intake and carb.

Oh yeah, all the crap on top of the car is my numerous drawings of cage proposals, the Excellence opened up to Roger Sheridan's car, my engineering analysis pictures showing chassis design v. deflection and stress (read that as NERD), and anything that I ran across on the internet over the past 5 months of planning this project! I literally have nearly a full binder of internet pictures I have taken to him. AJ is probably at that "goddamn engineers" point (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)

[byndbad914]

Here is an update shot - not a lot to see at the moment, but the interior cage is basically framed out. The top door bars will be lowered to fit between the window crank and door handle (everything is just tacked right now until I "agree" to weld). The downtubes will go through the stock vents (dash will need a little work to fit). The top hoop fits the targa incredibly well, but I couldn't seem to take a pic that didn't turn out blurry (too much caffiene apparently).

I put the trans and clutch all back together, have the dry sump pan on and so forth, so AJ should be fitting the engine today and said he is going to get cranking this week on finishing out the interior cage and mounting the engine/trans assy.

[byndbad914]

here is an updated shot of engine/trans - exceptionally clean trans care of CRC Brakleen - that stuff is straight from heaven! The trans was filthy because the overflow puked onto it the first trial day and it collected grime ever since. Brakleen made it shinier than when it went it I think (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

[Andyrew]

Awesome dude!

[turbo914v8]

I can’t believe my eyes. I am truly sick as I check often through the day for updates. Simply put WICKED. (IMG:http://www.914world.com/bbs2/html/emoticons/pray.gif)

[Jeroen]

very cool project... but those tubes look heavy

[Britain Smith]

Why are you running the tranny inverted instead of just flipping the diff?

-Britain

[Bigbohr]

... maybe to get a lower CG ...

Are you using a dry sump with that inverted tranny?
If not, are you not concerned about the angle of the axles? This is not meant as a criticism. I'm looking at the same problem ...

[Bigbohr]

ok, I see now you're using a dry sump. Never mind my question ...
Nice project I must say!!!!

[byndbad914]

Jeroen - bottom "square" outline in the interior is 2" OD .120" wall chromoly. Only 'heavy' part - everything else is 1-3/4" or 1-1/2" .095 wall chromoly. The whole base when done and welded should only be 148lbs, so even with some extra thick structure surrounding my butt (personal choice for added safety) that is still quite light. The overhead cage is 1-1/2", front and rear structure will be a mixture of 1-3/4" and 1-1/2".


Britain - I bought the trans with low miles for $2200 and it is essentially "free" to invert it. I would wrap up another $3-$4K in a ring flip by the time it is all said and done - it takes some machining and such to make that happen in a 930 - not as easy as a 915. Also, I can run the engine lower in the car as BigBohr mentioned.

BigBohr hit in on the head about axle angles though v. dry sump necessity. Originally (as in 1 month ago) the car was wet sump with a "short" 7-1/2" full sump pan and the pan was LOW to the ground and the axles were angled a fair amount. Now, the dry sump gains the room needed to make the engine/trans closer to even with the bottom of the car, then I am raising the combo about 1-1/2" in the tube car. That 1-1/2" in engine height will ultimately translate to an almost 4" shorter ride height (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)

let me explain that better... the wet sump pan was the low point in the car. To have a 3" ground clearance at the pan, I had to have a near 7" ground clearance at the car underbody (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif) screwed up all the suspension geometry a lot. My last track day back in January, I just "went for it" and dropped the car to about 1-3/4" clearance at the pan and it handled a ton better. Hence the "screw this noise, I am going tube chassis and dry sump" decision.

[Bigbohr]

... free to invert ... is what i thought too. Until I looked at prices for a dry sump pump, pan and reservoir (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif) Seems nearly the same total cost as having the ring gear flipped (I thought that was about $1200). What are you using for oil pump? Did you find anything for a reasonable price?
John