Rotary Lotus - RX7 / Miata mash-up for Sears Point!

[kreb]

I'm late to this dance, but it's fun to see the Stalker that I put together (The blue one). I miss that car! I'm also jelous about the Wyoming purchase. That's a hell of a deal! Rock on you guys, and hopefully I'll be back in a Locost sooner than later.

[redbull]

...it's fun to see the Stalker that I put together (The blue one). I miss that car! I'm also jelous about the Wyoming purchase...

Ah it is a pleasure to get this message from the builder whose' work I have often admired... thank you! As is often the case, I sometime wonder how I will make things work, and I have reviewed your handiwork. I would like to know your source for the very cool tail lights!

The blue Stalker you did seem like it may be turning into a SUPER Stalker, and I understand the transmission may also be in need for renewal, so the Wyoming investment has some immediate uses for the blower and transmission! I already repurposed the scuttle and nosecone for my project, so the “book” tubular frame and doe wheels, Mustang spindles and “off-the-shelf” A-arms will be part of the next build. I need to finish my Hydrogen supplement Ro7us before I start the next hydrogen / gasoline engine build. I’m still a fan of the rotary motors for my applications. Unless I am mistaken, I still believe that these have the highest power-to-weight ratio and have a 6+ year of proven Hydrogen (or) Gasoline fuel capability. Those “Stalkers” are really brutal with torque… and I am sticking with Torsen IRS suspension.

Please feel free to comment on my construction efforts… this is my first effort working with anything metal, so I have a lot of “learning opportunities”
Why just last night I finally had access to a friend’s hydraulic tube bender (My JD2 did not have the 1.75” die) and the .125 wall was OMG stiff! Now I have a esthetic dilemma. The SCCA and NASA rule book calls for +2 inches over driver’s helmet, so naturally I added another inch. Hum it seems a bit goofy to have the hoop this tall without a full cage. Now comes the “fun” task of “fish mouthing”
the tubes for a perfect (TIG) fit…

I attached a few photos of the HIGH roll bar and the low. I will post a question to the fourm to see just how high most people set the roll bar. When I am in the Kirkey (20 degree intermediate... with padding) my helment is 2.5" taller than the top of the head back... so I'm thining I will add just a few inches to the lower setting (of the photos attached) The tall setting is just goofy!

[kreb]

Thanks for the kind words. One of the cool things about kit-car building is that you intimately know every nut and bolt on the car. That's a bit of a curse because there's always things that you could do better in retrospect. But my quibble list with that build is relatively short.

The tailights came from Speedway Motors. They aren't real bright, and a safety-conscious person might consider augmenting them with a high-mounted brake light. The tranny did occasionally jump out of first when leaving from a stop. Otherwise it was fine. I understand the desire to make it even faster, since there's still one or two guys at track days who can keep up with the stock 3.4

I haven't looked through all the pages of your build, but on the face of it it looks like your skills are coming right along. Kudos. I've often felt that a rotary or bike engine was closest to the spirit of the original, although clearly 300 ft. lbs. is irrepressible.

[redbull]

It is something I have been wanting to do… well for months now… and now it’s time to “roll” Yep the roll bar is now getting fit to the car, and like most amendments, it only brings up more questions. I have read SCCA, NASA, FIS rule over and over, browsed the issues on the internet and ended up going with substantially stout 1.75” x .120 DOM tube.

I keeping with the rules of placement of the tubes (must be > 15” apart), I also needed to make sure the rear vertical supports to clear the gas tank so if needed, I can remove the tank. Rules also state that at least 30 degree angles so elevating the hoop a few inches higher than the minimum (+3” over driver’s top-of-helmet) I can also pass the “straight-bar test where by a straight edge is passed from top of hoop to (Leg / scuttle 1.5” x .120 DOM hoop) and clear both the driver’s helmet and the (13”) steering wheel. Did ya get all that! Later I will be adding a detachable forward support and two side impact bars also tied into the front leg / scuttle hoop.

With all this measured now, the hoop need to lose at least 7”. EEKS I just wasted a foot to DOM but I’ll use it in something I’m sure (right?)

Now the notched… and I have a modified Harbor Freight that was developed for motorcycle frames, and is so flexible it is a bit too clever for this simple fish-mouth notch. I thought that I could use an old toilet paper roll cardboard core to help me easily craft the shape of the compound notch since the rear tubes affix right as the tube completes the bend (another requirement). I’ve kept some thin walled scrap tube specifically for this mock-up and I used this to practice on how I will shape the compound notch as well as the relationship to the 45 degree flat-cut.

This was a very good call as I carefully notched, ground, and filed off the notch until I had a perfect fit as needed for TIG welding. Then I simply slipped over the toilet paper cardboard tube, traced and cut the crafted notch onto the cardboard tube.

I then made the exact 45 degree cut and aligned the mock-up tube with the new DOM tube (verified alignment, and slipped over the crafted cardboard tube, traced the edge from the cardboard template, and then ground off the new DOM tube to an exact duplicate of the mock-up tube.. worked perfectly! So all the time I spent with the mock-up tube was completely utilized. I need to be very exact in the next three tubes since I will only have 3 inches to spare as I complete both support bars and the seat-belt horizontal cross-bar.

Since this process worked well I will finish the other rear support tomorrow and then the horizontal seat-belt tube. If all goes well tomorrow I’ll post photos of the completed (well at least tacked) roll bar

[redbull]

Thanks for the kind words. One of the cool things about kit-car building is that you intimately know every nut and bolt on the car. That's a bit of a curse because there's always things that you could do better in retrospect. But my quibble list with that build is relatively short.

The tailights came from Speedway Motors. They aren't real bright, and a safety-conscious person might consider augmenting them with a high-mounted brake light. The tranny did occasionally jump out of first when leaving from a stop. Otherwise it was fine. I understand the desire to make it even faster, since there's still one or two guys at track days who can keep up with the stock 3.4

I haven't looked through all the pages of your build, but on the face of it it looks like your skills are coming right along. Kudos. I've often felt that a rotary or bike engine was closest to the spirit of the original, although clearly 300 ft. lbs. is irrepressible.

Thank you for the information on the lights. I will be incorporating LED into whatever tail light I end up with and plan on using the dam inspection holes in my roll-bar to facilitate the wiring to a roll-bar LED brake light (that is more the height that is visible to mom in the minivan!
Your right about the builds… I know everything good (and bad) as I crafted this project to this point so I’m looking forward to the utilizing the lessons learned on my next build.

As for the rotary… well it’s not just the 150 lb. motor, it the fact that this build will use gasoline AND Hydrogen (Browns gas), and the next engine I am setting up is gasoline OR Hydrogen (direct injection). Ya see Mazda has been building the Hydrogen (or gasoline) powered rotary vehicles for more than 6 years now! But surprise, you cannot buy them here in the USA. It’s really a political / economic issue and generating your own hydrogen (or reclaiming it from waste water treatment plants) is a not a big deal… and I am taking the theory to practice.

I have this vision of creating alternative powered cars that regular people with emerging talents can build out of junk-yard destine cars. Ya, I know… sounds a bit wacky, but as I progress in this project, I have become a practitioner of home-built hydrogen powered sports cars… and DOING is far more valuable than just talking. Besides, Pistons are so last minimum (grin). If you follow the rotary race circuit, than you know the challenges and benefits. Most people just po-poo what they do not understand… heck I’m just fascinated in a three moving part engine that can produce upwards of 200 (or a lot more) horse power… and use low octane gas, and hydrogen fuel!

Sorry, I’ll get off my soap-box now… so you see, building my “H2 Ro7us” is as much of a proof-of-concept as it is a fun drive with a serious education.

[rx7locost]

I just have to see that H2 Rotary!

As for the paper roll tube, don't discount the tubemiter.exe program. I used it a lot on my control arms. It would work very well with your fish mouthed roll cage bits.

Carry on.

[redbull]

I just have to see that H2 Rotary!

As for the paper roll tube, don't discount the tubemiter.exe program. I used it a lot on my control arms. It would work very well with your fish mouthed roll cage bits.

Carry on.

interesting, do you mean this one at this link: http://www.ozhpv.org.au/shed/tubemiter.htm
I need to make a compound miter as the bend of the tube meets the "straight" sections so it's a three-part cut all-and-all. Ya, I learned a LOT from paper templates! not to mention PVC (that I used for my A-arms)

[redbull]

After completing one side, I reconsidered the excessively tall main hoop, and ended up cutting off another 3" (total of 7" lower than my over cautious TALL hoops) Damm I wasted nearly two feet of DOM, but if I work smart I will have JUST enough to finish the other side and the horizontal seat-belt tube.

Since I reduced the hight 3" I could reuse my mock-up tube to make the driver's side rear support, again using the toilet paper roll tube and the thin walled tube permitted me to make the "perfect" fit that I will duplicate as did on the other side. (That I already corrected the other DOM tube for the new lower angle.) I am gambling with tight clearance for the fuel line, but WHEW! I was able to clear this as you see in the photos. I still pass the straight edge test and my "exact" rider with helmet hight (from roll bar hoop base) is 16" and with the two reductions in hight, it now has a total hight 20" (still twice as much as required per the rule book). With the weekend here I have a few family obligations so I will have to hold-off on cutting the last tunes until Monday... nuts! Still it is great to see the roll bar mostly ready for welding!

[redbull]

I took off for a short vacation in Tahoe, and right next to my hotel I heard this rumbling… 37 AC Cobras! (What is the name for a collection of Cobras? Pack, swarm?

[rx7locost]

That would be a NEST of Cobras.

Cool! Not my cup 'o tea, but I can respect them for their true British Heritage, with a bit o' help from Mr. Shelby.

[kreb]

Funny, I was having breakfast in Homewood when they came rolling by. Not a big Cobra guy, but it would be nice to putter around in one of those!

[GonzoRacer]

That would be a NEST of Cobras.

Nest??? Iffen I was standing there, it would be an ORGASM of Cobras!!!
(They'd probably ask me to leave...)

[laserracer]

That would be a NEST of Cobras.

Nest??? Iffen I was standing there, it would be an ORGASM of Cobras!!!
(They'd probably ask me to leave...)

LOL nice ...no orgasmic

[redbull]

LOTUS were racing just down the road from me so naturally I took a break from my TIG welding in my Roll bars! This is what I got done before I watched the INDY races and sat in the pit with Scot Dixon’s team that finished the same as his number (5) Although the car had LOTUS logo, it was powered by the Honda V8’s. Oh ya, I think it was Scott’s girlfriend that sat beside me at the pit, she sure make the LOTUS logo look very sexy!