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The pedals are now mostly completed. The pedals themselves are very close to the Tilton 600 series floor mount design while the assembly is my own design. I went with a 6:1 lever ratio for the brake pedal and a Wilwood balance bar. The clutch is the same pedal ratio as the Prelude and uses the Prelude master cylinder, but can also accept Wilwood master cylinders. The bushings and sleeves for the pedals were salvaged from the Miata and Prelude pedals. I couldn't think of an elegant solution for a brake light switch so I will probably be using a hydraulic switch. The tabs and slots really made assembly a cinch.












The fuel tank is nearly finished as well. The fuel pump, fuel level sender, and vent are from the Prelude. Fuel capacity is ~30 liters (7.75 usg).

Sweet!!!!! Russ

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You meet the nicest people in a Locost Se7en.

Any updates?

Wow it's been a while. There is some progress to report, although not a whole lot. The biggest thing is I've finished my engineering degree and have quit my Saturday job so I now have a lot more free time to work on the car.

The axles are now complete and assembled. The Prelude axle shafts were just large enough to be able to re-machine the ends to fit the Miata outboard CV joints.






I've also purchased a bunch of components. Shocks, springs, rod ends, header and exhaust parts, brake master cylinders and prop. valve, and I decided to go with a 12 gal RCI aluminum fuel cell instead of my own 8 gal fuel tank. I wasn't all that happy with how the tank turned out and by shuffling a few of the frame pieces around I could fit the purchased tank and get a little more range. The header and all the exhaust pieces are stainless parts from Vibrant. The build quality of the header is outstanding and it was priced quite reasonably too.












Some of you have inquired about the CAD for my pedal assembly. I have sent the files off to Jason to put up on the CAD wiki site so if you are interested in using them, that is where to look. As a cautionary note, I haven't finished building my pedals yet so I'm not sure if I will encounter any other issues with the design. One issue I have encountered is that the snout of the compact master cylinders from Wilwood are significantly longer than depicted in their technical drawings. This interferes with two of the vertical supports on the pedal base. You can either rectify it by moving the vertical supports, making the reliefs deeper or making 5/8" spacers for the master cylinders as I did.








The frame construction has just started. I've finished rolling all my large radius tubes with my Harbour Freight tubing roller, and I'm now in the process of cutting and notching all the other tubes. The tubing roller worked very well and it was pretty easy to keep the bend planar. I just used the seam of the tube as a reference and kept it at the edge of the first roller the whole time. Most of the tubes being rolled were under 10' but to minimize materials needed I had to make the top and bottom main tubes from one 20' length, and that was hard to keep from spiraling. The roller produces about 4" of waste at either end of the tube so I had to roll the 20' length to the top tube radius, then cut what I needed off and continue rolling the bottom radius.

Man sweet progress!!! What did it cost you to get the pedal parts laser cut??

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My build: http://www.locostusa.com/forums/viewtop ... 18&t=13096


You can build the most awesome thing in the world but at some point, an 80yr old man in a crx is probably going kick your butt on the track... don't ask me how I know.

LOL, I read this again Zac, and realized we used to race against each other at western. Looking awesome. Been down that road a couple of times before, so I know you've spent a ton of time and effort on your solid models, which will really pay off in the end. Nice work on the sheet metal design, locating tabs, etc!

You still racing these days? My race car was sold a couple of months ago...

Who resplined the axles?

The brake switch can be placed between the flanges of the brake pedal, with the actuating lever on the pedal short enough to clear the pedal frame and still contact the microswitch roller lever. Derate ac switch for dc use. I guess a 10 amp vac switch would be okay for intermittent dc brake use but I did no math. You might want to verify.

If you still want a hydraulic brake switch, consider wiring two with a warning when one has failed, like the old beetles.

If you resize your pics to around 800 x 800, they will fit the page and take up less memory on your computer and the forum.

What is the purpose of the offset in the throttle pedal?

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Yup I'm still racing my Miata. I just bought some fender flares for it so I will be able to fit the new wheels (15x10 6UL's) which will also be used for this car. The tires will be 275/35/15 Hoosier A6's.




Miatav8, the axles were resplined by Leech Machineworks. They're a local machine shop that regularly builds narrowed rear ends for drag cars.

Great idea for the brake switch. The tail lights are LED's so the current rating of the switch won't be an issue.

The pedals very closely mimic the Tilton designs so I maintained that aspect of the gas pedal. It's there so that if I ever decide to install the Wilwood remote bias bar adjuster I have a clear shot to it.

If you don't mind me asking, how much was it to have the parts for the pedals cut?

I don't know how much it would be for just the pedal parts because I had a lot of other stuff cut at the same time. I think it was around $600-$700 for everything but it varies quite a bit place to place so be sure to shop around.

The rear rocker arms are now complete. I may add some extra webbing for strength but for now they're finished.




I also finished the front cross member and front subframe. The cross member is a very integral part that connects the front subframe to the floorpan, and lower curved tubes. It also contains the mounts for the steering rack and coil-overs. The front suspension will be aligned using the same eccentric cam bolts as the Miata as well as through the upper ball joint.













My plan of attack at this point is to build the rear subframe complete with all suspension mounts. I'll then connect the front and rear subframes together through the floorpan and curved main tubes. Once that is finished all the critical dimension stuff will be complete and the rest will just be filler.

Zac88GT, how can I contact you?

You can email me or PM me using the buttons at the bottom of any of my posts.

After finishing the front subframe I thought it would be a good idea to assemble everything and check for any interference, or alignment issues before I got too deep to easily correct it. I was shooting for 3-5* of static castor but with the eccentric adjusters in the neutral position the castor is closer to 8-10*. Moving the adjusters all the way to the minimum side I get about 1-2* and then I can adjust the camber by threading the upper ball joint in or out, so everything worked out there.




Once all the components were in place I checked the motion of everything and it looks great, except for the steering column. When I designed the steering rack mounts the shocks were in the ride height position, but with the suspension in full droop the universal joint for the steering column contacts the drivers side spring. This was rectified fairly easily as I just cut out the drivers side mount and rotated the rack about its axis so the pinion part fit deeper into the pocket I created for it. I welded everything back up and now it all works beautifully.



With the front finished I moved on to the rear subframe. I welded together the basic structure and then clamped the suspension assemblies on. There isn't as much adjustment for the rear alignment so it was a little more critical to get the tabs welded on in the right places. I used a laser level to project lines on to the garage door and build table to make sure the toe and camber were correct with the adjusters in the centered position.



I also started to get skeptical of the frame strength at the shock and rocker arm attachment locations as these are on fairly long, unsupported structures. I decided to do some reinforcing with an extra tube between the top and bottom rails just after the rocker arm mounts. This will help cancel the loads between the two points as one is up and the other down. I also added 12 gauge plating to the sides of the tube all the way up to this extra vertical tube. Additional tubes were added between the top main curved tube and the top rear subframe tube, as well as some extra bracing at the front and back of the rear subframe. The result is probably a little over built, but at least I'm confident and comfortable with the design now. One downside to the reinforcements was that it now interfered with the cross brace on the lower control arm as the suspension moved through its range of motion. To fix that I cut the brace out and welded it back in 1" further outboard.




After that was done I test fit the engine and started making some engine mounts. With the engine in the position I designed around, I found that some areas were pretty tight for clearance (~1/8"). There also may have been possible interference between the rear passenger side spring and the shifter mechanism. After looking at my model again I realized the shifter arm was an area that got missed with the laser scanner so I was not able to design around it. I ended up shifting the engine forward and down ~1/4" so now I have a minimum of 3/8" clearance everywhere. After the engine mounts I bolted up the sway bar and welded the mounts for it on to the removable rear brace.

Left engine mount


Right engine mount


Rear engine mount on removable brace with rear sway bar mounts


There will be a front mount as well but that will have to wait until the rest of the frame is built.

I also put on the new header from Vibrant after cutting off the flexible section and flange to start test fitting the exhaust. Because the engine was now 1/4" further forward, and the Vibrant header doesn't exactly follow the same path as the original exhaust, I had to notch and reinforce the front of the subframe to gain extra clearance. Then I cut and tacked the rest of the exhaust up so it's now ready for me to take to work and TIG. It's REALLY short so it might be a bit loud but it should sound pretty good. From the 2.5" collector there is maybe 8-10" of pipe and then it goes into a Vibrant 2.5" single inlet, dual 2.25" outlet muffler.

That's an interesting muffler.

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Yeah I thought it was quite unique when I found it. It was exactly what I was looking for and makes for a compact exhaust. The muffler is from Vibrant, is all polished stainless, and is offered in either a 3" inlet with dual 2.5" outlets or with a 2.5" inlet and dual 2.25" outlets. Inside it has a Y from the center and then a straight through design on either side like a magnaflow.