I know, another copycat Corvette Kart build.

something to consider when configuring the exhaust.... you no longer have a body to muffle the noise from the exhaust to the driver... i am using the aftermarket exhaust system that was on my  car before conversion. it was perfect with the car body on, even with the convertible top open. however... now, with nothing really between the exhaust exit and the driver it is way too loud. Even with foam ear plugs in, if i drive for more than ~30 minutes, i get a tone/ringing sensation in my ears. so, if you are going to drive it much, plan on resonators and mufflers! 

Somehow I missed this when it first popped up, but I've been thinking about Vette Karts around the clock for the past few days, so I'll be following closely. Obviously, it takes a lot more work to do it right than to just hack away Roadkill style.

Does anyone actually sell a Vette Kart Excocet type tube frame yet?

   We have front suspension! I decided that the there were only 2 ways to get the chassis at the correct ride height, eliminating the front transverse mounted springs and mounting coil overs. The problem was in the packaging. Aftermarket coil overs are considerably wider than the stock shock. Here is my take on solving the problem. 

1. The bottom mount was pretty straight forward thanks to some coilover brackets from A&A Mfg. Their catalog is incredibly useful when building any racecar, it saves countless hours of fabrication.

2. Finding a spot for an upper mount. Since the chassis has those 2 additional forward rails, it was the natural spot to see if the upper shock mount would work there. It did! Again, another coilover mount and a tube clamp from A&A Mfg and we have a preliminary upper mount. This would allow me to get some dimensions needed for front shocks.

3. Once they were tack welded and bolted-on, next came the measurements. First was to set the chassis at static ride height and I started at 5-1/2”. Next was setting the front hub at ride height. I’m going to use a 25” tall front tire, so the center of the hub set to 12-1/2”. At this point, the measurement from the center of the lower mount to the center of the top could be around 19-1/2”. I’ve used QA-1 coilovers before, so when browsing through their catalog, there it was, the DD701. Its a double adjustable shock that meets my specifications perfectly. I ordered 2 and a pair of 500# springs as a starting point. They took a few days to get here, but it was worth the wait.

4. At this point and before any interference, there is 3-1/2” of compression and 2-1/2” of droop. At static ride height I’m at 16”. This couldn’t have worked out any better, but there was a bit more work to get them to fit. There was an interference issue between the spring and the frame. Not a big deal and nothing that some cutting, heating, hammering , welding and grinding couldn’t fix.

Hopefully I will get some time this coming week to finish both sides of the front suspension and get the exhaust done. 

In reply to lotusseven7 :

Very nice work!

Not much free time the last few weeks, but enough to get front and rear suspension straightened out. Front upper and lower coil-over mounts made, frame cut and welded for spring clearance, rear upper coil-over mounts made and lowering bolts installed. In measuring the rear suspension travel and ride height, the rear shocks just so happen to be the same DD401’s that are on the Lotus 7 that we are also building. Luckily there were 4 brand new ones sitting on a shelf for another build. Well, there’s 2 on the shelf now.

I was also able to pick up an Edelbrock Victor Jr intake manifold from CraigsList. I wanted an “air gap” manifold since it will allow for higher revs than most others. That and they look cool too!

Im hoping to get a few hours this week to get the exhaust finished up. I’m thinking a single 4” from the collector back. I would like to make an exhaust that will handle 500+hp down the road. I’ll keep you posted as to the final decision. 

Better pictures to follow........

Oh, I almost forgot, I did some shopping on CL and was able to pick up a set and a half of wheels for the kart. It might not seem like a big deal at this point, but I decided on a ride height and shock lengths based on a certain size tire, so I needed to get wheels and tires to get it on the ground. Most corvette drivers opt for wider wheels/tires in back and I’m guessing it’s mostly for aesthetics. Since there are LOTS of choices for Vette wheels out there, after a bit of research, I decided on the C5 “wagon wheels”. They are supposed to be lighter weight yet very strong(according to the interwebs). I picked up a pair of fronts with tires and TPMS sensors for $125! I also found a complete bare set for $200. My intention is to run the front 17x8.5” wheels on all 4 corners. This will allow me to run the same size tire all around, only carry one size spare wheel/tire that can go on any corner, run the 13” Z51 brakes and hopefully be able to tune the suspension easier. I also like to be able to “steer” the car with both the front and rear tires and having the smaller 275/40/17 tires on the back, it should rotate easier in the corners. No need for 315’s on back, they’ll just slow you down.

They might not be the most attractive wheels, but for less than $250 for a set, I can live with them unless a smoking deal comes along.

In reply to lotusseven7 :

We used 17 in wagon wheels on our 2016 challenge car. Although it wasn't a kart then as it's becoming now the 275 40 17s on all corners were plenty of tire. Car handled amazingly neutral especially when we got rid of oversteer by disconnecting rear sway bar. Truth be known I think the wagon wheels get a bad rap on looks. They're not that bad especially on an old C4.A.d slow start of our hack

BTW....if if you haven't already check out Facebook page titled Vette hack. Lots of projects to peruse their not that you'll need any ideas. Your project is coming along great

Not much done on the kart over the last few weeks due to a roofing project, but I finally freed-up a good part of a day to play in the shop with no distractions. I decided to tackle building the transmission tunnel, floors, firewall and rear bulkhead tubing. It took about 40’ of 1” x 1” x 0.125” square tubing, a 40 grit sanding disc, a can of brake clean, a level, some shop rags, a few clamps and a couple hours with a MiG gun in hand. Voila! One step closer.......

Oh, also picked up another set of C-5 wheels for a song! At the end of the day today, I decided to throw 2 of the wheels on the car to get an idea of what it will eventually look like. ITS SHORT! It’s shorter than my MGB that it’s next to in the shop! The front is going to need to be lengthened a bit to get bumpers to clear the tires.

lookin good!

Beautiful work!

Finished building some pretty basic bumpers but I’m not sure that I’m going to keep them. Maybe, but I was originally thinking something more squared-off. It’s just a length of steel, so if I don’t warm-up to these, I’ll give it another shot. The rear one needs to be shortened a bit if I decide to use the C-5 rear wagon wheels. If I use C-4 Grand Sport wheels(on the passenger rear), then it is fine.

Oh, and did I previously mention that it’s SHORT! With the bumpers installed, it’s 11’5-1/2”(137.5”) overall length !!! 

My shins hurt looking at those bumpers but the fabrication looks awesome.

Adam

With all of this rain, I was able to get a few hours alone in the shop to “play around”. The fuel cell arrived yesterday so timing was perfect. I was looking for something around 12 gallons and but more importantly, really wanted it to be around 7” tall. I looked but couldn’t find anything with the right size and configuration. The closest I could find was an aluminum cell manufactured by Rhodes, is 16 gallons and measured 25” x 17” x 9”. I’m trying to get this thing as light as possible but still want to be able to do a 45 minute track session at minimum. Some more 1” square tubing and we now have a fuel cell mount and a battery mount.

I also decided to go with dual 3” exhaust with a cross-over rather than a single 4”. Either would work fine, but what I have planned for the duals will look cooler. That’s for next weekend. I’m going to buy some steel sheet for the floors and aluminum for the tunnel, firewall and rear bulkhead and try to get them in this coming week. The pedals and seat should arrive in a day or two. Early Christmas!!!!!

How much front brake is too much? Is there such a thing as “too much front brake”? I picked up a BIG BRAKE set-up from a GT-1 car and might be using it if they will work with manual Wilwood pedals/master cylinders. The rotors are 2-piece(hat & rotor) and measure 14” x 1-1/8”. The calipers are radial mount 6-piston units. 

Since the donor car car was a Z51 model it had 13” rotors with PBR calipers. I’m sure that with the weight reduction of this build, the 13” set-up would be just fine, but if more is better, what does everyone think about running this Wilwood set-up?

I like big brakes and I cannot lie! Carry on!

Small update but still making progress and moving the build forward.

- Bent-up some 0.090” mild steel sheet and made a dropped floor pan for the drivers seat. Its 1-1/4” below the rails but I had to do something as the rollcage ended up a bit short. My mistake. Hoping to finish all the floors by the end of the weekend.

- Also finished the exhaust. Decided to go with 3” dual but wanted to do something a little different out back. I grabbed a cheap pair of Beyea “mufflers” from Summit. They are loosely described as “mullfers” but I’m using them as slash-cut exhaust tips. If they happen to muffle any noise at all, it will be a bonus, but I’m not holding out much hope. I just like the look.

I had a goal by the end of the week of having the floorboards completed. I finally made a freakin’ deadline for once! Floordboards are done, seat/sliders are drilled and mounted and pedals found their way to their final location. Oh and a few dzus plates welded in.

I also went digging into a tote of pieces and parts that I’ve been hoarding for years. I began accumulating these gems in hopes of building another Lotus 7 replica, but since I’m going to need gauges for this project, I’m putting them to good use in the Corvette Kart.

Next week I hope to have the pedal boxes welded in as well as the tunnel and rear bulkhead aluminum fit. Maybe if time allows, I’ll try to fab a dash/gauge cluster. 

Its finally starting to look like something!

Looks great! This is a very un-hacked looking kart. 

Another rainy day and no progress on the roof project, but that means I had time to spend working on the CK(Corvette Kart) project.  Several hours of making poster board templates and then transferring to sheet metal, then bending, fitting, cutting, grinding, cursing, bleeding, more grinding then finally welding it into place. After all that, it was off to do the other side! At this point, the “firewall” and “footwells” are basically done. I made these out of 0.055” steel instead of aluminum just in case anything would ever fly up from a car either on track or on the road. Also, since everything is welded, it’s structural now rather than just a bonded/riveted aluminum panel. I will finish the couple pieces of interior aluminum work the next time I have a few hours of free time.

At the end of the day my brother came by the shop to have a few pieces of stainless welded. While there, he asked what I thought the car would weigh the way it sits and then once it’s completed. I remembered back to the original Road Kill Corvette kart video and thought that they said the car ended up weighing 2400#. I’m guessing that it will finish around 2100-2200#, so we pulled out the scales and threw the “car” on them. I then went and grabbed the brake rotors, calipers, driveshaft, fuel cell, seat, pedals and put all of them basically where they go. I was very happy with what it weighs as-is, 1882#.

It’s beginning to look like a car finally and hopefully another decent day and the bulk of the metal fabrication will be com-peter.

coming along nicely. my C5 chassis stripped, but drivable was 2350lbs. I think, after caging (tube weight/ft and lengths are known so estimating is reasonable), removing my B-pillars, adding the rear wing, i bet i am at 2600. I need to get back on some scales...

it looks like you are leaving room to put the radiator back up front. is that the plan? 

to my knowledge, the C4 based karts i have seen all have a front weight bias that limits them somewhat... 

Based on my precage weights, i think i am probably damn near 50/50 with the cage being more on hte rear than front. But, season 1 of autocross has shown me more rear grip would help. C5s lack of available rear camber.... so i am planning on moving my radiator to the rear during summer autocross break this year.. I think it will be a nearly 50lb swing, from the extreme front to extreme rear.  have you considered the same?

We talked about radiator placement yesterday. The plane between the rear cage downtubes clears the fuel cell, so it can be placed there at an angle, but the lines are an issue. There is plenty of room in the tunnel but getting around the rear suspension and into the tunnel is an issue. With the fuel cell positioned all the way to the right for weight distribution and the battery location under the cell, getting from the tunnel to where the radiator would be mounted would take some doing. That and filling the cell would be impossible without making a remote fill. I’ll look at it after the holidays.

My brother wants me to mount it up front, flat, and build a diffuser/ducting to get air through it. I really don’t want any aero devices on the car right now. If after It’s done and needs either front or rear aero “help”, I’ll look into it at that point. For now, I want the raw look of the bare chassis and tubing.

If all else fails, I’ll have one made and mount it up front. Not what I want, but it’s function over form at some point, just to get it done. Time will tell.

yea, i def prefer the bare, minimal list look of just the caged frame. which is another factor in my drive to put the radiator out back... it might be enough to reduce or remove my wing strucutre. 

what i am planning, since my tunnel doenst allow passage, is running coolant lines literally through the frame rails. i dont know as much about the C4 frame, but that might be an option for you too... 

the plan would be to use either marine exhaust tube/hose or aluminum tube (and hose segments) passed through collars into the frame rails, probably run both lines in the passenger side for weight considerations. i see no other way to do it on a C5 (wihtin reason)...

VERY interested in this....

Need to set aside tome to read completely through this thread (when I am not at work)

Damn, this is incredible.