Hmmmm... DeadSkunk's Challenge Corolla... may need flares

DeadSkunk (Warren) said:

I don't know why ,but putting the VIN plate back on this thing makes me giggle......

I accidentally cut straight through mine on F-dat, but I'll find a place to put it back on for you. 

In reply to gumby :

I'm totally flipping mine over tonight for JPGs.

I stripped the chassis down and flipped it over so I could get better access to a bunch of spots that needed welding. Between my aging back, bifocals, a 110V sears welder and my minimal welding skills, overhead welding just isn't in the cards. It's easy to tell which welds I attempted to do it, too, so over it goes. I'm also at the point where I'm building the floors. I removed all the previously tacked round tubing in the floor structure and replaced it with 1x2 instead. It's easier to cut and weld where I want stuff.

Also, the floor will be about 3-3.5 inches off the road so there isn't a great place to run the gas lines from the fuel cell to the engine. I decided that some 1x2 would make a good passenger side support for the sheet floor, as well as being a conduit to run a couple of AN braided steel lines through.

I notched the cross members at the front and rear of the passenger compartment to accept a length of 1x2, then ground and filed it to fit....

Here's the conduit tube welded in place. There will be more 1x2 attached to it and the main chassis rail to support the floor.

Floor support structure complete. Next I'll add seat belt tabs and then then sheet steel flooring.

Some more progress..... I welded on the floor sheet metal and it was oil canning a lot, so I went at it with a 3" wide mason's chisel and a big hammer to create an X-shaped crease, which worked. For the remaining pieces I used the chisel/hammer on a block of wood before I welded the sheets in place. In the following pictures the underside and some of the chassis has been given a first coat of paint.

Here's a view of the partially painted chassis...

It looks really biege in the photos , but in person it's more gray, not that it matters. The paint was a $10 gallon I bought off Facebook Marketplace. I used about a dollar's worth of paint so far. I love the stuff . I put it on with a 1.5" brush, but it is sprayable. The beauty of it is you can thin it  and clean up with water, yet it's listed as outdoor use for things like chemical storage tanks. Should be plenty good enough for a Challenge car chassis and cage.

Today I got a second coat of paint on the underside of most of the chassis. I still need to leave lots of bare steel exposed until I'm done fabbing up the firewall and interior panels. To that end a new toy showed up on the FedEx truck this morning, so I spent part of the day welding scrap together to make a stand for it. A lick of the paint and it'll be ready to use.

A little more painting and welding on the chassis today and then I'll flip it back over. While watching the paint dry I tried picking up each end with the other end sitting on a sawhorse, and I can pick up both ends. Since I'm a 190 lb, out of shape 69 year old, that suggests the chassis isn't all that heavy, so I proceeded to weigh it with my old bathroom scale. I put that piece of wood under the windshield header bar and the scale under the main hoop to get one weight and then swapped them around to get the other. Combined weight was 330 pounds......I didn't think that was too bad considering. I figure there's about 20-25% excess in it, too, given that most of the tubing is 0.120 wall and could easily be 0.090 without Challenge budget constraints. I'm curious to see where the completed car ends up.......under a ton would be nice.

Major components are engine (400 lb), transmission (120 lb), rear end (200 lb), wheels and tires (170 lb), the body (haven't weighed that yet) and all the front suspension and steering. It all starts adding up quite quickly.

Edit: Add a few more pounds because the scale says I'm 192 fully dressed and I'm sure that's off at least 5 pounds from the good scale in the bathroom.

I went through the chassis and measured all the tubes that were made from purchased steel, which is anything square or rectangular, plus anything made from tubing scavenged from a Polaris RZR cage, and a small amount of tube from a Meijer's clothing rack. I still need to measure up the plate I used in the motor mounts, but so far I'm at $68.75 for steel.  Add in 5 rolls (2 lb) of welding wire from Menards and the chassis material cost will be around $110 plus whatever the motor mounts cost. All of the sheet for the floor, firewall, and rear parcel shelf is scavenged file cabinets or a pair of cast off sliding closet doors. Most of the cage is the original cage that was in the car when I bought it and it's been recouped down to zero. 

I need to sit down one evening and do accurate accounting of where I am, but with using gross numbers instead of prorated ones I'm in the $13-1400 range. I need to complete the car for $1900 so I have enough left for the HPTuner credits needed to unleash the LS.

I painted the Miata suspension and steering parts, put the rear axle back in with shorter link bars to correct the wheelbase, and started putting the engine in so I can do the rest of the transmission tunnel and support fabrication.......BUT, the steering rack is interfering with the engine a little bit...

You can see the edge of the oil pan resting on the hydraulic line port/bung......no bueno.....so I cut  up a second rack to relocate that bung...

You can see the original hole along the bottom of the tube and the bung sitting in the new location. I have zero faith that I can MIG weld that in place and make it leak proof so I'll have to outsource it to get it TIG welded. I'll also have to see if I can carefully bend the existing hydraulic line to get to the new location and avoid the  harmonic balancer while not kinking the tube. I can also see the need for a small "skid plate" under the front cross member to protect low hanging hydraulic tubes from errant orange cones.

I have the same bead roller but with a different brand on it, many hours of fun there!

To ask a dumb question, do you need power steering on this car? Seems light enough to not bother although if you're going ls then you probably do. 

In reply to 2Girlsracing (Steffi) :

I bet it comes down to tire size and driver fatigue. 

The car will be fast. Obviously. Taking a fast car to the Challenge means you may be asking a "Pro" to set the fastest lap with the car and if they can jump into a car that is super easy to drive it means they will be faster. 

Add to that Skunky claims to be older than I am (no proof of that ever given) and I get exhausted just turning a car on I'm guessing that he wants to drive and not do an upper body workout.

In reply to 2Girlsracing (Steffi) :

I intend to run a 275 or 295 tire on 10" rims on a car that has Miata MX-5 front suspension. I hope the overall weight is less than a Miata, but I don't know that yet. I've asked a couple of people that autocross Miatas on big rubber if running without power steering is feasible and both thought Popeye forearms would be needed without it. After the Challenge I intend to autocross it before I eventually sell it and , as John points out, I'm not a kid anymore so I think power is needed. I  do have two racks, so I can de-power one and try it at some point if I want .

In reply to DeadSkunk (Warren) :

I'm pretty sure hp turner credits have been ruled a tool not in budget.

In reply to Stampie :

I'll have to follow up on that then. The extra dollars might be needed.

From the rules :

Tool rental is not included in your budget. Buying credits for devices like HP Tuners is considered tool rental, and is budget exempt.

In reply to Stampie :

Thank you, Sir !

Stampie said:

From the rules :

Tool rental is not included in your budget. Buying credits for devices like HP Tuners is considered tool rental, and is budget exempt.

Same reason I hacked the TBI on my Firefly. The chip was budget, but the chip burner was not. Saved the money of buying some kind of ECU like Megasquirt or the cost of replacing it all with carb.

Thanks to Phil (PMRacing) for hooking me up with his buddy Rick. The welding in the photo is Rick's handy work. I don't weld this well even in my dreams. Thanks Rick !

A lick of black paint and it'll be good to go.

Moved on from the steering now that it's done. Next up .the transmission cross member......

Something to remember if you ever do something similar.....make the mounting points with a little draft to ease assembly or removal. The end plates and the mounting tabs on the chassis are tipped in slightly.

Today   I worked on getting a drive shaft loop in place to catch the shaft should the U-joint fail. There isn't enough room to use a conventional Jegs/Summit loop so I basically used half of one. In the picture the suspension is at full droop and there's plenty of room around the shaft.

Next, I started on the rear firewall. A roadside pickup file cabinet from a FB Marketplace ad gave its best for my little hot rod. Measuring, cutting and fitting around the door roll cage tubes was time consuming. I put beads in both panels with my new bead roller. They're far from pretty because it's not easy guiding a panel with one hand while exerting a fair amount of cranking force on the handle, but the panels are stiffer and welded in place...

Next on the agenda will be filling the gap between the gray rear firewall and the white firewall insert at the front. Before I close the floor up I need to route the transmission cooling lines somewhere. They exit the trans on the right side, but my Mustang race radiator has its connections on the left side. I'll need to cross the drive train center line, while avoiding the headers and I don't want to run anything below the bottom edge of the main chassis rails. The car will be low enough that mowing down a cone could result in low hanging gas, cooling, or oil lines getting ripped off. I also have to figure out my shifter mounting location to support it with the tunnel.

Yesterday I made a bracket to hold the Walbro fuel pump. It's just a couple of pieces of a file cabinet bent to shape and plug welded together, but it turned out rather nice.

......and then I bolted it to the top of the fuel cell enclosure, where there is ample room,

Then, after supper  I started reading up on what other stuff I needed to do to use a Walbro pump. At that point I discovered that the pump has to be mounted below the bottom of the tank........nuts!!!

There's not a lot of room around the fuel cell in any direction except to the rear of the car, as you can see in the following picture. The mufflers are sitting there while I figure out which way to orient them. I need to have the fuel pump low and away from the exhaust. Just another packaging problem on this little car...

I think I'll need to drill a hole in the cell, low down on one side and put fittings in it to have a bottom exit. It also needs to be able to go in and out of the steel enclosure with a fitting stuck out of the side........fun, fun,fun.....

Possibly it can go on the front side of the cell enclosure, at the passenger side. That end of the Panhard bar is the chassis end, so it won't move vertically very much, and the fuel lines need to be to the passenger side to run through a  1x2 tube that's basically a closed conduit through the passenger side floor.

Side exits with no mufflers for challenge!

DeadSkunk (Warren) said:

Yesterday I made a bracket to hold the Walbro fuel pump. It's just a couple of pieces of a file cabinet bent to shape and plug welded together, but it turned out rather nice.

......and then I bolted it to the top of the fuel cell enclosure, where there is ample room,

Then, after supper  I started reading up on what other stuff I needed to do to use a Walbro pump. At that point I discovered that the pump has to be mounted below the bottom of the tank........nuts!!!

There's not a lot of room around the fuel cell in any direction except to the rear of the car, as you can see in the following picture. The mufflers are sitting there while I figure out which way to orient them. I need to have the fuel pump low and away from the exhaust. Just another packaging problem on this little car...

I think I'll need to drill a hole in the cell, low down on one side and put fittings in it to have a bottom exit. It also needs to be able to go in and out of the steel enclosure with a fitting stuck out of the side........fun, fun,fun.....

Possibly it can go on the front side of the cell enclosure, at the passenger side. That end of the Panhard bar is the chassis end, so it won't move vertically very much, and the fuel lines need to be to the passenger side to run through a  1x2 tube that's basically a closed conduit through the passenger side floor.

 

I wouldn't put holes in the cell.

Fr9m my experience, those pumps will pull a bit of fuel uphill.  It's not ideal, but it's not horrible either.  Once they prime, they are fine.

Would it be enough to run a loop of fuel line above the fuel pump and back down to it? This would at least ensure you don't start the pump dry.