maschinenbau
maschinenbau UberDork
11/13/22 9:13 p.m.

In reply to TurboFource :

I have plenty of inspiration for flares, which I'll make out of fiberglass once I learn how to fiberglass.

barefootcyborg5000
barefootcyborg5000 PowerDork
11/13/22 9:22 p.m.

This thing is gonna be so cool to see ripping down the track. 

singleslammer
singleslammer PowerDork
11/14/22 5:33 a.m.

In reply to maschinenbau :

This is spectacular! 

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
11/14/22 9:04 p.m.

I love how that sick body bracket was sort of "oh yeah, that too".

Great work.

rustomatic
rustomatic HalfDork
11/15/22 1:31 p.m.

How much of that nasty particle board sammich is there?  I semi-envy your future fiberglassing experience . . .

maschinenbau
maschinenbau UberDork
11/15/22 1:49 p.m.

In reply to rustomatic :

Pretty much the entire firewall, but in 3 sections. I may try to make them removable panels for access, possibly from aluminum for extra safety. I am honestly looking forward to learning fiberglass. I've never done it before so I'm watching a lot of videos.

nocones
nocones PowerDork
11/15/22 2:54 p.m.

Ooh that's exciting.  Keep going!  Prepare to itch!

maschinenbau
maschinenbau UberDork
11/18/22 4:16 p.m.

I did the research and ordered some fiberglass supplies. I found out that Fiberglass Warehouse ships from Georgia, so shipping for my order was free. A gallon of polyester resin, MEKP catalyst, 10 yards of 1.5oz chopped strand mat, rollers, brushes, cups, PPE, etc. I have a lot of time off next week to play.

I also put a bathroom scale under each of the front wheels. 530 lbs front axle weight, with the radiator and few wheels in the front trunk to simulate the gas tank. Probably more like 600 lbs once the car is complete. Apparently not enough to overcome preload of the front springs, resulting in the Carolina squat. I need to disassemble the front coilovers and measure the spring rate and free length. I suspect they're stiffer than the stock 100 lb/in rate. I am open to chopping coils, but they have closed and ground ends on a coilover. I know for sure they are NOT standard 2.5" ID springs like most coilovers, so sourcing shorter ones may be difficult. 

RoddyMac17
RoddyMac17 Reader
11/18/22 4:36 p.m.

Are they 1.875 ID fronts?  If so, Southwest Speed does stock 8" and 10" springs in various rates.  I was running 8" springs on the front of my car but had to use a spacer to allow some adjustment.  

Southwest Speed

The springs used to cheaper, I think I paid something like $35 each a few years ago.  If shipping was cheaper, I'd send you the fronts I was using, but they were very stiff, something like 150 lb/in.

 

As an aside, 1.875" ID springs are very common for Spax, AVO, and other european coil over dampers.  

nocones
nocones PowerDork
11/18/22 5:03 p.m.

This thing is either really light or wil have hilariously rear bias weight. 

Either way it will probably pull tires at the dragstrip. 

 

Note that doesn't mean it will handle poorly.  In fact it may work in your favor with the stock size front wheels.  

Dusterbd13-michael
Dusterbd13-michael MegaDork
11/18/22 5:05 p.m.

Ping steve Stafford and tvr scott. They have taught me a LOT about race car fiberglass. 

RoddyMac17
RoddyMac17 Reader
11/18/22 5:25 p.m.

Also, in regards to the firewall, I took baltic birch plywood and laminted it both sides with cloth and polyester resin, then bonded it into the bodyshell.  I also cut out three access panels and filled the lower two with "smugglers compartments" (one side for an amp that's no longer used, the other houses the ignition computer) and the upper one received a cover for timing belt access.  I wish I had built my english wheel as the upper panel would've been much smoother:  

 

When you replace the firewall, dont forget to add some access dimples for the engine cover hinge fasteners (just below the rear window opening), provided you're still using the stock hinges.

TurboFource
TurboFource Reader
11/18/22 9:23 p.m.

I did this when I cut coils.....for my Europa..QA1 springs and I think Energy Suspension insulators 

maschinenbau
maschinenbau UberDork
11/19/22 9:31 a.m.

I appreciate all the tips from fellow Europa enjoyers! Looks like I have 2.1" ID springs. The coilovers will indeed fit a 1.875" coil spring. The spring I have is 12.25" free length and minimum preload length for these coilovers is about 9.5". I don't have a good way to measure rate at home, but with my full body weight on them they only compress about an inch. So probably 150 to 200 lb/in. This is actually a decent stiffness for my target ride frequency, just too long. This size seems too small for an off-the-shelf coil isolator, which are for standard 2.5" coilovers springs, so cutting might not be the best idea but it's a good last resort.

bumpsteer
bumpsteer New Reader
11/19/22 9:35 a.m.

Just keep in mind that cutting will reduce the pre-load, but increase the rate. 

Dusterbd13-michael
Dusterbd13-michael MegaDork
11/19/22 9:49 a.m.

Weld the flat back on the end. It'll be fine.....

laugh

gumby
gumby Dork
11/19/22 12:47 p.m.
RoddyMac17 said:

As an aside, 1.875" ID springs are very common for Spax, AVO, and other european coil over dampers.  

Also common for smaller circle track chassis cars. Should be plenty of availability on the used market.

*edit
And ATVs maybe?
https://www.ebay.com/itm/275530766258?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=SGeW5MKUQOa&sssrc=2349624&ssuid=Sj6PTWstTZi&var=&widget_ver=artemis&media=COPY

2nd edit, I just realized that ad is a GRMer lol. Those springs are likely still too long, just an application I didn't know existed.

maschinenbau
maschinenbau UberDork
11/19/22 3:03 p.m.

ATV springs on a Lotus might be the most GRM thing I could do to this build lol. I decided to forge ahead and just chop the springs I have as a first guess. 10" turned out to be a pretty good guess, though the adjuster is all the way at the bottom. I could probably use a 9" long spring if that exists, otherwise 8" with a spacer like Roddy is probably ideal. Still not sure what the spring rate is, but at least I can keep building with the proper ride height for now. Or I'll just run it like this because Challenge budget. After all, the shocks aren't in great shape either.

Sits MUCH better now!

TurboFource
TurboFource Reader
11/19/22 6:33 p.m.

Debating on removing the warts (front turn signals) on TCST...like on yours

stafford1500
stafford1500 Dork
11/20/22 9:13 a.m.

For options on front springs, check out quarter midget springs. 1 5/8 inside diam, short lengths, and low spring rates.

They may be a little small for your dampers, but damper and spring combos should be available.

I have a handfull of custom valved quarter midget dampers for a work project and they are really just scaled down vesrions of typical car dampers.

GM > MG
GM > MG New Reader
11/20/22 1:48 p.m.

Your getting there, looks great. Keep getting at it...

In the genre of (low LOW budget) fiberglass construction:

Long time ago, in a garage far way, I built few things this way, used heavy duty cardboard from a refridge box. Actually very strong in cross section (this is not beer flat cardboard, technically referred to per Google as: double wall board with AB flute, a.k.a. '5 ply'). Using very thin mix of FG resin (long ago maybe acetone or MeK?) it soaked into cardboard corrugations and was similar to honeycomb matrix. I added few internal baffles kept it from drooping when wet and added some compressive strength. I used CaD and plotter at work to make temples (it was free to me).

So, cheap (EG Free), strong for the application, very easy to work with, you can put Carbon Fiber Vinyl Wrap on it and say its CF which of course will add 10Hp...

 

maschinenbau
maschinenbau UberDork
11/20/22 5:41 p.m.

One major drivability item checked off the list: shifter. I got lucky that the end of the Toyota shifter is an 8mm rod end bearing. The stud at the other end of the Lotus shifter is 5/16". 0.315" hole for a 0.3125" screw. Perfect! Now just need a bracket to hold the housing in place. This took a few hours to make because of a key design constraint. There is only one opening in the frame large enough to stick an arm inside of. The bracket cannot block your arm or you'll never get the rod end bolted to the shifter. 

It shifts great! Something weird I noticed - the lever on trans lets you shift past D into what I assume is two lower gears. But the Avalon's interior shifter doesn't let you do that. Instead you go into manual shift mode with the +/- functions. Other vehicles with the same trans like the Rav4 have a physical shift lever position for "2" and "L". In my case the Lotus shifter doesn't have enough throw to get into "low gear". It will make it to D and that's probably fine because I can add buttons later for the +/- manual shift mode.

What else I got up to - removed the original seat belts. Amazingly all bolts came out of their 7/16 holes without much complaint. Obviously will need a new 3-point belts but it's good to know I can just thread in new bolts. Recommendations for junkyard belts?

I got curious about the stuck windows so I pulled the window regulators. Looks like a Delco unit with some travel-limiting washers welded in...very Lotus. Motor locked up unfortunately. 

With the windows sliding in their tracks (albeit manually), I decided to see if the glass is damaged or just dirty. 

It's just dirty! I can definitely use this glass. The rear window is also in great shape. All the rubber trim, not so much, but good enough for Challenge car. Unfortunately I will need a new windshield, but for now it's convenient not having it in the way. Planning to make one from Lexan polycarbonate, not just because racecar but also it's the cheapest path I can see.

Also made a few extra holes for the pedals. Not hooked up yet, but it seems to all line up well.

Jumping around even more, I started on a dashboard template. The dashboard is needed for driving because unsurprisingly it is structural for this car, as the sole support for the steering column. I'm indifferent between metal or wood so probably whatever I find cheapest.

It's nice having a whole car to work on now. Before with the chassis, progress felt very constrained to a linear path, which meant if I got frustrated, stuck, or waiting on an order, there was nothing else to do. Now I can jump in wherever I feel and still make progress. Well, not JUMP in. You have to crawl around carefully or risk punching through the very thin fiberglass. Everywhere I touch bows, bends, and makes awful crackling sounds like it's about to disintegrate. Must be a fast racecar.

automotiveflux
automotiveflux New Reader
11/22/22 3:51 p.m.

Cool to see the whole thing together. Actually looks like a car now!

maschinenbau
maschinenbau UberDork
12/1/22 10:37 a.m.

I did my first fiberglass! It went pretty well. I am using polyester laminating resin and 1.5 oz chop strand mat. My goal here is to add a few layers to the floor under the seat, since it is flexing an uncomfortable amount, and build a perimeter frame for the 3 removable firewall panels, which will be aluminum. 

First I completely removed all traces of old fiberboard, which was sandwiched between layers of fiberglass. I need nice flat sanded fiberglass to bond new stuff to.

Then I built a little form from new fiberboard, covered it in clear packing tape, and screwed it to the car. This will tie the floor into the lower flange, so I have somewhere to bolt through for the access panels, and adds stiffness to the floor.

After letting the resin cure, I was able to remove the form with some gentle prying.

It worked! I only did one layer since it's my first time. But now I can layer over and under this flange to add strength. 

Fortunately my body seems pretty tolerant of fiberglass. I am not getting itchy despite plenty of angle grinding. I wear gloves, respirator, and long sleeves, then change when I'm done. Unfortunately, I did this in a drive-under garage, which filled the whole house with styrene fumes, despite leaving the garage open with a fan running overnight. I was strongly advised to not do that again.

So, that means I have to roll the car outside to do fiberglass. In winter. Georgia winter, mind you, which can be very mild. But that also means tarping the car and not being able to work when it rains. But it doesn't roll right now because the rear of the body is on jack stands, so I have to build new body mounts...from fiberglass. Hmmm. 

nocones
nocones PowerDork
12/1/22 10:42 a.m.

Did you cackle maniacally like a animated film villain when you pulled the form and realized you new powers to form new rigid things out of liquid and fabric?  Because I know I did.  

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