SkinnyG's "Lethal Locost"

With the sale of the V8 Pontiac Firefly, I went to post a new picture of the Lethal Locost dusted off and put back into service, only I apparently didn't do a build thread.  I may have on the old site (there's an old site? Yeah, us old folks remember it).

What follows is going WAY back.  This project is NOT "in progress."

I wanted a Super 7 since I had a ride in one when I was 8.  It was wicked! I wanted one ever since. My Uncle owned one, only I'm pretty sure now that it was an Ontario-made Fejer Super 7.

Way back, "the book" came out. "How To Build Your Own Sports Car for £250." But while it super cool, I wasn't in a spot to take on that project at the time.  I passed on the book.

Then the reprint came out "How To Build Your Own Sports Car for £250 and Race it!" Oh yes.  Bought it.

At about the same time, I had a student show up with an old rwd Mazda GLC that didn't run. I thought this might be a great donor, so I bought it off the kid and started building the frame in the school metal shop.

The GLC had an automatic, and I had a hard time sourcing a standard transmission for the wee motor, so instead I just drove around residential areas looking for parked Corollas or something.

I ended up finding an '86 Corolla GTS AE-86 with a for sale sign, parked in front of a house. When I rang the doorbell, an elderly couple invited me in and served me tea.  Turned out they knew me from church (they know my wife and her family super well), and that the car was owned by a cousin of a girl I went to college with years before.  Picked it up for $800 and drove it home and cut it up.  Yeah.  I know.  Should have painted it and sold it, but it made sense at the time.

The GLC I bought off a student, I put a 60° V6 in it and then sold it to another kid.

I missed a few of the early stages of construction, but ended up here before too long.  This was the easy part of the frame.

Once the frame was reasonably complete, I dragged it over to the school auto shop and started sorting out the mechanicals.

I shortened the MacStruts from the Corolla so use as knuckles.  This was later poo-poo'd by The Man, and I later switched to Chevette Spindles.

And I shortened and de-powered the Corolla steering rack.  Which was also poo-poo'd and I later used a Chevette rack.

I also used as much of the Corolla brakes as I could.

After 100 hours into a nosecone buck, I priced out fiberglass and resin and decided this wasn't cost effective. I bought the fenders and nose from Curtis Unlimited out of Kneelands California (I heard they retired?  I might be mistaken). Figured out how to mount them, and fabricated a cowl. I also used the Corolla wiper motor, and I think I used the rear wiper arm from a pair of GLC's I found at the wreckers.  Or I didn't.  I don't remember.

About this time I had a really crappy group of Grade 12's come through, and by October I had the rolling chassis hauled home. I made a few alterations as needed, and then started forming the body panels and painting the chassis.

I sprayed Rust Bullet, which sticks like a Banchee to rusty metal, but flakes off of clean shiny metal with reckless abandon. 

Air rivet guns are awesome.

Also did a re-ring on the 4AGE that ended up being mmore expensive than sourcing a decent JDM motor.

And started figuring out the interior.

I modified shocks to hold AFCO Legend Car coilovers.  This involved welding a ring to the bottom of the shock, just below where it says "DO NOT WELD." I took my sweet time, and nobody died.

Front shocks are rears from a '75 Corvette, rear shocks are rears from an '85 Chevy Sprint.

Sheet aluminum I sourced from a scrap yard. They all showed some corrosion, but with some hefty scrubbing, they cleaned up really well.

I also worked on the wiring, pulling out wires I didn't need. Foolishly, I tried to keep as much Corolla as I could, so it could be easily serviced, as my intention was to build it, sell it, profit and build another. The wiring harness became needlessly complex, and not my proudest thing on the car.

Lots of sheet metal.

Also fabricated some exhaust.  Not my prettiest welds, but I have come a long way in my skills since 2005. I should have just made a 4-1 header, but I was trying to keep costs down.

The cowl kicked my butt. This was not not not fun.

Also fabricated an intake manifold so it would all fit under the hood. Theoretically, a good rule of thumb is make the runners have the same volume as the cylinder, and the plenum have the same volume of the engine. I dunno.  Worked. Especially at high rpm, not so good at low rpm, using the stock computer.

The rear panel kicked my butt too. Personally, I find the "Locost" chassis rear end to look like butt.  I should have made the bottom curves the same diameter as the top tubes, but oh no, I followed the book.  It put the Ugh into Ugly.

Also machined the oil fill riser and the oil cap itself down so it would -just- fit under the hood.

A local glass shop cut the glass for me.  Wrote "AS1-TINT" using a simple hand engraving tool, and wrote "Laminated Saftey Glass" on the receipt by hand.  Not as "official" looking as I wanted, but beggars can't be choosers.

The hood didn't kick my butt, but it wanted to.

I adapted the Corolla cluster into the dashboard in the best way I could figure it could look, and wrapped it in Marine Vinyl. Also painted the car in Polyurethane Enamel in the GTS factory red.

Yes, bicycle flag.  Which isn't actually designed to stay attached at 60mph.

Then we hauled it off so I could get a wheel alignment, and the day permit is from the alignment shop to the inspection facility (you are allowed an A to B permit for inspections on unregistered cars). My real "Caterham" taillights were not deemed "legal" by the fellow who was to inspect it, so I got creative just to get through.

Only it didn't get inspected.....

Skinny, thanks for posting. I enjoy the holy heck fire out of all your builds. This one is turning out to be no different.

Ahhh, rekindled love.

What was the inspector's reasoning for rejecting the Corolla based uprights? Sounds like no real engineering background, just beaurocratic  power trip. B.C. sounds almost like Germany

I shortened the AE86 two-piece driveshaft, making it into a 1-piece.  I've never had it balanced, and it seems just fine.

I initially had welded together a proper length steering shaft  out of DOM tubing.  That was poo-poo'd. You cannot weld on any part of the steering.

The fuel tank came from some guy off eBay.

I used a Facet low pressure pump to fill a surge tank, which fed an external 90's F-150 high pressure pump.

I found motorbike mirrors at the local bike shop.  They had some scratches, but you likely won't see them unless I pointed them out.

I made the panhard bar really low. Many folks complained that the Locost was a bit tail-happy, and the car I was autocrossing at the time (B13 Sentra) was VERY tail happy because the Tokico springs didn't lower it evenly and I had to lower the rear to get the roll center better. A low roll center reduces "jacking," which should increase grip in the rear. There are lots of discussion against running a low roll center on a 7, but it made sense to me, and I think mine is one of the few Locosts with a very low roll center.

The fall the year before I took it for inspection, our union was on strike.  My first born was only a few months old, Mrs. Skinny was on mat leave, and I needed to keep food on the table. I hit the bricks and found work at a shop pulling wrenches for the two weeks we were out. I'd picket early morning, then wrench until evening. Reminded me real quick why I left wrenching.

The shop did inspections, so I conversed with the boss about getting the 7 inspected. I tried to make sure I had what he needed to see.

When I brought it in in the summer of '06 for inspection, I discovered that he hadn't been entirely honest with some of his inspections in the past, and was under the watchful eye of the inspection folks. Yay. To make sure he didn't make things worse for himself, he called up the fellow in charge of inspections to come have a look at the car. There was talk that they wanted to see this car properly engineered for front, side, and rear impact protection. Triple yay. He was particularly critical of welding on the steering - fair enough. No inspection.

So with only a few weeks until school was to start, I hustled to make it less questionable.

Chevette spindles, Datsun B210 hubs (which give me 4x114.3 to match the Toyota axle), Chevette rack, and a collection of steering shafts that I could make look stock and unmodified.

I also knew a guy, who knew a guy, who did inspections, and was into "creative interpretation." I met with him, went through everything it needed to pass, and brought it in to this other shop. He was alright with me running the Caterham taillights, but suggested mounting them such that the brake/park light was on the outside to act as marker lights. Stressful, man!

It passed.

I got it registered, I got plates, and I was autocrossing it within hours.

It was an absolute riot!  It WORKED! it was actually a whole lot of fun, and not diabolical at all! While I wasn't running any sway bars, I -did- calculate spring rates based on suspension frequency, and pretty much nailed it.  It handled really well. I was ectatic!

This was a dream of mine since I was 8. I now had a Super 7!

During the inspections stress, I actually foolishly went through my receipts (this was 2006), and tallied up how much I had spent.  If I couldn't get it inspected, how much did I need to get my money back?

I had spent a total of $5700 CDN (roughly $4200US). This was actually one of the cheaper builds on the Locost forums.

And my wife was super supportive - she suggested just borrow her father's truck and get a trailer, and just run events with it before I get rid of it.  She's a keeper.

First photo shoot:

And of course, I autocrossed the can off it.

But of course, I can't leave it alone, eh?

The Chevette rack was s-l-o-w and wasn't right for the geometry. I found a Triumph tack, did the calculations, and shortened it to minimize bumpsteer. I'm not sure where I put the picture for that.

I had a friend who was interested in having  7, but I said you might want to try it out first, it's not for everyone. I loaned him the car for a couple weeks and he agreed: It's fun, but it's not really what he wants. He did, however, coughed up half the price of the slicks, and he co-drove with me for two years.

Oh. I see in that last picture, I started playing with sway bars.

I found as I got used to the car, it was tail-happy. I eventually found that the UHMWPE bushings I made in the 4-link out back were the culprit. I changed them to Triumph rubber bushings and that tamed that immensely. Kids - don't run poly in a  4-link!

But, along the way, I fabricated a 1/2" front sway bar out of regular cold0rolled mild steel. Then a 3/4" front sway bar, and eventually a 5/8" sway bar that worked the best. So far the simple CRMS has worked absolutely fine. Fear not, true believers!

Also, sometime summer 2007, the California Caterham Club was coming through my town on the PNW tour.  I invited them all to my place for a BBQ, and then I drove with them to Cache Creek, this being the furthest I had ever driven in the car.

There were come Westfields (not all pictured), a Birkin, a Locost, a number of Caterhams. Good times. Below you can see Skinny-ishGramps holding SkinnyKid2.

In late summer 2007, my co-driver (PhatG) and I took the car to the Canadian Nationals in Pitt Meadows. We did ok, talking up the last two spots in the class, but in the only street-driven D/Mod car that DROVE to the event and back. The drive there and back was the most fun.  Every stop "What is it?" "Is it legal?" "What's it got in it?" "Can I take a picture of it?" So much fun.

I also fab'd a small 1/2" bar for the back, but I can't remember exactly when I made that one. I went through my books to figure out a more calculated method of sizing a sway bar vs. just experimenting as I had on the front. I ended up with a calculated size of bar, I made it, it worked! Yay math!

TurnerX19 said:

What was the inspector's reasoning for rejecting the Corolla based uprights? Sounds like no real engineering background, just beaurocratic  power trip. B.C. sounds almost like Germany

You're looking for logic and reason. The sooner you can suspend logic and reason, the sooner you can embrace a whole world of weird.

The slicks lasted a total of 15 minutes worth of autocross, and then they seemed to go "off." We continued to run them a full two years or more.

But, with PhatG and me driving every local event we could do, it gave me a fantastic opportunity to sort out the car, observe the car, try things, and gather feedback.

One of my biggest complaints was turn-in was horrible. I tried all sorts of suspension tweaks, I had the front ride height VERY low, the rear ride height as HIGH as I could go, I tried bars, adjusted bars, no bars, camber, no camber, blah blah blah. Eventually I started to think the brakes were the issue.

The brakes on the 7 are Corolla discs on the back, and Chevette discs on the front. Both a Corolla and a Chevette are about 2500lbs, with about 55% weight on the front, with the weight relatively heigh up. When you peg the brakes, all the weight shifts forward, and the brakes are designed for that transfer.

The Super 7 is under 1275lbs, has a low center of gravity, and 55% of the weight on the rear wheels.  When you peg the brakes, not weight is there, and not much shifts forward. Nevertheless, the front brakes are doing their job, which in this case, is too much.

So, armed with a cut off wheel and a welder...

This was probably the single most significant improvement I have ever made to the whole car.

Again math, and I calculated what size masters to use based on weight, weight distribution, rotor size, piston size, pad size, etc etc. With the balance bar in the middle, the brakes are perfect. Adjust one way and the front plows, adjust the other way and you swap ends.  Amazing!

I think I also put in a Toyota factory LSD with a Techno Toy Tuning rebuild kit.  I can't remember.  That was a good mod too. Not too aggressive for a car this light (though it feels it).

The trip to Cache Creek confirmed that I was out of travel up front. So, I relocated the lower shock mount from a basic C bracket to a through bolt in the arms.

And then the clutch I reused to save money went.  So I pulled the clutch. This is where you discover just how not service-friendly your vehicle is. This was one of those experiences that helped me build the V8 Firefly so much more service-friendly (if there is such a thing with that car).

Did I mention I had a buddy lighten the flywheel?  Don't worry - my feet are still there.

While I was running the factory ECU on the 4AGE with my own intake manifold, it wasn't a totally happy arrangement. It was "ok" around town, but freaking screamed past 4500, all the while running rather rich. I had deleted the TVIS system which probably contributed to it.  What I needed was full tunable control out of the engine.

Two words: Megasquirt!

And if I'm going Megasquirt, why not built something significantly different enough to warrant it! ITBs! Through the wonder of eBay:

I also ordered up Megasquirt V2PCB3.0 and soldered it together. It took about 10 hours, taking my time and checking everything along the way. Definitely a shout out to DIY Autotune - they have been wonderful with EVERY interaction I have had with them.

I cut and modified my intake manifold to fit the ITB's.

I also removed the distributor and ran Ford EDIS 4 because I could, and because apparantly that heat shield is important.

Since I wasn't using power steering, I machined its pulley off the balancer and pressed on a 36-1 wheel I scoffed off a dead motor from work.

I really liked how  RoddyMac17 mounted his EDIS on his 7, so I copied it.

Using pretty much the default setup except for engine and injector specifics, it fired right up! Almost first try - I had the crank trigger polarity wrong.

Youtube vid which isn't embedding again.

At some point around here I must have machined the lettering off the valve covers.

I spent a considerable amount of time trying to make ITB's work with Speed Density.  They all say you can't, but I'm stubborn, resourceful, and determined.

In a nutshell, you can't.

If I datalog while driving gentle all over the place, I end up with a table that is way too lean. If I datalog while driving aggressive all over the place, I end up with a table that is way too fat. Where I live, atmospheric pressure is about 96kPa. Crusing on the highway is about 95kPa.  Megasquirt can't tell the difference between cruising and full throttle in 1kPa.

Oh yes, I tried setting up my bins as .... 88kPa 90kPa 92kPa 94kPa.... forget it. Go Alpha-N. Alpha-N looks at throttle position, not MAP. In theory, with ITBs, where you are in your fueling table is WAY more related to the actual throttle position than MAP sensor.  Did it work?

Heck yeah!

Never better!

In fact, hands down, no question, just go straight to Alpha-N.  Don't even waste your trying to prove me wrong, I tried it, and I am hell stubborn.  Speed-Density doesn't work. Alpha-N works.

Then somewhere around here I wanted newer slicks, and I wasn't getting the 20x9.5x13's hotter than 135°, so I bought some used 7" slicks on widened vintage Corolla steelies.

They actually felt pretty much the same, and heated up to about the same. I usually soaked them in a 50/50 mix of Xylene and Toluene to soften them.

Around this time, I had another really crappy group of Grade 12's come through so I had to take the V8 Firefly home, which meant moving the Locost into the garden shed (Mrs Skinny's Sunfire, my Hardbody, and the Firefly were all in the 2-car garage).

One time, on a trip to a BC7s gathering in Vancouver (4 hours away), the car left me stranded on Highway #1. The IAT sensor was just zap-strapped (zip-tied) to the intake manifold, and it was not sensing reality. It read such a high temperature that it pulled all the fuel, and it wouldn't run. I had to sit, in rush hour, on the side of the highway with the hood off, waiting for the engine bay to cool off so I could get going again. 

When I got back home, I made this:

It was good gathering:

And not too long ago, some dude snapped of pic of me at the local grocery store, which a buddy found on Facebook and forwarded it to me.  Cool!

When I first got it on the road, I was using Corolla GTS "snowflakes." Not sure why, I think they looked classy at the time.

Then I changed to GTS Steelies.  I liked the look of these a whole lot better. My co-driver PhatG was an upholsterer, and he made the bikini top for it.

All the while, I was running Sumitomo HTR 200's 185/60R14 because they were cheap. I ran them 10 years, and then bought Federal SS595's in 185/60R13 and ran them on the widened Corolla steelies. They are a bit short.....

Somewhere around here I sold the Hardbody and brought home the '77 Silverado.

Looks like we also bought the inlaw's Buick by then.

The Sunfire brought me to my $1000/year philosophy with cars.  Mrs. Skinny paid $17,000 in 2000 for the Sunfire, we had is 16 years, and sold it for $1000.  That's a grand a year.

If I spend a grand on a car, it needs to last a year.  Five grand? Five years. Sixty five grand on a new truck? Sixty five years, and ain't no truck going to last sixty five years, so why do that?

We paid $1000 for Buick; it lasted two years.  Money maker! I hated the seats though.  Even when I drove it brand new, if you're not a spheroidal octogenarian, you won't find the seats comfortable. It was painted geriatric gray, complete with large print speedometer.

Things I would do differently if I were to do it all again:

Well, one thing I LIKE that I did, was shorten the cockpit and lengthen the engine bay.  That improved the proportions WAY BETTER than your typical book locost. I'd go another 3 inches or so.

I hate the bottom corners at the rear. I should have made the curves the same as the top. But I stubbornly followed the book.

The book doesn't give you enough rear suspension travel - make the diff opening at least 2" taller.

Make round tubes around the wheel arches instead of flat bar. Your sides will thank me later.

Raise the rear deck so it's the same height as the scuttle (cowl). The book makes it shorter, and it looks dumb. Stupid me.

Design the front suspension such that the front arms are nearly parallel, which gives you a VERY low front roll center.  You want this for turn-in. BUT, for good camber gain, you will need a shorter upper arm. The front geometry on mine is not optimal, but it ended up where it ended up trying to make it handle:

Make the font of the chassis kick up to meet the  nose, so you don't get that stupid gap on the bottom.

Spherical rod ends for the suspension. Trust me.  Don't worry about the suspension noise, you're going to be pummeled with 119dB of wind noise anyway (I measured).

The scuttle is the hardest part.  To do it right, you need a bead roller and a sheet metal shrinker. I have them now, but I didn't then. I'm not pleased with the scuttle.

Figure out how to make the pedal box air tight from the engine bay. It gets OMG hot in there if you don't. Mind you, if you get exhaust fumes coming in too, eventually it won't matter.

The trans tunnel gets OMG hot too.  Keeps you warm on cool autumn nights, but bakes you in the summer.  Like "can't touch this" hot.

Same with removing the hood. OMG hot.

Make sure the fuel filler comes out the back, not in the boot.  It is a pain in the boot to have to unstrap all your luggage and empty the boot just to fuel it up.

There might be other tips, but I'll remember them later.  It does kind of seem like the Locost Craze has die down?  Or am I just out of the loop for too long?

And now I'm ready to post the picture that I came here to post.

"Out with the old, in with the old."

With the Firefly sold, time to dust off the Super 7.

Fired up with fresh oil and no drama. Washed it off, and added a bit more accel enrichment to the tune, and took it for a rip!

Oh, and as far as correcting design flaws of the "Locost...."

Dimensionally correct to an original Lotus 7 Series 2, with selected improvements as done by Caterham, DSK, and Frasier. I also have a Caterham scuttle panel (have I mentioned I didn't enjoy making mine?), as well as an original Lotus 7 windscreen, and Caterham doors and top for it. And a 2.0 Duratec to go in, that I pulled eleven years ago and stuffed in my garden shed.

But that car will be a different story, once the '61 Apache is done, which is the project at hand right now.

An original Lotus 7 has the same curve radius top and bottom, why did the locost make it more difficult? Must be engineered by a B.C. vehicle inspector Here in PA I built a DSK for a customer 25 years ago, and we picked a non existant Lotus chassis number, then sold it through a no title state and back to get a Lotus title. That eliminated the initial build inspection for a kit car.

I have heard that the unused serial numbers of Shelby Cobras have been registered in all 50 states.

In BC, if your vehicle has a VIN but has "missing papers" and ICBC cannot find your registration, you can still register it, but you MUST undergo a vehicle inspection. Anything coming in from out-of-province MUST undergo a vehicle inspection. I don't like inspections.

I've been dailying this car whilst the '77 Silverado has had the axle and driveshaft rebuilt.

With my recent experience hacking the '88 TBI computer in the V8 Firefly, I've gotten a quite a bit better at sorting out drivability. Stuff I didn't even realize way back when, I fully see now, and I have a better idea what to mess with. Made quite a few tweaks to the Accel Enrichment and I'm quite pleased.

If I can get it good enough (one issue I think I have is the TPS is on the opposite end of the ITB's, and it seems delayed in sensing), I'd like to try having the MAP continuously sample, and not read the engine at all (I'm running Alpha-N).

Also put fresh spark plugs in, too.  That made an improvement.

Fun, fun, fun car to drive.

In reply to SkinnyG :

Part of the reason I build and race race cars is to avoid all the hassles with inspectors.  Early in my life I went round and round with one on a car I wanted to drive to the race track.  

A few hours welding up a trailer solved that problem and the inspection consisted of them confirming the decal they provided for the serial number was on the tongue of the trailer. 

I’ve always loved this car; glad to see it is still getting good use! I’ve pored over the details on your site plus the Locost USA site more than once.  The plan for Lethaler Locost awaits the completion of the current pickemup project, correct? If you ever get to a point of selling Lethal Locost, let me know!

There was a few moments where I was enjoying the Firefly and I debated selling the 7. But the enthusiasm for the 'Fly didn't stick like it has for the 7. The 7 is just plain fun.

You are correct: I want to do the '61 Apache before moving onto Lethal Locost 2 - Even More Lethalerer. Currently it hangs from the ceiling in the house garage:

Hey Greg, thanks for the trip down memory lane. It was great meeting you at the BC 7s gathering back in 2010. That's me in the yellow shirt next to my Locost with the black nose cone.

I sold the car back in 2014 to fund a new scratch build car project, but I'll always have great memories of my time with my Locost.

In reply to SkinnyG :

One quick question regarding the frame. 

What was the wall thickness, oops two questions.  What grade of steel did you use?  

I used just regular 16ga mild steel.

Original 7s used mostly 18ga mild steel, which I used on 7#2, except for higher stress areas where I went 16ga.

In reply to SkinnyG :

Thank you! 

 I’m surprised Colin used such thick metal for a light car.  Jaguar used 22 gauge on their XKE and considering the engine in series one weighs 740 pounds plus accessories you’d think Colin would have used the lighter gauge. I mean the “D” type of 1955 used the same basic frame.  ( and later on the XKE was actually crash tested ) 

That plus the XKE frame wasn’t welded but brazed.  

Sorry, I got interrupted. I’ve always admired the Lotus 7 / locost  and I’m going to build a version of it except I’ll have it look like a MGTD only use Jaguar mechanicals. ( V12, suspension, etc. ) The V12 is too tall to fit under a Lotus 7 body hence the MGTD shaped body. 

In reply to SkinnyG :

Just when I thought I was past my desire to own a 7 clone, and now you have me drooling all over yours!

frenchyd said:

I’m surprised Colin used such thick metal for a light car.

The Series 1 was the strongest frame. Later Lotus 7s had less and less tubes, and it turned out the aluminum sides did a lot of holding it together, especially the interior panels which most racers removed. That sounds a lot more like Colin now, eh?

The Lotus frames were Bronze welded, not brazed. Though I'm not sure I fully understand the difference.  My first frame is MIG'd, my second frame is TIG'd.

In reply to SkinnyG :

Yeh that’s the term Jaguar used, Bronze welded. When I asked a few British racers what the difference was they described a process that sounds like brazing. 

I could be wrong. When I made a replacement Lotus 11 frame I used 4130 chrome Molly that Was TIG welded with silicon bronze welding rod.  

The factory frame was 3 pounds lighter which  I attributed to internal rust and repeated sanding etc. during various restoration process.  

I did notice a lot more triangulation on the Jaguar  frame as well as extremely clever use of gussets with big dimpled holes making the total weight of the gusset mere grams. 

The bizarre thing is the space frame was simply bolted onto the Monique which I question the rigidity of that connection. 

Yet  there they are decades later sliding into a corner dicing with Ferrari and Cobra.  Giving nothing away.