LocostUSA.com

growing up watching races and reading magazines i heard things like gut wrenching torque and eyball flatening acceleration, white knuckle speed etc but when i got to an age where i could drive, the cars that i had never got to that breathtaking point. i wasted a ton of money on cars making them faster and cooler but it never got to the "OH MY GOD" level.

granted, fast cars are only fast for about two weeks and with the small incremental increases in power i may have missed what WAS actually happening but thats not especially relevant to the build log.

i dont have a crazy amount of money but i am capable doing what it takes to get there. after a bit of thought and conversation, building a lotus made the most sense as far as making that happen.

in hind sight i probably should have bought a shifter kart as they are the the answer for violent acceleration and unbelievable handling at a really reasonable price. i know that now but a lot of benefits came with building a car from scratch that were totally unexpected so really i wouldnt change a thing aside from not spreading myself across so many projects at once because it stretched the timeline to 7 years and counting. but the end is near, so the log begins.

Welcome Dave! What took you so long to start a log?

Shifter carts are great, I'm sure. But this car will take you for a nice weekend drive with a girlfriend too!

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Yeah, Welcome Dave! And don't let your wife find out that you're taking your girlfriend for a long ride...

So,anyhoo... What ya building? Tell us more! Got an engine in mind? Chassis style? (Wooden or carbon fiber?) Single donor car? Junkyard Raider Mix-N-Match? Stolen parts?

And put up some pictures. Bubba and Perry don't read so good, ya know?


JDK

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JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

after i settled on a lotus (have you seen an ultima? omg.) i started drawing. and making lists. lots of lists. i picked up ron champions book and started with his drawings and a bunch of finished lotus pictures (i have huge files full, ill show one of my faves). basically, i took the original plans, cleaned up the lines, changed a few details, pretty much like anyone else, and added mods for the components i had available.

i like nissan 240s, theyre great ive had probaly three or four, one of which was in the shop as a parts buggy for my friends datsun 280z. great performance and i know them pretty well so, motor of choice. i picked up another one out of someones yard for a couple hundred bucks. it was a 91 with the ka24e and a manual tranny (and ten disc changer). fyi all canadian 240s have a limited slip. snow etc.

at the same time i built a pretty sweet table for the build and started laying out the pattern.

around this time my friend showed me dpcars.net if you havent been there..

ok. with the engine choice made, i need some way to put power to the ground. real sevens have solid axles, the book says use a solid axle, my dad says use a solid axle.. i want independent rear suspension, the 240 comes with independent rear suspension. at around the same time, my friend was modifying his 240z to accept a 240sx rear subframe among other things, so there happened to be one laying on the floor not far from where i was working.

essentially what went down was

1- the thickness of the table was called ride hight.
2- the rear subframe, arms and wheels were lifted on to the metal fab bench/lotus table
3- squared the sub frame to the table in its ideal static position
4- the differential was tacked to the metal bench with scrap plate
5- the control arms were tacked to each other with 3/8 rod
6- the new 'control arm assemblies' were also tacked to the bench
7- all the bolts were pulled from the control arms etc and the subframe was removed

this left me, with floating arms and differential. if youre going to try it this way, cool but keep in mind that you dont want anything welded in the path of what youre going to do next..

oh and as a p.s. around the time i was doing this, i got a ton of books. a lot of them were gifts from my friend. i cant overstate the value of carroll smiths books tune to win etc. so many things there that are more than just racing. life lessons. not only taught me about building and tuning cars but in many ways changed the way i see and deal with problems, plans, budgeting.. utmost respect for him. be carefull with engineer to win. its heavy. like reading 2013: space odyssey.

i spent some time today learning how to resize photos. great success.

with the rear suspension floating at ride height, i got the angle of the rear seat rest from the book and placed it as close as practical to the arms while leaving me room to create structure for the control arms to connect to the frame. i may have also sat and looked to see where the rear tire was in relation to the driver. from there forward i made a classic book frame. ..well, sorta.

one of the things that mmm, bothers me? about locost 7s is the exhaust. even on the new caterham r500 etc it is just stuck there on the side, which is fine if you have a team of designers and engineers to make it something that functions and looks passable but if you have a look at some of the cars out there, yikes. no offence intended but its one of the things i was pretty convinced i had to improve otherwise id be parking so i dont have to see it while im eating lunch.

i did a few drawings and its working out fairly well but first i had to make room for it IN the chassis. plans were to take a pair of 3 1/2" cherry bombs and run them in series down the side of the car and split the side of the second while capping the end.. pictures will make it make sense. building the pocket is really what matters for this instalment though.

wow. resized photos upload soo much faster!

just noticed my old harley under the bench, hah. oh and the motor under the bag is a VH45 out of an infinity, going twin turbo into the Z youll see sometimes. hybrid Z website is a great resource and there is another SONID southern ontario nissan and infinity drivers thats good for info.

Well, that's a unique way to do it.

Good luck on the build!

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Trochu Motor League

I like this build. I agree with your dad, but I also think you have to do it your way. It's your car. Looking forward to seeing it come together.

Good stuff man!

the exhaust tunnel continues forward along the left side of the car through a radius cut in the fire wall giving about 3/4" inch gap to the frame. fire wall ends up being fairly stout. rather than sheet metal i went up to 1/8" plate to restore some of the strength lost with the cutting, when your talking stressed panel, nothing beats over kill in this situation.

not too much crazyness went on in the nose section as far as deviation from the book. after doing some balsa modelling and research we came up with some bracing solutions that are specific to the suspension (and they make the frame look hella tech) ill cover that when it comes up.

oh, i did flatten out the overall silhouette of the car, boxed it up a little. youll notice i took the dip out of the 'door' area and im going to beef up the look of the transmission tunnel. a big chunk of the reason i went lotus was simplicity. and i wanted the lines of the car to echo that idea. raw facts etc. Elemental.

Did you steal my Z? I'll have to go check. I have on in just about the same shape and color.

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mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

id like to take a second to thank everybody for the kind welcome. my girlfriend is pretty much my lotus for now. jons dad jokes my '23 Tbucket is my mistress. not sure how much he knows about the harem. skidoo mxz, yamaha R6, suzuki samurai... i have a problem. model planes, dirtbikes, atvs, go karts, muscle cars, bmx, mountain bikes, boats.. if any of your understanding wives have attractive, equally understanding younger sisters. let them know ill be in the garage

sooo.. brackets! the book suggests drilling and bending up your own. what a load of HS. lucky for me the metric conversion on the dimensions the engineers assigned to the rear control arms on nissan 240sxs happens to be almost identical to the ID of 2" square pipe. i cut and drilled and ground the BRACKETS into shape and reused the original bolts to hold them in place while i waited for inspiration for how to fit up the rear end.

if i had the extra money at the time, i might of gone straight to tubular rear control arms. the nice thing about the 240 is now it has a fairly heavy aftermarket and you can order them fairly cheap straight from china.. but if i build for those and cant use stock arms in a pinch, ill be sitting at home. racing is a lot about budget. and i planned the build to be upgradable. for example jdm 240s have a 2L turbo motor you can get pretty cheap and will make a fairly reliable 400hp. bolts in. later.

sorry if this instalment is a bit wordy. and confusing. its friday before spring brake and, ive had a few beers.

the rear diff is mounted to the original subframe by four studs so i built out a square to support a vertical plate to hold it. that same square makes up the bottom of the car and is kicked up on even more of an angle that creates negative pressure under the car because the gap to the ground increases. a bit of down force. you might be thinking "nah, the air wil be too turbulant with the engine hanging down", just wait. that intersects with the bars that hold the LCAs (picking up lingo) it might seem a bit random but i modelled it about five times in balsa before execution. one of those i converted into the worlds most fragile R/C car. if i find it ill post a pic.

missed a day, but so worth it. wasted at my favourite mexican restaurant.

the rear suspension was going together fairly smoothy and now i had to find a way to support the car on some sort of shock spring combo. initially i looked at using the original struts but passed on that because they dont look nice, and it was a bit awkward of an install with their height etc. i also looked at turning the uca into a rocker and mounting a coilover inboard but that was a bit messy and overcomplicated too.

so a few things happened at once.

we bought a couple infinity Q45s
jon bought and built a tubing bender for making his roll cage and subsequently my rollbar.

somewhere we found out that you can use a 300zx diff, and the q45s also fits in a 240sx. the bolt pattern is the same on the cover and its pretty easy to swap them out. they have a limited slip and favourable gearing too. as a bonus are built to take a smashing from the beefy DOHC 4.5L infinitys '325' horspower which is great if you're a power hungry monster with dreams of excessive turbo boost.

something else that works pretty smoothly its the q45 has extremely similar control arms that are now a direct bolt on for my lotus. the uca being different as the have a solid bent arm to the 240s stamped donut version. oh and the spindles are aluminum for everyone who is unsprung weight conscious. after they were on, the only difference i noticed was a little more toe in but if its an issue ill install adjustable ones they are available cheap.

you may be noticing i did a really terrible embarrassing job of notching, bending, and rewelding curved square tubes for the rear boot area because i have cool plans for a top that requires a flat mating surface. ive since fixed that problem with some over generous support from a friend of mine who is a machinist thatll ill cover tomorrow.

once the control arm structure was there, i started work on the rear shape of the car. To be fair, my initial effort was just that. i was experimenting with the tools and material i had available and ill admit freely that it turned out looking like dog crap, haha. i had moved onto other things on the car while i was trying to sort out what i was going to do about it. in conversation with my machinist friend i had mentioned i was struggling with making the bends clean and consistent. he asked what material i was using and what the radius was and nothing more.

two weeks later i hear that he has built something that aught to do the job if id like to come pick it up. oh wait, no. he asked me how many one inch bolts i had lying around cause we need them. to mount it to something sturdy.
what he built is shown below.

its made from 1 1/4" thick steel with a top plate that happens to be steel diamond plate. you wont notice any of the diamond of course because he took the time to machine them smooth and replace them with numbered degrees. those degrees in turn have an accompanying stop for all of us wanton pipe benders who cant be bothered watching to see where we are at. the pulling arm is also solid steel and the entire arm assembly rotates on needle roller bearings. the outside of the bend is held square by a 4 inch diameter roller wheel with a machined channel and if i remember correctly it was made on the mill not the lathe using the table to rotate it. the inside of the bend is pressed in by a curved piece of 3/8' rod that rests in a machined groove, as it bends to keep the other three walls from distorting. all the fasteners are countersunk tapered head allen machine screws. it mounts to an i-beam i have lagged to the concrete of the shop floor and it does a beautiful job of bending 16 gauge, 1"x1" square tube in a 6" radius... and nothing else.

people like him are in high demand at all times, and the fact that he made time in his schedule to build something like this for me on this scale is. ..i just dont have words to thank people enough for going so far out of their way to help me out. but thank you all the same.

front suspension.

set ride height
establish track width
tire size
nearly flat lower control arms
book caster
few degrees of camber gain
adjustable everything
dom tubing
5/8" bolts
shoulder bolt pivots
tacked together
cycle check for binding
chassis bottoms before suspension

i have all the math somewhere but i doubt anyone else is going to try a q45 donor 7 ...but it is possible ill dig in the note books and take some photos, give me a few days.