LocostUSA.com

Hello all. I am about to start building my locost.

My goals:
1400lbs
240 hp
Somewhere from 50/50-40/60 weight distribution
Square steel chassis (mostly, fish mouths are hard)

My plans:

NA Miata parts:
-engine
-transmission
-differential
-half shafts
-steering rack

Other big parts:
TD04 turbo
DIYPNP Megasquirt
Kirkey aluminum seats

Additional:
Not sure if I want a windshield or not yet, or even if I have to
Aluminum bodywork
Not sure what I want to do for the exhaust

I just got my donor car and will be dismantling it in the near future. As a college student with work and also FSAE, I don't have the most spare time.

Also I hear a.moore is a PittFSAE alumni so hello.

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There is no replacement for displacement... Except for turbos

Welcome. Do we call you Zoltan or Pup? Your off to a good start. If you're doing engineering school take a look at the models A.Moore has posted of the locost and his improvements in the FEA thread...

Keep at it!

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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.

Or Yoyo? Or... But I digress... (You'll find I do that often.) Welcome to the forum. Yep, sounds like you're off to a good start, and we look forward to your "progress reports." Don't forget those pictures! As for being an enga-neer, well... Nobody's perfect, it'll be OK...


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

Welcome.

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-Andrew
Build Log
Youtube

Most call me Zolten ha

My donor was bought from a local salvage auction through a friend for $500 and after fees and towing the total came to $700. Other than the accident the car is in perfect shape. If I wanted to rebuild it I probably could. The car was hit in the front left and the upper and lower control arms as well as the steering tie rod are bent/ broken. Hopefully the upright is not bent, but if it is, a replacement shouldn't cost too much.



It did not come with a key so there was no evidence that it ran but thankfully the car started and ran quite well on the stock ECU. I want to get it running well on the ECU I will be using for my build. I have already built the DIYPNP unit and started the car on it. It runs kind of rough but I forgot to calibrate the sensors. Next time I try I think I will get it to run properly and I can start tearing it apart.

The ECU plugs into the stock harness and works with all of the stock sensors. It was much easier and quick to build than I was expecting. If anyone else is considering a Megasquirt DIYPNP unit but might be scared of screwing it up, don't be, it wasn't that bad.

The picture I have of the board is 90% complete. It is missing a few jumper wires.



Case with small plug for laptop, large for extra inputs and outputs and a MAP line input.



Car harness plug

_________________
There is no replacement for displacement... Except for turbos

Reporting that my DIYPNP unit has successfully started my donors engine, and appears to be running normally, although slightly rich but this comes down to tuning later. Now I can start tearing this Miata apart.

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There is no replacement for displacement... Except for turbos

Yo- That's a greeting, not your name... I think...

About the Megasquirt box, and the connectors. Did it come with a "car harness plug" for the Miata, or is that something you sourced and installed? Horizenjob and I were talking the other day about how aftermarket ECUs connected to the harness. So, how do it work?


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

Most aftermarket ECUs have their own connector and will come with a generic harness (connector with wires attached). It is the up to you to splice each wire to your cars wires or run them to sensors, etc.

My ecu can plug into my stock wiring harness directly because the pin-outs are customizable. My main board, the large one with "proto area" written on it has the orange jumpers that connect it to the jumper board (the board with the car plug) with specified pinouts for my year and model of car.

The kit that I bought came with pretty much everything to plug into the stock harness and run the car. There is a lot of support for the DIYPNP unit, especially for miatas, on their site.

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There is no replacement for displacement... Except for turbos

I have bought a td04 from a Subaru (actually i bought 2). By scanning the gaskets on my printer I recreated the flange profiles in solidworks. I then laser cut them out of .25in mdf to test fit and perfect the flange profiles. These are the 3rd set as I keep adjusting it to make it perfect. Slightly obsessive but laser cutting is easy and fast so...




RTz, another member of this forum, posted scanned point files of a NA8 miata engine/transmission and differential. I am working on converting those to something I can use in solidworks. So far I have a STL of one of them.

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There is no replacement for displacement... Except for turbos

So I ordered most of the steel I will need to make the chassis. There is something I need to figure out first and could use some help.

I will be making essentially a book chassis except for every transverse tube that is in the middle is sort-of moved back 4 inches (and IRS), similar to what a user did in another forum (forum is down at the moment will post when/ if I can, user is skinnyG on grassrootsmotorsports EDIT: https://grassrootsmotorsports.com/forum/grm/lo-cost-101-how-do-i-make-a-cool-caterham-replica/17266/page2/).

Anyway, here are some pictures to explain what I mean. Note: Green represents my chassis and red represents the book chassis.







As you probably guess, the transverse tubes moving back (along with everything that lines up with them, such as the scuttle/ dash) will shrink the cockpit opening and lengthen the nose a little bit. I think that the book chassis has just a little bit too stubby of a nose and too long of a cockpit for me. I also want to be able to reach the dashboard while strapped in, as I will be putting switches on there.

I plan to order the "lotus s2 +1.5in height" nose from Curtis unlimited. I would order the TTL nose from kinetic, but I want to have a slight horizontal bump around the suspension points and the pictures I have seen of the curtis nose have this. My problem is that I cannot find any dimensions for this nose. My thinking is that if I make the top main chassis tubes the same outer width as the rear most part of the nose then the lines will flow smoothly and for now I have used the dimensions (very rough dimensions) of the TTL nose. Does any one have or would be willing to make some more accurate dimensions of either of these noses? I will return the favor with as accurate of a 3D model as I can make.

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There is no replacement for displacement... Except for turbos

How tall are you? Move the scuttle back 4 inches, no big deal. Move the firewall back 4 inches and I wouldn't stand a chance at stuffing my 6'!" frame in there.... not enough legroom.

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Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216

Good start. If I'd paid closer attention to Greg's build log when I started mine I would have done the same smaller cockpit. Oh well, next time.

Ron

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They say a journey of a thousand miles begins with a single step. By the time you finish the car it'll feel like you've done it on your knees.

Have you done any measurements to see if moving the pedals back 4" will matter?

Shortening the cockpit is definitely a good thing. Making the opening shorter won't hurt stiffness.

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-Andrew
Build Log
Youtube

Same thing Im thinking. I wouldn't fit if the firewall on my car was further back

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Too much week, not enough weekend.

OOPS I did it again
http://www.locostusa.com/forums/viewtopic.php?f=35&t=17496

Blood Sweat and Beers
http://www.locostusa.com/forums/viewtopic.php?f=35&t=15216

[quote="Yoyopup"]So I ordered most of the steel I will need to make the chassis. There is something I need to figure out first and could use some help.

I will be making essentially a book chassis except for every transverse tube that is in the middle is sort-of moved back 4 inches (and IRS), similar to what a user did in another forum (forum is down at the moment will post when/ if I can, user is skinnyG on grassrootsmotorsports).

I did similar on my build, I moved the scuttle back 6" on my Haynes from. I left the firewall and pedal box in the normal Haynes location, but the cockpit opening closed up substantially. I agree that the normal book chassis cockpit is to open and hood/nose too short.

Tailwind also moved his scuttle/dash back by a few inches, but that was after he finished the car and in an attempt to improve buffeting. There is a thread on here somewhere where he documented the process of moving it after the car was finished. You are doing the right thing though and moving it before you build the car.

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Build on

Chris
Build: NA Miata based +221 Se7en