LocostUSA.com

My locost has been on the street for over 6 months now…so I guess the official build has been completed! (still have a long list of TODO's, but all of those are optional/enhancements)

Build link:http://locostusa.com/forums/viewtopic.php?f=35&t=9631&sid=8287498fc8de31938b8b8da3e6a6ace8&start=0



I revisited my initial post where I laid out a lot of my expectations/rational/goals…I amended some comments to reflect current realities, but was surprised to see many things I assumed/planned actually came true!

Why a Lotus 7:
-Classic sports car Front Engine / Rear Wheel Drive layout
-light weight minimalistic approach
Cons:
1) while power/weight ratio is superb, top speed is limited b/c top speed to related to Aero and Power, not weight (plus most miata's are geared to a top speed around 135-140MPH)
2) Having no electronic aids and a really light car can feel a bit unnerving…car feels twitchy, no ABS, no traction control…while I absolutely love driving it, I don't feel as comfortable pushing the limits at higher speeds, especially when it's wet. (Could also be that this is my "baby", and I'm not willing to take as many risks)

Kit vs. Scratch build:
-After lots of research and reading through peoples blogs, I decided that buying a complete kit as that would give me the best chance of finishing this project in ~6 months. I figure if this takes me more than 1 yr, the project would be in serious jeopardy of never being completed.
-At the start of the project, I had never welded….1/2 way through, I bought a cheap HF MIG welder so that I could at least Tak weld pieces together, then bring them to a friend to finish w/ his TIG. Choosing a 1.8L donor, when the MNR Vortx was designed for the 1.6L ended up causing a lot more issues than I would have ever guessed….just because Miata's can swap 1.6/1.8L parts, doesn't mean a locost can (I never imagined how tight some of the clearance are!)

Purpose of car:
-I'm moving away from a purpose built AutoX car, and looking for something that can do a little bit of everything...Street/Sunday drives, Track, AutoX, possibly Drifting,...
-This will stretch my mechanic abilities: I've done a lot of car projects...swapped engines, suspension, added a Turbo,...but this would be a complete package build.
-Wiring was by far the hardest part, and I've done plenty of wiring in the past.
-a fun project for my wife and I. We've been looking for something to do together...autoX is fun for me, but quite boring for her (I'd be bored just watching too!). Rather than being gone all weekend racing, I’ll be at home in the garage, where we can take more breaks together and hang out. While my wife got bored of the project fairly quickly (somewhat expected), me being at home was a huge boost to our relationship!...and could even be linked to our first girl, who's due this month

Why a MNR Vortx:
-I wanted to do a Miata build…I’ve owned and worked on a handful of miatas and think they’re great and don’t cost a bundle to get. MNR just came out with a specific kit for the Miata – perfect timing!
-MNR is well know and widely used in Europe. Lots of ppl racing them w/ good results.
-inboard shocks/springs, round tubing for frame
-UK pound to Dollar is at an all time low, so the final price was comparable to other similar kits (ie MK Indy R)…other kits like the Caterham or Westfield are considerably more expensive (but they seem to be closer to a “touring” package…interior carpet and the like)
-Chris at MNR was very responsive and I heard great things about their customer service.
-Really glad I stayed with MNR…even with some front LCA issues, they stuck by their word, replaced/re-designed parts. Very happy and would recommend them to anyone.

Car Engine vs. BEC
-I still long to bang through a sequential gearbox with the engine screaming at 10K+ RPM's…just sounds intoxicating!
-BEC would have it's issues: electric reverse drive, harder to register in WA state (possible impossible), oil sump re-work needed, low TQ, more regular maintenance
-IF I had done a BEC, I would've concentrated more on weight…ie. Only a rear roll over hoop, smaller brakes,…could end up spending a lot more money.

My Donor Car:
-’99 Miata sport edition w/ 100K bought for $3,200 (Sport edition-->Torsen LSD)
-Sold more than $3,400 worth of parts...NB’s seem to fetch higher prices than the normal “locost part out NA Miatas". The one thing I hadn't realized was how time consuming selling so many parts was!

Engine Mods:
-Garret T25 Turbo, running ~7psi
-Mega Squirt ECU and 420 cc/min injectors (Mazda RX-8), sequential injection.
-Dyno'd at 188 wHP (plan to keep power around this area…it's about 225 HP at the crank. 5 sp trannys start to break around 250 HP, OEM Diff's break around 300 HP…)

Schedule:
3/14/10: bought Miata
5/10/11: deposit to MNR
7/18/10: Kit on the boat (England to Baltimore)
8/11/10: Kit arrived at my door
12/18/10: First engine start
4/8/11: First Drive
5/2/11: Registered/licensed


Time Chronology in Pictures:

The Donor – we picked it up in Salt Lake City…picked up some extra items along the way!


Sub frames dropped from car:


Picking up the Crate:


Bare chassis w/ body:


Painting cage:


It's a Roller:


Blue taped monster…looks like a real car!


Tight bonnet/engine clearances:


First Drive: stripped bare…wanted everything open in case of needed fixes


Heading to State Inspection:


SCCA Solo National Tour, Packwood WA:


Local AutoX event:


Top Time @ the local out door PGP Go Kart Track:



Lessons Learned:
1) Really Really glad I did many of the Engine mods prior to pulling the engine! Knowing that the engine/tranny/diff/brakes/ect was running well prior to being pulled removed a lot of doubt when trouble shooting once it was in the new frame.
2) I should have planned for more power…I'm already thinking of bumping the power, but I would be smart to upgrade to the 6sp tranny (much stronger). It would've been soooooo much easier to have done that 1 yr ago! With such a great power:weight ratio, I just never thought my top speed would be so limited…I should have looked at the tracks I would most likely do, and figure out the top speed I would want to attain; IMO 155-160 MPH would be a good goal (both power:Drag, and gearing)
3) I should have filled the block w/ coolant for the ~4+ months it was laying in the garage…the rust built up so quickly!

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Building a MNR Vortx w/ '99 Miata donor: viewtopic.php?f=35&t=9631

Nice job, looking great and results to be proud of. 160 you will be hanging on I can tell you that. You will probably need a little more aero in the front to keep it down. How fast have you had it?

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Graham,
www.earleymotorsports.com

You have a little kid on the way. You need a lot of life insurance for this. In my experience, not everyone comes home every time when you get to this level...

Just saying...

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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.

For being that serious, I would lower the car a good 3" or so, no more then 2" ground clearance and make sure everything is up to real track car standards. Real slicks etc. Proper suspension setup for the new ride height. This is a light car, those speed s have serious aero loads. What's going to happen if you get backwards at 150, I'm not telling you not to do it, but maybe another year of seat time would be good.

Get weight off that car. You need the slicks and light weight for when you get sideways at 130 or something. No headlights or big batteries etc. Get the battery on the floor. Your car is way top heavy for this stuff. My Formula Ford feels top heavy for this. It's been thirty years since I've gone down a straight backwards at that speed and I can still see the smoke rising off the pavement like yesterday!

You have no idea yet what getting a kid thru their first year is like. driving a less then 1200 lb. car at 160 takes real attention it's not a casual exercise. When I started this stuff race drivers died every month or two, locally, nationally and internationally. No one took it casually. These days safety has improved a great deal and people gloss over this a bit. The car in my avatar has an aluminum gas tank, with no foam, that wraps around the driver (to provide cushioning on impacts - instead of air bags we had fuel cans) and the bucket seat weighed 3 lbs. with the steel frame. People seemed to take this more seriously though.

So, I'm not actually discouraging you - I think it's a great thing to do. You need a lot of seat time. A lot. You need your head to be in the right place. You have to make the right choices. Be aggressive, maybe the more the better. That go kart track looked like a great training spot. It's very hard to learn car control just at a fast track. You need to be able to drive the wheels off that thing at the kart place, clean drifts on the line, to a foot, right to the edge on exits.

Have a blast, but really next year is going to be hard...

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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.

I hit ~135 MPH a few weeks ago at Pacific Raceways (I've done 150 MPH in a 350Z when I was there a few years ago). Front aero is in the works…

For track days, I remove the top element from the rear wing…so downforce/drag is much less. AutoX/Go-Kart tracks I leave the upper element on and at a steeper AoA to get some downforce at the lower speeds.





155-160 will likely never happen…it's more of a design point that I wish I had done early on for gearing and equipment (which I could have then just kept slowly increasing power to finnaly attain). At this point, it's a fairly large project (re-tune ECU, large fuel pump, 6sp Tranny, different LSD, different final drive ratio,…then add all of the other items you mentioned), so it's not practical…especially with a baby on the way; I suspect I'll be doing less and less track days as the months/years go by.

Thanks for the input on safety - it's good to have other eyes on this type of potential change!

*good point on the Go Kart track...it seems to be one of the best places to really push the car in many respects; very active w/ lots of turning, shorter straight sections limits cooling (so it really tests brakes and radiators), lower top speeds allows myself to push the limits more b/c the consequences are reduced, also revealed a lot of ergonomic issues with the car (steering wheel & shifter placement, seat position...).

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Building a MNR Vortx w/ '99 Miata donor: viewtopic.php?f=35&t=9631

With a young one, I'd suggest tempering your desire for more speed & power. Keep in mind that the additional energy involved with a speed increase is essentially the square of the new speed minus the square of the old speed, not the (much smaller) square of the difference. (All times mass, of course.)

That energy will need to be dissipated in some way every time the car slows down from those higher speeds, through braking, skidding, and hopefully never through an impact. It will also move you into an area where speed differential can become more of an issue on some tracks. Closing on two slower cars near a corner and having one pop out into your braking zone can be a much bigger issue at 160 than 130. Also as speed increases, costs tend to grow in the same squared manner as the energies involved, lol.

I appreciate your addiction, I share the same one. But please remember to prioritize your family and carefully consider the risks. Love your car, btw.

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.. in the world

I have another question. How many rolls of blue tape did you go through?

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Graham,
www.earleymotorsports.com

Yeah, that alone takes this out of the category of Locost, that stuff's expensive!

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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.