JMR's MR2 based Middy - The Wycked 7
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Author:  Kartracer47 [ September 20, 2010, 4:43 am ]
Post subject:  JMR's MR2 based Middy - The Wycked 7

I have been lurking since last November when I joined the Locost forum. I have always liked the Seven and have owned 3 early Elans. As a side note - the last one I converted to LHD, installed a 4AGE and did a frame up rebuild. I lived in SoCal at the time and sold the car after enjoying it for a few years. I moved to Port Angeles, Wa. and was contacted by the new owner who lives just across the Strait in Vancouver, B.C. Kart racing has been my passion for about 10 years but that has pretty well burnt itself out.
So now ---- I started to design a middy with inspiration from Midlana (Jim Langan lives nearby - beta builder), LaBala and tons of info from this forum. I bought an MR2 Mk1 for a donor. I am using Wishbone for susp. calcs and started there as I feel the vehicle should be designed around the suspension. I am old school - sketches and good old drawing board. And many more sketches - many solutions are based on "what fits and looks good".
I have previously designed and built 2 - Formula V's and 2 - A Sports Racer cars - see my website for a couple of them. The last ASR had an aluminum monocoque with a stressed SBC, Hewland LG500 gearbox and Gurney Eagle uprights. The tub was made from .063 6061T4 - overkill strength wise but also a little heavy. I like the larger safety factor. I am comfortable with monocoque/tub style so that is what I am using on the new project - front and rear steel tubing subframes carrying the engine and suspension with the tub for me and a possible passenger. The seats will be built into the tub.
I settled on a 3" RC at the rear that stays with the chassis and a 1" RC at the front that also stays with the chassis. 3" of bump front and rear with 1" droop front and 2" at the rear (spring rate dependent).
I started actual construction in July and now - mid Sept. the front and rear subframes are done and the suspension is completed and am now working on the pedals.
Rear suspension is based on the MR2 upright. I actually used the rubber bushed mounting for the lower radius rod. Upper radius rod with upper control arm. Push rod suspension using R1 shocks (from RacerDan) and fabricated rocker arms. The rocker arms use caged needle bearings on VW wrist pins. Do you know how much money the bearing surfaces cost for the needle bearings??- a lot! I happened to have 4 used wrist pins so I put them to good locost use.
I struggled with the front suspension and finally decided on Chevette front spindles. I am using VW upper ball joints from a Bug and Chevette lower ball joints. A rodend is attached to the arm on top (instead of below) with Speedway 1/2" shock mount adapters. Pull rod suspension is from the upper ball joint carrier to the rocker arm on the lower front sub frame. The shocks are mounted horizontally across the lower sides of the front subframe.
Rear brakes are standard MR2. I cut the rotors off the Chevette rotor/hub assemblies to allow use of the MR2 vented front rotors and calipers. I will make caliper adaptors for the front. The Chevette spindles are front steer while the MR2 is rear steer.
I started out with a Miata rack but am using a Triumph Herald/Spitfire rack due to packaging, light weight and slightly faster ratio.
Body design is still up in the air - I have sections of one of Jack McCornack's Catfish noses and like the styling of the British Aviator type seven. Time will tell!!
Fuel injection will use a Megasquirt II and ITB's from a 750 Yamaha - manifold was the first project completed.
I have been signing on with Kartracer47 but moving on I will go with my initials - JR
On to pictures --------------OOPS - start at the bottom of the pictures and work up- my mistake. JR

Author:  Kartracer47 [ September 20, 2010, 4:53 am ]
Post subject:  Re: JR's MR2 based Middy

More pictures ---------


Author:  egoman [ September 20, 2010, 10:16 am ]
Post subject:  Re: JR's MR2 based Middy

Very nice work! It looks like you plan on building the car as subframes and then tying it together. I did the front suspension on my car as a subframe and it made it a lot easier.
Are your lower control arm pickup points parralell with the chassis or do they angle? Its hard to tell from the pics.Seeing as you are using a pullrod style front the extra bracing in the lowers is probably not necessary. Do you have all the donor mr2 stuff yet?

Author:  Kartracer47 [ September 20, 2010, 12:22 pm ]
Post subject:  Re: JR's MR2 based Middy

Hi Egoman, The front LCA has an optional set of mounting holes that allow the arm to be lower in the front by about 3/4" for anti-dive if needed or desired. This is something else to screw with be screwed by. The UCA inboard pickups can be lowered (as can the rear UCA) for increased camber gain with only a minor RC change.
I bought a MR2 last Christmas to start getting measurements. It is the donor except for Chevette spindles and a Spitfire steering rack.
There are 2 - 4'x12' pieces of .063" 6061T4 aluminum sheet to tie the 2 sub frames together, waiting to be cut and folded, in the shop.


Author:  JSullivan [ September 28, 2010, 12:11 am ]
Post subject:  Re: JR's MR2 based Middy

Kartracer47 wrote:
I bought an MR2 Mk1 for a donor.

Oh did you pick up that mr2 that was for sale in the walmart parking lot?

Author:  Kartracer47 [ September 28, 2010, 3:43 am ]
Post subject:  Re: JR's MR2 based Middy

That might have been a better donor!! I did not see it. I found one about 60 miles away. Tried to drive home with it but was losing too much coolant (mosquito abatement vehicle!!). Ended up towing it home on a dolly on Christmas eve! Found a broken head bolt with no other damage.
I will admit what a pain to remove the engine and trans. Used a chain hoist off of the header of a garage door to lift up the back of the car almost 3 feet. Factory recommendation is with a vehicle hoist.


Author:  JSullivan [ September 29, 2010, 4:14 pm ]
Post subject:  Re: JR's MR2 based Middy

Yeah a friend's head gasket turned into an engine swap with his old mr2. That was a pain to do in the driveway!

I almost bought the one recently at walmart to drive. ~170k miles on the chassis, jdm motor swap ~30k ago(supposedly), and was in really nice cosmetic shape. Was $2k. Figured I don't really need to spend money I don't have on a car I don't need however. :lol: I have a bit of an objection to used car prices here. Maybe you can explain them? But the prices here are ridiculous across the board in Port Angeles for used cars compared to Texas or Colorado.

Author:  RIKIMOTO [ October 29, 2010, 2:28 am ]
Post subject:  Re: JMR's MR2 based Middy

HOLY SH@T! This guy has some mad fab skills. My only hope is someday to be as good. Nice work, you have made some good progress since I last saw the parts laying on the bench. Personally I would have went with M/C power but thats just me. :lol: Guess I will get to see it again when I pick up my molds. Keep up the good work John....... :cheers:

Author:  JSullivan [ November 1, 2010, 5:19 pm ]
Post subject:  Re: JMR's MR2 based Middy

Any progress on this?

Author:  Kartracer47 [ November 1, 2010, 9:59 pm ]
Post subject:  Re: JMR's MR2 based Middy

I have gotten a little further. A big HONEYDO got in the way.
I now have rivets (over 3000) and adhesive ( $140) to continue. Drilled a lot of holes!!
Thanks for the positive comments (surprised at how FEW I have gotten!!!!!!!). I will post more pics as I progress or maybe just leave the forum????


Author:  erioshi [ November 2, 2010, 3:16 am ]
Post subject:  Re: JMR's MR2 based Middy

I wouldn't worry about the lack of comments, lol. I'm enjoying your build and would really like to see more of it. I appreciate the detail pics, but perhaps a few general pics would help us get a better feel for the car you are building.

Author:  ckouba [ November 2, 2010, 6:55 am ]
Post subject:  Re: JMR's MR2 based Middy

I'd post with positive comments but I don't really have actual content to contribute here and I am not a huge fan of the "yay, rah-rah" types of posts. This forum seems to be a high signal to noise ratio and I appreciate and support that mentality.

That said, you clearly know how to swing a torch and your fab stuff looks fantastic. I would appreciate seeing more of the overall view (if you have pics of that) as well. I am jealous of the fab skills. Please keep posting and don't walk away from the forum...


Author:  eurokraft [ November 2, 2010, 5:21 pm ]
Post subject:  Re: JMR's MR2 based Middy

Great job, I like the way you are doing the rear set up, using the MR2 set up, I have done something similar to my midy mini, I'm also using the first generation MR2.
Keep up the good work.
Cheers, Tony

Author:  Kartracer47 [ November 3, 2010, 1:10 am ]
Post subject:  Re: JMR's MR2 based Middy

Thanks for the encouragement!! I have been sidelined with a large honeydo project but will be back on THE project in a few days.

Author:  Kartracer47 [ November 3, 2010, 2:02 am ]
Post subject:  Re: JMR's MR2 based Middy

More pics.
There will be 5 bulkheads in each sponson for rigidity. Thank god for cleceos!! I will pre drill all the rivet holes, sandblast the subframes and scuff the aluminum prior to riveting and using Scotchweld 2216 adhesive.
I have 2 pneumatic riveters, just in case and hopefully fast hands.

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