Cool build - CRX - Mid engine and RWD - Builder - Zimsplat Epic thread on Honda-tech

The people who have the creativity to truly fabricate a FWD car to a RWD car are impressive. But even more when the engine is mid mounted!!!.

I found this on Build threads: http://www.build-threads.com/build-threads/mid-engine-rwd-turbo-crx/
and here: http://honda-tech.com/welding-fabrication-53/my-mid-engine-rwd-turbo-crx-2609439/

Simply Amazing!!!

Mid Engine RWD CRX turbo!


It seems the there are many members of the Honda fraternity who still undeniably love the marquee, yet are quite bored of the whole FWD thing. On this website alone there are 3 other builds documenting Hondas being DIY’d away from their standard drivetrain layout. There’s a front-engine RWD F20C CRX, a mid-engine rear wheel drive DC2 Integra, and an AWD Twin Engine Del Sol. This latest build uses a mixture of those combinations, giving us a mid-engine rear wheel drive CRX. Honda, are you listening?
Thanks to Daniel for submitting.

The next step for my planned mid engine conversion was to find a doner vehicle's front core support to use as a jig to line everything up in the back of the crx. I was blessed in the form of a FREE 1990 civic 4door from a friends back yard, as long as I agreed to take the rest of the car to the junkyard. A fun and sawzall filled afternoon with from friends produced the desired result of front core support including, suspension, motor mounts, front crossmemember, some 13's for a later burnout, and even a d15 I threw on the ground... the junkyard was a little confused when I brought this in, Ha ha

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Re: My mid engine RWD turbo CRX my plan for getting the rear suspension streight in the car was relatively simple. 1) Level the car, and measure the center point of the stock rear suspension with plumb bob, and the fender gap at the desired ride height. The doner core support was completely stripped down to the bare minimum. the steering rack was removed in favor of small 1/8' steel brackets to hold the stock tie rods straight, and as much excess metal was cut off as possible for weight savings. I was aiming more to use to core support only to line everything up, and not so much to be structural. 2) I then figured out at what point in the suspension travel of the stock front end the axles were as straight as possible. I took a spare set of front shocks and installed them on the core support and welded them solid in this position. this might be used as stiff drift suspension later (joke)   Once the core support was prepped and ready to install, It was time to cut out all the stock rear suspension, gas tank, brake lines etc and make a huge hole in the floor big enough to fit the core support into. I had wait a few days to do this until the car finished passing smog... No turning back now... It seemed like this project was charging ahead until i got to the current step. Measure Cut Test Repeat. because the suspension was locked in the position that it should (hopefully) be by the welded struts, it was a simple matter of getting the core support positioned so everything was straight. I wanted to leave as much of the thin sheet metal from the back of the crx intact as possible to help with closing all the gaps up. once I had it where I wanted it, I tack welded it in place, and put the car on the ground to check everything I temporarily removed the struts completely to check the suspension travel. once I had double, and triple checked everything was straight, I started fabricating 1/4" steel brackets to tie to all together. There are Two of the brackets shown that tie to the core support to the rear section that held the stock tow hooks. Working with a unibody car turned out to be difficult because there arent any outstandingly strong areas to weld to. The front section of the core support was connected to the rest of the body with similar 12"x 3" plate steel brackets, as well as a large box assembly that welded, and bolted to the stock trailing arm center mounts. I decided that the worst possible thing that could happen to this project was to have some sort of structural failure after it was all said and done, so all of the attachment points are probably much stronger than they have to be. after i was satisfied that it wasn't going to move, the stock gas tank was zip tied it on top of the whole new rear suspension.... and took the car for a drive with the stock front motor. other than the welded rear shocks (lol) the car drove straight enough to satisfy me, so i set to closing up all the sheet metal gaps in the wheel wells.         #30 Re: My mid engine RWD turbo CRX filling up all the small gaps with small pieces of 16 gauge steel turned out to be the most time consuming part of this project. every gap was a funky, concave shape and it took many hours to cut the pieces out and weld them in place. the rear shock towers had to be completely re-done to accommodate for the upper control arms.   #31 Re: My mid engine RWD turbo CRX I forced myself to finish all of the gaps before I test fit the engine, because i knew I wouldn't want to go back to cutting and welding little pieces of metal after seeing the drive train in place. Overall, it took about a month of constant evening welding after work to close it all up. the next major fabrication challenge was to build the transmission mounts. even know i had purchased a set of B series mounts for a civic, I planned on using a hydrolc transmission, which has a different tranny side mount. I started by making a template for the bracket that would bolt to the transmission the motor and tranny were then lowered into the car I used the polyurethane mount from the kit, and cut it off at the correct length to mount to my transmission piece. looks good, but will it handle 250 lbs of tq?      #32 Re: My mid engine RWD turbo CRX Ah yes, this project officially is getting somewhere...   Shift linkage The idea for the shift linkage literally came to me in the middle of the night before I was ever serious about the project. If you are familiar with how the stock rod linkage works, you know that there are 2 parts to it; the stabilizer and the torque/push pull. if you think about it, it doesn't really matter what shape the rods are, as long as they are solid, and connect to the same place in the end. the stabilizer is easy, its purpose is to float in order to accommodate the engine movement on launches etc. So as long as it somehow goes from its mounting point on the transmission, and ends up holding the shift lever ball joint, it should work fine. The same goes for the pushpull/torque rod. the key to my design though is the 180 degree SOLID bend at the end of the torque tube. this make the left/right movement the same, and also (if you think about it long enough) the push pull functions the same way. the end of the torque linkage is visible in this picture just to the right of the muffler updated picture of the linkage I know this is a vague description without more pictures, anybody understand?   #43 some other random pics turbo, wastegate, downpipe fitment.

So now that the motor is sitting in the car, I started the long process of wiring. the first step was to remove ALL of the stock crx wiring. Because i planned on only having this car as a drag car, every inch of stock wiring was taken out (except for leaving a few behind for tailights and headlights). I also was going to use completely OBD1 wiring colors, sensors, ecu(hondata) etc. my goal was to make all of the wiring as SIMPLE as possible, with all unnecessary things removed...this was about the time that I pulled the dashboard, all the vents, heater, stock fuse box etc, and preformed "stage 10 weight reduction" on the interior. I used a stock ex harness from an EG for the engine harness, then chopped off the matching plugs, as well as the fuse box to make the crx side of things. whenever possible, I tried to maintain standard OBD1 colors, plugs, etc for ease of future modification or replacement of parts. I separated all the wiring that I would have to complete into a few categories before i started, and attacked each group one at a time. I built an aluminum control panel, with 3 main controls. A master switch, ign switch, and starter button. both the master and IGN switches were wired to terminal board, to make later connections easier. also visible in this later picture is the high/low boost switch, and a set of annunciator warning lights (aviation influence) for oil pressure, check engine, charge system, etc. after hooking up all of the power, ground, and misc wiring associated with the main relay, hooking up all of the sensors was not really difficult, but more time consuming to make check and double check every wire. interestingly, the stock 89HF harness contained every color that i needed to copy the 92-95 scheme. Last edited by zimsplat; 07-28-2009 at 11:23 PM.

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	Re: My mid engine RWD turbo CRX I had planned on totally gutting the car including dash and stock gauges, but then I started to have second thoughts. I had a friend that got into trouble for removing the stock VIN number on the dash, so I decided instead to keep a "dummy" dash in the vehicle. I cut out all the unnecessary plastic parts from the underside, leaving only the top shell of the dash. After doing this, I started to wonder how difficult it would be to make the stock gauges with tach and water temp gauge work with the all OBD1 wiring. a little tinkering, and I had both working great. I also modified the stock HF green shift up light to work with Hondata. The only other thing that I was missing was a speedometer. The stock crx gauges work with a cable driven speedo. first of all, there was no way I was going to find a cable long enough to make it work. second of all, I used a hydrolic transmission with the electronic speed sensor. I noticed that the speedo from a DX 94 civic was about the same size as the crx one... So with a little modifying with a dremel tool, I had it fitting nicely Plus some trustly shoe goo to hold it in place Most people look right past the "stock" looking gauges :-)

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Re: My mid engine RWD turbo CRX Also under the dash, there was another major project to be completed. I wanted to change the car completely over to a hydraulically activated clutch. I figured if i could mount a master calendar on the inside of the firewall, i should be able to use the stock clutch pedal. So i fabbed a quick bracket and drilled a hole in the top of the pedal. I ran some hard lines back to where the firewall would soon be, and hooked it up temporarily to check the pedal effort and travel. works flawlessly! reservoir access please ignore the wad of headlight wires. I had to jimmy rig them to get home from the drag strip one night and havn't fixed them since! looking from the front core support back. the fuel feed and return lines, as well as the walbro 255 external fuel pump. on the far right is the hardline for the brake booster      Quote: Originally Posted by RickyLee53 Nice, wheres the intercooler mounted? I'm guessing just under the rear bumper? Can you get it in the engine bay somewhere? it'll soak a lot of warm air at the back, and the bay wouldn't be that much longer on the pipes i'd guess. for now the intercooler is mounted in the rear bumper. horrible positioning... but better than nothing. the new setup that will be getting installed involved an air to water intercooler with a heat exchanger up in the front bumper. it will also only need about 1/3 the length of charge piping to complete. I'm sure ill gain significant power from that alone.    Still using the stock water pump. In fact, it runs quite cool. if i drive it on the freeway for a period of time it actually cools off below the normal operating temp. the ground clearance on the water tubes is decent. I mounted them towards the sides in order to clear the shift linkage, and leave room for the fuel pump and lines. i have thought about the plate in the front, it will definitely be incorporated into the tear down and rebuild that's coming up soon. gas door cold air intake mod :-)   the motor was a little floppy in the engine bay, so i stiffened it up by building a 1/4" steel plate front mount. its SOLID now Re: My mid engine RWD turbo CRX Random fusebox and main relay detail Ecu mounting under the "dash" I used a tandem bike shifter cable to extend the throttle cable pre- intercooler some intercooler piping shots Hey, new build has started! car has gotten stripped back down to prep for paint and new motor setup. Ive also been doing some work on the suspension to stiffen it up and hopefully make a little more stable at high speeds. Ive been fabbing traction bars with heim joints to replace the stock radius rod bushings that are totally worn out. Also got some new stiffer springs, and koni yellow shocks for all 4 corners. Finished my front suspension today, should be much less flexy than stock. Started sizing up and building brackets for the rear also 43 I am not looking forward to this part Spent pretty much all day stripping, and sanding 3 days worth of stripping, wire wheel scotbrite and sanding later.... finally Sprayed with etching primer Last edited by zimsplat; 05-26-2010 at 12:43 PM.   05-25-2010, 12:58 PM   #228 zimsplat Honda-Tech Member Join Date: Mar 2008 Location: mckinleyville, ca, usa Posts: 174 iTrader Rating: (0) Re: My mid engine RWD turbo CRX I don't know anything about bodywork and I've only sort of painted a car in the past, But I am nearly fearless with a cutoff wheel and a mig welder. The rear right quarter panel was extremely rusted out, with several holes and thin spots. I thought about just trying to fill it, but then decided what the heck I already fit a motor in the trunk...why not try to replace it? I love harbor freight Semi-finished product Updates.... Quarter panel is still going places Getting very tired of stripping off spay-paint So I bribed a few of my friends to help out Jeff made a nifty gas strut to hold the engine cover open Tthe radiator is the stock unit, in the stock location. I just built some tubing that ran back to the engine. just make sure you have a way of completely bleeding the system. go to your local bike shop. buy a shifter cable for a tandem bike. cut your stock one in half and splice it in the middle. done. :-) I made all the fuel lines and clutch lines with aeroquip AN fittings from the airport I work at. look them up on summitracing.com, or your local autoparts store might have them... no fuel pressure problems at all. the car has an external walbro 255 pump mounted under the floor. the length of the lines shouldnt have any effect on the pressure or flow. no problem man, I love to hear about other backyard projects   Updates! finished the new rear crossmember/traction bar mount. Bonus transmission mount is also part of it. Some people expressed a dislike for my decision to move the radius rod mounting points outward, but It should only add a MINOR amount of caster with the suspension compressed all the way, while yielding a much stronger mounting point. mocking up the front mount started installing water lines for the water intercooler system. Made it from hardware store 3/4" copper pipe soldered together. Hooked up the pump and it even holds water! It seems like it flows quite a bit Can't wait to see some hopefully low intake temps. I decided that my passengers are just going to have to deal with water lines and wires running between their legs    Decided to brace up the T-bracket   Had a pretty sucessful last few days. I've never built a roll bar before, or even really tried to notch tubing. I got a main hoop, and fabbed the rest of it myself with the same old die grinder and mig welder. I decided that welding in all the base plates was by far the worst part, and even notching the tubing by trial and error wasnt that bad once I got the hang of it. I'm pretty curious to see how much it stiffened up the car... just in case I atually get to drive it again someday. :-) so I need some more opinions. I have opertunity to buy a garett gt37r ball bearing turbo. Its huge. too huge? I'm actually leaning more towards a smaller less laggy turbo, but all that top end sure sounds fun too! If I could really have my way, Id throw a gt3076R in it... MAYBE a 35r. Anybody have 37r experience? notching some tube. For those of you who are wondering, thats a TRAIN WHEEL in the background not too bad of a fit harness bar  started making up the downpipe... out of a single 3" U bend. It needs to fit through this hole... sexy bends :-) Lol who votes this is the end of the exhaust fabrication?? I'll probably put some sort of muffler on it. in this pic you can also see the water lines for the intercooler, engine coolant lines in progress, fuel lines as well as hardline to the brake booster  did some tinkering on the car the last few days. got the intercooler and charge pipes all figured out. Short!! built the coolant lines Wintertime around here sucks! We had some good weather so Ive been trying to get all of the things that require me to lay under the car finished New and improved shift linkage transmission front mount Oh by the way, some pictures of new brakes. Car now has 11.1" redrilled prelude front rotors with 17CLVN calipers from an acura ledgend with DA knuckles. previous civic EX front brakes have been moved to the rear. I also modified a DA with ABS 1" master cylendar and booster to fit. IT stops VERY well now, but now all of my alignment needs to be reworked before after front brake comparison   I'll be brutally honest. I hate asian cars. I've come across a few that I have looked at, but overall I don't like the way they look or sound. Hollywood and 16 year old ricers have not helped me along any. I'm purely a muscle car enthusiast, so this may be the only time I ever post on an import forum, but I want you to know that I for whatever reason have always had an unusual (for me) appreciation for the CRX, and I read all 26 pages of this thread. I wondered if someone had done a mid-engine conversion to one, so I googled it, which lead me here, and now I know. Congrats on the mag cover story btw. I will have to pick it up off the rack next time I'm at the store. There are a few suggestions I'd like to make though if you don't mind. If you do a more streetable version 3, what I would do if it were mine would be to see if I could fit a gas tank in the center hump where your coolant lines are currently run. I own a Fiero, and that's where the tank is from the factory. The coolant lines are then tucked behind the sideskirts. Battery would be up front with the old engine bay converted to a trunk. Other mods I would do would be to put a vent in the hood to let out hot high pressure air. Many Fiero owners do this to improve handling as it keeps the car from floating at high speed. The gas door intake was ingenious, but I think V3 should be more professional, like the car came that way from the factory. I would shave the gas door lid and either put scoops on the quarter windows or go with lower quarter panel scoops. I would also cut the rear hatch window in an inch or two on the sides and put full length vents running down to let hot air out of the new engine compartment. Because many exotics also showcase their engines this way, I wouldn't bother covering the motor up with an aluminum sheet so spectators can see it in all its glory under the rear glass. Instead I would separate the passenger compartment with a piece of Lexan running from the roof down halfway where it would meet the firewall. I have seen this in a few exotics as well. Lastly, I would probably go with small block Chevy or at least a GM 3.8SC, but that is the muscle car guy in me talking. I know you all have your own ways to getting power. I'm no fabricator, so I don't know what it would take to do all this, or if some of it would be legal on the track, but I thought there would be no harm in putting it out there. Hope I didn't hijack your thread and ramble on too much. I wish you the best of luck. Please keep building because I hope to read more on this project later and it's just pure awesome!!! [IMG][/IMG]