making a mx3 rwd.

[SpatialTerror]

so i am currently building a my 92 4ycl into a bpt dragster and if possibly to swap in a rwd setup possibly switch it up between drag autocross and drift. just kinda a good all around race car if you catch my drift. so far i have the motor built to handle about 20psi with 10.5:1 compression with a good tune. but i have just started working at a shop reciently and noticed that on a miata that we had in the shop the rear end looked like it would almost bolt right into the rear of the mx3. i didnt have to do mesurments but basically thats all im worried about is if it will bolt up in there or if there is a different rout that is better. but so far the miata is looking like its gonna be a good choice for doner parts. from what i understand the wheelbase on mx3's is unique to its self or something like that. but i dont care about how much work its gonna be ive already put far past too much work into this car. and i want it to be something that will be in the relms of 8 or 9 seconds on the 1/4mile after changing up the motor again to run 35psi or so on 8:1 compression.
but what would really be helpful is if you could find me the year of miata that i gotta look up parts for because from what i understand the wheelbase changed on the miatas over the years
any advice would be helpful.
other than the dont do it advice cuz my mind is already made up that if i can get the parts to make it rwd im gonnna do it.

[Josh]

You will change your mind trust me I know.

So you mention several things here that are going to be issues. first off if you are looking for a 8 or 9 second car Miata parts are not going to hold up... AT ALL... you should lean towards a solid rear axle like a ford 9"..

secondly if you use Miata parts you will want to use 94 and up, that's the introduction of the BP and they beefed the rear end up a bit over the earlier 1.6L models.

Since RWD is what i wanted to do originally before i decided to go with AWD I did a lot of research on it. The Best and strongest trans you will find will be from the RX7 Turbo II. The Bell housing can be swapped with others a little research and you can find out what will interchange.

The rear end. Best thing for you to use if you dont want to completely fabricate the entire chassis will be a 323 GTX, GTR, or AWD Protege rear end. They use McPherson struts unlike the Miata or RX7 do. STILL HAVE TO FABRICATE a complete rear subframe. Nothing will be bolt on.

After that which is the easy part. You will have to do something with the front end. the easiest thing to do with the front wheels is chop off the end of the axle and leave it bolted into the the Hub (its what a lot of Subi and Evo guys do to go RWD for drifting). then you have the cross brace and fire wall that will have to be cut out and re fabricated. the easiest thing to do would be to have a donner car to cut the tunnel and firewall from. but you will still have the cross brace and the engine cradle and you will have to figure that out when you get there. NOTHING and i mean NOTHING will be bolt on for you until after your done.. hopefully..

If you plan on having a shop do this for you, I would plan on it costing no less than 7K.

[SpatialTerror]

yes i know about all the fab its gonna take and honsetly i cant wait.
my only problem is im on a slow budget. and well i dont want it to constantly run 9's i just want it to do it 2 or 3 times to prove its capable then just bracket race in like 11s or 12s but the miata i was looking at was outa a 2000. but if uve been under the back of an mx3 the whole rear end is held in by 4 bolts right into the unibodys subframe. on the rear end or the miata its held in the same way i just need to know if i cant bolt that up in the back. because b4 this thing goes full blow drag car ill be running it on the street tweaking and tuning and ect. at like 7psi. then basically i plan to chop up the unibody a bit for a body cage mill my pistons and do some upgrading with the turbo and such but for now i would like rwd and if that bolts in it saves a whole lota work. cuz i have alot already as is just making rwd in the front end of the car and all the way back to the rear end plus exaust routing
if it is possible i would take that option atleast for now where it will be a street/mainly strip/track car. thats has working rwd. untill i can go with beefier rear end.

[SpatialTerror]

ok so today i was doing some measurements and i actually think that ford rear axle idea is a pretty good one.
does anyone have the measurement of the distance between the ubolt mounts on a ford 9" rear axle. because it would be fairly easy to make it a solid rear end if i wouldnt have to make like spacer plates to make the u bolt mounts meet the leafs or solid beams.
but i am still interested in the miata rear end ive seen aftermarket suspencion kits that make that rear end mcpherson with adjustable height. ive also came to the conclusion that im gonna have to remove my gas tank and go with a fuel cell.
im thinking just like a 2 gallon cell or so because when i first get it done and running its just gonna be a n/a 10.5:1 compression bp rwd mx3 with a fully built for boost motor because of slow budget. but hopefully i have around 200bhp or so with standalone ems. but my plan once its that far along is to run an individual coil system and try to runthe car off of hho. or atleast mostly off of hho thats the reason for the 2galon fuel cell. because with this idea i still need gas to start the motor but then with the megasquirt system i can switch it over the hho system which ive spent alot of time doing the research and designing of a cell to atleast hit the 200mpg range. which would be sweet
and basically i will have the stock 12v system running the car and all the 12v systems in the car and where the a/c compressor was i plan on mounting a 24v 120a alternator charging a 4 battery pack on its own electrical circut that will run the hho generator.
then the hho cell will be build to hold atleast 120psi and generate around 4 to 6lpm of hho .it will charge 2 5gal pressure storage tanks that will be fed into the running engine by vacume on a almost completely sealed manifold.
basically ive done enough research to figure out that just to make this paticular engine idle on hho will take just under 4lpm acceleration can take as much as 25lpm or more but cruising takes about as much as idle with about 4 1/2 lpm. to 5lpm.
so basically my goal is to have a hho system that can drive on the freeway untill i run outa water. because what could happen if i dont make enough to run cruising on the freeway i will basicly have to stop every 50miles or so to let the pressure tanks build back up.
and i forgot to mention the saftey devices but yes there is saftey devices becuase theres alot of hho in this system enough to take out me and an intersection if it blew up. but there is plenty of saftey devices.

but the end resualt im working to get is a rwd turbo bp mx3 that runs on hho.
and when i go turbo i am gonna beef up my hho system to the max put bigger storage tanks that way i can run 14psi or so down the 1/4mile. its a big project but its not all happening at once. b4 i can do hho i need a running rwd mx3.
i also though about going awd but i cant find any awd cars anywhere within 300miles of me. that would be a good doner car.
plus price is a factor too.

[Josh]

ummm.... ummm... yea

OK, so your on a budget, you wont attain your goals without some cash. I spent close to 4K on my BP and I did everything but the machining. My engine is rated to withstand about 600hp.. about. even then it would be a stretch to hit 9's in the 1/4. HHO, street/ strip. you have to make up your mind on what you want more. having a 9 sec car isn't streetable especially with a 2 gal fuel cell. my BP averages 16MPG's, HHO isnt going to stretch it that far, and each track that your wanting to use it on requires entirely different setups. like suspension and tires just to start.

I would not recommend you do this without a donner car, perhaps a MX5. Cut the body from the under carriage on both cars and weld them together.

The MX5 uses different trailing arms and uses a completely different rear strut than the MX3. the top mount and angle of are also different. SO its EASIER to use a 323 or Protege rear end, I am not saying you cant use the MX5 rear. Its just a bunch of additional head aches. And the only rear end that will bolt up is the one that came in the car. even if you could just bolt one up the frame rails could not hold up to the torque.

If you decide to go with a Ford rear end YOU DON'T USE LEAF SPRINGS!!! you cant drift with that very well, you will want to go with a 4 link rear end and actual springs and shocks.

Check cardomain, there is a log on there of a RWD Escort you may be able to get some ideas from.

Good Luck with your build!

[Nd4SpdSe]

Using the words RWD and Budget is an oxymoron. That's the most complex and expensive thing you can do on a FWD car because of the amount of parts required and especially the custom work and custom parts required. Most people don't ever complete their RWD swaps, exactly those reasons why you don't seen many out there. Even with how the AWD is almost bolt in, they're still rarely completed. Ironicly enough I just watched a video of a V8 Hyundai Excel. There's videos of V8 Civics and Focus' too.

Here a good link on a V8 Probe that I came across a few weeks ago, it's completed with a good read:
http://ls1tech.com/forums/conversions-h ... -4-8l.html

Even if you're thinking that ya, those are V8 swaps and they're irrelevant, think again. It doesn't matter if you make a RWD V8 Mx-3, or make a RWD BPT Mx-3, once you rotate the motor 90 degrees and have to drive a shaft to the back of the car, it doesn't matter if it was bolt it, you've totally changed the game.

I wish you luck on that, but to be pestismistic, I would put my money on that the only thing you'll have in the end is 2 cut up non-running cars....

[Josh]

+1^^

Although I wouldn't say that the AWD was near bolt in, still requires a fair amount of fabrication in the front end as well as in the rear.

The easiest way to complete a RWD swap IMO would be to cut out the rear end and drop in a font clip... Rear engine... If you know what your doing and do the work yourself it can be done on the cheep. For the bulk of my project I spent somewhere around 1200 bucks on my AWD swap and that's it. 600 on a parts car and 600 on a trans. The rest was just hard work

[wytbishop]

+1^^

Although I wouldn't say that the AWD was near bolt in, still requires a fair amount of fabrication in the front end as well as in the rear.

The easiest way to complete a RWD swap IMO would be to cut out the rear end and drop in a font clip... Rear engine... If you know what your doing and do the work yourself it can be done on the cheep. For the bulk of my project I spent somewhere around 1200 bucks on my AWD swap and that's it. 600 on a parts car and 600 on a trans. The rest was just hard work

I have actually toyed with that idea in the past myself...just in my head. Still tonnes of fabrication, but I agree that would be doable and the cool factor is through the roof.

[Savin]

+1^^

Although I wouldn't say that the AWD was near bolt in, still requires a fair amount of fabrication in the front end as well as in the rear.

The easiest way to complete a RWD swap IMO would be to cut out the rear end and drop in a font clip... Rear engine... If you know what your doing and do the work yourself it can be done on the cheep. For the bulk of my project I spent somewhere around 1200 bucks on my AWD swap and that's it. 600 on a parts car and 600 on a trans. The rest was just hard work

I have actually toyed with that idea in the past myself...just in my head. Still tonnes of fabrication, but I agree that would be doable and the cool factor is through the roof.

You mean like this guy? rear engine 3800 supercharged mx-3
http://www.cardomain.com/ride/3350506/1 ... tchback-2d
http://www.youtube.com/watch?v=OAkufZdvFys

[Josh]

Yah, I have seen this one. I would actually like to see a finished project. I have seen a couple of civic hatches with Rear engine conversions. I really DON'T like the way they did this install. I would be very hesitant about driving this one around. Great idea but I think the execution could be better, but like most major projects it is not finished.

One thing I have always thought of was a AWD subi drive train with a 13BT... would be sweet and light.

Another Idea that I have seen in a civic 4 door, as well as the C6 uses it, is a rear mounted trans with a front mounted engine and a continuously rotating drive shaft . this could be executed easier than a full RWD swap, but still entails some fab work. works out better for that 50-50 distribution too.

The civic 4 door i saw was years back but used a Acura legend transverse mounted FWD trans mounted in the rear and some twin turbocharged Acura V6 had perfect 50-50 according to the seller and over 500 whp.. I will try to find it again.

[Nd4SpdSe]

I would actually like to see a finished project.

That's always the issue, finding someone who actually got one of these custom projects finished....

The civic 4 door i saw was years back but used a Acura legend transverse mounted FWD trans mounted in the rear and some twin turbocharged Acura V6 had perfect 50-50 according to the seller and over 500 whp.. I will try to find it again.

Ohh, please!

[SpatialTerror]

Sorry guys i think i gave the wrong idea on budget. i dont have like a maximum amont im willing to spend. this car has alot of sentimental value to me and well i will spend whatever it takes to make it rwd. but what i mean by budget is i dont make alot where im currently working but i work in a shop so i got alot of access to parts and materials for cheap. and i am willing to fabricate anything that needs it that is one of my favorite things to do is fab. and acutally i want to fabricate as many parts as i can for this car. and well i got good news for you guys. i will be finishing this car as rwd. i am part of a local drag racing team and well this is my race car.
and i really appreciate the support. because i want to do it right the first time and the way that i want it.
so you all have a good understanding of my goals. i want a versatile race car mainly becuase there is a local race track here in idaho that does drifting events. and i would like to be able to switch a few parts over the week to switch my car from drag to drift. i know thats alot. but my plan is to have a car that is not 100% drag or 100% drift. but a car that can be to the best of both worlds with a little switching and tuning.
as for hho. i will run this car off of hho i have done all the research and already have a complete design. its just a matter of getting to the point of building the system installing and tuning.
also for the power factor/ efficiency factor. i have reciently discovered that the head off of a 2001 miata has vvt on the intake cam and from what ive been told will fit on the bp block. so i might just invest in one of those. but i would like to be sure it will bolt up. and well its not too late to make this decision because my motor and head are currently in the machine shop. my block is done and completely build with gt-r rods from corksport, toga bearings, weisco forged 10.5:1 compression pistons. and yes this is a boosted application. but my reasioning for the high compression is hho efficiency because it takes alot of hho to run a motor. but basically my head hasnt been touched in the machine shop yet. it is 100% straight stock cams and the valve train is still strong and holds pressure so i dont think im gonna have them do anything. i can do porting and polishing myself.
and well for boosting on high compression my theory is low boost with higher numers.
but if i can get a 01 miata head i will have it gone over in the machine shop. if it all checks out i will give it some work and stick it on.
now i also have put some serious though into rear engine mount as well and i do like the idea. but i dont like $$$ amount to do that.

so for right now i am basically at this point with a decision on a head and rear end. because i think im gonna go front engine mount rwd.

at this point i am leaning twards the ford 9" rear end keep in mind this car will be completely caged and i will make it strong enough to handle the numbers i wanna get outa it.
the only problem i have the the ford parts is well its making it less mazda. and i really want to keep it as 100% mazda as possible now i know ford and mazda are pretty much the same. and they are under the same ownership. but like i told a good friend of my who put a chevy 350 in a 88 bmw. its just not a bmw anymore its just the shell of one.
thats why i want a miata rear end. but its been said that a escort or 323 rear end will work? atleast somewhat.
my next problem is where im at you cant find a awd 323 or awd escort. and i dont know if the escorts ever came in just rwd. all i know about the escort is some came with the bp and the cosworth is a badass car with the bp motor.
but i know for a fact there is between 0 and 1 escort cosworts in idaho and i know if this is one its not gonna be for sale or parts.
miatas on the other hand are a dime a dozen around here.
so if i could get something from a 323 or escort i would defenently do that. but so far its looking like miata rear end or ford 9".
and well the thing thats gonna make me jump on the ford rear end is weather or not i can build the miata rear end to handle 1000hp big number the car certainly will not produce that ever but someday once its all said and done i would like to mill the pistons to 8.0:1 compression. get more hho storage. and bigger turbo and try for around 800bhp.
now thats along ways down the road. and basically is just a dream for right now. but i feel you guys need to know the whole story and plan to give the correct help.
so main tips i am currently needing is:
1. how strong can i build a miata rear end
2. does anyone know where i could find a 323 or escort awd setup or cheap donar car near southern idaho.
3. if someone knows the answer to question 2. how strong could i build that rear end.
4. what transmission will i need. im assuming for rwd i will need a miata trans. (i had a friend in collage that showed me a trans kit for the cosworth escort that rates the trans to handle 1000bhp. and he also said this kit should fit in the mx3 trans which i doubt but i am wondering if it could fit in the miata trans. this kit ranges i belive from $4000 to $6500 depending on options like adjustable 4th and 5th gear and lsd)
5. does anyone here know of the kit he showed me and if so could a link be provided. and does anyone know if this kit will fit in a miata trans.
6. would i need a custom drive shaft? or would one out of a miata work.

i would like to give you guys thanks for all the help you have provided to this point.
i am very greatful and well i thank god and all of you and the forum owner operator for bringing the forum to the web.
without this website i would not even be able to come close to finding the answers to the questions i ask.
and when i can i will donate to keep this forum alive and well.
so remember budget is not the problem. its my income that is makeing this a timely build. so any deals on parts i am open to because once i know what i need i will start buying it up.
my car is currently still a daily driver. with the 1.6 sohc motor with 250000+ miles running strong. but once my garage is free i am gonna put a 100shot of nos through the 1.6l down the highway till the motor blows. i think it would be a good way for the motor that hasnt ever let me down for nearly 5 years and let me put almost 70000miles on it to go out in style.
the reason i havent started the tear down of the car yet is because my only other vehicle is a 1991 toyota pickup with a 5mge supra motor in it. and right now its in my garage getting restored to 100% new condition. i had to get a new bed for it and i am currently sandblasting the whole frame and refinishing it. rebuilding the rear axel with a stronger ring and pinion. also refinishing the case. then once the body and chassis is done im putting a 7mge head on the 5m block (basically for a small hp boost) i already have the head i got it for $100 its straight and ready to drop in. just gotta buy a head gasket and timing belt..
and im probally gonna drive it like that for about 6months then put a 1uzfe with vvt-i in it. and call it complete.
then that will become my daily driver while i build the mx3.
i would already be driving the truck as a daily driver. but when i bought it the wiring harness was a mess there was quite a bit of rust. (not too much pitting thank god) and because of the wiring harness being a mess there was alot of electrical problems.
i have sense then fixed all electrical problems and cleaned up the wiring. all i need to do is buy a main relay so the battery doesnt die overnight. but its been a fun project and already has attracted alot of attention around my area. so many people flip out when i tell them i have a supra motor in my truck with working 4wd. its not that badass right now but it has improved a ton sense i bought it and is looking to be a fun dependable truck that me and everyone that i know will love.
so within the next 2 months ill have my truck in daily driver condition and ill be starting the tear down on my mx3.
i have fond a lot of little rust spots. and ill have to cut some metal out of my donar mx3. (my formar kl mx3) yea i know i probally shouldnt just ditch my kl. but after 2 years of being a reliable daily driver and race car with great gas milage my kl now has more problems than is worth. its got about $500 worth or body work that needs to be done. it needs a new distributor new rear caliper and now gas tank battery hood and well a huge list of parts. and well ive just decided that its better off as a donar car. ill be pulling the motor and either selling online or to a close friend i helped do a kl swap to his mx3. his motor is a us junkyard motor thats getting tierd with the 8.5:1 compression. mine is a japan import engine with low mileage that has the higher compression. so its a little bit better engine than what hes got right now.
but the donar car is pretty much rust free just not dent free.
so it will be good for patching up my 4cyl.

lol sorry for writing a book about my projects. but were all car guys here i thought u guys might like to read that. so as you all know its about finding what i need then getting it as fast as i can. then when i get it and start putting it together i will start a worklog on my 4cyl.
heres a link to some pics of it. the pics of it grey is when i first finished it when i was 15.
viewtopic.php?f=21&t=74440
the second pics are after i fixed it up after i had to repo it because i sold it at one point.
and the bottom pic is what it looked like when i got it back. minus the red door. that happened afer i got it back. because for a week or so i planed to make it a parts car. and well then i did research on the bp and well yea i brought it back to life as the 88bhp black beast lol. but i do like the way it looks now even though i either got to buy a whole new body kit or build one myself

and like i said im sorry for dragging this out. i busted my lip pretty good the other day and i think these pain killers are makin me write too much.
so ill be done right here lol.

[Nd4SpdSe]

The early Escorts overseas were RWD until 1980. When they came into North America, they were all FWD.

You want to build a 1000bhp BP?

For rear ends, a Ford 9" is really nothing related to Mazda, that's a purely Ford part really. The only tie it would have would be that the Ford Probe (aka Mazda Mx6) was going to replace the Mustang, and the Mustang used a 9". How about looking into Rx-7 rear ends, or maybe seeing if the old 929/MPV will be stout enough for your application if you want to stick to Mazda parts...

[Josh]

SpatialTerror

So is the block you have built a 1.6 or a 1.8? a am assuming its a 1.8 as you want to use a 01 miata head. On average with boosted applications the 01 head will yield up to an extra 50HP. With running HHO and the High comp, I would strongly recommend changing your valves to sodium filled, Stainless.. something that will handle the heat better or you wont have the longevity. while your at it put some stiffer springs in there so you can handle the higher revs as to not float a valve if your going to be racing.

Drive train... If you want to drag and only drag its easy to do a solid rear axle. BUT seeing as what you are going for I would run 2nd gen TurboII rear end and trans. they are some of the strongest parts Mazda has ever made when it comes to the trans and rear end. so If you could source a donor TurboII that would be the best bet. You will want a Full Posi track diff for the rear. this will work the best for drifting and drag racing, but not so much auto X or track racing. it you want it somewhat open for track racing you can get a 2 way LSD and that will work out best for all worlds.

With the TurboII trans you can get bell housing adapters or swap parts from the B2200 or ford currier truck and then it will bolt right up.

All the rear diffs are almost the same when it comes to Mazda through those years. there are some differences when the miata changed in 94 it got just a little bit bigger. I would go with the RX7 parts, they are some of the strongest mazda ever made. check the miata forums there are many guys on there that have adapted them to their miatas.

[SpatialTerror]

now were talkin. yes im building the 1.8l i will take your advice on the valves. i was considering it befor ehand but now that the guys down at my local machine shop told me why there better i will defiantly opt for sodium filled valves. i assume that i will probally have to stick with stock cams on the miata head. sense im sure its custom to the timing gear. atleast for the intake cam. and any good recomendations on valve springs? i already decided on titanium keepers. are there aftermarket lifters available for the 01 miata?

as for trans and rear end that gives me some research to do.
its looking like its gonna be around $500 to get the rear end and trans its gonna be a little while b4 i can go get them on account of i gotta finish my truck first. but thats not too bad of a price to get the parts. im thinking its probally gonna be about $300 in materials to mount it all up over all not too expencive buy to make the car rwd.
i still gotta build it to handle the power the turbo will make it produce. but to just mount it in, re tub it and add some more structure thats not too bad of a price. i still got a big expence in a lsd and i was also thinking of making it a solid rear end with no suspension travel. and make it to where i have the option to switch it to springs just for added versatility. plus i havent done much research into what suspension setups are best for drift so i dont know if this ability for change is even necessary. what ive been told is you want little travel in the suspension a good camber gain and a good lsd for drifting.
and well with a solid axle rear end you have no play and no room for camber adjustment which i dont see mattering much with the right power to weight ratio . but i do see potential problems in not having any play at all in the rear atleast. i figure it would be good to have at least an inch or so of travel. but im no expert on suspension and steering.
so now that i have leads its time to look for aftermarket parts for this setup.
any idea on what the ratings are on the rear end and trans?

and yes i would like to run 1000bhp atleast for like 3 quarter mile runs just to get it on video and see what the fastest possible time i could run is. but after that i would like to stay in the 450 to 650hp area so it last more than 3 races. then i think after proving the car at the quarter mile i will just stay in the bracket racing so i dont have to run it real hard on the strip. you have to remember putting that much traction though a drivetrain is alot of stress on parts. and with those kind of numbers for output you get a good power to weight ratio for the traction and timing on the quarter mile then when i switch over to the drift track for a weekend i could switch out the tires and possibly the suspension and run the same hp and have a good reliable drift car.

i got some new wires for my 1.6l workhorse they were like $17 for 18mm plug wires from napa. there cool lookin and took care of a slight miss it was developing. but now its starting to tick after 250000+ miles and i fear its end is near. oh well as soon as my truck is done my boss is supplying me with a nos kit to supply a huge dry shot to the motor to blow up the good old 1.6l. i figure its a good way to go out after being so reliable for me for so long. i just hope it holds up to that point. and i think it would be fun to make my 88hp 188hp for a little bit.