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20V 4AGE,,,,, begun

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Ok so the 4AGE install is making progress, slow, but progress IS there.

The car is most likely going to break stuff so I am wondering if any of you has a detailed account of what is involved getting this RX7 rear end into the car with trailing links a panard bar and coil overs in back?

Obviously a "kit" would be deluxe but haven't been able to find anything.

Frontline front suspension looks great but is god awful expensive for seemingly what you get. Any other ideas?
 
I dont belive your going to find anything in a kit but if you look aroiund the web a bit you'll see a few conversions that have been done. Most I belive include cutting threw the rear floor arear to make room for coil overs. The front spring perch area can be adapted to accept some type of trilaering arm or 4 link setup.
 
Here you go (an RX7 shortened disk brake rear in a Spridget):

https://the-mite.com/mite22.htm

I think the author of this page is a member here at BCF...he may chime in.
 
Jay-
I put an RX rear in my sprite and did a little documentation of the process on the link above that Nial posted. It works well, is strong and small(ish) for a rear axle. Moser cut and shortened the axles, and I narrowed the housing. 3 things come to mind:
1. To center the input (pinion) you'll need to shorten the axle different amounts on each side. I did not and my my driveshaft exits the tunnel quite close to one side, not in the center.
2. I think Moser will do the whole job: axles, housing and brackets. You'll need to call to make sure
3. I don't think the Mazda calipers will interfere with a coilover setup, nor with a 1/4 elliptic setup. This should simplify the parking brake setup.

~Bob
p.s. 140 HP in a Sprite is FUN! https://youtube.com/watch?v=l3yZtayy_DU
 
That REALLY is making me re-think my entire goal with the car! Man, that looks like fun.

Maybe a turbo/SC on the 1275 is in order after all!
 
Oh my goodness gracious me. Now that's the way they should have come from the factory. Good on ya.
 
Thanks for the link to Bobs site guys. I will try to find a shop in Denver that car do this for me as I don't weld.

Branson, are you going to have the rotary Sprite running in time for the lake gathering.

I hope to see at least one of the Suzuki G13b powered cars there too so we can all exchange notes and Ideas.

Anyone know how much a Spridget weighs with no engine or transmission in place?
 
Don't laugh, but Hyundai make a great little 1.8 and 2.0 that puts out 130/140 hp repectivly w/ 10.3/1 compression stock. They are plentiful and CHEAP !!!! I built an '01 Tiburon(2.0)into a Stinger dirt track car and it is currently undefeated. Honda, Acura, VTEC whatever, Altima, it doesn't matter. It SMOKES EVERYTHING, including cars that have been modded and are illegal. I've got two extra 1.8's here and have been tring to thing what cheap tranny I could addapt to it. Opperative word here is cheap. Allot of drifters use the Corrolla package and prices are high. Besides, it's soo much more fun smoking folks with a Hyundai !!!!!! I just need to figure out what to put behind it.
 
unfortunately I wont have the car done in time to go to missouri. My build has hit a snag as we have sold our house and are in the middle of a move. I have started test fitting the motor and mocking up motor mounts. I hope to get the mounts nailed down in the next few days and get my two motors sent off to be rebuilt and ported. In the meantime I will start the wiring, plumbing, and get the RX7 rear end narrowed. Id like to get it running and sorted before winter so I can work on the interior and finishing details while the weather turns cold..
 
Well YEAH!

If I paint my motor green at least it has pistons in it...

Whereas yours has those magical spinny things flying around in a trichoid-ish pattern. What are you going to do about a muffler? I used to Marshal corners for the 100 Acre Wood Rally in Missouri,,,, at three in the morning a rotary (Rod Millen) coming up a hill sideways at 10 grand sounds like its going to make all the bark on every tree spontaneously combust.
 
At high RPMs rotarys CAN breathe fire!

Im removing the original fuel tank and putting a 10-12 gal fuel cell in the trunk (between it and the battery I will have no trunk)This will open the entire rear area for the exhaust system. I am thinking about running a racing beat pre-silencer and a muffler. I may wrap the exhaust header and pipe up to the pre-silencer to deaden some of the noise. I have already applied bedliner to the tub and will add some dynamat or the like to it before I put down the carpet and interior panels to help quiet things a bit more.

I think the exhaust is going to be a bit restrictive but with my engine builder saying he can easily make a reliable 185-200hp out of the bridgeported 12a I think I have some room to loose a few ponies.
 
Hi:

I'm a first time poster ( Intro here )debating putting either a Miata engine or a 5-valve in my Midget. I don't want to make this any more difficult than it needs to be.

On your 5-valve install, it doesn't seem like you had to cut the transmission tunnel. Is this true? If so, that may very well be the deciding facor.

Any help is appreciated.

--Cheers, Chris
 
Well I'd love to tell you no cutting is needed but the truth is that although nothing on top needs to be cut, and therefore looks stock inside the car, the center of the cross member does have to be cut because the T-50 is lower further back than say the original trans or the datsun 210 trans. So once you cut or notch that cross member you obviously need to replace that strength. Some folks weld a cross member under the floor side to side. We put mine inside the car butted up behind the original running from side to side after notching both sides on the tunnel. Don't really car if the seats could go further forward than half way because if you need to adjust the seats all the way forward in a midget,,,,,,,,, well,,,,,,

The early 4AGE, 16v, has the distributor forward on the motor drive off the front of the ex cam where as the silver top motor has it running off the back off the ex cam so since I was planning on moving the battery to the trunk anyway, yup, cut that whole shelf out too. No heater but planning on doing a small marine type on the inside of the car, and actually there is plenty of room. battery is now a smallish gell in the forward part of passenger footwell, computer is directly above it inside the car mounted onto the removable panel blank for RHD pedalset.

Will post more pictures within a week or so.

So if i made template for where to cut and made a couple sets of the new mounts modeled after mine,,,, would there be any interest in a 4AGE "kit" ?

jay
 
Now a kit would be interesting! I thought about creating a kit for the 12a swap since there is no cutting on the car but I figure as time goes on there will be fewer 12a and 13b engines to go around which would limit the popularity of a kit. Not to mention the fear that people have of rotary engines
 
Yeah what the heck, I am going to build five sets and see if there is interest. A quick experiment that wont cost me that much if it falls flat.

Branson, 12As are litering my nearby junkyard, and how much does racing beat get for a refurbished one?
 
most of the rebuilt 12a's that I have seen go for $1,800.00 + if you want it ported then you are looking $2200 - for a street port to upwards of $3000.00 for a bridgeport.

I pulled the entire drivetrain from an '84 RX7 GSL, nets me a 12a, 5spd transmission and a rear axle with disc brakes and a LSD. That set me back $350.00 I picked up a spare 12a for another $100.00. I have a buddy here in OKC that rotaries and rx7's are his thing so he is rebuilding my engine and bridgeporting it for $100.00 + his cost for parts.

If you go with the 12a swap, its pretty easy. the motor has a steel plate that mounts to the front cover and then has tabs that mount to the frame rails using donut style isolators. the transmission mount hits the crossmember of the spridget almost perfectly. If you use the tailshaft housing and shifter from a mazda b2000 pickup, the shifter location is almost smack dab in the middle of the hole in the transmission tunnel.

so you need to fabricate a steel plate for the front mount, get a set of rubber or polyurethane isolation mounts for the engine, either drill 2 new holes in the spridget crossmember or fabricate an adapter to mount to the original holes to mount the transmission, shorten a drive shaft, narrow the rx7 rearend and have the axles drilled for the 4 on 4 lug pattern, and thats about it. with the 12a I dont think you have to remove the heater shelf either. Mine was already removed by the previous owner.

Once I get mine sorted I will post pictures and even templates of the mounts that I used which would make the swap a bolt in type of job. I will have done no cutting on the car. worst case scenario I will have only drilled a couple of new holes.
 
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