I've got a 12A Rotary installed into a 63 MG Midget that I autocross. There isn't much midget left, as I fit a narrowed 2nd Gen rear end and front spindles to the car, fiberglass fenders, slicks, asphalt sprint car shocks, and more. I've has so much trouble with tuning the carb for the G's I pull while cornering I've decided to go turbo and add a megasquirt EFI. I've gathered 4 450cc DSM injectors, a Garett T4 and all the flanges and U bends to make my own manifold. I'm down to a few things I need to buy and some ?'s

A. What's a good external wastegate to run on the rotary that isn't too expensive?I despise XS autocrap I'd like to buy from someone else. Will the diaphram take the heat of the rotary?

B. Are my injectors going to flow enough fuel for 10lbs of boost on a stock 12A?

C. What kind of power can I expect? This car only weighs 1300lbs I'm only after about 200-250HP

If you want to see I will add some pics soon.

 

i would run a turbonetics delegate mark II gate, i had one on my old 12 a t-04 turbo and it worked fine

 

wow, a rotary in a mg midget?...that sounds awesome!

definately post some pics when you get a chance i'd love to see that!...

nick

 

Jeebus, what does that car weigh? 500 KG?

 

1 300 pounds = 589.670081 kilograms

From Google.com

 

I bet that **** is fast! No wonder the carb cuts out on you during cornering!

 

12A Stock Port? I dont think you'll make 250HP. Or even 200HP for that matter.

 

put a turbo on it you will

 

Pics!!!

 

the fuel injectors are way to small.
a stock se 13b uses 2 680cc injectors
try running 4 of those.

a turbo II motor uses 4 550cc injectors
the 4 550cc injectors max out at around 250 flywheel hp

i run a turbonetics evo gate. cost around 200 bucks.
also cbperformance.com sells a waste gate they use on vw bugs that will work well. its allso a great priced part.

the weight of your car will make 250hp EXTREEMLY fast.
we are talking awd 911 turbo fast.

 

Here's some pics...

 

OMG i would be terrified to have 250 hp turbo engine in that little go cart!!

 

It goes good with the 140HP it has now, but as you know it's never enough. It's fine in the tight courses but at our big street event I found myself waiting for the engine to rev and ended up losing to a turbo miata(17 PSI) by about a second on a 1-1/2 minute course. I thought maybe I was just driving bad but a freind had videotaped both our cars and everytime the Miata hit a straight it would pull alot harder-just more power.

 

Look at that! The cones are as tall as the hood on the friggin car! 250 HP would get you killed EASY!

 

I was just looking at some of the sites about injectors. Looks like I need some pigs like 800cc x 4 or something. That kind of fuel consuption is crazy. This thing is gonna be like gallons per mile! I've got a pair of 680's from the GSL-SE here somewhere maybe I can find 2 more. Either that or use 8 of the DSM injectors, but that would be a pain in the fuel rail dept.

 

Nah won't get me killed. You'd be amazed how well such a light car grips and handles with alot of power. It's pretty little it's 52" wide and 10'8" long. As for the injector thing I could also bump the fuel pressure up and run the 450's? The pump I'm planing to run is a ford truck EFI external pump good for 85 PSI.

 

Well, it probably wouldn't get an experienced driver killed, but I know that if just anyone [like me] jumped in it, chances are, bleeding would somehow be involved.

 

On street tires I would be scared of it too, but with 9" goodyear slicks it feels good.

 

seriously i wouldnt go turbo on that car...ever think about bridgeporting and webers? that thing will dominate with a setup like that, blowing turbo miatas doors off.

 

yeah I'd actually be happy with a streetport and EFI, but the engine isn't that old it was rebuilt in 2001 was in a street car for 3000 miles getting broken in, then got autocrossed 4-6 times a year. It's probably only got maybe 15,000 miles on it. Hard miles but it'd be a shame to take it apart just to port it. Not only that but I'm after some more low end torque, and I think the turbo will provide that. Our autocross's are pretty tight and quick cars tend to get the fast times. I tried webers but was dissapointed with the lack of tuning parts and cost of what little is out there. EFI is going in regardless, but the turbo thing I'm still questioning I don't want to make it unreliable. I did win our clubs A-mod class championship with the car by being flawlessly reliable and fast. 398.7 points out of 400 possible.

 

EFI is the way to go with what you want...good luck

 

250 Flywheel HP or 250 Wheel hp??

for 250 flywheel you can get away with 4 550cc injectors for a TII engine.
In fact i will have an extra set of them in about a month if you want them.

for 250+ whp I use 550 primarys and 1600cc 2ndary injectors in my car.


someone mentioned porting. Big ports and autox are not good whoever said that.
autox needs a WIDE powerband.

I think his idea of going turbo for a little extra torq and hp is the best option.
I wouldnt expect 250whp out of your 12a though.
i would say 200whp is closer to reality.

 

That's about all I feel I need, around 250 at the flywheel would be plenty for a 1300# car. I'd just like to run around 7-8 psi and install a top mount IC and hood scoop maybe with a water spray rail on it if I need it.

 

I got 2 more 680cc injectors from a forum member thanks for those. I'll be good for almost 3 liters of fuel gobblage per minute now Now I'm sniping on ebay for my megasquirt system. I'm looking for about 180-200whp by the way, It won't be that hard on things like the tranny and the stock motor that way, and I'm also a big believer in making only as much power as you can lay down. The next engine I'm planning a mild intake port and street port style exhaust port to help get the heat out of the engine. Probably the worst part of the whole project is that the motor has to come out to install the turbo oil drain because I can't get the oil pan off with it in the car. My favorite thing is that I got about $3500 into this car. Lots of junkyard parts, a free 2nd gen RX-7, and a $400 Midget chassis. Most of the money went into the wheels/tires guages and fiberglass flared fenders. Feels great to take the trophy away from the guys with $30-$50k into their cars

 

WOW!!! A shoebox on wheels. I likey very much.

Have you concidered adapting an S4 TII intake and turbo system to the 12a. A few of the members have done it here, parts are reasonable and should be do-able. I don't know how much room you have in the engine bay, but it might be your simplest option.

You would need to custom make adapter flanges for the intake and exhaust. The rest could be plug and play with the S4 ecu and the R-Tek chip for the 720 cc secondary injectors, 550 cc primary. FMIC would be the best way to go with that, even if it was the stock one with water spray.

Please post pics of the engine bay.