I have heard that a 2nd gen upper intake manifold will bolt up to a Dellorto lower intake manifold for a 12a. Does anyone know if this is true? I have already contacted RB to see if this is true before I start laying down $. They said the intake ports line up but the bolt pattern is different. They also said that Mazdatrix has an adapter that would make the bolt pattern fit. I called Mazdatrix and they acted like they didnt understand what I was talking about, but said it sounded like a good idea? Niether one of the people I talked to acted like they new the difference betweeen a pissed-on and a rotor?

12a to 2nd gen EFI swap? anyone know anything about this subject?

 

IIRC the 13b injectors are mounted in the center plate

 

You'd just need to run an aftermarket ECU and large injectors in the manifold location.

 

Hey bud, I think the best thing for your buck would to get the IDA style throttle body they make, and it bolts to the IDA manifold. You need a few things to get it running and thats it, take it to a dyno and get it tunned. It is a very good idea and I'm in the mist of getting it. I'm choosing the Mega-squirt CPU. Mind me, but I have to re-locate all the stuff I need again, because I put it all to the side when I got laid off, but I'm back to work again now. I'll do some searching.
Here is a link that I remember off my head
www.injectionperfection.com

Hope I help a little, and mabye we'll be helping each other out soon.
Later

 

The IDA throttle body won't make the torque that a stock intake manifold will. Driveability will be better with the longer runners and a real manifold.

 

if you are staying N/A then i wouldnt worry about that in the first place.

 

So your saying no matter how you tune it, no matter what, it'll have bad torque? I'm quite new to the IDA style type, but really want FI and that looks the best way to me.

 

Well, I think it'll create nothing but problems if you go with the stock manifold design. But they are right, if you are staying NA, I wouldn't worry about which you use because torque is going to suck either way.

I would personally go with the Weber style throttle body and intake manifold. Its easyer to set up and probably will make better power in the end.

 

I've got no experience with a FI 12a but I can tell you what I've experienced with my 13b and why it works the way it does.

On the same 6 port 13b, I've had both a Weber 48 IDA and the stock FI manifold from a '91. Aside from drivability issues with the big Weber, the low end torque from the stock manifold is significatly better.

The lower end torque comes from air momentum created by long intake runners. Top end power suffers a bit due to higher intake restriction but the dynamic effect manifold makes up for some of that.

An IDA intake has very short, large runners, the engine breathes well at high speeds, but it can't force extra air into the intake port at lower speeds as it opens the way the stock intake can.

It's all up to what you are looking for. Like FBII says, the 12a is no low end monster, but I'd bet that torque would be better with an S4 or S5 intake than it is with the carburetor. At the same time, the IDA intake will make a real top end screamer which can be a lot of fun as well.

 

If you want torque, get a turbo. The cost of a IDA throttle body and a decent EFI setup would rival the cost of a blow-through turbo setup...And the power would be MUCH more pleasing...

Good luck

 

So, basically, no one knows if the 12a Dellorto lower intake manifold will bolt up to the 2nd gen upper intake manifold? And I know the lower intake needs to be tapped for the injectors.

And if I could afford $1000 for webers I wouldnt have posted this thread!

(off the subject) No one who has a rotary is looking for low end grunt, it is all about the screaming top end power ! ! ! ! ! ! ! !

Just like no one with a deisel is looking for screaming top end performance!

 

I think anyone looking for low end torque starts with a 13b.

 

I DONT WANT LOW END TORQUE ! ! ! If I wanted low end torque I would drive a truck!

I want an ear peircing 8000-9000 rpm screaming rotary that can be well tuned easily with ALL the power past 3500 rpm's. Also cost effective ! ! !

That is why Iam looking into a complete EFI system I can get out of a junk yard for $150 and mate it to the Dellorto lower intake that cost $170. Which the complete system would cost under $400, but no one seems to know much about anything Iam talking about so Iam assumeing It cant be done cheaply?

 

Don't you want SOME low end torque? You can't drive around at 5000 rpm all the time.

You won't be able to do it with the stock ECU. It's built for a larger engine with different port timing and two more injectors very close to the intake ports. So you're at least looking at a stand alone.

 

It just won't happen for $400! $400 MIGHT cover the costs for parts (upper S4 intake, delorto lower intake, injectors, ECU, oxygen sensor, there are more). Then you need someone to tune it for the 12A, so thats easily another $400. So no, it can't be done cheaply. I would much rather go out and get the Weber style throttle body for $1000. You would get MUCH more power out of that.

 

I think you might be pioneering new teritory here my freind, I say go for is and let us know how it works.

If racing beat told you that the intake ports line up then as you said, it stands to reason that all you have to do is tap the manifolds to connect them.

I don't think the 2G EFI is particularly easy to tune though.

haven't seen many posts from you latley, welcome back

--Alex

 

12at engines were efi....

i can get my hands on heaps of 12a efi parts

 

double post

 

I have a complete fi for you, you'll have to do the tuning though, pm'ed you.

 

Alex-7: I have been busy and my home comp has died hopefully for a short period of time? The tapping of the manifold sounds good on paper, but what if their is no manifold where it should bolt too?

High-rpm: You are in Aus. and Iam on the other side of the world. The shipping alone would cost more than a Sterling prepped carb. Talk prices, maybe I dont know what Iam talking about?

 

you're right
im just stating that if you really wanna waste your money, we can work somehting out

 

813KR$ : Good idea!

I`am allso thinking of going EFI on my 12A.It will be a standalone system,using T2 injectors.

I think the diffrence that it will make will be good,and worthwhile.I`am just not up for changing jets anymore.

Karis