1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

12a engine management

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Old Nov 25, 2004 | 11:34 PM
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12a engine management

first id like to say that this thread is for any 12a owners who are sick of carbs, and or want boost..

i have a 83 rx7 with a mazda spec rebuilt 12a, that i put in about 3 months ago, along with it i installed headers /full exhoust, and mikuni 44 carbs i was generally unimpressed with the performance, although i had great power through 5+ rpm, it wasnt enough, and it lacked drivability.

my question is what is the best aftermarket computor system for the money in terms of 12a power, drivability, and use with a single turbo,

i have heard good things about haltech, but am turned off by the problems they have been having, any input on peoples success in finding a good dealor, and thier personal experience would be greatly appreciated


I am not mocking the carb setups, but i personally would rather spend some money and get a reliable setup,
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Old Nov 25, 2004 | 11:51 PM
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lack of performance

Is this a stock motor, no porting done? rx7doctor
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Old Nov 25, 2004 | 11:55 PM
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If you don't mind keeping a dizzy, check out megasquirt


(although I believe they will have ignition control offered in the future if not already)
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Old Nov 26, 2004 | 12:28 AM
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yes the engine is bone stock other than fresh( 5000k) rebuild,, i will look into anything half descent, with or without ignition controll
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Old Nov 26, 2004 | 12:29 AM
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i was also wondering about prices where i might find such units, .... whats a dizzy gsracer???
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Old Nov 26, 2004 | 12:38 AM
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dizzy--distributor
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Old Nov 26, 2004 | 12:56 AM
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mods

If you are running twin 44phh's you are over carb'd. You should be running a single
44phh. I have run that system on many 12a's, driveability was excellent, throttle
response outstanding, easily do a 130mph plus with it. When i kept my foot off of it on the freeway i got around 23-25 mpg on the highway and around 17mpg in the city. I was running rb header system complete, jabobs coils, ngk wires, 205/50/13 tires and a lightened steel flywheel. Ran a carter hp fuel pump set at 3.5 psi. Too much fuel, not enough air with twin carbs on a stock motor. Rethink your carb situation and you will see the results you are looking for. rx7doctor
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Old Nov 26, 2004 | 01:09 AM
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I've got a MegaSquirt and am currently keeping the dizzy. It's on the back-burner for now because I have other more pressing matters to attend first.
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Old Nov 26, 2004 | 01:16 AM
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Go to a single phh44 and build up a blow-thru turbo system with it. The mikuni's are one of the best carbs to turbo with!
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Old Nov 26, 2004 | 07:01 AM
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The megasquirt is the way to go if you are at all handy, and it keeps getting better, with megas spark, and now megadash.
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Old Nov 26, 2004 | 07:34 AM
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you can get the same amount of power out of a carb compared to FI.

i am running a single 44 phh mikuni now. its fun fun. but yes. it does need a little boost! PSSHHHHHH
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Old Nov 26, 2004 | 07:50 AM
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If you have the money Haltech, if not go with Megasquirt. And remember this isnt going to be a slap it right on thing your going to need to make a few custom things $$$
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Old Nov 26, 2004 | 11:41 PM
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ive got single 44s, sorry bout the confusion, by carbs i meant that it has two throttle bodies, but it is a single carb, i am running the stock fuel pump, the carb iether needs to be tuned a great deal or might need to be rebuilt,
so you think i should blow through setup on it?, what all do i need to do, besides reworking the carb, and how reliable/ what kind of hp are we talking about, safely of course. ???
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Old Nov 26, 2004 | 11:57 PM
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for anyone with electronic engine managment, can you give me a clue as to how much i can look to pay for one of these units megasquirt or haltech or whatever.(canadian) i still like the fi idea, i want to be able to tune it from inside the car,

can i pass emmisions with haltech or megasquirt or is this obsurd?

what are the benafits of the electronic engine management? someone convinse me of something
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Old Nov 27, 2004 | 12:05 AM
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I have a Megasquirt that I am in the process of building. It cost me $140 in parts. I am still going to use the distributer. If you don't want to build one yourself, you can get them on eBay for $325. It is programmable through a laptop.

As long as your porting isn't obscenely huge, you have a cat, and an air pump blowing into it, you can tune damn near anything good enough to make it pass emissions. You must have both the airpump and the cat though.
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Old Nov 27, 2004 | 12:08 AM
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Originally Posted by autopaul
ive got single 44s, sorry bout the confusion, by carbs i meant that it has two throttle bodies, but it is a single carb, i am running the stock fuel pump, the carb iether needs to be tuned a great deal or might need to be rebuilt,
so you think i should blow through setup on it?, what all do i need to do, besides reworking the carb, and how reliable/ what kind of hp are we talking about, safely of course. ???

If you're still running the stock fuel pump with a 44phh you need to swap that piece out of there. You're most likely starving for fuel in the higher rpm range!

As far as setting up for a blow-thru, get this book:

http://www.amazon.com/exec/obidos/AS...440888-4230534
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Old Nov 27, 2004 | 12:31 AM
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325 is cheap what does that include, about how much is it new, can that controll boost, and is there better options over the stock ignition?


how do i make a megasquirt i am interested and my brother is more than competent at electronics, ?
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Old Nov 27, 2004 | 12:35 AM
  #18  
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yea its true, you can tell when the float bowl is empty, and have to coast while it fills up.


just at the mall and some b@#$@$tch hit my baby (rx7) already in the process of being a write off , looking for a good gsl se body bad motor in b.c. if anyone knows about one...
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Old Nov 27, 2004 | 12:51 AM
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Originally Posted by autopaul
just at the mall and some b@#$@$tch hit my baby (rx7) already in the process of being a write off , looking for a good gsl se body bad motor in b.c. if anyone knows about one...
Damn, that sucks!
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Old Nov 27, 2004 | 01:07 AM
  #20  
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i dont want this to get off topic though, the goal is to find; best bang for the buck on engine management (12a), especially prices, and wether or not it controlls ignition, thanks.
oh and wether or not it can "compute" boost.
so far its haltech vs megasquirt vs carb... still know nothing about haltech or megasquirt
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Old Nov 27, 2004 | 01:49 AM
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not trying to dissuade you in the least from EFI, but you may want to check THIS out ...
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Old Nov 27, 2004 | 02:21 AM
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like alienrx7 recomende id get maxium boost and read it b4 you started in on this kind of thing it will give you an idea of what you getting into with a project this size
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Old Nov 27, 2004 | 02:32 AM
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My advice is to get a programmable fuel injection system and then install it on a non forced induction car first. Learn how to tune it properly. Your margin of error is much greater this way. Actually this is true of a carb setup too. Once you've mastered this, then add the forced induction. Learning how to tune combined with boost equals a potentially bad day and an engine swap in the near future. Here is some info for Megasquirt. Unlike the Haltech, their support group isn't as big. Alot of people have a Haltech and can help you easily if you get in a jam.

http://www.bgsoflex.com/megasquirt.html
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Old Nov 27, 2004 | 12:32 PM
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I would recomend a microtech Mt4 with stock ignition or Ltx 8 with a cas from and fc.
You can modify your intake manifold to accept a throttle body form gsl-se and add 4 injector
bun. You can use a bosch fuel pump and bosch boost sensative regulator. Its more expensive but It will be set up for future improvements (bigger turbo, porting ect ect.)
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Old Nov 28, 2004 | 06:27 PM
  #25  
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thanks for your help i think im leaning towards a megasquirt, not only do i love the catchy name, but its cheap, and i dont mind making it myself, im just so distraut that i never heard of it before, someone in marketing needs to get the word out for more cheap dutch people like me, thats cheaper than a mikuni on ebay... just dont know if im ordering the whole kit yet... thanks evertyone
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