QuagmireMan

do you guys remember some one saying they are making a FI kit for cheap. I used to goto the website all the times lookin for updates but nothin.... i dont know why that came into my head but it did. i think the website was seriousre.com now i cant remember. someone refresh my mind if you could.

gsl-se addict

iTrader: (3)

Here is the original thread by v8kilr:

https://www.rx7club.com/showthread.p...ght=megasquirt

It looks like that you remembered right on the website. The megasquirt is not hard to build or wire for the most part. The most difficult part for the 12a cars is all the other stuff (manifold, fuel rail, EFI fuel pump, etc.). Hopefully, he will still make a kit so that the 12a cars have an option to easily upgrade to EFI.

QuagmireMan

i forgot to do a search shame on me

Felgar

Have you actually used a megasquirt addict? I'm very curious to gain an understanding of how they work because I want to put one in my car to ditch the AFM. What would be the general process in getting one working? Does anyone sell them pre-configured for the 1st Gen SE's? At this point I have a little more money than time.

2wankel

iTrader: (1)

http://search.ebay.com/megasquirt_W0...ectZ1QQfromZR8

gsl-se addict

iTrader: (3)

Yeah, I have one. I haven't got it really running good or anything on MS yet since I am busy with school (trying to finish my PhD) and my apartment doesn't allow me to work on the car. I taped into the stock sensors and used a multiple pin connector from RadioShack so that I can easily switch between the stock system and the MS. There hasn't been many people that have set one up on an SE, so I am not sure on a real good starting map. There has been several setups on 2nd gens using the 4 injectors in a staged fashion (renns on here has been running one for awhile). My car will currently run on the MS, but not good enough yet to really drive it and tune it. I have considered using a 2nd gen intake with the 4 injectors so that I could use renns map as a good starting point. If you want, you can pm me and we can discuss it further. I would be happy to answer any question you have.

Kent

Felgar

That's great addict, thanks. I had a feeling that getting the mapping down would be tough. Also wondering about what sensors you actually use to control the mapping cuz it's not like the SE has a rotation sensor or even a full-scale TPS.

To complicate issues my injectors are oversized and that's a main reason I want one... So that hopefully with the etxra flow from the removal of the AFM combined with proper fuel delivery I can achieve some pretty impressive power while not running waaayyy rich like I am now. It does seem like I'd probably be a lot better either putting the injectors back to stock or else just reconfiguring the AFM so that the stock CPU comes out with a better fuel mixture in the current setup.

Thanks for the info; I'll PM you if I get a little more serious about the whole MS installation.

gsl-se addict

iTrader: (3)

For stock sensors, you need the TPS, O2 sensor, coolant temp sensor (in water pump housing) and an air temp sensor (I am using the stock one by the BAC). The MS would be perfect with your larger injectors. Renns wrote a code (EasyTherm) that allows you to be able to use the stock sensors with MS. It works nicely.

If you had a good SE base map, the tuning software (MegaTune) will allow you to just scale the whole table to account for your larger injectors. I do think the combination of a 2nd gen intake, with the MS, and the lack of the AFM, could produce a substaintial increase in power. One of the great things about MS is that it has a flood clear mode (hold down accelerator while cranking) this turns off the injectors, so no need to be pulling fuses or installing a fuel cutoff switch for those times when the engine gets flooded.

You can get away with the stock TPS not being full range. The TPS is used to determine:
- open or closed loop operation (use o2 sensor feedback or not)
-acceleration enrichment (extra shot of fuel during acceleration to keep for hesitating)
- flood clear mode (determines if accelerator is depressed while cranking

Since the stock TPS is not full range, you can either change the set point where it switches between closed loop and open loop or you can install the MapDot code (uses changes in manifold pressure to determine acceleration enrichment and can be modified to use manifold pressure to determine open/closed loop operation). With the MapDot code, you don't need the TPS, but you will loose the flood clear mode without it.

Kent

Felgar

I already have a fuel-cutoff switch where the choke goes on the 12A's, so I'm ok from that point of view. Probably MapDot would be the way to go. That would require the installation of an intake manifold pressure sensor though, eh?

gsl-se addict

iTrader: (3)

Well, the MS already uses a manifold pressure sensor. It is how it figures fueling requirements (manifold pressure and RPM, also known as Speed-Density). The MS comes with a manifold pressure sensor that you mount to the circuit board. You just connect a tube from the sensor to a manifold vacuum source on the manifold.

The MapDot code just uses this information in place of the TPS because many older cars have a throttle switch instead of a TPS or they have a TPS that is not full range (like ours) and is a good alternative than trying to adapt a full range TPS to the throttle body. The MapDot code has been shown not to work well in turbo applications though.

Felgar

Ooohhh, ok - I get it.

I'm definately in over my head which is one reason why I've resisted taking the plunge so far.

Thanks again for your insight.

Jeff20B

iTrader: (13)

I've got it easy. I already have a dizzy modded for my 20B that was going to be used in conjunction with a carb. I scrapped the carb idea and decided to go with a MegaSquirt. The injectors are high impedance, the TPS is full range, the engine parts already have temp sensors in them etc. I'll keep using the dizzy untill I can figure out a way to get the type of ignition I want out of the MegaSquirt. The current option on my engine is to use a Ford EDIS 6 (renns suggests an EDIS 4 for 12As and 13Bs, but I have my reservations on EDIS in general). I'm staying away from it for now due to the lack of a late leading spark (DLIDFIS and most every other direct fire ignition system on a 12A or 13B has late leading sparks which cause both leading plugs to spark together every 180° of eccentric shaft rotation; trailing is kept stock through the cap and rotor or is not used at all).

For now, I'm going to run the dizzy with MegaSquirt on a code that I modded a little to bring back fast idle functionality (renns and others have modified it for EDIS output as well for staged injection etc). I may experiment with the EDIS stuff just to educate myself about how to control ignition with the MegaSquirt. Then I'll use a newer code that allows for all sorts of variations and mod it to run three seperate ignition channels; one for each leading ignitor. It would produce the sparks of an even-fire V12 condensed down to 3 spark plugs. In other words, the MegaSquirt would take over for my modded dizzy and output the late leading sparks that we all love so much on our 1st gen and older rotaries. If it's good for 2 rotor engines, how do you think it'll run on a 20B? I bet it'll change the sound of the engine like it does the 2 rotors. I'll be the first one to find out (the first 20B MS user at least). Infact, I already test fired it earlier this year with a makeshift carb setup and it sounded like it had more ignition events than what I've heard on sound clips downloaded from the 'net and stuff (the open header allowed me to easily hear the action hehe). When it's running better, I'll make some new recordings.

jayroc

I did a MS conversion early this year before I came to Japan, but I didn't get it roadworthy before I had to leave.
Doing it on an SE would be worlds simpler I would think, since you already got a fuel system, several sensors and, of course, injectors. I did it to a GSL and had to fab lots of stuff.
What I did was have a friend fab a custom manifold, then I used an IDF style throttle body with injector bungs. For the IAT, I mounted it inside the throttlebody, for the CLT, I tapped the choke temp sensor bung behind the water pump for 3/8s NPT and installed a GM sensor. I used 2 low impedence 2nd gen injectors, the fuel pump was from a Ford F150, and the regulator was off of a vg30 nissan motor.. TPS is full range aftermarket unit.. (I'm sure I am forgetting something..)
The only hangup was the fuel rail. The injectors I had didn't fit the rail that came with the TB, so I was kinda screwed. I will have to fab a new one up somehow when I get back...
I did get it started, but a friend of mine had to hold the fuel rail down to keep fuel from spraying around...
Anyways, it is a fun project if you have the time and extra cash. I think I got around $800 in parts and stuff.. Maybe a little less. The good thing is, all the stuff I bought can be easily ported to just about any other motor. MS is very adaptable.
I still think it's really cool to hook up the laptop and see all the sensors monitoring your motor.

Felgar

Seems like if I can my 4th gen vette for this summer I'll have a good summer project on my hands for the RX.

79+80+84_rx-7

dave owns the site... v8kilr is his handle on here...