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-   -   Easiest Way To Dich Afm (https://www.nopistons.com/2nd-generation-specific-17/easiest-way-dich-afm-41137/)

threcixty 06-27-2004 01:42 PM

87GXL, 91 SP Engine, RB Headers/Exhaust, Very free flowing engine. Problem is this.. My accel at about half throttle is very similar to when it is floored. This leads me to believe that the AFM is the weak link now. I want to change to either a hotwire MAF or something like speed density control, or just about anything that is better then the flapper door. Would a SAFC do this for me?? Other then just going Haltech, what are my options?? Is WolfEMS still around?? I just dynoed 182rwhp at 7000 at a local car show thingy, so Im on the right track, but this thing HAS to be capable of more then this!!.. Thanks!

ColinRX7 06-27-2004 03:33 PM

Alot of people say go microtec or haltec, but I wouldn't mind voicing the route I took:



GSL-SE distributor setup +

http://www.bgsoflex.com/megasquirt.html



This controller will operate with bare necessities, and it's fully customizeable.



I just run a coolant sensor, air temp sensor, and oxygen sensor for tuning. There's a built in MAP sensor in the controller that you just run a vacuum line too. NO AFMs or other bullshit sensors.



Very tiny wiring harness.



Dirt cheap and more options than some of microtecs lineup. If you know assembly language (this product is open source), the possibilities are endless. The catch is you have to solder it yourself, or know someone who can. It's not an impossible task to solder it together, don't be too afraid.

MPM 06-27-2004 04:35 PM

Colins version is a good way to go if you on a budget. You can buy assembled megasquirts on Ebay for $275. I don't mind the wiring harness but I'm uncomfortable with building the board. Otherwise stick with a haltech or microtech. Check for any local tuners and see what they recommend.



Also, there might be some HP from exhaust mods such as a long primary header instead of the short primary type you get with the standard RB header. Bad part is you really have to dyno tune each setup only to find out your porting combination works best with what you already have.

threcixty 06-28-2004 05:28 PM

Thanks, guys! I will definately have to check out the megasquirt setup. I heard of it back in my Starion days, and it seems like a fun project to undertake. Back to the original question, does Wolf EMS still exist?? I cant find anything on the net about them. Thanks again!

1Revvin7 06-28-2004 06:24 PM

Did I mention how much I love my haltech? https://www.nopistons.com/forums/pub...#>/biggrin.png



Oh and nice signature ColinRx-7





Those are some good n/a dyno numbers!

threcixty 06-28-2004 08:16 PM

Ok, here is a dumb one.. What about "porting" the stock AFM? Yes, I am bored with way too much time on my hands! What I mean is leaving the rectangular hole the same size, but beveling the inlet and outlet a little to create a venturi of sorts. I'm just interested in what a stock EFI is capable of. The Megasquirt looks awesome, and it may be the next step, but it looks like you can't really run a primary/secondary injector setup with it. I guess the GSL-SE only uses 2 injectors, so it would probably work just fine, but I would like to hear from someone that put a megasquirt on a worked over 2nd gen. Something to think about though.



P.S. Not that it matters, but how can I become more then a F.N.G?? https://www.nopistons.com/forums/pub...>/rolleyes.gif

mazdaspeed7 06-28-2004 08:22 PM


Originally Posted by threcixty' date='Jun 28 2004, 09:16 PM
but it looks like you can't really run a primary/secondary injector setup with it.

You need to read more, Im runnign staged injectors with a megasquirt. If you want to see my mod list, click for the sale link in my sig. And ask anything you want after that.



edit: You cant port the s5 afm, it will throw off the readings. I havent looked in a long time, but there may be some areas in the s4 afm you can port, but Id have to ask why. The hp gains are very unlikely to justify the work.

threcixty 06-29-2004 05:39 PM

My car is running the S4 EFI at the moment. Probably won't get around to screwing with it unless someone else has done it with some kind of success. How is the driveablity with the Megasquirt?? Kinda seems like the way to go for the price they are asking. Thanks again for all the help!

mazdaspeed7 06-29-2004 06:17 PM


Originally Posted by threcixty' date='Jun 29 2004, 06:39 PM
My car is running the S4 EFI at the moment. Probably won't get around to screwing with it unless someone else has done it with some kind of success. How is the driveablity with the Megasquirt?? Kinda seems like the way to go for the price they are asking. Thanks again for all the help!

The stock ecu cant even compare. My engine is a tuning nightmare, and it runs very well. It runs well enough I have no complaints driving it 70 miles a day, a good portion of it in traffic. I could get a closer to stock car to run like a honda.

threcixty 06-29-2004 06:48 PM


I could get a closer to stock car to run like a honda.
U sure that is such a good thing?? j/k https://www.nopistons.com/forums/pub...R#>/tongue.png

threcixty 06-29-2004 06:59 PM

Mazdaspeed7.. I looked at what you have done to your car, and it is suprisingly similar to my own. The only differences seem to be that you run the Turbo drivetrain, which I really should have done.. My S5 n/a tranny sucks, and Im sure it is only a matter of time before it scatters itself at a busy intersection.. Just wondering.. what do you think about taking out the exhaust sleeves?? I ported the divider out of mine, and then enlarged the sleeve itself about 1/16" all around, but was left with the ugly air injection gap. I welded it closed and then ported it back to smooth, but it would have been about 10 hours and $75 worth of carbide bits less to pull the sleeve out. I just never thought of it. As for intake, I know a bridge is the way to go, less a Pport, but a street port does seem to come close for everyday driving. Anyways, I like what you have done, and you sold me on the Megasquirt. Ill let ya know how it goes when I get it together! Thanks again for the help!

mazdaspeed7 06-29-2004 07:20 PM


Originally Posted by threcixty' date='Jun 29 2004, 07:48 PM
U sure that is such a good thing?? j/k https://www.nopistons.com/forums/pub...R#>/tongue.png

I never said fast as a honda. Hondas are known for their incredible tuning. You cant drive a honda in any way that upsets the stock ecu with a relatively stock car. My goal was my friends S2000 in driving manners, redline, power, etc. Ive surpassed the redline, right there with power, but quite simply, Id need a much more advanced EMS to make my drivability as good as the S2000. My car still drives better than most new cars Ive driven, though. I have a few little drivability quirks, like my car is sensative to shifts, but in all honesty, its no worse than the WRX/STi, and barely worse than the S2000. It took a little getting used to for me to be able to shift all of those cars smoothly. Oh, and my low end stomps the S2000, despite the stupid tall gears I have compared to the S2000.



I used to be all about removing the sleeves, but Ive realized something since. It makes the exhaust much louder, and on top of that, its incredibly sensative to backpressure. Check out this thread about my exhaust to see how I dealt with it. But its still very loud. The exhaust offers almost no restriction, but I could still feel a loss in power when I added the 2 moroso mufflers. You notice it most in the low end, and my true dual exhaust costed me 30+ ft lbs of torque in the low end compared to this one. And power started falling off around 6k rpm simply because the backpressure was too high and the overlap was causing a lot of intake dilution. With this last exhaust, my car is still pulling hard at 9500 rpm. If I had to do it again, Id leave the sleeves in, and keep the exhaust port more reasonable. Keeping the exhaust port smaller will allow a more restrictive exhaust(quieter) with a lot less power loss. But the torque curve is so nice. It pulls good, even at 1500 rpm, the torque keeps building until 4500 rpm, and the engine just keeps pulling through 9500 rpm.



If I was keeping this engine in the car, Id switch to FD internals on the TII tranny. Im going to break 2nd gear all together if I dont get something better in there. It wont even go into 2nd half of the time shifting above 8500 now. The synchro is long past broke, Im doing damage to the gear now. The TII tranny is simply VERY unhappy above 8k rpm. Its hard to shift at 9500 rpm when it will go into gear.



BTW, if anyone wants a 9500 rpm S5 streetport, its for sale, with or without the car.

threcixty 06-29-2004 09:38 PM

Yeah, Ive noticed the problem with shifting the rx up high.. I'm going to swap the tranny oil from Mobil1.. (Yes, I know it is bad for the synchros) to Redline or something. Wonder if a Miata tranny is any better. btw.. I know what you are talking about with the backpressure.. I tried a RB presilencer on my car and it wouldnt pull much past 7500, but with a dynomax, it pulls a million times harder up high. It just sucks having to replace the stupid glasspack every 3 months. Ive thought about cutting the glasspack outer housing open, taking what is left of the molten glass out, and replacing it with chore-boy stainless steel wool or something. My car started out as a $250 wholesale from the friendly Mazda dealer, and has been nothing but an experiment in progress ever since! One other thing is about the aux. intake ports.. I tried the car with a JBweld "ramp" into the port, without a sleeve, and I had **** for power below 6. I replaced it with the stock sleeves, beveled the rod that goes down the middle, and put the Pineapple inserts in with mucho locktite and center-punching, and it made a HUGE difference in the driveability. It may have lost a whole 1hp up high over no sleeve, but I can pull into traffic at 5 mph in 1st, hit it, and light em up as long as I please. It is nice to hear people ask me what kind of aftermarket turbo I have on my car!

roadkill669 06-30-2004 06:49 AM

You could always go crazy and build a MAP signal converter. It took me a little while to figure it out. But it has a few downsides to it. You have to have a piggyback of some sort, the SAFC will work, and you have a S5, so you have a full range TPS already. The one big problem is that it isnt as accurate as a system just running a MAP. Since you convert the signal from a linear 0-5V to a exponential 2-5V, you loose a little bit accuracy. But, you spend about $20 in parts, and if you have a piggyback already, not a bad way to spend $20. You use the stock pressure sensor, the box plugs right in (the rear speakers hookup is the same as the pressure sensor, so its plug and play)



I have to find the schmatics for my converer and build another one. When I was testing it, it worked great. The signal was pretty damn close to the AFM. I never ran the car though. My ECU blew, so I went Microech.


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