The most capable for the price is the Megasquirt 3. It is completely programmable and there is a great forum for getting help. I'm in the process of installing one right now on my 95priority Cavalier with a 2.2 OHV. 5 speed.
www.DIYAutoTune.com

MasterFlight wrote:The most capable for the price is the Megasquirt 3. It is completely programmable and there is a great forum for getting help. I'm in the process of installing one right now on my 95priority Cavalier with a 2.2 OHV. 5 speed.
www.DIYAutoTune.com

Stupid predictive tying added "priority"

Megasquirt 2 is more than enough for most cavalier owners.....



PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

I have read about Megasquirt, but for not having to assemble or piece it together myself I am willing to pay a premium for the AEM setup. What would have to be done though so I can keep my stock gauges? I wouldn't mind adding another gauge or 2, but if I will lose my tach, speedo, or fuel gauge then that's a few hundred extra that I am trying not to spend.

I don't think you could handle this. Your fuel gauge will work without the stock computer on the 95. You will need to piggy back any stand a lone with your factory computer to maintain speedo and IDK about the tach, my car didn't have one.


- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs

Didn't the OP state in the first post that he has a 2004?

-MD- Enforcer wrote:Megasquirt 2 is more than enough for most cavalier owners.....

Correct that it will handle most everything. I got the MS3 for the ability to have sequential injection.
d

Actually I know I can handle this. I'm a diesel mechanic, have been working on gas engines for a long time, and have extensive experience with wiring, but I just have never done a standalone system. I am just trying to find out what gauges I will lose by removing the stock ecm/pcm, whatever it is supposed to be called. I am willing to replace all the gauges if necessary, I would like to save some cash by keeping whichever ones I can though. I dislike the Megasquirt due to the fact that I prefer not to piece together or build the new ecm myself, and secondly the Aem will have more product support if I run into issues. I'm not worried about sequential injection, I know I can save a few mpg, but right now with the rough tune between the Portfueler and the stock ecm I am getting around 15mpg normal driving (not babying it, but not raping it all the time either) so if i can get anywhere near stock mpg while being able to have complete control for the higher power levels (I'm making pretty decent power already, but I want to go over 400hp/tq on pump gas w/ water/meth) I would be happy. I have to drive over an hour just to get to a tuner with HPtuner, and I know a few people in my town that could easily do the tune on the Aem ems.

I would be more worried about it working and properly tuning it. Its easy to wire up I aam sure.......

I see what you mean after looking into it more. So Megasquirt 2 or 3 can be programmed to use the 6+1 crank trigger in the L61? Also, Is there any soldering involved with either Megasquirt? I hate soldering.

If you look on ebay there are ebay stores that sell already assembled MS units. They are more expensive but save all the headaches of soldering all 10 thousand pieces together.

You can retain use of your stock gauges by keeping the factory computer hooked up. I believe you put resistors on the wires where the injectors would go to fool the ecu into thinking its running the engine. Also erase all codes for unattached sensors with HP tuners.

You don't need resistors. All the resistor trick does is fool the PCM into thinking the injectors are firing. It's not required. I used to use resistors up until a couple years ago, but they burnt up real quick (used 1/2W). Worst case scenario, you have a check engine light.

Running a parallel installation to retain your stock gauges isn't difficult. It's just a matter of knowing what the stock PCM needs to see.




I have no signiture

AEM EMS4 looks like a great system. I'm planning on running it, the tuning sweet looks really nice and actually seems to make sense. Though like most stand alones I cant find a way to have it handle its own data log data and still have to use excel to do it rather than being able to create histograms in the program like you can in hptuners/efi live.

Wiring wise, you just have to be smart, give the stock computer the signals it needs to run the gauges (crank position, speed, fuel level). Basically T off the same signals going to the stand alone. Make sure the ground for the standalone and the stock computer are very close to each other or it could effect the temperature reading, but the pulsed signals (crank and speed) shouldnt be effected by a ground offset unless its huge. Then just turn off all the codes in the stock computer so that it doesnt show a check engine light.

Before you switch over realize that you cannot copy and paste your alpha-n maps over to the speed density stand alone. BUT you can take a log from hptuners and have it reverse engineer you speed density maps based on all the parameters from speed density (map, injector pulse, rpm, temp, ect). Which will get you pretty damn close to what you need, at the very worst the car should run somewhat correctly and you can tune from there.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer

i would just make sure that the ems you choose to go with with work with the j body crank trigger


RIP Cpl Derek Kerns And Cpl Robby Reyes
24th MEU VMM-261 (REIN) V22 Crewchiefs
11 April 2012 Morocco (African Lion)

That is the one thing I noticed might be a problem. I'm just try to find an external crank trigger with a more standard pattern I could use. I understand very little about programming an ecu so I will find someone that could do a good street tune, then take it to my previous tuner for a good dyno tune. Thanks though for the idea of leaving the stock ecu to keep my gauges, after thinking it over it shouldn't be too difficult. I really want to keep the speedo and fuel gauge at a minimum, but if i can save the other ones that would be nice.

60-2 wheel should be easy to find.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer

louis cobarruviaz wrote:I see what you mean after looking into it more. So Megasquirt 2 or 3 can be programmed to use the 6+1 crank trigger in the L61? Also, Is there any soldering involved with either Megasquirt? I hate soldering.

dude.... ugh.

the first question you want to ask yourself is "What do I want to control?"
Until you know what this means, and how to answer it, soldering is the least of your worries.


You sound like a little kid saying you wanna be an astronaut.

Let's see. I want to control fuel and spark, off course. I want the ecm to be able to add fuel and retard timing for boost levels, and controlling water/meth injection isn't a bad feature either. Thanks for the little kid analogy though, I'm trying to learn as I go with performance modifications, everybody can't be born as smart as you guy.

im running aftermarket gauges on mine cause i refused to leave the stock POS computers in the car when i switched to the Haltech


RIP Cpl Derek Kerns And Cpl Robby Reyes
24th MEU VMM-261 (REIN) V22 Crewchiefs
11 April 2012 Morocco (African Lion)

I don't have to worry about emissions as long as I stay stationed in AZ, so its just a personal preference. What all gauges would I lose if I ripped out the stock computer? Would I have to get all new gauges, or just temp, fuel....? Either way I am going standalone, I just wanna be prepared so the car is down for only as long as it needs to be.

you would loose fuel, temp, rpm, and speed.


1994 Saturn SL2 Home Coming Edition: backup car
2002 Chevy Cavalier LS Sport Coupe: In a Junk Yard
1995 Mazda Miata R-package Class=STR
Sponsored by: Kronos Performance

WPI Class of '12 Mechanical Engineering
WPI SAE Risk and Sustainability Management Officer

Ok, well as long as I can get aftermarket gauges to cover them i guess I'll just get all aftermarket gauges, I've been wanting to build a new dash anyways, so that's a good reason to. I know I can get speedo, tach, and water temp, but will any aftermarket gauges work with the stock fuel level sender or will that need to be replaced with the gauge?