Has anyone tried these stand alone ecus? They work wonders, relatively cheap, limitless online support community. BMW guys over a E30tech use them. They use them on custom turbo set ups to get 300-450hp out of 2.5 liter 6 cylinder engines. I can only imagine what we could get.

 

I have a megasquirt... What do you want to know?

The magasquirt is a DIY kit that is very cheap... The top of the line one is about 250 for the kit.

It has the ability to run almost any engine, ever. It will even run 2 stroke and rotary motors without any modifications.

It won't work wonders on a stock engine.... It will allow you to get a little more power out of it because of the removal of the smog equipment. The real selling point is the fact that you can do whatever you want to your engine, and the megasquirt will be able to run it. There is one guy running a car with about 1500 HP on a megasquirt.

 

Hi Toehead, Ive recently acquired a full SBC twin turbo kit for my 91 TPI engine which is onway but in the meantime im looking to move from the stock ECU to megasquirt so I can tune for boost once its on. When you set yours up did you need any extra electronics to interface the sensors etc or was megasquirt happy using all the stock stuff as is ?

Im a lil worried also because mine is MAP not MAF and ive not found many posts at all on non MAP with megasquirt.

-TIA Andy

 

The megasquirt has it's own MAP sensor onboard and defaults to speed density. You can use a MAF as well, it is made to use the ford 0-5v sensors, but that is less supported.

The megasquirt comes setup by default for GM sensors. All your sensors should be well supported. IN addition, the megasquirt can control the stock HEI Ignition module with no additional changes. It can also control a MSD ignition. Some people have had problems with signal noise with the HEI ignition, but (knock on wood) mine worked perfectly the first time.
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The stock tune that comes with the megasquirt is actually for a tpi 350!!!

 

Thats great news mate and a big relief, i'll order it ASAP now. Thanks heaps -Andy

 

No problem man. Go hang out over at www.msefi.com It is a great forum and they will help you out a lot. The main point is to make sure all your wiring is correct before you apply power. Because the user is required to do wiring, sometimes they hook things up incorrectly and fry things. I used the short harness from DIY autotune and it worked very well. In fact, the colors matched what was in my stock harness about 95 percent.

Are you going with a kit or an assembled? I went with a kit. It took me one whole saturday to put together carefully. I found it a very rewarding experience, especially when it worked the first time.

In any case, the instructions for assembly, as well as wiring diagrams for the HEI and MSD ignitions are on the site www.megamanual.com

 

Yeah Ive been looking at msefi.com but figured if anyine had done it to a 3rd gen it would be here Theres a guy not far from here that supplies them assembled and tested and does repairs too etc. Anything to shorten the time till Im bolting up those twin spinners im going for so hes probably the go as he has them in stock. Its not much more here for the assembled over the kit job so i'll avoid the hassle. I'll be adapting the stock harness most proably but i'll see what this guy has on hand re generic harnesses. Thanks again for all the help. -Andy

 

any news?

 

Slow progress, got a ready assembled unit but having wired in into my orig chev loom found that the CLT sensor circuit was faulty so they are sending another unit over. I did fire it up on it for about 30 seconds and it started fine but as it permanently thought it was -18C it was fuelly as hell. Hopefully will have the replacement ECU next week. I have everything else in hand now for the install except the knock module which I hope to have next week. Ive opted for #42lb bosch green top injectors & 044 bosch pump. What do you think of the std fuel rails, are they up to the job feeding big injectors on a twin turbo TPI?

 

Ah thats a pain.



Did you try reloading the firmware?

I had a situatio where i tried burning a value with the voltage low, and the firmware got corrupted. That caused my coolant reading to be stuck low, just like you described.

Just something to think about.

As for the fuel rail question, the guys over at power adders have a lot more expereience then me!

 

>Did you try reloading the firmware?

No I just reported all my findings to the supplier and they agreed to ship a new ECU. It wasn't actually hard low, it was all over the place at low resistance, the symptoms I reported were;

2.7K Ohm across pins #19 and #21 = -18C
330 Ohm across pins #19 and #21 = -18C
180 Ohm across pins #19 and #21 = -18C
15 Ohm across pins #19 and #21 = 1226C
20 Ohm across pins #19 and #21 = -18C
10 Ohm across pins #19 and #21 = -13C
5 Ohm across pins #19 and #21 = 1638C
2.5 Ohm across pins #19 and #21 = -13C


They did not suggest a firmware reload and offered a new ECU so I accepted.

-Andy

 

can i run the gm mass airflow sensor with mega squirt? will i need to install a map sensor?

 

Megasquirt has its own MAP sensor all you do is put a vacuum line from the manifold to the unit. Toehead was saying above that its capable of running a MAF sensor if you really want but I've not checked it out.

The question is why would you want to ? A MAF sits in your airflow path and restricts it. Probably not a problem at all on a stock engine but as you opt for more power all the extra air has to be dragged through that fixed CFM device working against you. With megasquirt you simply remove your MAF sensor all together and it does all its stuff using the vacuum line and your MAT sensor.

 

There are advantages and disadvantages to each system(like everything automotive related). The MAP setup essentially guesses how much air is going in using the MAP signal, CLT, IAT, and sometimes more. Unless all of these variables have perfect skewing equations, you may need to run a different tune in the winter versus the summer. The more sensor variables you have(i.e. more money), the more accurate the 'guesses' are.

The MAF setup uses the pricey(biggest disadvantage) MAF sensor to directly measure the air and the ECM gets an actual value as to how much air is moving past, so no seasonal tune change, and very consistant operation(biggest reason to use MAF). It is in the airflow path and technically a restriction. It also has a limit as to the amount of air it can measure. In essence, a limit on hp. When you hit that wall, time to open your wallet for that aftermarket sensor.