Megasquirt in a 72 1.7L 914 ???, Need advice Options

[rotary914]

I'm new to this list........ So Hello

Well - the title says it all.
I will probably keep my 1.7L for at least another year and I want to replace the 33 year old F.I. with something new.
I'll probably get new injectors too.

Has anyone converted to a Megasquirt on a 1.7L??
Any significant improvements over a properly running stock F.I. system??
Any negatives??
Easy to tune (I have a LM-1 Wideband meter)??
Any particular megasquirt model??

Any recommendations??

thanks

Steve C
72 914
81 RX-7
99 Volvo S-80

[fiid]

I had MS running on a 1.7. It was relatively easy to set up, ran really nicely. It did require some tuning, but I was very happy with the performance.

The standard Megasquirt was what I used - some people have used the EDIS ignition stuff - which is cool, but it's tricky to mount the trigger wheel.

[Mueller]

i did it a few years ago when the megasquirt (MS) first came out....ran great and I was told by a few people that it started up and idled better than any stock 914.....

there is tons of support for it, and there are at least 4 guys running it right now on /4 motors

with the LM-1, you should have it running darn near perfect in just a few hours...

no need for new injectors unless you feel yours are bad, you can get them tested...

the newer the MS, the more options it'll have, the older units can be upgraded to some extent and that is what I will be doing, I see no reason to purchase the latest and greatest, but if you are starting from scratch, that might be the best method

if you can read and follow simple directions, then you can build and install an MS unit on your motor.....

[lapuwali]

Do a search here on Megasquirt. Yes, it's been done, more than once. The most significant improvement is you get to remove the mechanical MPS, and thus remove a part that's pretty hard to replace anymore. The biggest problem in the installation appears to be fabricating a TPS mount, as the stock throttle body spins the wrong way to use the commonly available units. Some of done this, and you can also use relatively recent MS code to simply skip using a TPS altogether (so-called MAPdot code). Some people have also had some trouble getting the stock distributor points to reliably trigger the MS w/o causing resets. Using one of the Hall Effect or optical ignitions will cure this.

Other than relatively small revisions, there's really only one "model" of MS readily available. There are several different software packages you can install, but these have mostly been distilled into one package now (the "extras" package, I believe). The MS forums are a better place to get info on software. The newest MSII stuff that's only just come out (like in the last few days) isn't required, and isn't yet available in quantity. The stock v2.2 kit in use now should be plenty adequate.

On installation, everyone seems to be going their own way. One person has installed everything in the rear trunk, but is having heat-related problems (the rear trunk gets pretty hot). Others have run the wiring harness through the firewall and installed it up under the dash. Me, I'm going to make a complete waterproof housing and mount it where the relay board goes (this area doesn't seem to get as hot), but I may have to fall back to installing it in the cabin if this doesn't work out.

The stock injectors are large for the application. They're also low-impedence, so you'll either need to use a resistor pack or the "flyback" board or the external relay board. You should only need to get new injectors if yours are broken, which is unusual. The stock plumbing should be just fine, as is.

[Mueller]

QUOTE

On installation, everyone seems to be going their own way. One person has installed everything in the rear trunk, but is having heat-related problems (the rear trunk gets pretty hot).

BTDT...twice, cause I didn't learn the 1st time...also, do not store your laptop in the rear trunk, cause when you get to the dyno you are paying $75 per hour for, the laptop might not turn on due to it getting cooked by the muffler and the 90° weather outside (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)

[anthony]

Have any of you megasquirt guys followed this thread:

http://forums.pelicanparts.com/showthread....rt&pagenumber=1


This guy has developed a complete EFI kit for the flat six using Megasquirt. The horsepower gains over CIS look pretty good.

Here's his home page

http://www.bitzracing.com/index.html

The kit:

[lapuwali]

I'd be happier about paying that price if he offered decent electrical connectors and a proper crimp tool. That hardware store stuff he has in that photo is junk. If you buy the CIS to EFI injector adapters from them ($120 for the set), and bought all the rest elsewhere, I'd guesstimate you could do the whole job for $800 or thereabouts. That includes a pre-assembled MS ECU ($250). Paying a 25-30% premium to save yourself some hassle seems fair. Paying 100% seems excessive.

I'd expect a top-end power increase simply from removing the CIS airflow meter. Much more power could be obtained by using better cams than CIS can handle, which an MS swap would allow.

As far as I know, this is the first complete kit to use MS. There's been some anguish in the MS community over commerical reselling of the product. I think it's only a matter of time before someone contracts with an overseas firm to assemble MS units at an industrial scale. Zero R&D costs would mean very low unit costs ($50 per in quantity, I'd venture). You'd then see a lot more similar kits offered for sale. I would not want to be in the aftermarket ECU business right now, except for the high-end guys like Motec. SDS, Perfect Power, Wolf, et al are very probably going to find business increasingly hard in the next couple of years.

[anthony]

He might appreciate your comments regarding the connectors. He's obviously put in lots of hours figuring out every detail of the installation so I don't begrudge him a 100% profit at this point. I imagine as the Megasquirt gets more well known in the 911 community more people will be making kits or parts for kits which will allow one to easily do it cheaper. He also sells a partial kit and I think he will even sell just the fuel rails if you wanted to do everything else yourself.

For the 911 guys I think it's an ok deal considering you don' t have to do any fabricating. I'd still like to see proper before/after dyno runs on the same car with CIS and then with Megasquirt.

I'm not ready to do this to my SC but the combination of SSI + megasquirt yielded a 41hp increase over stock hp which is damn impressive.

I noticed he was able to do this without a TPS. This is part of new code in the megasquirt, right? Can we do that for the 914 and not need a TPS?

[Mueller]

QUOTE

I noticed he was able to do this without a TPS. This is part of new code in the megasquirt, right? Can we do that for the 914 and not need a TPS?

I believe for most applications the TPS is really only needed for fuel enrichment during acceleration (it should be a little quicker than MAP based) and for decel, so the motor will get less fuel on coasting...the MAP will do the rest...

[lapuwali]

QUOTE (Mueller @ Apr 6 2005, 02:07 PM)

QUOTE I noticed he was able to do this without a TPS. This is part of new code in the megasquirt, right? Can we do that for the 914 and not need a TPS? I believe for most applications the TPS is really only needed for fuel enrichment during acceleration (it should be a little quicker than MAP based) and for decel, so the motor will get less fuel on coasting...the MAP will do the rest...

I believe the very latest code (the "extras" code) has a mode that allows you to only use the MAP sensor, even for accel enrichment and fuel cutoff. Decel generally results in a MAP value below idle MAP, so you just set a threshold below the idle value for fuel cutoff. Accel enrichment can be done using a MAP rate of change as easily as a TPS rate of change. There probably is a better response rate with a throttle sensor, but ditching the TPS seems to be a win to me. Using a TPS makes things a touch more reliable, as the MAP thresholds are going to change from car to car (even engine to engine). Set the fuel cutoff too close to idle and you'll find the car stalling at lights regularly. Set it too low and you'll get popping on the overrun because the cutoff never happens.

The set price is pretty good compared swapping to a complete aftermarket system. It's admittedly not a big market, either. If he maps the ECU to work with your CIS engine (2.4, 2.7, 3.0, and mods), then it's a much fairer price.

[anthony]

On page 5 of the Pelican thread he posted a graph of map vs. tps response and found them to have almost the same response rate. I'll repost the graphic. You guys can look at the link if you want to read his description.

[anthony]

Anyway, I've been thinking of building an engine for a long time and would love to get away from the stock cam. The way carbs have skyrocketed in price leads me to believe that Megasquirt is the way to go. Kit Carsen FI would be nice but at $1500 it's kind of pricey.

[greg.treadway]

I am designing a new fuel injection kit for my car. You can see some of it here... Feel free to email me questions. I am unveiling my new design complete with hardware and electronics at the WCC. It will be for sale as a kit later.

[anthony]

What is MSRP going to be?

[greg.treadway]

I wish I could say. Since I'm still making it work I'm not sure. Until the car runs and is fully tested which is all happening in the next two weeks all I'm willing to go on the record with is over $1 and under $3000. It'll be the best EFI kit out there though when I'm done.

[Mueller]

The EFI wars are going to be interesting....Steve @ Type4 is supposed to be unveiling a supposedly $1000 EFI at the WCC as well.....

stay tuned people (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

[lapuwali]

QUOTE (anthony @ Apr 6 2005, 04:06 PM)

Anyway, I've been thinking of building an engine for a long time and would love to get away from the stock cam. The way carbs have skyrocketed in price leads me to believe that Megasquirt is the way to go. Kit Carsen FI would be nice but at $1500 it's kind of pricey.

From what I understand, no one is going to see the Kit Carlson system anytime soon, for the worst possible reasons. Kit's apparently having family problems and isn't proceeding with the systems right now.

IMHO, this summer, when the MS v3 systems are out, there will be little reason to use anything else. They're adding a lot of nice stuff there, and doing fuel and spark with much better reliability (esp. in tach input) will be pretty easy.

[greg.treadway]

Competition can only be a good thing.

[Qarl]

Well.... if you follow Greg's link and go to week 23...

http://autoatlanta.com/service/914makeover...ver-week23.html

...it looks like he's using an SDS kit.

He's probably just providing all the right components and programming to make it plug and play.

[Mueller]

QUOTE (Qarl @ Apr 6 2005, 08:21 PM)

Well.... if you follow Greg's link and go to week 23... http://autoatlanta.com/service/914makeover...ver-week23.html ...it looks like he's using an SDS kit. He's probably just providing all the right components and programming to make it plug and play.

We should buy some stock in SDS.....

Jake is going to start making them a optional or standard item and now AutoAtlanta......

still on the fence on what FI I am going to....I'm 90% sure of which one, just have to clear up some info......