yeller

iTrader: (1)

I have a procharged 502 with Mefi3. It's running too fat for my liking, so it needs a tune. I'm also hoping to build another motor this winter, so rather than pay for a tune, I've been contemplating a MS3. That way I can use it on my current motor and when I build the new one, I can transfer it over and purchase the MS3X expansion card for sequential fire. The MS3 has enough capabilities, so the MS Pro isn't necessary. I do have a budget, otherwise I'd go with the Holley, for the ease of tuning.

So the question I have is: how difficult is it to tune the MS? I realize that's a fairly subjective question, because "easy" is relative to "ability", but to try and give you an idea: I'm a reasonably competent backyard mechanic and I have an electricians ticket with a background servicing/installing/programing computerized control systems, (although, that was several years ago).

I just got my boat running after 4yrs of downtime, so I'd rather run my boat as is than kill another summer dicking around with it.
Does the auto-tune work very well on the MS3? If the auto-tune can get me close, I don't mind spending time tweaking it. I just don't think I want to spend the time learning and building a tune from scratch.

Also, what have you guys done for a knock sensor? Is the Megasquirt kit really necessary or can the Merc sensors be monitored directly with the ECU somehow?

I appreciate any input. Thanks in advance.

airbats801

well first off get a wideband installed. I believe there is some really good autotune software available for like 50 bucks that works with ms3.

Frankly it would be worth your time to pay 500 bucks to have someone dyno tune it after you get it close, but I could see tuning it in boat.

I really dont know if sequential fire is gonna be that big of a deal on a boat, but I could be wrong, more accurate timing, but can you tune to it?

Frankly as long as you arent running pig rich, id just run it and enjoy the boat. A bit of hp doesnt matter as long as you are out enjoying the boat on the river lake ocean

Wasted Income

I have had both the MS3x and a Holley EFI Dominator on a turbocharged LSx street truck.

They MS3x is every bit as good as the Holley, and possibly better in some ways. You will want to purchase TunerStudio for the MS (the software that airbats alluded to). It's as easy to tune as the Holley setup. The only downside is the customer / tech support is not quite there like it is with the holley. You will probably be spending a lot of time on the MS forums asking questions....but they are pretty helpful.

The "auto tune" is a misnomer. It doesn't automatically tune anything except the fueling (VE table) based on wideband O2 feedback. You will still need to load a base timing map and adjust that. You will still need to decide what your target AFR table will look like. You will still need to populate and tune a cold start enrichment table. There is still TONS to do that the "auto" tune doesn't touch. It's the same with ANY "self tuning" EFI....MS, Holley, AEM, FAST...etc.

I don't run knock sensors. I tune conservatively enough, and run good fuel, so that detonation isn't a problem. By the time it's knocking, and the sensors are pulling timing, damage has already been done.

If you know the range of your sensors and the caibration values, you can indeed run your Merc sensors if they're wired to the MS. You can even setup outputs based on fuel pressure, oil pressure, water temp, water pressure, etc to turn on a buzzer or light and reduce power / rev limit to act like the merc guardian.

Good luck.

yeller

iTrader: (1)

Thanks guys.

I plan on installing O2 bungs regardless of whether I leave the Mefi or not. I'd like to know where my A/F is at. The sequential isn't something I plan to install. It's just that if I do another motor, it'll be an LS, so it'll come with. I know it's not a big enough motor for most on this site, but I find them very intriguing and believe it'll work well in my boat.

I guess it was wishful thinking that an auto-tune would get me close enough to run without much adjustment. I was thinking if it could get it running reasonably well, I could still enjoy the boat while I educated myself on tuning.

Might have to take airbats advice and run it as is for now and maybe get into it over the winter. I just hate the black transom all the time.

Wasted Income

There are enough "base tunes" floating around that you could get it close enough to run pretty easily.
Would it be good enough to run down the lake at WOT in boost on a rough base tune? I wouldn't. lol

getrdunn

iTrader: (7)

Only used one once and ended up on my dashboard and windshield of an 85 monte ss. Never seen anything like it.

Wasted Income

Is that a jizz joke?

getrdunn

iTrader: (7)

Close I guess... Involved a she and MegaSquirter. Just a little humor but true.

SB

iTrader: (1)

Wholly fuk ! I laughed so loud I think I broke my uterus.

getrdunn

iTrader: (7)

Wondered when you'd be by...