496 HO eeprom calibration
 

I'm thinking of having my ecm's recalibrated for more hp. It would also be nice to have less transom soot. Has anybody had it done? Any effect on driveability or docking manners? I don't want to burn a piston. Reliability is more important than hp to me. I've heard up to 40hp increase. How many rpm's did you pick up? Worth the $$? How big a deal to go back to stock?

I think you're talking about these:

http://www.whipplesuperchargers.com/...sp?ProdID=1190

Unfortunately, 40hp ain't gonna happen with a PCM cal alone. However, I'm sure Dustin has a fix if you let him. :D

Some stock PCM's do have sooting issues (mine did as well). I've learned that some of the sooting issues could be from poor fuel quality. In fact, if I don't run Sunoco through mine, I still have some. With my upgrades and Sunoco gas, I get very little (if any).

All I run is Sunoco. They say 7-10% increase which is 29.75 to 42.5hp. I have no idea if that is realistic. It would need to be to be worth moving from 87 to 91 octane.
How do you like the Raylar package?

I can't tell you a thing about ecms, eproms or pcms go4broke, but I can tell you the blowers you sold me kick azz! I picked up 8 mph! So far so good. I thought you might like to know that. Now back to your regularly scheduled topic........... :p

BT

Nice work. You must be talking about the stage 2 with stock goodies. I've yet to be ill-informed by either Ray or Dustin, so I guess it's possible. That being said, I personally wouldn't like stock internals running on 91 with aggressive mapping.

I've got +30 Mahle pistons along with the Raylar package, a custom tune from Dustin and really like it. I picked up a solid 8 mph in my floating brick which is pretty good. It hasn't been dynoed, but all my numbers tell me I'm running 525-550 hp. :D

I've been wondering about you! Good to hear, 8mph is great!
Now if I can just find a deal on blowers for my 496's......
Of course they would probably come with a divorce, that would be expensive hp!
I better stick with calibrations and lab props.

Anyone else tried different calibrations for the 496's?

One thing I did G4B with the blower installs is buy .02 sensors. I bought the innovate LM2 meter which gives data logging of a/f relative to rpm. That would be a good tool for you to determine if there is any room to lean down. The black transom could be a rich spot somewhere other than WOT.

I was very concerned with my hyper pistons (same as 496) and starting with 9.5:1 compression and blowing a piston, but the results have been very good. And I know my af ratio is right where it needs to be to keep the pistons cool. These engines have been run harder than ever too and I am feeling pretty good on the tune.

BT :cool:

Thanks BT. You are right that O2S are the only way to find the line and not cross it.

The people I know G4B that have great success maximizing FI applications are doing thier own mapping. I believe the software and cabling can be had for pretty cheap these days. You then just need a lap top and some patience. Sending ecms out for recal and hoping for an improvement is like pissing in the wind.... feels good at the time, but you end up smelling bad.

Great analogy, cracked me up!

In my case, it took two trips to Dustin after the mods were complete. With the right readings (rpm, manifold pressure, fuel pressure & a/f) it is possible. I sent all this info @ 500 rpm increments and she's dialed in nicely...from idle to WOT. I also have a FASS O2 sensor mounted on the dash to monitor when I'm running hard. :ernaehrung004:

That's the other good way to do it H4T. With the data logging capabilities of the LM2 G4B you could actually send a ecm tuner a graph from 500rpm to WOT and they could really dial you in. I believe the logging will graph up to like 10 inputs. I just look at A/F because my stuff is old tech.

If you want a good result you will need to supply good data like H4T did and make sure you have a quality tuner doing the work.

Got running buddy that has his done by Dustin, uped rev limit and changed timming. He has soot on his transom after running. He and I have not figured out if soot is from low RPM or from running at high RPM since he is almost always at high RPM. When he did the ecms he also change the exhaust and installed shorties. He gained I think around 8-10 mph

[QUOTE=blue thunder;2679622]That's the other good way to do it H4T. With the data logging capabilities of the LM2 G4B you could actually send a ecm tuner a graph from 500rpm to WOT and they could really dial you in. I believe the logging will graph up to like 10 inputs. I just look at A/F because my stuff is old tech.

Got a link to the data logger and O2S?

http://innovatemotorsports.com/

The LM2 comes with the bosch 02 sensor and all cabling. You are best to buy direct from them I believe because you get the most recent firmware revision. I got mine from summit and had to fart around with downloads. They also have a tuners forum you can go to which would be good to do before you buy just to learn some. They are very helpful.

BT :cool:

Great stuff from these guys. I bought thier first gen LM1 wideband setup when I was car tuning. They hhave come along way in 6 years.
Good product.
So there are a fews folks out there tuning the 555 pcm????

I know the guys at mefi burn are working supposed to be working on software for it.

I just purchased Diamcom to log my 496ho's . New Gateway laptop took a dump. Sent it in a month ago and still not fixed. So no diacom results yet.

Thanks BT.

We can do just about anything in that PCM, but as a few of you said, if I'm provided some decent info, af ratio, rpm and manifold pressure, I can get it pretty darn close to perfection. Without it, I can only do what I know from prior applications.

HP gains are 20-30hp and it depends on rpm. Its about 20 at 5200, but with higher rpm limit, its 30 at 5400.

Dustin

Not the Mercury computer. It's almost impossible to find all the address's of the table/data in such a complexed system. There are multiple tables and functions that have to be modified, and each model PCM and ECM are different, so the address would move depending on base setup from mfg. Then, having someone tune that has never done it before, reading hex or manipulated numbers is impossible. You also can't program on the fly without additonal ram, which is not there on the stock computers. So even if you could do this, it would be trial and error. Make a change, if you knew exactly where to, then run, read data and see if it worked/didn't work.

We have the software from the mfg and lisc. to do the work, we have access to every single parameter and table in the computer, and believe me, there are thousands upon thousands. So nobody is selling an "inexpensive" cable and prom. These have the Motorola 555 chip, nobody is replacing those.

Thanks,
Dustin

Whipple is the only lisc. company to do such a thing. If MEFI Burn or someone else can work and work to find the fuel and spark tables for all the different models, then thats great, but guarantee they won't be able to find all the other parameters needed in a modified tune. You can't just change an rpm limit on a stock cal, there's over 500 tables/parameters counting on the stock system running to stock rpm limit. Your up to the original programmer and base setup, did they even call out for the MAP pressure to go above 5 psi, or 10? If they did, did they even extrapolate the table? Chances are, no. The old MEFI 3 cals, if you just bumped rpm limit, you could go from 28deg to 38deg in the matter of 200rpm, could destroy engine. What about knock, and with the 555, the knock is incredibly complexed, is it filtering the right amount of noise past the load or rpm points that factory ran? Chances are, no.

In some cases, you may get away with whatever small change, but in the big picture, your playing with fire. It's not like a car that can only hold WOT for a few seconds, if a boat engine is not right, it doesn't make it. We spent gobs and gobs of money, and countless man hours to get where we are, only Mercury and PCM mfg have more knowledge on these.

On the 496 SC kit, can you run just 4psi for about 550HP?

Thanks for all the info Dustin.
How do the whipple supercharger kits and the raylar kits compare for price and hp?

Yes, 4psi will make right around 550hp, extremely safe, as is our kit in general. It's shipped out at 5psi, colder plugs, cooler stat, intercooled, run slightly rich (11:1), colder spark plugs and 25deg timing. Very safe.

Never tried to compare. Pretty hard to compare to the SC torque and throttle response. But I think you can do a Raylar 525hp for less than SC, but 600 is quite a bit more I think, but again I really have no idea. Both are great products.

:evilb:How 'bout a Raylar 525 with a SC?

Now your talking!!

Hey Dustin, if you don't mind me asking, what is the max EGT you would feel safe with? 496 with forged internals.

If your measuring at the head, with a accurate, open style sensor, then 1700deg F. If your using the gauges that go in the boats, no idea because they're not accurate. If your measuring after water has been introduced, really have no idea because its been cooled already.

Some will throw some #'s, but they really don't mean anything. Better off welding a bung in one collector, odd side, then getting af meter from Innovative motorsports, and measuring to make sure your no leaner than 12:1 on a forged motor, with sc, at WOT.