500 EFI Upgrade
 

Who can reprogram the ECU on these motors? If you did it did it help any? I know about AS&M.

Has anyone turned this motor into a 540 and used the ECU with reprogramming? Did it need new injectors?

Has anyone purchased the mono blade throttle body from AS&M? What where the results?

Any help appreciated.

Re: 500 EFI Upgrade
 

Lister, I put the AS&M throttle body, kit with the reprogramd ECU. I gained one to two mph. 288 Sunsation. It really helped with the transom soot.

I'm selling my boat, and would part with this kit if you want to swap Computers?

Re: 500 EFI Upgrade
 

I think the guys at Boostpower USA sell a similar kit. There have an article from a mag on their website. They say they have performed this on 150+ engines so far.

From what I hear the kit includes:

Mono blade throttle, intake manifold spacers, modify intake at throttle body, reprogram ECU for improved airflow, add more advance, and increase rev limit to 5800.

Re: 500 EFI Upgrade
 

Jeff,

I may want to do that. I need to think ablut it a little more.

I went to Boostpowers web page and saw the 65HP article gain. I will call them today to see what they have to say. That seems like too much for what they did.

Any other replies?

Thanks Linnie

Re: 500 EFI Upgrade
 

I talk to them when the article came out. First of all it took them like three days of calling to get some one to talk too, and the price at that time was out to lunch. But that was two years ago now. I forget, did they dino test it.
If I remember, they wanted you to install a crossover too.

Lister, what ever the cost is from AS&M I will sell mine for half price, you pick up the shipping. Keep in mind, my computer shows 268 hours!

Re: 500 EFI Upgrade
 

Ask to look at the dyno sheets. Probably nearly the same curve until 5800 rpm where there is 65 more HP than stock because the stock curve is falling off.

Re: 500 EFI Upgrade
 

Cobra Marty is right on. Check the dyno sheets. They say 65hp and another 25hp if you install the crossover instead of the reciculating pump. That's 590hp out of a 500. But you are spinning 5800rpm now, ouch. Merc builds them the way they do for a reason. To provide safety margin.

Re: 500 EFI Upgrade
 

65 hp My a**. It is more like 25 hp max increase. The hp 500 pretty much stops making power around 5200rpms.

Re: 500 EFI Upgrade
 

What corrected hp are you using on your dyno?

Re: 500 EFI Upgrade
 

call mark at PRECISION 504 469 7463 he can give you the advice you are looking for. e

Re: 500 EFI Upgrade
 

Yah call them, and then inform the rest of us what was suggested!

Re: 500 EFI Upgrade
 

All tuned port/ multi port e.f.i engines stop breathing in the 5200-5400 rpm range, due to the nature of the plenum's they use. As far as a 540, no problem. Just remember to enhance all phases of the engine. You'll need more fuel, bigger pump, regulator, injector's (45lb disc type by Lucas work well) throttle body, e.c.u, knock sensor, etc,,,,,. These engines will make some good power 600 + with out killing them, just don't turn them too high. Believe it or not Lingenfelter has a host of info on t.p.i/m.p.i engines. And after all these h.p's 500/525 are giant tune port vette and z28 engines just 10 year's behind.

Re: 500 EFI Upgrade
 

Thanks for the reply.

I pretty well guessed 65HP was BS. I never had that kind of increase on a Carb engine by adding the same conditions. I figured 25HP was right.

I did talk to ASM for a good while. They tell me the EFI manifold is good for way more than 700HP if you open up the ports at the heads. Apparently they are real small there & Merc does not spend the time to open them up.

Jeff, I will work with you on the offer if you wait just a little.

Open, Didn't you do the 540 EFI upggrade? I talked about 6 months ago from someone in LA about this who was getting ready to dyno the setup. Thanks, I will call Precision today

I like the ASM throttle body.

Thanks for help, I have two motors coming out in the next week or so.

Re: 500 EFI Upgrade
 

Linster,
If you look on the boards here or over at Hotboat.net there is a guy who recently converted a pair of 500's to 540's. I believe he goes by Infomaniac, if I remember right he even has the build up on his website. Good luck,
Rick

Re: 500 EFI Upgrade
 

I will look up the other guy. I know how to get power out of motors, I have not experimented with the EFI ECU. To me thats like have your arms tied on the timing and jetting of a carb motor.

I did talk to Performance Marine. He was very informative and willing to help. That may be what I was looking for.

Re: 500 EFI Upgrade
 

http://www.pfaffengines.com/ they do a 540, the challenger. 600 hp.

http://www.pfaffengines.com/challenger600na.shtml

Re: 500 EFI Upgrade
 

Ray, it looks like the Challenger is a 502 not a 540 or am i looking at it wrong?

Re: 500 EFI Upgrade
 

Here is link to Info's site- http://marineassault.net/
Has been a while since I looked at his site but think on main page there is a link for projects and the 540 deal was under that.

Re: 500 EFI Upgrade
 

performance or PRECISION??

Re: 500 EFI Upgrade
 

I'll second Precision Marine. When you see the number of computers that show up from all over the country, Mark must be doing something right. Tell him Mooner sent you.

Re: 500 EFI Upgrade
 

Open, Sorry about getting the name right. It was Precision Marine. He was very informative.

We talked a lot about heads. Both PRECISION & ASM have had poor results with Merlin heads. Both push the Dart Pro 1. Here's a interesting comments from both them. The Dart 308 Iron Eagle heads are the same casting in the runners as the Pro 1. PRECISION tells me they will make a little more power than the Pro 1 with the same engine setup. He said the heads hold the heat better and make a little more power. The problem is they are more prone to detonation after 9.25CR. You must use 92 octane if you go over that. Both like the Air Flow Research but agree they are better for larger engines and mechanical cams intended for max power.

Both PRECISION & ASM want to specify what cam to use so the ECU can control the engine. I have always found on cams, a little little is better than too big.

I still think the key is to increase the compression in these engines. 8.75 is very low. Most new GM engines with EFI control are much higher than 9.0CR. They allow the knock sensor's to work. At 8.75, a knock sensor will not come into play. I still think that the 142 degree thermostat will make more power than the 165 degree that Merc now puts in the engines, from the shear heat temperature generated in the engine compartment. With the 142 degree thermostat, I think the engine compartment runs 40-50 degrees cooler in the summer.

Thanks for the help finding PRECISION Marine. He sounds like he really cares about his customers.

Re: 500 EFI Upgrade
 

http://www.lingenfelter.com/home.asp

My motors would be in their hands no some fly by night wanna be speed shop.

Re: 500 EFI Upgrade
 

I could lighten my boat and gain 1-2 mph just take less women and less beer :drink: :D

Re: 500 EFI Upgrade
 

Yup, I run with a buddy of mine that has the same boat, and same power (he's carb hp) . Its was worth it to be able to just get by him and shut him up. So yah, it was worth it. No internal work, all external, transom is nice and clean, and I did it all.

If I was keeping it, I'd whipple it, and leave the CR alone.

Don't rule out the whipple just yet, compare pricing before you go and pull the engine! The whipple can be installed without pulling the engine. And you can net 600 with 3 or 4 lbs boost.

Re: 500 EFI Upgrade
 

Now who the hell is going to run a boat without women and beer? We not in a poker run all the time!

Re: 500 EFI Upgrade
 

yup , and he does like the dart's. i myself have a set of canfields. he will take the time to speak with anyone. e

Re: 500 EFI Upgrade
 

ouch :D

Re: 500 EFI Upgrade
 

Innovation - Talk with Dennis. They do great work. - Remember, you get what you pay for!!!!!