I just bought the headers,raylar kit, and whipple programed ECM in the classifieds. http://www.offshoreonlyclassifieds.c...o20706-en.html

My biggest question is how important is the headers over the stock exhaust! How much difference will the headers make in power and how much of a concern is reversion with the stock 496 manifolds??? I need an exhaust for my procharged pachanga and this system would work well.

2nd question...If I need to keep the headers on the 496 how well would the 496 exhaust work on my procharged 454? I have the stock 330HP mercruiser exhaust now and I guess I don't have a reversion problem! Is it worth the extra bucks to upgrade to headers from the 496 exhaust?

3rd question...I would appreciate any other tips about this conversion anyone else could add. I know I have been told it's a waste...the 496 is in a 2003 260 Powerquest Legend. LOL! I just have ta try somin!

Contact Bob at Full Throttle Marine(OSO screen name--bobl). I think he can answer all of those questions. He is usually in the Nordic section on OSO.

3rd question...I would appreciate any other tips about this conversion anyone else could add. I know I have been told it's a waste...the 496 is in a 2003 260 Powerquest Legend. LOL! I just have ta try somin! [/QUOTE]

We just did my Raylar upgrade and I would have to disagree on the idea of it being a waste!! I picked up a little over 5mph with the Raylar BCK-103 Kit AND I have a prop that is not dialed in yet with a small hook in the last two feet of the starboard strake. When these two issues get satisfied soon, I'm thinkin' maybe 2-3 more mph. Raylar is a very good company and their service is excellent. I'll post some pics and experiences etc as soon as we get everything together. I was thinkin' bout that controller today and you bought it. Ed Noonan @ West Coast Yacht & Marine Service did 99% of my upgrade. We did it together over Xmas Holiday. His username is "Westcoast". The entire bilge area looks nicer now than when it was new. Ed's attention to detail is unmatched! He did a superb job and will be able to give you some very valuable pointers.

I was saying it might be a waste of time because of what alot of members told me in the Powerquest Forum. http://www.offshoreonly.com/forums/s...d.php?t=174162

As for the ECM....I was iffy on buying it because unlike the headers and raylar kit it has 300 hours on it.(Not the reprogram,the ECM) Anyone know the life expectancy of one of these ECM's?

THanks for the input...I'm thinking I'm going to do this install myself. Been awhile since I skinned my knuckles,etc! I'm sure I will run into a few scratch my head and ask situations where I need to ask a few questions!

If you don't short it out etc..... that ecm will last a long long time. the 555 is a very stable box. motorola made it and it's bullet proof in most cases. motorola is an engineering driven company; not a marketing driven company. typically with electronics like that one, the problems show up very early in the game. 300 hours is nothing. i can not comment on the re-flash but i don't see how it would be any different in terms of longevity if the box worked well right after the flash.

We just did my Raylar upgrade and I would have to disagree on the idea of it being a waste!! I picked up a little over 5mph with the Raylar BCK-103 Kit AND I have a prop that is not dialed in yet with a small hook in the last two feet of the starboard strake. When these two issues get satisfied soon, I'm thinkin' maybe 2-3 more mph. Raylar is a very good company and their service is excellent. I'll post some pics and experiences etc as soon as we get everything together. I was thinkin' bout that controller today and you bought it. Ed Noonan @ West Coast Yacht & Marine Service did 99% of my upgrade. We did it together over Xmas Holiday. His username is "Westcoast". The entire bilge area looks nicer now than when it was new. Ed's attention to detail is unmatched! He did a superb job and will be able to give you some very valuable pointers.[/QUOTE]


Hmmmmmmm......i was hopeing a little more than 5mph with the correct prop pitch. and then maybe 1 or 2 on top of that with a lab finished deal. I wont keep this boat long enough to find out anyway.

Hmmmmmmm......i was hopeing a little more than 5mph with the correct prop pitch. and then maybe 1 or 2 on top of that with a lab finished deal. I wont keep this boat long enough to find out anyway.[/QUOTE]

well, again. i'm killing my limiter right now. have another prop coming. I'm guessing right now until i get the prop labbed but it's starting to look like a total increase of 7-8 mph for me. I'll post again on this once I'm done.

Can anyone offer any insight on my exhaust questions?

Contact Ray @ 866.496.8181. He has compared headers to the Dana System on 496's with his dyno.

We did the dyno work with Raylar on a 496 converted motor with our exhaust. The Raylar kit brings the engine up to roughly 525 HP. With the Dana Exhaust the engine made 555HP and 602 ft lbs of torque. The torque curve was incredible, at 2500 RPM's it was over 500 ft lbs, and through 90 percent of the range it never dropped below 550 ft lbs.