is it possible to chip a 2002 5.7GXi

[sunchaser630]

Have a 2002 5.7gxi and wondering if I can put a chip module to increase hp. Running about 320hp

 

[Bondo]

Re: is it possible to chip a 2002 5.7GXi

Have a 2002 5.7gxi and wondering if I can put a chip module to increase hp. Running about 320hp

Ayuh,.... Welcome Aboard,... Nope, it ain't gonna happen,....

 

[sunchaser630]

Re: is it possible to chip a 2002 5.7GXi

Thanx. Just trying to figure out a way of getting alittle hp out of it

 

[MikDee]

Re: is it possible to chip a 2002 5.7GXi

No easy way, you could get a hotter marine cam, but that would be labor intensive. Do you have 3", or 4" risers, & manifolds? You might get a little there. But, I figure maybe the 350 Mag already has them? Thru-hull exhaust may help, and synthetic oil definitely will! All of these are little tweaks that actually work when combined.

 

[sunchaser630]

Re: is it possible to chip a 2002 5.7GXi

Thanx for the suggestions. I do have thru hull exhaust but have to admit I completely forgot about syn. oil though that was the one things I did do to my hemi.

 

[Bondo]

Re: is it possible to chip a 2002 5.7GXi

Thanx. Just trying to figure out a way of getting alittle hp out of it

Ayuh,.... Without another 20 hp to 50 hp, you'll never notice the difference,...

I suggest goin' to a Big Block, if ya want more horsepower,...

 

[agallant80]

Re: is it possible to chip a 2002 5.7GXi

I see this topic come up from time to time. I don't know what it is with marine engines but no one really makes much in the performance department for them and the time/money to HP ratio is way out of whack.

 

[Tail_Gunner]

Re: is it possible to chip a 2002 5.7GXi

I see this topic come up from time to time. I don't know what it is with marine engines but no one really makes much in the performance department for them and the time/money to HP ratio is way out of whack.

It all center's around wet exhaust and reversion, think of how many different types of boat's there are and then how many exhaust type's..that is.... how boderline are they to reversion..Little light boat's say 18\22' are not going to squat much in the water now a 28 ' cruiser it is going to squat in the water..It's called Static line by some...

The static line is a measurement of the true water line on the engine to the top of the riser.(example half way up the exhaust manifold.)The way you find the static line is to take a one inch clear hose that's about 15 feet long. You take one end and put in in the water the other end you fill with water and bring it in to the boat. You make a loop in it and hold it up against the engine with the top of the hose above the engine with the loop below the engine with water still in the hose. What you end up with is the level in the hose is the true water line. You then make a mark on the engine usally on the exhaust manifold and you measure to the top of the riser. This is the static line. The water line to the top of the riser. Since the roller cam being used in the marine engine it has made the static line be increased because of the duration of the cam being used.The positive pull on the exhaust on the compression stroke. All engine manufactures are fighting this problem. (Water reversation) The manufactures have redesigned there exhaust requirements when installing the roller cam engine. There have been extentions made that go in between the manifold and risers. New style exhaust flappers. Mercruiser has made a resignator and Volvo has done some redesign on there risers they have tried pulse tubes. Now they have new guide lines for there exhaust requirements. Now they require so much drop with 90 degree turns on each turn.


The above is cut and past from a old iboat link..with that in mind how could any company go out and market one product to that many boat's....not going to happen. There are many engine builders who know the ragged line and build right up to it but they are expensive..Now if you do know about where that line is and are somewhat of a mech and like to tinker..it doesnt cost much to get 50 hp....a 100 hp no problem just bolt up some dry exhaust...there's the problem dry exhaust is about 2000 or much much more..Hence the term just buy a larger motor.

With all marine motor's it just a bigger cam new valve train and your off to the race's...just the nasty speed bump called reversion and the cost of getting around it.

 

[Walt T]

Re: is it possible to chip a 2002 5.7GXi

It's the weight of the water being pushed aside that sucks up the HP not the static line. Static line limits cam profile but if what you say were true dry exhaust boats would fly with a simple cam. Doesn't happen. Water's too heavy. Good point about the static line though, its often overlooked.

 

[Tail_Gunner]

Re: is it possible to chip a 2002 5.7GXi

It's the weight of the water being pushed aside that sucks up the HP not the static line. Static line limits cam profile but if what you say were true dry exhaust boats would fly with a simple cam. Doesn't happen. Water's too heavy. Good point about the static line though, its often overlooked.

Well what limits are there with a dry exhaust..reversion will not happen... the only thing limiting factor would be application..aka power band. I do not know however how fast a drive could turn and live with some degree or reliabilty what 6500?

As to static line the higher the water rise's into the exhaust system ..magnify's the reversion pulse's..read more vacum in a confined area..

 

[Walt T]

Re: is it possible to chip a 2002 5.7GXi

The reversion issue happens at idle or lower rpm with a high duration cam. Once the rpms are high enough the water can't come back in. This is why there are diverter valves for wet exhaust on high performance applications. Most high performance or racing engines use dry exhaust anyway so it's not an issue.

 

[Scott Danforth]

Re: is it possible to chip a 2002 5.7GXi

Thanx. Just trying to figure out a way of getting alittle hp out of it

you could build a stroker motor and re-program. that would get you a bit more power. or sell the existing boat, and buy a faster boat.

 

[Bondo]

Re: is it possible to chip a 2002 5.7GXi

Well what limits are there with a dry exhaust..reversion will not happen... the only thing limiting factor would be application..aka power band. I do not know however how fast a drive could turn and live with some degree or reliabilty what 6500?

As to static line the higher the water rise's into the exhaust system ..magnify's the reversion pulse's..read more vacum in a confined area..

Ayuh,.... When ya cam a motor for 6500 rpms, ya can't Get there,....

With a Huge cam, ya can't pull off Idle, to get anywhere near the peak power band,....

Ya only got 1 gear to go from Nothin', to White Knuckle Ride,.... :lol:

 

[Scott Danforth]

Re: is it possible to chip a 2002 5.7GXi

agree with one caveat.

there is the 2-speed IVSS gear box for certain volvo penta outdrive.

 

[Bondo]

Re: is it possible to chip a 2002 5.7GXi

agree with one caveat.

there is the 2-speed IVSS gear box for certain volvo penta outdrive.

Ayuh,.... 'n I've got a Torque-Shift prop,... But I still ain't gonna over cam my motor,.....

Some of the ole TRS were power-glide transmissions,... Never seen a 6500 rpm motor with one though,....

Jet-drives seems to be the drive for Monster cams,....

 

[JustJason]

Re: is it possible to chip a 2002 5.7GXi

You can stick with any cam you want as long as you have dry exhaust and an open engine compartment.

I've always had the idea to fart around with and old ski boat and install a powerglide 2 speed auto transmission just to see what the heck happens.