I just cant leave anything alone !!!
10-04-2022, 05:14 AM
#51
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Thread Starter
Looking at a set of Dana Marine manifolds right now... these are supposed to be good for 40+hp out of the box.
Apparently the VP manifolds and stupid-tall risers are horribly restrictive.
Currently in talks with Marine Industries West trying to figure out a riser/spacer combo that will work with my system. May need to shorten my Corsa drop tubes to the Y-pipe to lower the system a couple inches... or stack Dana spacers to raise the Dana system.
Just need to get busy with a tape measure.
https://www.marineindustrieswest.com...productid=3670
Apparently the VP manifolds and stupid-tall risers are horribly restrictive.
Currently in talks with Marine Industries West trying to figure out a riser/spacer combo that will work with my system. May need to shorten my Corsa drop tubes to the Y-pipe to lower the system a couple inches... or stack Dana spacers to raise the Dana system.
Just need to get busy with a tape measure.
https://www.marineindustrieswest.com...productid=3670
10-04-2022, 05:20 AM
#52
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Thread Starter
After reading his OP "I am in talks with Larry Hofer at Raylar Engineering and he tells me I need to find a GXi ECM for the easiest way to make his stage1 525hp top end work... so that hunt is currently ongoing."
So did Mercury crack down on reprogramming ECU's on inboards too? I thought it was only the outboard market but havent done any mods in forever. Does anybody still reprogram inboard ECU's?
So did Mercury crack down on reprogramming ECU's on inboards too? I thought it was only the outboard market but havent done any mods in forever. Does anybody still reprogram inboard ECU's?
Larry Hofer said the GXi ECM is a plug-n-play upgrade to my Gi ECM and will work with his 525hp heads/cam package. He also speaks highly of the Dana Marine manifolds noted in my previous reply.
A GXi-H ECM, part# 3889007 is what should work in my 2007 boat... but very difficult to source one.
The current engine/ECM:
Last edited by Dragracer_Art; 10-04-2022 at 05:58 AM.
10-04-2022, 05:30 AM
#53
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Thread Starter
Also worth a mention...
On the Facebook Chaparral owners page... there's a guy with another 256ssx for sale. Same boat as mine.
His is powered by the mercruiser 496HO that I had been shopping for... unfortunately his hit the market a few weeks too late and $10k too high... BUT... he is advertising that his boat will go a GPS verified 65mph with the current combo.
The previous owner of my boat claimed he has nipped 60mph with it already... but I cannot confirm if that was by GPS or a generous speedometer... so maybe my 55.4mph run was a little low/premature. New from the factory they claimed 56mph with this engine in it.
Either way... it's lends credibility to the possibility I may be able to push this hull to 65mph without spending $100k to do it.
Stay tuned.
On the Facebook Chaparral owners page... there's a guy with another 256ssx for sale. Same boat as mine.
His is powered by the mercruiser 496HO that I had been shopping for... unfortunately his hit the market a few weeks too late and $10k too high... BUT... he is advertising that his boat will go a GPS verified 65mph with the current combo.
The previous owner of my boat claimed he has nipped 60mph with it already... but I cannot confirm if that was by GPS or a generous speedometer... so maybe my 55.4mph run was a little low/premature. New from the factory they claimed 56mph with this engine in it.
Either way... it's lends credibility to the possibility I may be able to push this hull to 65mph without spending $100k to do it.
Stay tuned.
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ICDEDPPL (10-04-2022)
10-04-2022, 06:58 AM
#54
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A 256ssx with a 496HO has 50 more HP than your mill. I'm not convinced it is 10mph faster however.
When I did customer deliveries for a Cobalt dealer, the Merc boats were always 3-5 mph faster than the Volvo boats when comparing Gi/Gxi to the non HO and HO motors. We did have one customer that ordered a 496 HO boat with a Bravo 1 and that was clearly faster than the B3 boats by a good margin.
When I did customer deliveries for a Cobalt dealer, the Merc boats were always 3-5 mph faster than the Volvo boats when comparing Gi/Gxi to the non HO and HO motors. We did have one customer that ordered a 496 HO boat with a Bravo 1 and that was clearly faster than the B3 boats by a good margin.
The following 2 users liked this post by techman:
Dragracer_Art (10-04-2022), ICDEDPPL (10-04-2022)
10-04-2022, 07:33 AM
#55
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Thread Starter
A 256ssx with a 496HO has 50 more HP than your mill. I'm not convinced it is 10mph faster however.
When I did customer deliveries for a Cobalt dealer, the Merc boats were always 3-5 mph faster than the Volvo boats when comparing Gi/Gxi to the non HO and HO motors. We did have one customer that ordered a 496 HO boat with a Bravo 1 and that was clearly faster than the B3 boats by a good margin.
When I did customer deliveries for a Cobalt dealer, the Merc boats were always 3-5 mph faster than the Volvo boats when comparing Gi/Gxi to the non HO and HO motors. We did have one customer that ordered a 496 HO boat with a Bravo 1 and that was clearly faster than the B3 boats by a good margin.
I'll take that as a positive development.
10-04-2022, 08:20 AM
#56
Platinum Member
Platinum Member
Incremental improvement is going to frustrate the pee out of you.
Drop 2 grand - convince yourself you see 2 mph from it, but you know in your heart that it is more like 1.2 mph.
Drop another 2 grand - maybe-another mph.
Drop another 3 grand - picked up 2 more real mph but made it a hassle to get on plane..
You have said ONE thing in all of this that made good sense. Build an engine. A 600hp big block with carb. Drop it in. Go run it. If you don't like the results, Drop it in a Camaro.
If you do like the results, then determine how much of the VP fuel injection stuff you want to try to transplant over to it.
Drop 2 grand - convince yourself you see 2 mph from it, but you know in your heart that it is more like 1.2 mph.
Drop another 2 grand - maybe-another mph.
Drop another 3 grand - picked up 2 more real mph but made it a hassle to get on plane..
You have said ONE thing in all of this that made good sense. Build an engine. A 600hp big block with carb. Drop it in. Go run it. If you don't like the results, Drop it in a Camaro.
If you do like the results, then determine how much of the VP fuel injection stuff you want to try to transplant over to it.
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Dragracer_Art (10-04-2022)
10-04-2022, 08:39 AM
#57
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Thread Starter
Incremental improvement is going to frustrate the pee out of you.
Drop 2 grand - convince yourself you see 2 mph from it, but you know in your heart that it is more like 1.2 mph.
Drop another 2 grand - maybe-another mph.
Drop another 3 grand - picked up 2 more real mph but made it a hassle to get on plane..
You have said ONE thing in all of this that made good sense. Build an engine. A 600hp big block with carb. Drop it in. Go run it. If you don't like the results, Drop it in a Camaro.
If you do like the results, then determine how much of the VP fuel injection stuff you want to try to transplant over to it.
Drop 2 grand - convince yourself you see 2 mph from it, but you know in your heart that it is more like 1.2 mph.
Drop another 2 grand - maybe-another mph.
Drop another 3 grand - picked up 2 more real mph but made it a hassle to get on plane..
You have said ONE thing in all of this that made good sense. Build an engine. A 600hp big block with carb. Drop it in. Go run it. If you don't like the results, Drop it in a Camaro.
If you do like the results, then determine how much of the VP fuel injection stuff you want to try to transplant over to it.
I will give a buddy of mine a call and see what he can whip together for me. Andy Jensen is pretty well known in Drag Racing and has always been my go-to guy for machine work.. been friends with him since mid-90's.
Last big boy I built was this 632 in my Camaro in 2004. It made 881hp at the rear wheels on a single Nickerson Dominator.
I'd love to have something like this in my boat... but obviously detuned for pump gas and hydraulic roller.
The following 2 users liked this post by Dragracer_Art:
the deep (10-04-2022), Wildman_grafix (10-04-2022)
10-04-2022, 08:48 AM
#58
Registered
Nice looking split bumper
Yeah... I am leaning in this direction.
I will give a buddy of mine a call and see what he can whip together for me. Andy Jensen is pretty well known in Drag Racing and has always been my go-to guy for machine work.. been friends with him since mid-90's.
Last big boy I built was this 632 in my Camaro in 2004. It made 881hp at the rear wheels on a single Nickerson Dominator.
I'd love to have something like this in my boat... but obviously detuned for pump gas and hydraulic roller.
I will give a buddy of mine a call and see what he can whip together for me. Andy Jensen is pretty well known in Drag Racing and has always been my go-to guy for machine work.. been friends with him since mid-90's.
Last big boy I built was this 632 in my Camaro in 2004. It made 881hp at the rear wheels on a single Nickerson Dominator.
I'd love to have something like this in my boat... but obviously detuned for pump gas and hydraulic roller.
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Dragracer_Art (10-06-2022)
10-04-2022, 09:09 AM
#59
VIP Member
VIP Member
Yeah... I am leaning in this direction.
I will give a buddy of mine a call and see what he can whip together for me. Andy Jensen is pretty well known in Drag Racing and has always been my go-to guy for machine work.. been friends with him since mid-90's.
Last big boy I built was this 632 in my Camaro in 2004. It made 881hp at the rear wheels on a single Nickerson Dominator.
I'd love to have something like this in my boat... but obviously detuned for pump gas and hydraulic roller.
I will give a buddy of mine a call and see what he can whip together for me. Andy Jensen is pretty well known in Drag Racing and has always been my go-to guy for machine work.. been friends with him since mid-90's.
Last big boy I built was this 632 in my Camaro in 2004. It made 881hp at the rear wheels on a single Nickerson Dominator.
I'd love to have something like this in my boat... but obviously detuned for pump gas and hydraulic roller.
Dart Big M Block Questions - Offshoreonly.com
Thanks. Brad.
(937)545-8991
10-04-2022, 09:43 AM
#60
Registered
Thread Starter
This should make the swap pretty straightforward with respect to exhaust port height/alignment and engine compartment fit.
I think a 10.2 block with a 4.600 bore and 4.5" stroke would be a pretty bulletproof and reliable combo @ 598 cubes and should be a pretty clean swap.
Thanks for the link above. I will read through it !
