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-   -   what to do to get more speed ? (https://www.offshoreonly.com/forums/general-q/262836-what-do-get-more-speed.html)

1997 advantage27 09-23-2011 04:04 AM

what to do to get more speed ?
 
I have a 1997 advantage 27 footer with 502 mercury motor, came with 400hp from factory. the motor trimed up does 59 miles at 5000 rpm.

I like to bump up to 65 to 70 miles per hour, any external modification that can be done on this motor to get more horse power.
Also besides the external modifications , what would give me the best bang for the money to increase hp and speed.

thanks

Edwin

tinman565 09-23-2011 04:42 AM

Whipple..or Procharger. :drink:

blue thunder 09-23-2011 06:17 AM

Raising the outdrive 2" with a shorty is always the best bang for the buck mph wise. Plus you can easily sell it when done and recoup a good amount of the money spent. You just need to do a little homework up front to make sure your boat will respond well to less prop shaft depth.

pitts1313 09-23-2011 06:28 AM


Originally Posted by tinman565 (Post 3510325)
Whipple..or Procharger. :drink:

Yep, turn your hat around backwards and drop 6k on a blower setup if you're going do it external! 15-20hp = about 1 mph. Flame arrestor, exhaust, carbs,mpi mapping upgrades equate to minutiae gains without a major component like a blower added. Enjoy as is, or blower, don't waste any money on the other.

Jeff P31 09-23-2011 11:14 AM

Why is it that so many people think that you just buy one or two majic part's and you will go 20 mph faster ? And oh yah I want to do it for less than 1 hundred dollars ! :rolleyes:

blue thunder 09-23-2011 12:00 PM


Originally Posted by Jeff P31 (Post 3510568)
Why is it that so many people think that you just buy one or two majic part's and you will go 20 mph faster ? And oh yah I want to do it for less than 1 hundred dollars ! :rolleyes:

One thousand dollars per mph is my experience on a twin eng boat. 500 on a single.

My boat started in the 60mph range and it has a best now of 94mph. Biggest pop I got was from raising the prop shaft depth 2". Superchargers next. You need to have your engines built for blowers to do blower engines so that gets costly fast.

HTRDLNCN 09-23-2011 12:07 PM

I picked up ten mph with a weiand 256 at 5lbs on my 502powered 27 Carrera tuned with a wideband AF meter I already had , total cost was around $2500,bought everything on the swap shop on here.It can be done if you can wrench it yourself and are a patient shopper.

pqjack 09-23-2011 12:29 PM


Originally Posted by tinman565 (Post 3510325)
Whipple..or Procharger. :drink:

have one of each for sale for 454/502 mpi...
pm me if interested

CrownHawg 09-23-2011 02:17 PM

The Advantage while being a solid boat, is not what could be considered a "speed" hull. With roughly 750hp (twins) I'm in the mid 70s. Your 502 could take a whipple fairly well. My 496s, not so much.

ezstriper 09-23-2011 04:18 PM

yell more power scotty !!! going to need boost to get you there in my opinion..time to call procharger

snapmorgan 09-23-2011 05:52 PM

I have a 2000 27 Advantage mid cabin. Mine with the original 454mag would run 54 mph. I dropped in a 575hp 540 looking for 70 mph and came up way short. It will now run 63mph. Gained 9mph by adding 190 hp. I have purchased an XR upper and -2 Imco lower, but have not installed them yet. From speeking with other Victory owners, i expect it will pick up considerably with the outdrive swap. I am also running the stock 454MPI intake and plan on swapping it out this winter. I am sure it is costing me lots of hp and rpm. I think with these 2 changes i will get to 70, but you never know.

On my engine I just could not find the room to add a procharger. I only have 1" between the crankshaft pulley and the back of the seat. Would have had to completely redo the seat and engine cover to install one. Yours may or may not be the same.

Good luck

pqjack 09-24-2011 06:03 AM


Originally Posted by snapmorgan (Post 3510815)
I have a 2000 27 Advantage mid cabin. Mine with the original 454mag would run 54 mph. I dropped in a 575hp 540 looking for 70 mph and came up way short. It will now run 63mph. Gained 9mph by adding 190 hp. I have purchased an XR upper and -2 Imco lower, but have not installed them yet. From speeking with other Victory owners, i expect it will pick up considerably with the outdrive swap. I am also running the stock 454MPI intake and plan on swapping it out this winter. I am sure it is costing me lots of hp and rpm. I think with these 2 changes i will get to 70, but you never know.

On my engine I just could not find the room to add a procharger. I only have 1" between the crankshaft pulley and the back of the seat. Would have had to completely redo the seat and engine cover to install one. Yours may or may not be the same.

Good luck

i agree,the 454 intake is definitely costing you quite a bit of power...there's a couple of places that port/modify them for more air...with a goal of 575hp,i think you'd still be at the limit of that intake...got that info from eddie young a while ago


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