StingrayBR

Thanks for the info kornegle. The SX and LX were not too dissimilar in weight and design. If I recall Stingray would post speeds about 1-2mph higher with the 230 SX set up the same way on their claimed performance. I am boating on Newfound Lake in NH which is 600feet and is humid more often than not and have never come close to their speed. I think they claimed the stock 230lx with 300mpi was 60-61mph and I never saw more than 57 gps and usually ran closer to 54. I was running a 21 laser too which is about 1mph faster than the mirage on my boat having run both. You are definitely getting more speed with 375hp than I would. I forgot to add that my 385PT has headers and captains call exhaust which supposedly makes it closer to 375hp pre-whipple and I think I saw 62 once. 58-60 was more like it.

Did you get more chine walking with the additional bow lift? Now that I am running high 60s that is my limiting factor. Particularly when there is a small chop which used to be my best top speed conditions.

ACrooks69

If it's any help, 2001 230LX
Stock 5.7TBI B3, 26p - 56gps
383 - 480hp B1 (corrected, Kodiak Exh Dyno),mirage 21p - 70gps.
413 - 440hp, B1 (corrected, EMI), Offshore 21p - 68gps
413 - 620hp Procharger, B1 (corrected, dyno headers), B1XS 24p - 80gps, P5X 25p - 80gps

kornegle

Well, horsepower wise, I had a 496 Mag (375 HP rating) in a 230SX Stingray. I think the hull bottom on the 230SX and yours is the same (I might be wrong). The 375 HP with a 25P Mirage Plus prop pushed mine to about 67 mph at 4600 rpm (about 8.4% slip) with my wife and me and a bit less than 1/2 tank of fuel. Your small block is lighter, even with the blower so I would expect it to be at least as fast with the same HP. If it has 515 HP, I would think it would run closer to 74 mph?

RHAMLIN45

Hey Guys, new to the forum. I'm purchasing a 05 230sx with the 8.1/496 ..


Can anyone tell me the realistic top speed please?

Here or dm is fine!

kornegle

Mine 230SX ran about 67 mph at 800 ft elevation and mine was a 375 HP Mag not the 425HP Mag HO. The 425 HO should run at least 71 - 72 mph. The Stingray website said mine should run 68 - 69 mph but I never hit that. Perhaps in colder weather with less than 1/4 tank and me in it alone it would have hit 68 mph? Running the Silent Choice exhaust open or closed made no difference in top speed on mine. It was a good comfortable boat, on smoother water. I sold it and bought a new 2400 Checkmate Pulsare with a 300R, and it has only run 76 mph so it was not that much faster.

RHAMLIN45

Any idea why this one is hitting 58? The wake tower shouldn't make it drop 12 mmp should it? In order to hit the 70s should he have to trim out or no?

liberator221

Trim- Yes
Trim setting is a constantly moving target. Depends on load, speed, water conditions.
At WOT bump your trim up while watching speed. When speed/RPM stops increasing stop increasing trim.
(RPM can increase without an increase in speed, that means you are trimmed out to much.)

StingrayBR

First an update. After a winter with Jason Saris the 385PT has really woken up. Dyno sheet attached. I ran it for a few weeks and realized that the air vents on the side were too small. Took me a while to figure this out. Jason hit 76mph GPS on Lake George where he is with no engine cover in hot and humid conditions. With the cover on I saw 72-73mph in the early summer humidity. I found a set of vents that are slightly more than double the size of the old ones and with those I hit 75mph @5300 rpm with my labbed four blade Bblades OBFX (14 inch diameter, 25 pitch). I had 5 people in the boat, half a tank and it was 80s and humid. Unfortunately after that I had an electrical issue with my fuel system and decided instead of troubleshooting it I would take it back to Jason for an upgraded system with a single pump. He is so good I think it is a confidence thing to bring it back rather than risk someone else now. He also tweaked my fuel map a little bit but it ran really well with his first custom program. I am excited to try it again next summer. Given that the extremes of hot and humid vs. cool and dry were worth about 4mph the summer before I think it may be possible to see 80 @5,600. I am taking Jason's advice and propping for 5,600 max.

One thing I realized about this boat now is that it takes a lot longer to get to top speed. It will very quickly get to what appears to be a steady level and will consistently rise about 1mph or 2mph over the next couple of minutes. A little bit of that is coaxing it with trim until it chines but I think it is mainly from the smaller diameter prop getting full grip and losing its slip.

To speculate on speed of the 230sx mentioned above, here is my speed history based on the most optimal conditions I could find:

Stock 300hp - 57mph
385PT stock + headers - 350hp (said 370 w/headers) 62mph
Whipple added 5lbs boost and XR drive - HP unknown but speculate 470 - 70-71mph
Now - 561hp (@5300) - 75mph with my boat loaded - I think 588hp @5,600 rpm and 80mph possible in very ideal conditions

StingrayBR

I was thinking about it this morning and realized I should have added the realistic speeds for my Stingray in addition to the fastest. I would say realistic means 1/2+ tank of gas, a few people in boat and weather where you want to be on the water so 75+F. See below:

Stock 300hp - 57mph; realistically 52-53mph
385PT stock + headers - 350hp (said 370 w/headers) 62mph; realistically 57-59mph
Whipple added 5lbs boost and XR drive - HP unknown but speculate 470 - 70-71mph; realistically 66mph - 68mph
Now - 561hp (@5300) - 75mph with my boat loaded - I think 588hp @5,600 rpm and 80mph possible in very ideal conditions; in this case the 75mph was the realistic speed.

One other observation on these boats is that weight definitely impacts speed more when my hp was lower particularly weight in the bow. With the higher hp weight is less of a factor than it was before and weather seems more of a determinant. I remember when I was running the 350/370hp I had two ~180lb boys in the bow and three adults in the back on a hot day. Boat ran 53mph with the boys in the bow and just having them move to the bench seat in the back made it accelerate to 56mph.

On top speed and trim when I was lower hp I could get a little bit of porpoise by overtrimming and could rev up too. Once the boat got over 66mph overtrimming would cause chine walking before I got the rev increase or porpoise from over trimming. Also, at 60mph or less my fastest speeds were in about 1'-2' chop with following wake. Now I need closer to calm to really trim it up without chine walking.

kornegle

My 230SX only ran about 67 mph so it was too slow to chine walk. Perhaps that heavy big block kept the stern planted and reduced the chine walk? I could trim it to the stops and it would not really chine walk/