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View Full Version : Max RPM Indmar 350 TBI


tommyadrian5
12-14-2011, 06:34 PM
I'm wondering what the max recommended RPM is for the 1999 or so era 350 TBI is. The only reason I ask is that I have a 4 bladed prop on my 1999 sportstar OB which seems to be more for raw pulling power than speed. I don't think i've ever actually given it WOT since I got it since it seems to be absolutely screaming when i'm almost there.

The boat came with a tower and several fat sacs and I've run 2400lbs of ballast in it with no problems getting out of the hole quickly, which is why I believe it is propped for power over speed.

Also, i've heard over the years that props can actually affect the ride of the boat. The trip to and from most of my riding spots can get very choppy by the end of the day, and the boat tends to slam hard as well as blast into larger wakes (i'm usually careful to slow down and not smash the boat up). Some people said a 3 blade will cause a smoother ride than the 4 blade. Is there any truth to this?

-V-
12-14-2011, 06:35 PM
2400 lbs of ballast? thats a lot!!

thatsmrmastercraft
12-14-2011, 07:32 PM
I'm wondering what the max recommended RPM is for the 1999 or so era 350 TBI is. The only reason I ask is that I have a 4 bladed prop on my 1999 sportstar OB which seems to be more for raw pulling power than speed. I don't think i've ever actually given it WOT since I got it since it seems to be absolutely screaming when i'm almost there.

The boat came with a tower and several fat sacs and I've run 2400lbs of ballast in it with no problems getting out of the hole quickly, which is why I believe it is propped for power over speed.

Also, i've heard over the years that props can actually affect the ride of the boat. The trip to and from most of my riding spots can get very choppy by the end of the day, and the boat tends to slam hard as well as blast into larger wakes (i'm usually careful to slow down and not smash the boat up). Some people said a 3 blade will cause a smoother ride than the 4 blade. Is there any truth to this?

Eric Johnson to aisle three...................propeller question:popcorn:

GT500 MC
12-14-2011, 07:35 PM
Eric Johnson to aisle three...................propeller question:popcorn:

That's good. We need an icon for that--kind of like a smiley for a prop question. Maybe a pic of a prop and put it over in the Smilies section. Whenever someone has a prop question, they just post that and it automatically sends an email to Eric.

thatsmrmastercraft
12-14-2011, 08:00 PM
That's good. We need an icon for that--kind of like a smiley for a prop question. Maybe a pic of a prop and put it over in the Smilies section. Whenever someone has a prop question, they just post that and it automatically sends an email to Eric.

Forget the email, just something like this with a propeller.

tommyadrian5
12-14-2011, 09:36 PM
2400 lbs of ballast? thats a lot!!


Yea, only did that a few times years ago. Mellowed out as I got older. The wake was nuts though, but I was never comfortable with anybody else driving it like that...

swatguy
12-14-2011, 10:01 PM
Depending on boat, trans, and use combo believe it or not a good 3blade can give u a benefit and a little smoother rude. However no disrespect to Eric here but I just feel Acme'has a much better 3 blade than Oj. ..........Oj just doesn't have that part covered in the 3 blade performance area. Fwiw we used to yank the factory 4 blades on all our wakeboats from a diff mfg and put on an acme 3 blade. The performance was unbeatable. There are a ton of guys with wakeboats still running 3 blades over the 4. Just again depends on engine, trans, hull, and what you need from your prop. And I would say more than 75% of the 3 blades are acmes. Certain 3 blades will have more surface area than a compareable 4 blade

It also helped the wake for boarding. While I don't remember exacty sabre it did the 3 blade gave the boat a very very slight difference toxins altitude just enough to adjust the wakeboard wake and make it a bit more firm on those boats and eliminate a small portion of wash. I just don't remember if the 3 blade made boat ride just a fraction higher or lower than the 4. Again its not noticeable per say for cruising where u will notice for that, but the wake will be a bit different.

However I an not the expert so I would give acme a call.

JimN
12-14-2011, 10:46 PM
I'm wondering what the max recommended RPM is for the 1999 or so era 350 TBI is. The only reason I ask is that I have a 4 bladed prop on my 1999 sportstar OB which seems to be more for raw pulling power than speed. I don't think i've ever actually given it WOT since I got it since it seems to be absolutely screaming when i'm almost there.

The boat came with a tower and several fat sacs and I've run 2400lbs of ballast in it with no problems getting out of the hole quickly, which is why I believe it is propped for power over speed.

Also, i've heard over the years that props can actually affect the ride of the boat. The trip to and from most of my riding spots can get very choppy by the end of the day, and the boat tends to slam hard as well as blast into larger wakes (i'm usually careful to slow down and not smash the boat up). Some people said a 3 blade will cause a smoother ride than the 4 blade. Is there any truth to this?

Sportstar OB- is that 'outboard'? They didn't make a Sportstar outboard, they made a Barefoot 200 with an outboard. if you try to exceed the engine's top RPM, you'll know it. The rev limiter kicks in at 5000, IIRC. You won't notice much difference between about 4500 and 5000 RPM, either.

-V-
12-14-2011, 10:53 PM
so what is better, a 3 or 4 blade?

ddanenberger
12-14-2011, 10:59 PM
so what is better, a 3 or 4 blade?

or 5 blade?

thatsmrmastercraft
12-14-2011, 11:05 PM
6 blade anyone???

east tx skier
12-14-2011, 11:12 PM
Sportstar OB- is that 'outboard'? They didn't make a Sportstar outboard, they made a Barefoot 200 with an outboard. if you try to exceed the engine's top RPM, you'll know it. The rev limiter kicks in at 5000, IIRC. You won't notice much difference between about 4500 and 5000 RPM, either.

In 99, they made the Sportstar OB (open bow), which later became (briefly), the Pro Star 195/X5..

willyt
12-14-2011, 11:32 PM
Depending on boat, trans, and use combo believe it or not a good 3blade can give u a benefit and a little smoother rude. However no disrespect to Eric here but I just feel Acme'has a much better 3 blade than Oj. ..........Oj just doesn't have that part covered in the 3 blade performance area. Fwiw we used to yank the factory 4 blades on all our wakeboats from a diff mfg and put on an acme 3 blade. The performance was unbeatable. There are a ton of guys with wakeboats still running 3 blades over the 4. Just again depends on engine, trans, hull, and what you need from your prop. And I would say more than 75% of the 3 blades are acmes. Certain 3 blades will have more surface area than a compareable 4 blade

It also helped the wake for boarding. While I don't remember exacty sabre it did the 3 blade gave the boat a very very slight difference toxins altitude just enough to adjust the wakeboard wake and make it a bit more firm on those boats and eliminate a small portion of wash. I just don't remember if the 3 blade made boat ride just a fraction higher or lower than the 4. Again its not noticeable per say for cruising where u will notice for that, but the wake will be a bit different.

However I an not the expert so I would give acme a call.

are... you on crack? name me a manufacturer that puts 3 blades on their wakeboats from the factory... there are SOOOOO many different pitch/diameter combinations you cannot accurately compare a '3 blade prop' with a '4 blade prop'. Apparently the newest thing from OJ is the 5 blade which is suppose to increase efficiency (each specifically designed to be paired with a different engine), and threads on this site seem to confirm that.

While different pitch/diameter combinations will give you different RPMs at cruise/wakeboard speed/holeshot, i believe the 'smoothness' your seeking from the ride is totally controlled by the weight and hull design of your boat. the 25/35/55 line will be the best in rough water, while the old flatter-bottom hulled boats will be the worst (I happen to have one, 05 X2).

I actually have a 14.5x14.25 acme and a 14.25x14.5 OJ. I prefer my OJ. May just be preference though, IMO.

agarabaghi
12-14-2011, 11:53 PM
we run 2400 lbs + people + gear regularly. 4 blade, 14.25 x 14...

No one runs 3 blade for wakeboarding. I dont have anything else to add to this thread lol

mikeg205
12-15-2011, 08:40 AM
are... you on crack? name me a manufacturer that puts 3 blades on their wakeboats from the factory... there are SOOOOO many different pitch/diameter combinations you cannot accurately compare a '3 blade prop' with a '4 blade prop'. Apparently the newest thing from OJ is the 5 blade which is suppose to increase efficiency (each specifically designed to be paired with a different engine), and threads on this site seem to confirm that.

While different pitch/diameter combinations will give you different RPMs at cruise/wakeboard speed/holeshot, i believe the 'smoothness' your seeking from the ride is totally controlled by the weight and hull design of your boat. the 25/35/55 line will be the best in rough water, while the old flatter-bottom hulled boats will be the worst (I happen to have one, 05 X2).

I actually have a 14.5x14.25 acme and a 14.25x14.5 OJ. I prefer my OJ. May just be preference though, IMO.

well explained....+1

east tx skier
12-15-2011, 11:42 AM
The 3 blade advantages over a 4 blade have been more applicable to slalom boats. The acme 541 has the same blade surface area as the comparably sized 4 blade they offer. Acme does not, to my knowledge, recommend a 3 blade for wakeboarding applications. But for slalom, some people, prefer it.

swatguy
12-15-2011, 12:25 PM
are... you on crack? name me a manufacturer that puts 3 blades on their wakeboats from the factory... there are SOOOOO many different pitch/diameter combinations you cannot accurately compare a '3 blade prop' with a '4 blade prop'. Apparently the newest thing from OJ is the 5 blade which is suppose to increase efficiency (each specifically designed to be paired with a different engine), and threads on this site seem to confirm that.

While different pitch/diameter combinations will give you different RPMs at cruise/wakeboard speed/holeshot, i believe the 'smoothness' your seeking from the ride is totally controlled by the weight and hull design of your boat. the 25/35/55 line will be the best in rough water, while the old flatter-bottom hulled boats will be the worst (I happen to have one, 05 X2).

I actually have a 14.5x14.25 acme and a 14.25x14.5 OJ. I prefer my OJ. May just be preference though, IMO.

Actually I am not on crack just filled with correct info that has been proven over and over again. If you noticed I stated on boats from different mfg and also having to do with engine/tranny combo. You are making a blanket statement regarding every boat performing better with a 4 blade and now a 5 blade. Current certain model Sangers, Centurions, Supremes are boats that they would put Acme 3blades on a take the factory 4 blades off. I am sure Eric will gladly provide the scientific info on why some 3 blades give better performance. The op has on older boat with older engine and specs. While most newer boats def perform better with the newly designed 4 blades and now some with4 the newest 5 blade its just not the case for everyboat out there. Especially older boats. There are again so many factors on the prop you can't just assume because the prop is the latest design it's the beat for everyboat. I could have possibly misunderstood the smoothness he wanted, but in some cases at certain rpmsa 3 blade will spin smoother and you won't notice as much vibration. While not blatantly obvious at wakeboard speeds up that to the 35-45mph range and it becomes apparent very quickly. Lets remember again the op has an older boat with older hull design, older engine tranny package


we run 2400 lbs + people + gear regularly. 4 blade, 14.25 x 14...

No one runs 3 blade for wakeboarding. I dont have anything else to add to this thread lol

Again this a completely incorrect statement. While no MC wakenoat runs a 3blade better than a 4, its just not the case everywhere and for every boat that wakeboards primarily.

swatguy
12-15-2011, 12:32 PM
The 3 blade advantages over a 4 blade have been more applicable to slalom boats. The acme 541 has the same blade surface area as the comparably sized 4 blade they offer. Acme does not, to my knowledge, recommend a 3 blade for wakeboarding applications. But for slalom, some people, prefer it.



PRECISELY,

However Acme will still recommend a 3boat blade for some wakeboats as well. Some current wake hulls have been around a while from other mfg and still need/recommend 3 blades the Sanger V210's, Centurion Cyclones/elite v c 4's'/falcon v, and Supreme are the most commonly known v drive wakeboats that perform the best with the 3 blade.

east tx skier
12-15-2011, 05:13 PM
PRECISELY,

However Acme will still recommend a 3boat blade for some wakeboats as well. Some current wake hulls have been around a while from other mfg and still need/recommend 3 blades the Sanger V210's, Centurion Cyclones/elite v c 4's'/falcon v, and Supreme are the most commonly known v drive wakeboats that perform the best with the 3 blade.

And the converse is true with some ski boats. For example, they recommend the 422 four blade for the TSC/TSC2/TSC3 Ski Nautiques.

Also, on the 3 blades, I think the language I have heard over and over again to describe one performance advantage is "they spin up faster." Not exactly sure what that means though.

Double D
12-15-2011, 07:10 PM
I have the 350 TBI with a 1:1 Transmission in my 205. I upgraded to a 4-blade this past summer and did some very basic tests before and after related to speed and RPM. Here are the results:

3-Blade:
Speed: 0 to 32mph - 8.6 Seconds (average of 3)
Top Speed 41.2

4 Blade:
Speed: 0 to 32mph - 8.0 Seconds (average of 3)
Top Speed 40.8

I did my RPM tests later so I dont have them for the 3-Blade:

Tests using the original RPM dial:
30 mph = 3200 rpm
33 mph = 3400 rpm
40 mph = 4400 rpm

Tests using the Perfect Pass RPM indicator:
30 mph = 3050 rpm
33 mph = 3350 rpm
41 mph = 4300 rpm

Not sure if that is what your looking for but good luck!!