21SDC 250R Question

[sowenssw]

I have a 2022 21SDC, 2020 250R (was flashed before the crack-down), Sportmaster 1:75 gears, 14" Bob's hydraulic jackplate, 28 Hydromotive 4 blade prop. Ghost troller, 10' power poles. All Lithium batteries.

For the sake of not getting into a loaded / light discussion, let say no tackle, full tank of fuel, live well empty.

Folks who are running similar set ups, what are you seeing as far as top speed? Is anyone seeing mid to upper 80's?

I looked through the "set up" page, but was wondering if there might be more current info floating around out there?

I appreciate the feedback.

Thanks!

[rocketmanjp]

I fish solo mostly & dont have any topend numbers with 2 people and I dont have power poles. Best run when I first had the engine and a lighter troller was 92 & chg solo full fuel empty livewells & all my tackle (light, nothing heavy in front)….29 bravo. Best I have seen with heavier troller & 28 promax prop. is 88…all else the same. Original run was all agm batteries. I now have a lithium cranker & agm troll batts.

[PatriotAW4]

From everything I have seen there is a pretty considerable jump in HP going from a 250R to a 300R. It's more like a 70-75 hp jump instead of the advertised 50hp.

[sowenssw]

Thanks Rocketman, I would be very happy with 88, I just can't seem to get there. I can only turn this 28 hydromotive 5800 and 79-80 mph. I know the 1:75 don't string out, but no way could I turn the 28 and 1:60's and get out of the hole or turn any RPM's on top. I just feel like something isn't jiving with my set up. Hole shot is really strong, jumps out of the hole, pulls its a$$ off mid range, but dies off quick on top.

I've tried lots of different props, and the 28 Hydromotive seems to be about the best of everything I've tried so far for my set up.

[sowenssw]

From everything I have seen there is a pretty considerable jump in HP going from a 250R to a 300R. It's more like a 70-75 hp jump instead of the advertised 50hp.

The flash is supposed to put the 250R to ~325hp, but I've never had it dyno'd so I can't prove or say with any certainty.

[rocketmanjp]

Did you ever run it without the power poles? 10’ power poles is a lot of wind drag & ghost is heavy too. Any big graphs on the front? Seems like you should be on the limited w/28 prop & 1.75 gears. If the motor is mechanical have you had the throttle chkd for WOT? My best run was in summer at 92.2 @ 6120 rpms w/3-31 optimas, 29 bravo & 24v MG X5 TM. Was either 1.5” or 1.75” above pad, I caint remember. Hydraulic plate & 16” setback.

[Tim Powell]

I have a 2022 21SDC, 2020 250R (was flashed before the crack-down), Sportmaster 1:75 gears, 14" Bob's hydraulic jackplate, 28 Hydromotive 4 blade prop. Ghost troller, 10' power poles. All Lithium batteries.

For the sake of not getting into a loaded / light discussion, let say no tackle, full tank of fuel, live well empty.

Folks who are running similar set ups, what are you seeing as far as top speed? Is anyone seeing mid to upper 80's?

I looked through the "set up" page, but was wondering if there might be more current info floating around out there?

I appreciate the feedback.

Thanks!

IMO, you are going to need a Max 5 to carry the boat well enough to make it run to its full potential. We have setup and ran the 21XRS/300R with poles and 4 units to 92-93 mph. We have also ran the boat without poles to 95-96 mph.

A 4 blade will run decent light and solo but it will fall on its face when you add a passenger.

Also, if the throttle isnt calibrated properly, you can throw props at it all day long and it will never spin up. If your flash truly worked and your throttle is properly calibrated, you should have no issues spinning 28 pitch props beyond 6200 RPM.


1.75 gears have zero issues stringing out, and is also my preferred gearset for a single engine application.

[PatriotAW4]

The flash is supposed to put the 250R to ~325hp, but I've never had it dyno'd so I can't prove or say with any certainty.

Ok I missed that part, who flashed it?

[sowenssw]

Ok I missed that part, who flashed it?

The dealer I purchased the engine from did the flash, but as I mentioned, that was in 2020 before the crack down.

[sowenssw]

Thank you all very much for the info!!!! This is very helpful, and gives me hope there is more on the table.

Rocketman - I never ran the boat without the poles, however I had a 20' XDC before the 21SDC. I ran it with and without poles, and the poles did make a few mph difference even on the 20'er. Only a 9" graph on the front. I agree, the Ghost is a heavy dude.

Tim Powell, I actually had a MAX5 before, and the boat did seem to work really well with the 5 blade, however it was a 32 and too much prop, so I went to the I have 4 blade only because it was available at the time, and knowing it isn't the best prop for the set up. I would really like to have a MAX5 in a 29. I completely agree with you it should be on the limiter with the 28.

As I mentioned, thank you all so much for the feedback!! This is exactly what I needed. I think a good starting point is as Rocketman suggested, make sure I'm getting 100% throttle. To me it seems like its not, so I'm starting there. I do have access to trying a lot of different props, so going to try another 5 blade once I determine I'm getting 100% throttle.

[Tim Powell]

Thank you all very much for the info!!!! This is very helpful, and gives me hope there is more on the table.

Rocketman - I never ran the boat without the poles, however I had a 20' XDC before the 21SDC. I ran it with and without poles, and the poles did make a few mph difference even on the 20'er. Only a 9" graph on the front. I agree, the Ghost is a heavy dude.

Tim Powell, I actually had a MAX5 before, and the boat did seem to work really well with the 5 blade, however it was a 32 and too much prop, so I went to the I have 4 blade only because it was available at the time, and knowing it isn't the best prop for the set up. I would really like to have a MAX5 in a 29. I completely agree with you it should be on the limiter with the 28.

As I mentioned, thank you all so much for the feedback!! This is exactly what I needed. I think a good starting point is as Rocketman suggested, make sure I'm getting 100% throttle. To me it seems like its not, so I'm starting there. I do have access to trying a lot of different props, so going to try another 5 blade once I determine I'm getting 100% throttle.

Return/Idle throttle position is just as important as WOT. If it goes 100% but only returns to 10% then you will only have 90% at the next key on. It must return as close to 0% as possible and definitely less than 2.5% at dead idle.

[sowenssw]

Return/Idle throttle position is just as important as WOT. If it goes 100% but only returns to 10% then you will only have 90% at the next key on. It must return as close to 0% as possible and definitely less than 2.5% at dead idle.

I checked and it was not returning to 100%. I'm guessing at least 10-15% short of full return. I adjusted and have it scheduled with my dealer this week to check on the computer to ensure its seeing 100% WOT. Thank you all again for the great info. I'm hopeful this helps my performance.

As a side note, I did all the rigging on my boat and engine. So when I initially rigged everything, I wasn't aware of the return to idle being a must, so I totally missed this, and has never been correct, but my fault.

[Tim Powell]

I checked and it was not returning to 100%. I'm guessing at least 10-15% short of full return. I adjusted and have it scheduled with my dealer this week to check on the computer to ensure its seeing 100% WOT. Thank you all again for the great info. I'm hopeful this helps my performance.

As a side note, I did all the rigging on my boat and engine. So when I initially rigged everything, I wasn't aware of the return to idle being a must, so I totally missed this, and has never been correct, but my fault.

There is no way to check it without getting it on G3 to verify the demand linear. Make sure they see 100% but also as close to 0.0 as possible on the return. Anything else is not correct.

[sowenssw]

There is no way to check it without getting it on G3 to verify the demand linear. Make sure they see 100% but also as close to 0.0 as possible on the return. Anything else is not correct.

Thanks Tim! I have an appointment with my dealer this Friday to hook up to the G3. I was only referring to physical arm wasn't all the way back to return, so hoping it wasn't seeing full return, thus being my issue. Will know Friday. Thanks again for all the advice! I'll let you know what he finds.

[Tim Powell]

Thanks Tim! I have an appointment with my dealer this Friday to hook up to the G3. I was only referring to physical arm wasn't all the way back to return, so hoping it wasn't seeing full return, thus being my issue. Will know Friday. Thanks again for all the advice! I'll let you know what he finds.