Simon Performance Flash - 2017 175TXW w/75HP Fourstroke

[G4bama]

The flash for the 75 Opti 2 stroke has always performed better than the 4 stroke. To gain the performance with the Opti it required the flash, removing the air restrictor, a 6" jackplate, and a Laser II 24P prop. My 2012 topped out @51mph turning 6100 rpm. It would cruise @43mph turning 5600 rpm. Not say that it isnt possible but I have not seen or read of results from a 4 stroke equaling the results of the 2 stroke. Another thing to remember is that each aluminum hull is different from the other and none of them are true.

[TritonTRXV8]

Just as it was with the opti there is more different between the mots than just the computer tune. On the opti the 75 and 90 had different block porting than the 115 and each had a different throttle body bore even without the restrictor plate. On the 4 strokes i would imagine theres a throttle body difference and if i remember correctly a different camshaft between the 75 and 90 to the 115. Neither will ever perform like a true 115 but obviously the 4 strokes miss the bar by a bit more.

[bshort]

Just as it was with the opti there is more different between the mots than just the computer tune. On the opti the 75 and 90 had different block porting than the 115 and each had a different throttle body bore even without the restrictor plate. On the 4 strokes i would imagine theres a throttle body difference and if i remember correctly a different camshaft between the 75 and 90 to the 115. Neither will ever perform like a true 115 but obviously the 4 strokes miss the bar by a bit more.

The main difference between the 75 and 115 is the camshaft. Throttle body, injectors, etc are all the same.

[TritonTRXV8]

Must be a pretty big difference in the cam then. Doesnt seem like alot of gain for the cost of the flash. I remember seeing guys running 40-42 with stock 75 optis on this hull.

[bshort]

Must be a pretty big difference in the cam then. Doesnt seem like alot of gain for the cost of the flash. I remember seeing guys running 40-42 with stock 75 optis on this hull.

Recall the main difference being the gear ratio.

[msupc]

Recall the main difference being the gear ratio.

There are/were two gearcase option: 2.07 & 2.33

[alanhore]

Seems like the lower gear ratio lower responds better to the tune. Maybe just better props for that ratio.

There are/were two gearcase option: 2.07 & 2.33

[msupc]

Seems like the lower gear ratio lower responds better to the tune. Maybe just better props for that ratio.

There is definitely a difference somewhere. I just got the Vengeance prop back from getting cup added and a little bit of pitch so I am told. I will try her out this weekend (potentially tomorrow afternoon) and report back with my findings! The nice gentleman at East Tennessee Propeller seemed to believe that raising the engine probably hurt more than it helped, but testing the newly modified prop would ultimately help clarify that. He suggested even a small (4") jack plate may provide the opportunity for more precise fine tuning. I haven't even begun to consider a jackplate, so that is foreign territory for me honestly.

[TritonTRXV8]

Your prop guy is right about the jack plate. You will never dial it in to get ever mph out of it if that is what you are seeking without a jack plate. It comes down to 1/16” increments to truly fine tune the engine hieght and to run high you need setback as well.

[msupc]

Your prop guy is right about the jack plate. You will never dial it in to get ever mph out of it if that is what you are seeking without a jack plate. It comes down to 1/16” increments to truly fine tune the engine height and to run high you need setback as well.

Well I had it out this past weekend with again underwhelming results. The newly cupped prop essentially performed the same as before. I believe I am going to put a 6" jack plate on from Vance Manufacturing based on input I have received here and various other places.

[fishon396]

Tell us what your goal is maybe someone can help or point you in the right direction.

[msupc]

Tell us what your goal is maybe someone can help or point you in the right direction.

I would like to maximize the boat's top speed while having a good hole shot. I just ordered the Vance 6" manual jack plate model JPL4500 with the performance plate and stainless steel bolts, and it should be here Wednesday at the latest. I will start around 5-1/2" below pad and go from there.

[bshort]

Well I had it out this past weekend with again underwhelming results. The newly cupped prop essentially performed the same as before. I believe I am going to put a 6" jack plate on from Vance Manufacturing based on input I have received here and various other places.

You might pick up a mph or two with that. At the end of the day, that 75 can only give you so much.

[TritonTRXV8]

If the ecm flash on these 4 strokes only gains you 2-3 mph then i would think it best to save your money. You dont have any shops nearby that demo props really think you need to try a 19p laser prop on there. Even that vengeance with work done to it i doubt would compete with an out of the box laser.

[msupc]

I installed the jackplate from Vance last night - Model # JPL4500 w/6" setback and performance plate add-on. I set the center of prop height at 5.5" from the bottom of the boat; it was approximately 5.25" previously. I will try to take it out this weekend with the 18" cupped Vengeance prop for testing and report back.

IMG_8457.JPG

[Boondock]

I installed the jackplate from Vance last night - Model # JPL4500 w/6" setback and performance plate add-on. I set the center of prop height at 5.5" from the bottom of the boat; it was approximately 5.25" previously. I will try to take it out this weekend with the 18" cupped Vengeance prop for testing and report back.

IMG_8457.JPG

looks nice for sure but as someone else said. It’s a 75 and maybe 115 flashed but it doesn’t sound like it. A person on walleyecentral not seeing any performance increase after having a 90 flashed.

At what point do you just upgrade the boat?

[Chainslinger1959]

I purchased a 2017 Tracker 175TXW w/ 75HP Mercury Fourstroke in November of 2019. At the time of purchase, it had a 18" pitch Vengeance prop. The boat would make 39-40mph @ roughly 5400 RPM. I was looking to increase speed and performance and learned, through searching the forums, that the intake restricting plate could be removed to add power (essentially turning it into a 90hp engine). I removed the plate and took the boat out, and under full-throttle the Mercury Monitor would kill power once on plane. I was able to achieve 40mph @ 5250 RPM with the 18" pitch prop and restricting ring removed, but I could not go full throttle.

I thought that the factor tachometer may be off, and I was running into the limiter, so I purchased a 21" pitch Spitfire X7 prop and put it on. I was then able to achieve 39-40 mph, and the engine would only spin up to 4700 rpm roughly. Again, once under full throttle, the Mercury Monitor would kill power. I later deduced this to the engine running lean?

I then decided to send my ECM off to be flashed by Simon Performance hoping that the increased power would spin the 21" prop faster and increase speed. I received the ECM back this week and took the boat out. Now with the 21" Spitfire X7 prop I could only spin it to 5200 rpm @ 41mph. I decided to swap the 18" Vengeance prop back on, and the RPM increased to 5800-6000 (depending on trim) and can see 42 MAYBE 43 MPH.

Does this sound right to you all? I have seen all of ship's and other's posts regarding flashing their 75 Optimax's to 115, and they are spinning 24" laser 2's and seeing 48-50 MPH.

This is all with only me in the boat (195lb), half a tank of fuel, and rods/reels and tackle. Also, the engine is mounted in the second hole from the top.

Got a friend with same boat number 1 18 pitch is to high for that engine . Should have a 17 pitch and far as a 21 pitch you are way off. 43 sounds right doubtful you’ll get much more than that . Change to a 17 pitch that boat will jump and go proably closer to max rpm.
J D

[msupc]

So I had her out this weekend for some test and tuning and the results were quite intriguing. Please see below:

Saturday - 18" Cupped Vengeance
First run was with the jack plate set at 4.5" below "V"
Average MPH was 41 @ 5800 RPM
Second run with jack plate set at 4.25" below "V"
Average MPH was 41.5 @ 5900 RPM
Third Run was with jack plate set at 4" below "V"
Average MPH was 40.5 @ 5900 RPM

This yielded, to me, an optimal setting somewhere around 4.5" to 4.25" below "V"

Sunday - 21" Spitfire X7
First run was with jack plate set at 4.5" below "V"
Average MPH was 43.5 @ 5200 RPM
Second run was with jack plate set at 4.25" below "V"
Average MPH was 43 @ 5250 RPM

This is where things get interesting. I decided to attempt to trim the motor all the way up while running, and the results were a maximum of 48 MPH @ 5200 RPM! Once I trimmed past the point of the prop "chopping" it smoothed out, lift increased, and speed increased substantially. I had done this before the jack plate, and the results were not the same. This was with the engine sitting at 4.25" below "V". Visual inspection yielded plenty of water streaming out of the engine and the ventilation plate sitting just above the water's surface. I lifted the jack plate up to 4" below "V", but speed decreased.

Results: With the Spitfire X7 I can now achieve 45-48 MPH @ 5200 RPM fully trimmed out. The motor literally will not trim up any more. Steering is not bad at this point, and I feel satisfied with everything. I found it to be strange however.

What say you all?

*EDIT*
By the way, it is important when setting the prop to pad that you level the pad or "V" in this instance before setting/measuring the distance. I thought I was 5.5" before, but once I leveled the "V" and the ventilation plate, I discovered that it was actually 4.5".

[bshort]

With the X7, how was your time to plane? Too bad you couldn’t try at 17p X7

[msupc]

With the X7, how was your time to plane? Too bad you couldn’t try at 17p X7

With the X7 once pegged, RPMs jump to about 3200 and climb until plane. I would guess it takes 3-4 seconds to plane. With the 18" Vengeance it is probably a second to a second a half quicker and hits 4k once pegged.