RT188 top speed

[GeauxTide]

I consistently hit 46-47 before I installed the port console. Now, 45.4 with 20" Laser. Got X7 19" on order and will raise to Hole#3

[tcesni]

I hadn't thought of the second console being a possible factor in top speed. Obviously we need some wind tunnel data.

[Tim Kelly]

The second console can't catch much wind as it doesn't catch much rain! Not much to hide behind when it's hammering down.

[Deerchaser]

mine is 400 off

Analog tachs are notorious for not being accurate. When I installed my MercMonitor there was a 250 rpm difference. Analog my max RPM’s was reading almost 5900 rpms. Actual according to the monitor it was a little above 5700 with my 115 Optimax’s max RPM being 5750. So he more than likely is okay on rpms. Besides if he really was running that high he’d probably heard his motors alarm go off.

[Buggs247]

2016 Merc 4s with 4" jack plate. Laser II 20 pitch 46-47 consistently loaded. Squeak out 48 every once in a while by myself in the right conditions. Really do wish I could hit 50 mph but not sure what else I could do to get it, feel Im just about getting all I can get now!!

[mouabass]

17 Merc ProXS 115 CT 4stroke with setback plate, 24P Tempest 46-47 regularly and once in a while 48.
best was 49.2 GPS with a tailwind.

[GeauxTide]

I hadn't thought of the second console being a possible factor in top speed. Obviously we need some wind tunnel data.

Don't think it's the profile, it's the weight.

[TheBoo]

ProXs 2 stroke. 47 - 50 me, gear, and fuel. 5600 rpm.

Motor on third hole. 20" lazer 2 worked by Holeshot Propeller in Houma. Trip tabs cut off. Had about 2 inches of skeg bit off by a rock and after filing it smooth it seems to handle a little better.

[lilduckx3]

yesterday I hit 47.4 gps at 5400 rpms full tank just me and all summer tackle is out of the boat

[tnbassin]

I get about 43-45 on mine (2017 RT188C, 115 CT) but could get more except for the porpoising gets way too bad. I thought about having my 23 tempest prop cupped but not sure if it would help porpoising or not. Also, would it stop the porpoising but lower the speed? I know little about props. I asked a couple times on the prop forum a few months ago but never really got an answer. Doesn't seem to be much interest in aluminum boats over there.

[GOTTA BIG SACK]

For those without a jack plate what hole is your mounted in? Mine is the second from the top and I think its too low?

[Lowerider58]

My 2015 Triton TX18 came with motor mounted in the third hole. I've noticed that all the Rangers I've seen come mounted in the second hole from the top.

[Buggs247]

[QUOTE=tnbassin;8861961]I get about 43-45 on mine (2017 RT188C, 115 CT) but could get more except for the porpoising gets way too bad. I thought about having my 23 tempest prop cupped but not sure if it would help porpoising or not. Also, would it stop the porpoising but lower the speed? I know little about props. I asked a couple times on the prop forum a few months ago but never really got an answer. Doesn't seem to be much interest in aluminum boats over there.[/QUOTE
I cant speak for the CT lower unit but mine also porpoised terribly when I first got mine whenever I tried to trim up or with an extra person or a full live well. Switching to a laser II 20 pitch and adding a JP and raising the motor cured my problems!!

[GeauxTide]

If you're porpoising, bring it back to the dealer. What RPMs are you turning. All the 188/115ProXs CTs down here get a 24" Tempest and those that don't have JP are in Hole #3. They consistently hit 49. You've got tabs welded on the bottom/transom junction, which is supposed to be the cure. I'd also have them check motor mounting (exactly level) because they mount them at the factory. I had a Lowe that had the motor mounted in a 1/4" cant.

[drtyrat30]

If you're porpoising, bring it back to the dealer. What RPMs are you turning. All the 188/115ProXs CTs down here get a 24" Tempest and those that don't have JP are in Hole #3. They consistently hit 49. You've got tabs welded on the bottom/transom junction, which is supposed to be the cure. I'd also have them check motor mounting (exactly level) because they mount them at the factory. I had a Lowe that had the motor mounted in a 1/4" cant.

Yep, when i had my 24p Tempest + i would hit 49mph easy. Then Ranger said that these CT motors should have a 21p Tempest +, so now i can only hit 47.5mph with a quick hole shot. But i also burn a lot fuel with the higher rpm's

[ZR1driver]

RT 188. 115 merc 4 inch set back laser2 22 pitch, clear costed hull. I can run 53 all day and have hit 55 on good water days. Center line of prop shaft to bottom of boat 41/2 inches.

[alanhore]

RT 188. 115 merc 4 inch set back laser2 22 pitch, clear costed hull. I can run 53 all day and have hit 55 on good water days. Center line of prop shaft to bottom of boat 41/2 inches.

Do you mean clear coated hull? Please explain.

[GeauxTide]

RT 188. 115 merc 4 inch set back laser2 22 pitch, clear costed hull. I can run 53 all day and have hit 55 on good water days. Center line of prop shaft to bottom of boat 41/2 inches.

GPS Speed or Speedo? What are your RPMs at WOT? You've posted the fastest numbers, by 7-10mph, that I've seen on this forum.

[cdemarse]

If it's gps I'd be getting the unit checked...

[oldgoat188]

If it's gps I'd be getting the unit checked...