Prop question for ETEC owners...

After several years of deciding whether to repower from a perferctly good Mercury 4-stroke to the ETEC, I finally convinced myself to do it.

So far am am very pleased with the decision and very impressed with the motor, however...

the motor is propped with a Viper 13 7/8 X 15, very quick out of the hole. My poor ole dog was laying up by the bow and ended up against the raised casting platform at the stern. Top end is 42 mph @ 6K rpm.

I feel the motor has plenty of torque to still have a far better hole shot and top end than the 4-stroke by going to a higher pitch. The question is how high?

I found a compromise of holeshot and top end with an 18P Vengence SS on the Merc - about 44 - 45 mph. Thats where I would like to be with the ETEC or better. Any thoughts.

Boat(see sig), 1100 lbs, motor 370 lbs, Gear 200lbs max, fuel 22 gallons, me and dog 200 lbs. What would your suggestions be. Boat at dealer ship due to some minor rerigging problems, so now would be a good time to take care of this small detail. Motor is currently mounted in the 3rd hole!

Thanks for your help in advance.

Re: Prop question for ETEC owners...

I checked the 115 performance tests they were running 17 and 19 stainless
on boats heavier than yours.A 17" should get you about 5,600 still have hole shot and maybe a couple of mph.You also may want to try raising your motor.
Antivent plate even with the bottom is considered a starting point.
I'm not an expert but it appears to me your under propped if your lookoing for more top end.

Re: Prop question for ETEC owners...

According to Turning Point Propellers website the max rpm's for your motor should be 5500rpm's. I first checked iboats but they do not list the rpm's.

Re: Prop question for ETEC owners...

BRP site says 5,500 to 6,000 their tests are running about 5,500 to about 5,875.

Re: Prop question for ETEC owners...

Which gear ratio do you have, the 2.0 or the 2.25? I'm assuming the 2.0 since you achieved 42 MPH at 6000 RPM.

When you hit the 6000 RPM with the 15 pitch prop, were you fully loaded with fuel? I assume you had the dog with you. Is that your typical load or do you usually have more people on board?

If you had a full tank of fuel you should consider increasing to a 16 pitch. The 17 pitch may get you going faster but I think you'll loose too much hole shot. Plus, because of the narrow power band, if you add one or two more people, you'll really suffer on the bottom end and fall below the minimum WOT range.

With the narrow 5500 to 6000 power band, you really are better off staying as close to 6000 as possible. The 15 pitch may be the best prop for your setup if your fuel tank was 1/4 or 1/2 full.

Being already mounted in the third hole, I'm not sure you should raise the motor any more. Maybe one more hole in order to keep a 16 pitch turning close to 6000 but you may ventilate a little with the Viper prop.

Re: Prop question for ETEC owners...

Thanks for the replies, I am normally by myself with the dog (35lbs). Wife or daughter occasionally go out with me, but they are not speed freaks so its normally a slow cruise with them (they weigh in @ a wopping 110 lbs each). Have a fat buddy (he says its ok to call him that ) who fishes with me on occasion, but not very often. Gear ratio is 2:1 already mounted in the 3rd hole. I don't pull skiers or tubes. Full tank of fuel. I think I answer everyones questions.

Re: Prop question for ETEC owners...

You may be able to get away with a 17 pitch but I wouldn't feel comfortable running so close to the low end of the WOT Range. Adding a couple hundred pounds of people weight will put you below the 5500 minimum. I don't think you lose much on the hole shot but 2" of pitch does change the performance aspect fairly significantly. Maybe compromise on a 16 pitch if that is available.

Re: Prop question for ETEC owners...

Dealer changed prop to a 13 7/8 x 17 Viper. Top end now where Merc was, just gets there quicker. Couldn't really notice a difference between the 15p to a 17p coming out of the hole. Can still put the dog to the back of the boat if I want to. RPM down from 6000 rpm WOT with the 15p to between 5700 - 5800 rpm WOT with the 17P. I'm satisified with the combo now.

Again thanks for the responses