09' Tahoe Q5i SF Prop Upgrade Recommendation PLEASE...

mschmidt33

Petty Officer 2nd Class
Joined
Sep 7, 2010
Messages
110
All,

Just bought a used 09' Tahoe Q5i SF. See below:

1) Performance issue you are trying to correct ? I was not happy with the hole shot during the test drive before buying this boat. I plan on doing quite a bit of wakeboarding/air chair with up to 3 adults and 3 kids in the boat. Time to plane and bow rise were also a concern. Adding Smart Tab SX is also in the works. This was my only serious issue with the boat and I knew a prop change could help alleviate the concern. I?m not too concerned about losing top speed. Our lake is only 300 acres.
2) Current prop manufacturer, model, aluminum or stainless as a minimum ? Stock Quicksilver Mercruiser 3 blade aluminum.
3) Current prop diameter and pitch (required) - 14x23p
4) Wide open throttle RPM and speed with an average load (very helpful) ? With the 3 adults (600 lbs) during the test drive it did 44mph via gps at exactly 4400 according to dash tach. Water was a little choppy and this was when I trimmed back a little. I expected more according to reviews. Speedo was bouncing up to 47mph.
5) Engine/drive make, model, year, and HP ? 2009 Mercruiser 4.3l TKS carb, 190hp, Alpha One 1.81 FD, Engine rated up to 4800rpm.
6) Boat make model, year, length and weight ? 2009 Tahoe Q5i SF. 19? 5?. Weighs about 2800lbs with all my gear.

Since when pitch decreases rpm goes up, I first want to get closer to the 4800rpm. I assume the power curve on the 4.3L has a few more pony?s near 4800 anyway. Not that I would be running WOT very much but going to something in the 19? to 21? range is a must I think. I read that reducing your pitch 2", you should gain 400 rpm's (200 for each inch) but you will lose 3 - 5 mph off top end. Might limit me to 21? but I have heard plenty of people running 19? on this setup? Maybe they overspeed the engine a bit? Perhaps my tach was off?

I also think I want stainless due to less flex/better performance. Thinking 4 or 5 blade as well to help hole shot and keep vibration down. I'm also going to be running (trying to that is) with inboard LSX boats all day so looking for my best option here to get to 35-40mph as fast as possible. I can go fishing in the morning and they can't... I?m also concerned with slippage in general and if I hit the prop on something I don?t want to tear up the lower unit. Growing up my dad hated stainless and will likely criticize me for buying one in our lake that has some shallow spots. Hasn?t technology advanced on the Alpha one to prevent this? I also don?t plan on swapping ever and would keep the 23p as a spare only.

Thanks in advance,
Mike
 

zzchipster

Cadet
Joined
Apr 11, 2008
Messages
17
Re: 09' Tahoe Q5i SF Prop Upgrade Recommendation PLEASE...

i have gt185xl glastron, 2315#, 4.3l 190hp alpha1 and just replaced factory 14.25x 21 with mw apollo 19ss. just put on tonight. i usually have 7 in the boat and one on a tube. the 21 is ok but i want more hole shot and power on the low end...i dont care if i loose a little top end. my spare is a 23 i have never used. am trying to decide if its worthwile to repair alum 21 or just wait until i toast the new prop...the lake i am on is nothing but underwater hazards, u can be 100' off the shore in apparent open water and hit something...your selections are 19,21,23 in ss or alum with either 3 or 4 blades....there are several combinations which will work. i know from my prior boat, i was in these same ranges, the 19 was a power prop and the 21 was an all around performer and the 23 was for go fast.....consideration of elevation to sea level will also effect engine performance and prop selection...
 

mschmidt33

Petty Officer 2nd Class
Joined
Sep 7, 2010
Messages
110
Re: 09' Tahoe Q5i SF Prop Upgrade Recommendation PLEASE...

The lakes in our areas are about 1000ft above sea level. Any other suggestions?
 

wtx

Seaman Apprentice
Joined
Dec 23, 2010
Messages
38
Re: 09' Tahoe Q5i SF Prop Upgrade Recommendation PLEASE...

I have been looking at a high 5 or rev 4 19 pitch. I am at 3200 feet to prop gods dot com plenty of information in that form
 
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