Pa Angler Posted August 21, 2011 Posted August 21, 2011 Hi, I need some info on the Tempest Plus prop's plugs. I have a 2011 Nitro0 Z7 with a 150 Pro X/S Optimax with a 6" manual jack plate maintained at the factory settings. After running solo on the St Lawrence River in mid June 62 degree water temp and running on Black Lake, NY at the end of June 72 water temp I'm only turning 5,100rpms on both waters after taking the boat to the dealer to check WOT I was told I'm getting that Mercury specs state that the motor should run at 5,250 to 5,750rpms the dealer stated I should try pulling the plugs one at a time and log the results and adjust the jack plate. Has anyone out there ever messed with the plugs on this prop and what were the results? Has anyone messed with this type of jack plate? My thought was that Nitro propped for hole shot. The prop has a 14 5/8 dia. and 24 pitch. Pa Angler Quote
Super User Hooligan Posted August 22, 2011 Super User Posted August 22, 2011 The Tempest, across the board, is a prop that runs well with a higher outboard height. The first thing you should try is to set the jackplate at 3" to 3.5" BP and run it. You should see improvement from that alone. If you're still seeing low #s, I'd pull two plugs and run it. I know the Z7 with the 150 is somewhat goofy in terms of finding the balance, but from many, many accounts you're already running the right prop to see those numbers. I've seen a Z7 with a 150 do the 5750 and 70.4 mph on GPS. It might take you a little tinkering but you should see it. In terms of the plate, I ran a manual on the first two that I had, only on the last did I change out to hyd. It isn't too big a deal to make the changes, really. Edit: I'll add that if, in your runs, you start to feel it walking, back down your jackplate in 1/4" increments. Quote
Pa Angler Posted August 22, 2011 Author Posted August 22, 2011 The Tempest, across the board, is a prop that runs well with a higher outboard height. The first thing you should try is to set the jackplate at 3" to 3.5" BP and run it. You should see improvement from that alone. If you're still seeing low #s, I'd pull two plugs and run it. I know the Z7 with the 150 is somewhat goofy in terms of finding the balance, but from many, many accounts you're already running the right prop to see those numbers. I've seen a Z7 with a 150 do the 5750 and 70.4 mph on GPS. It might take you a little tinkering but you should see it. In terms of the plate, I ran a manual on the first two that I had, only on the last did I change out to hyd. It isn't too big a deal to make the changes, really. Edit: I'll add that if, in your runs, you start to feel it walking, back down your jackplate in 1/4" increments. 3" to 3.5" BP What does BP mean? What are the reference points to make the measurements? Pa Angler Quote
Super User Hooligan Posted August 22, 2011 Super User Posted August 22, 2011 BP is below pad. The reference points are pad on the hull of the boat, with the second point being the actual shaft of the propeller. Quote
Pa Angler Posted August 22, 2011 Author Posted August 22, 2011 Thank you for the response. The 2010 -2011 Z7's have that RPS rapid planning system the pad is more forward under the hull I'm going to contact the Nitro dealer and find out were the factory setting is relative to the prop centerline and pad. I'll be going to Black lake, NY from August 27 to September 11 I'll keep in touch with you on my results. Thanks Again Pa Angler Quote
Super User Hooligan Posted August 22, 2011 Super User Posted August 22, 2011 Thank you for the response. The 2010 -2011 Z7's have that RPS rapid planning system the pad is more forward under the hull I'm going to contact the Nitro dealer and find out were the factory setting is relative to the prop centerline and pad. I'll be going to Black lake, NY from August 27 to September 11 I'll keep in touch with you on my results. Thanks Again Pa Angler Yeah, I'm well familiar with the RPS. The pad isn't that far forward, most boats are like that anymore, it's rare that they sit all the way back at the transom. I'm pretty sure spec is something like 4.25" below pad with the 150. Quote
Al Wolbach Posted August 23, 2011 Posted August 23, 2011 I could be wrong but I thought the plugs on the tempest plus were only for hole shot performance and had no effect on top end. Theory- Exhaust escapes thru holes and allows the prop to spin up quicker in the air bubbles and at speed all of the exhaust goes through the hub. I thought I remember reading somewhere?.......Al Quote
sodaksker Posted August 23, 2011 Posted August 23, 2011 Al, you are correct on the prop plugs for holeshot. I do not believe they will effect top end rpms but, it is real easy to check. Worst case scenario you will get blow out on holeshot if you have too many plugs out. Based on the age of the optimax I would doubt that you have an engine problem. My guess is that your prop to pad setting is too low or your 24p prop needs to be worked. 24p is about the max that opti should turn and if the pitch is off a little and closer to 25p you would get lower top end rpms. Another question is how far are you trimming up? I am sure you are aware that the higher you trim up your will typically pick up some top end rpms. Quote
Super User 5bass Posted August 24, 2011 Super User Posted August 24, 2011 I could be wrong but I thought the plugs on the tempest plus were only for hole shot performance and had no effect on top end. Theory- Exhaust escapes thru holes and allows the prop to spin up quicker in the air bubbles and at speed all of the exhaust goes through the hub. I thought I remember reading somewhere?.......Al Correct. The PVS holes allow more exhaust to flow over the blades so the rpm's turn up quickly on holeshot. I've got dual PVS holes on a 28 Bravo1. You can buy small, medium and large hole plugs or solid plugs. When you go to buy them, buy a couple different sizes and buy some extra's because they are pretty much uselss after you pop one out. You really have to work with the plugs to figure out the right combination that will spin your wheel up fast, then grab and shoot you out of the hole. I'd try to locate some others with Nitro's that have a 150 and at least get an idea where to start by what they are using. If you start plugging blind and totally miss it, it's a real pain pulling the boat out of the water after every run and popping in and removing plugs over and over. If you can, find a ramp where you can just leave your trailer in the water. Quote
Super User Hooligan Posted August 24, 2011 Super User Posted August 24, 2011 So, you guys don't see any performance difference in terms of plug size and number? I'm somewhat confused now and here's why: 2010 Z8 with 225 with a 26P fury 2 plugs, 3" below pad, 5500 rpm, 8" jack plate, GPS of 72.8 MPH. Keep everything the same, minus the plugs and it's 5700 RPM and 76 MPH. Quote
sodaksker Posted August 24, 2011 Posted August 24, 2011 I guess I never really looked at the top end difference. I thought they were just for holeshot, so when testing mine,I just tested the holeshot. Quote
Pa Angler Posted August 30, 2011 Author Posted August 30, 2011 Thanks guys, I'll be doing some testing this week and next as I'm at Black Lake, NY for a two week stand. Pa Angler Quote
Al Wolbach Posted August 30, 2011 Posted August 30, 2011 I guess I never really looked at the top end difference. I thought they were just for holeshot, so when testing mine,I just tested the holeshot. Ditto- I would have thought you would have severe blowout problems if the plugs passed exhaust at speed.......Al Quote
Pa Angler Posted September 1, 2011 Author Posted September 1, 2011 So far I have moved the jack plate up 1/2" and have gained 500 rpms from 5,100 to 5,600 rpms and 3 mph 57.5 mph to 60.5 mph on the GPS today I'll test another 1/4" up. Pa Angler Quote
Pa Angler Posted September 1, 2011 Author Posted September 1, 2011 I ran the boat today with the extra 1/4" on the jack plate to bring the total to 3/4" up ran a 60.3 mph GPS into a 2 to 4 mph wind going to try another 1/4" tomorrow that would bring the total to 1" up from stock. I don't know how much more I can go before the prop loses grip. Pa Angler Quote
Al Wolbach Posted September 2, 2011 Posted September 2, 2011 I ran the boat today with the extra 1/4" on the jack plate to bring the total to 3/4" up ran a 60.3 mph GPS into a 2 to 4 mph wind going to try another 1/4" tomorrow that would bring the total to 1" up from stock. I don't know how much more I can go before the prop loses grip. Pa Angler Be sure to keep an eye on the water pressure gauge........................Al Quote
Super User Hooligan Posted September 2, 2011 Super User Posted September 2, 2011 From those I've talked to, the factory setting on most of the Nitro jackplates are between 4" and 4.5" below pad. So, from what you're saying, you're hitting that magic mark of 3.25-3.5 below pad. Like it was mentioned, keep an eye on your pressure gauge. Quote
Pa Angler Posted September 3, 2011 Author Posted September 3, 2011 Tried 1" today and ran 62.3mph GPS with the wind 60.1 GPS against it with some minor chine walk I trimed dowm but lost top speed. Tried 1 1/8" more chine walk and water press. down slightly tried 1 1/4" even more chine walk and lower water press. seems 1" is a good number. I'm going to try to tweak the 1" a very little at a time less that 1/16" at a time to see if there's more there. Water press. is staying above 18 psi at 1" at a 1 1/4" dropping below 15 psi. I don't know what the good lower water psi level is on a Mercury 150 Pro X/S. So far I have gained almost 5 mph. Pa Angler Quote
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