Props and rpm
08-05-2002, 11:24 AM
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Props and rpm
I picked up a real clean 1989 272. 7.4's what do others run as far as props on this setup. what kind of rpm as related to speed should I be seeing. I am running 25 pitch 3 blade mirage no prblem with the hole shot seems to be hooked up all the time as far as i can tell. When I give it the go it does not feel like it is slipping. What gets me is I am only seeing 55 mph at 4200 rpm 2/3 tank fuel 3 people. I would think 65+ whats up??
Russ
Russ
08-06-2002, 01:56 AM
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props/RPM
Hi Russ
I'm new here, I my not have the correct answer for you, but can tell you what I did to my 242 LS/SR1 1984 with twin 350s.
Yours are 330hps?? Bravos? I found I don't need to sit on 100 gallons of gas. If I'm playing I don't carry any more than 1/2 a tank. You can try different drive trim settings , tab settings [ full up for TOP end]. have you had the props checked ??
The best for top end are Merc Clevers. I may get some flack on that, but I have tried different props, and the clevers are the fastest. But you will loose the hole shot.
Maybe you can borrow another set of props and try them.
You gotta remember Formulas are very heavy, and with 330s your top end is very respectable.
If all else fails go to the engines. Are they tuned right, Type of Gas , Gonna sound silly but this will work. Open and SECURE the engine hatch up a few inches. If you pick up any MPH/RPMs your engines are not getting enough cold air.
I changed mine to both sides cold air intakes with boxex directing the air towards the carbs, larger flame arrestors, and Added 4 exhaust vents to the transom.
Good luck keep us informed
Vinnie NY
I'm new here, I my not have the correct answer for you, but can tell you what I did to my 242 LS/SR1 1984 with twin 350s.
Yours are 330hps?? Bravos? I found I don't need to sit on 100 gallons of gas. If I'm playing I don't carry any more than 1/2 a tank. You can try different drive trim settings , tab settings [ full up for TOP end]. have you had the props checked ??
The best for top end are Merc Clevers. I may get some flack on that, but I have tried different props, and the clevers are the fastest. But you will loose the hole shot.
Maybe you can borrow another set of props and try them.
You gotta remember Formulas are very heavy, and with 330s your top end is very respectable.
If all else fails go to the engines. Are they tuned right, Type of Gas , Gonna sound silly but this will work. Open and SECURE the engine hatch up a few inches. If you pick up any MPH/RPMs your engines are not getting enough cold air.
I changed mine to both sides cold air intakes with boxex directing the air towards the carbs, larger flame arrestors, and Added 4 exhaust vents to the transom.
Good luck keep us informed
Vinnie NY
08-06-2002, 08:59 AM
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I run 23 pitch Mirage Pluses on my 89 272 w/7.4's. Best I've seen is 64 on gps with just me and 1/2 tank. I think it was spinning around 46-4700. That was in a steady 1-2' chop and the boat was really aired out, no tabs, trimmed way out. There was a post a while ago about this boat and 63-65 is what you should expect. I did talk to a couple of people 2 weeks ago that told me I should be going alot faster. One guy had an 87 or 88 272 with 350's and he does "70". Right. I'm hoping to run with him some day to verify this. Another guy has a 32 baja that he claimed goes over 80 with 454 mags and 23" props. That sounded unlikely until he said he can spin them 6800 rpm. Hmmm, is it just me that's skeptical??
08-06-2002, 01:55 PM
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RPM/Speed
Hi Bill272
I gotta hand it to you, don't see many Honest guys as far as speed goes. Your top end is very good for a 272, are yours 330s or 365s. Bravos ?
I would Love to meet the guy in the 272 with 350s doing 70 plus.
I would pay to see that and BET against it!!!! big time.
My 242 [1984] SR1/LS yes they did make a SR1 version. Mostly for Looks. short windshield, no bow rail.
I have two New 350s, punched 40 over, 9 to 1 pistons, Dart 2 heads, milled 10, Cams Int. 443/214 ex 465/224 @ .050 , Lifters/Push rods. Comp. cams Roller rockers. Hi Po GM High rise intakes [ same ones used on the Z/28s]. tickled Holly 650s, dual feed double pumpers. ThunderBolt Dist. Jacobs wires, MSD coils.
Large Flame arrestors, cold air intakes on both sides, 4 bildge vents. Alpha drives [1.50] spinning 24 "Merc Custom clevers reworked By S&S. Nose cones, about half a tank of High test with Real Lead added. Two people, 1 to 2 foot chop, clear warm day, Aired the hell out of it, Timming advanced , Went as far as haveing the Hook taken out of the Bottom [ as per Formula} and moveing both batteries to the starboard side to compensate for the Torque of Non counter rotating drives.
I can get at best 68 and thats trimming the hell out of it turning around 45/46 Flaps Full up above zero.
She won't do this all the time , only when set up as described.
And she comes in at around 5200 pounds. Now a 272 gotta be
6000 pounds. gee I must have a whimpy boat going so slow
I gotta hand it to you, don't see many Honest guys as far as speed goes. Your top end is very good for a 272, are yours 330s or 365s. Bravos ?
I would Love to meet the guy in the 272 with 350s doing 70 plus.
I would pay to see that and BET against it!!!! big time.
My 242 [1984] SR1/LS yes they did make a SR1 version. Mostly for Looks. short windshield, no bow rail.
I have two New 350s, punched 40 over, 9 to 1 pistons, Dart 2 heads, milled 10, Cams Int. 443/214 ex 465/224 @ .050 , Lifters/Push rods. Comp. cams Roller rockers. Hi Po GM High rise intakes [ same ones used on the Z/28s]. tickled Holly 650s, dual feed double pumpers. ThunderBolt Dist. Jacobs wires, MSD coils.
Large Flame arrestors, cold air intakes on both sides, 4 bildge vents. Alpha drives [1.50] spinning 24 "Merc Custom clevers reworked By S&S. Nose cones, about half a tank of High test with Real Lead added. Two people, 1 to 2 foot chop, clear warm day, Aired the hell out of it, Timming advanced , Went as far as haveing the Hook taken out of the Bottom [ as per Formula} and moveing both batteries to the starboard side to compensate for the Torque of Non counter rotating drives.
I can get at best 68 and thats trimming the hell out of it turning around 45/46 Flaps Full up above zero.
She won't do this all the time , only when set up as described.
And she comes in at around 5200 pounds. Now a 272 gotta be
6000 pounds. gee I must have a whimpy boat going so slow
08-06-2002, 04:28 PM
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Thanks
Bill 272, just got off the phone with teague. They seem to think that 24p bravo 1's are going to solve all my problems do you know any one who has tryed them.
Russ
Bill 272, just got off the phone with teague. They seem to think that 24p bravo 1's are going to solve all my problems do you know any one who has tryed them.
Russ
08-06-2002, 04:34 PM
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Bill 272,
It might be posible you know this boat I just purchased it off of Lake ST. Clair out of a harbor named Bell somthing or other it's an 89 that is teal and gray with black stern. Let me know posibly you have some history.
Russ
It might be posible you know this boat I just purchased it off of Lake ST. Clair out of a harbor named Bell somthing or other it's an 89 that is teal and gray with black stern. Let me know posibly you have some history.
Russ
08-06-2002, 04:44 PM
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I don't know of anyone who's tried them and I never saw a 272 for sale out of Belle Maer (?). but then again, I haven't been looking either. Most of the 272's I see around here are older or they have the exact same graphics that we have (palm beach colors). Ours is getting new vinyl right now and we're eliminating the black and pink off the bench and sunpad.
I did get 3 extra props with the boat, 2 mirages and one plus, all 25 pitch. One of the matched set is fairly chewed up, so I haven't tried them yet. Plus I'm right in the WOT range I should be. Let me know how the Bravo 1's work out
I did get 3 extra props with the boat, 2 mirages and one plus, all 25 pitch. One of the matched set is fairly chewed up, so I haven't tried them yet. Plus I'm right in the WOT range I should be. Let me know how the Bravo 1's work out
