311 Props Questions
 

Running A 89 311 With 454 Ho 425hp Crate Motors Emi Exhaust Holley 800's Bravo Drives. Has Anyone Run Mirage 25? How Was Cruise Speed Around 3500?, And Did It Turn 5000? Any Input Appreciated, Going To Try A Set Was Just Wondering Thanks

You should know my boat. Equal power and upgrades except mine is a 292. It has 25 Mirages. Runs approx 47 at 3500 and turns 5100 on 1 and 5000 on the other. Just bought it from Courtney in May. I was curious about trying a set of 4 bladers for improved mid range speed and to raise the ass end a little.

I have an 88' 311 with 420's and 25p mirage plus. At 3000 I'm running about 34 with the nose buried. With a little trim 36. Was on Erie so didn't trim it to much. Tabs were down a tad too. I'm running TRS drives too. I was on a 87' 311 with 365 MAG's Bravo 1's with 24p 4 blades and the thing walked on plane with very little throttle and fast too. Mid range was great. Top end was about 64 at 5k.

I ran 25's on mine and it was to much prop. I got the best speed out of it but had to trim it to the moon and eventually blew a drive. I am going back to 23's.

Audio Do U Have A 311? What Rpm Did They Turn Trimmed To Say 6?

I have a 311 with TRS drives. I was at 73 MPH on GPS and trimmed WAY off the indicator. These boats LOVE trim and they go faster and faster the more you trim them, but eventually what you do is chatter the gears in the lower. That is what I did. I don't remember the RPM's off the top of my head. I have another friend with almost the same boat (year newer) and he is seeing the exact same numbers as me.

My 89 311 ran well with 26 Bravo 1s, right at 72 with 502 Mags (425 at crank). It did run slightly low on rpms, like 4900 trimmed out. Ideally it probably would have been good to de-pitch the props to 25, but I never got around to doing that.

Hey jiffy292,

I have a '88 311 w/330's and Bravos ....

When I bought the boat it came with a pair of labbed 23p Mirages which are a three blade prop.

I saw once 64 mph on gps ... the rest of the time was 62s at WOT. Using the Mirages.

I called Brett @ BBlades and he hooked me up with a pair of 24p Mercury Revolution 4 which are 4 blade props ...... the reason I went to these is I gain approx. 4-6 mph at mid range but I lost it at the top end .... which I really didn't care about with these motors ... there is always a faster boat .... lol

Using the Revolution 4s the big gain for me was @ 3000 rpm getting 40 mph ..... 4000 rpm getting 50 mph ..... on gps all day long no matter the load meaning fuel or people or water conditions (with in reason of coarse) .....

Give Brett a call .... tell him what you are trying to accomplish and he will let you try props until you are happy with your results.

The power you put in your 311 is exactly what I am planning to do as well.

I will be interested to find out what you ended up with so I will then know where to start.

Good Luck!

Jeff

TWINS, these motors are the way to go, my boat ran 70 best in may with 1/2 fuel. 24 hydromotives 4 blades. going to try the 25 mirages this week and see how it goes

Let us know the results. I'm very curious as to the differences at various rpms.