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I recently purchased a 1993 23 Powerquest Conquest with a 454 mag w/ a bravo drive. Boat has been racked stored in near mint condition. I'm running the stock Mirage 23 pitch prop spinning at 45-4600 rpm with 2 adults and 1/2 tank of gas or less I can get 62 mph out of it. With a full tank and 4 plus adults 55-58mph. Was looking to get min 65mph. Have considered a prop change
but was wondering if there were any easy mods to the engine that could be made??? Would a K&M flame arrestor help??

Thanks

Raypanic

To get a minimum of 65 Mph your going to have to do some work and spend some $$. The prop is close you could have the prop labbed that may gain you 2 - 3 MPH. I believe the 454 Mag can run 5100 RPM. The K&N Way might give you 1 MPH but there have been mixed results with the add on. There are some $1,000 +- "super tuner" kits from Arizona Speed and Marine that may give you a couple of MPH too. To get to a MINIMUM of 65 You would have to look into engine mods or a supercharger.

Using Bams' Calculator you would need about 425 Hp to get there. I am assuming you have the 385 Hp 454. I dont know where you are at but Tyler Crockett offers a engine re-work and I think it will give you 480 Hp with a stock 454 Mag. It is mainly head work and ECU re-tuning. It is arround $4,000.00 You would have to have him pull the engine though.

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Thanks for the info Ray. By the way I'm in Southwestern lower Michigan running on Lake Michigan. I promised my wife I'd be happy with the boat after being without for 6 years, but after 3 weeks I need more. Was looking at a Hydromotive 4 blade prop
which I had put on my Scarab with great results.

Thanks Brian

Raypanic

4 Blades typically run slower than 3 blades, But your 3 blade is not set up perfect for the boat yet either. Have fun!~

Gary C

I have a 98 260 with a 454 mag carb. I assume you have a carb? I have a 21 pitch Mirage plus that I'm spinning at 5050. My speedo reads 63 at that. I tried my friends 23 pitch Mirage and turned the same rpms and got the same speed, but with more slip. I also assume you have a Mirage not a plus. I also tried a 24 pitch bravo 1 prop. I turned just a tick shy of 4600 rpm and got 61 on the speedo. I really liked the way the 4 blade worked. I was suprised with the way it handled. The midrange speed was faster. At 3600 the 21 does 41 the bravo I got 48. I want to try a 23 Mirage plus. I hope this helps. I would try a 21 pitch Mirage plus. You will feel the difference in handling. Maybe a 19 plus will get you to 5000. That is where you should be. I would also try a 22 Bravo 1. I'm thinking you will like that. But to get to 65, I agree, you will have to spend some money. Exhaust, intake, carb, flame arrester. But that stuff will get 1-3 at the most. If you can get your prop to spin to 5000 that will get you more speed. Good luck! It never ends! We always want to go faster!

Kentz

Gary C - 454 MAG w/Carb, is that original? my 97 260 was 385 EFI. Carb'd mags were 365hp. you should be 4800-5200 rpm. Sounds like way to much pitch, unless your heavily loaded.

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You are correct on the HP it is a 454 mag w/ 365hp. I know the 385 are the later model. I just bought the bought and almost think it was proped to maybe save on fuel. I only say that because I took a Fotmula out and the made a comment regarding he was spinning a 23 but had a 21 but went through the gas. I have noted I've had as many as 11 people in the boat with a top speed of 55 mph at 4500 RPM. With 2-4 people on a good day I'll hit 62 mph at 4500 rpm. I'm thinking a 21 pitch but not sure on the dia nor if I should go 3 or 4 blade. I had a 3 blade Hydromotive on my last boat and loved it.


Thanks Brian

Gary C

Kentz,
I bought the boat used last Aug. The guy ordered it with the Mag carb. It's 350 hp. The 365's were older, and rated at the crank. The 350 hp mags are rated at the prop. I think 97 was the first year of the mag efi. You could still get the 454 mag carb. This boat is one of the first 98's, so Powerquest must have had some Carb motors left. I got a real good deal on it because it was not efi. As far as me having too much pitch the motor is rated at 4600-5000 rpm. I'm running 5000-5050 with the 21. That's with 3 people and full tank and all my sons water toys. So that's about right. It's a beast out of the hole! I could go bigger, as I found out testing. I really liked the 24 Bravo. But as I said I'd like to try a 23 Mirage plus. From what I understand the EFI's were propped with 23's What were you turning? And what speeds were you getting? The EFI should be a little faster maybe 2-3 mph?

Kentz

Yea, now that I think about it, EFI's were out about 96/97. A neighbor has a 97 with a 7.4 carb. If you ordered a boat tomorrow, you could probably still get a brand new 502 if you wanted. Someone, somewhere, probably has then in stock

PQCon - if your mag is rated for 4800-5200, your actually severly lugging the motor @ 45-4600. This is not good