Rpm's ?

[T&T]

What's the proper Rpm's for a 260 on a 18' Mirage River racer, I bought the boat last week. First tunnel boat, so any info is appreciated. The boat is tricked out, but is turning out the R's, it has a 24 Yamaha drag. What do you think would be the ideal range at the end of the 1/4.

[patchesII]

what are you turning now? i would think you would be real close to the stock 7750 rev limiter. maybe aroun 7500 to 7600. maybe one of these guys with some experience with mirages can get you closer. good luck, erik kiser p.s. if you can, look at the back of the ecu box and tell us what numbers are back there. has anything been done to the motor or is it stock.

[Nosubforcid]

Some of the super stock racers claim 9500-10200 rpm. Stock except no limiter and a proper fuel curve anything over 9000 is stout with a good 24 and 1.87-1 gears. Try some 1.78-1 or 1.75-1 if you get a chance some essentially stock 260 combinations really like them.

[T&T]

It's running 1.87-1, I have both the A-48 and the A-63 chips with it also. But, 10,000 is no problem. The motor is stock, and the prop was tricked out special for this boat. It feels smooth and pulls hard. But I am going to try to find something in a 26p or 28p to try . Also, has a CLE gearcase with a Allison Torque tab and blow out ring. This is my first tunnel boat, I'm not used to something turning up so fast. The V-Bottoms(Allisons) I'm more experenced with.

[patchesII]

i've got a 25 you can try. it hasn't been ran since coming from the prop shop. looking to trade it for a 24 or 22.

[T&T]

I was talking to the man who set this boat up today. He said I need a lighting 26p ET. For just playing around, but the 24p Drag is the prop for that set-up in the 1/4. But for just playing around I need the 26p, So if any one has one let me know.

[Rusrog]

did you get this boat and how long have you had it? Just curious. I friend of mine just slold a Mirage RR and I was wondering if it was the same boat.

Take care,

Russ Rogers

[T&T]

I bought the boat from a guy named Mark in Port Neches, Tx. The hull is a 1988, but you would have to see it. Taylor's Marine in Bridge City set the boat up for him. Steve Taylor the owner is a friend of his. he races in Pro Gas,and very strong. So I know the boat is set-up right. I just have to pull down some of the R's. If were talking about the same boat mine is Purple,teal,and white. Custom painted hull and cowling. With a 99' 260ss.

[liberatorx2]

hey ive got a brand new 26 et. i live in atlanta tx. if i see you around any of the local water holes ill let you try it to see if its what your looking for. im running it on a 19ft mirage ski racer (its a clone built by liberator in crowley tx) have a 1997 2.5 260 thats stock and running stock chip with 7800rpm rev limiter. yours sounds alot stouter than mine. i have a buddy that runs a river racer on big cyprus bayou (30 miles from here) with a 2.5 260 hes turning about 10000 too

[T&T]

Rick,
Thanks for the reply, I'm going to buy a new 26 ET before this weekend. If I can find one close to me. I believe it is what I need. Your buddy you refered to, is he turning the same prop @ 10,000. If so maybe I need a 28p. At those R's on a stock motor your leaving the power curve. When I say stock, nothing really done to the powerhead. Except computer work. I have plans on some performance work, but have to try to deal with one thing at a time. Also, the hull I'm running, 18' RR was ordered special for nothing but the 1/4. I haven't pinpointed the hull wieght down, but I know it's under 500lbs. I plan on getting the R's between 8500-9000. One thing I don't understand is these guy's running a 22p with a modified engine and only turning 10500. (Same Hull) I have a hard time staying under 10,000. With what I'm running. But I'm still learning.

[Unloaded Racing]

You might want to check your tach, just to see if it is right. I ran a 90 model River Racer that would turn 9000 to 9200 RPM in the quarter mile with a 24 pitch Yamaha and stock 2.5. My Diamond motor would only turn 10400 with the same prop on the same boat. Might want to check that hull weight too. Unless someone did something to lighten it. I talked to Brad Collins in depth at Jasper last year about the River Racers and I am almost certain he did not build any less than 500 lbs.

[Rusrog]

Sounds like a nice rig though. Good luck with it. You will get some very good info and help on this board.

Take care,

Russ Rogers

[liberatorx2]

he was running a 24 et. it was awesome in the 1\4, but now hes running a 28 et. he mainly just halls ass up and down the river nowadays not sure but i think he turns the 28 @ 9000, havent talked to him lately hes been out of town. what kind of topend are you running? i just bought a 48 chip tuesday it ought to be here by saturday! i want [more] rpms! ive been running about 96-97 at about 7600rpms. need more! would like to have more hole shot too. what kind of difference do you notice in the 48 & the 63 chip? i was told the 48 was best for what i was wanting to do. good luck rick

[tonye]

Man....that is one strong running motor 10K in the 1/4 on a river racer. Could it be that you are running 2:1 gear ratio? Either way sure sounds like fun. Just a thought

[T&T]

I am having my Tach checked today. I bought a new 26p ET to day also. I'm not sure about the hull weight. I'm just going by what I was told. Maybe the prop will get me where I need to be.


Rick, I think there is a considerable diffrence between the two. It just depends what you like to do. I thinking about the programable chip's, Chip one out for your specific needs. All you need is a lap top. And you change your setting right there.


I am running 1:87 gears, on a CLE gearcase. I would hate to even thing about 2:1's

[Ziemer]

If you get a software and hardware to reprogram chips for your ECU, you don't need a special chip, you would be able to reprogram the ones you already have. My buddy just did mine about a week ago, it was a stock A-42 chip that he reprgrammed to a 39 psi, 11,500 rev limit, drag chip (a-48 or 49?).

[T&T]

I quess I didn't make myself clear about the chip's. True you can program most chips(not all of them) , But I already have the A-48 and A-63. I'm wanting to experiment with one. To fit my specific needs.

[T&T]

I would to thank everyone for their in-put and good advise to my question. I bought the 26p ET, pulled my R's down to 9000 where they needed to be, and put some MPH on the end. Made a few good passes until the skeg came off, That will be something to remember!!!

Todd