changing yan 150 to 180 on r25sc

Status
Not open for further replies.

nzfisher

Well-known member
Joined
Jan 26, 2009
Messages
592
Fluid Motion Model
C-26
Vessel Name
Swims with Tuna
I am curious to know if it is possible to change the Yanmar diesel from 150 to 180 and if possible, what are the downsides- I am guessing

new prop
less fuel efficiency

But would the increase in speed be safe for the r25sc design? If this is just a "chip" like a truck diesel and a prop change it would be worth it for me to get the increase in speed for longer distances involved in tuna fishing. Then change back when season is over.

Any information?

Thanks
 
I have heard from a factory rep that its more than a chip and is a little spendy. I think I would call or e-mail a Yanmar distributor and ask this question.
 
I happen to have a 180 in my rig. You can check out the following post, at the end of it, you'll see where I posted speed/rpm info. viewtopic.php?f=2&t=3079

In my own opinion, I would have to say it probably wouldn't be worth it, UNLESS:

You run the boat very, very light all the time ( I know you want to go fast to the tuna grounds)
You go through the process of getting your prop correctly pitched and cupped (you'll over run redline if you don't)
You are happy being the pioneer on how these boat handle on plane because it will.

I'm not sure you'll get what you want. I really do think these boats will plane if you run them extra light with the higher horsepower and the correct prop, but it will be right on the edge.

Let me know if you want any more info, I'll be out chasing lings all weekend and would be happy to test something in particular for you. If you're not going to try to plane the boat, I'd say don't bother. Mine runs about the same speed as everyone else's. If you do decide to do it, and your boat does indeed plane, I'll be the first one asking you for prop information!

Getting this done is similar to "chipping" a diesel truck. The difference is that a "chip" is a stand alone goody that is first programmed and then installed in an ECM Engine Control Module. What you will have done is a "tune". The engine manufacterer (or anyone with a laptop that knows how to program) simply hooks up a programmer to your ECM, loads a new program or tune onto it and whalah! 30 more Hp. My diesel truck has been chipped and I actually get 80 more Hp and 2-3 mpg better than on the factory mode. The advantage to chips vs tunes is that chips can be changed on the fly, tunes are stuck in your ECM until it is retuned. My chip has 6 settings on it for 6 different towing situations.

Rob
 
Wanted to add something else regarding diesels and tuning or chipping. EGT (exhaust gas temperature). It's very important. If you overload the engine with an incorrect prop (bog), the engine will be "overpropped". When operating a diesel in an overpropped state for too long, or without the additions of such things as a proper intake, exhaust and possibly some turbo work, you stand to overheat the engine in short order. Overheating a diesel from being tuned up or overpropped causes them to melt starting at pistons,heads, valves and possibly taking the t-wheel (turbine) with it. Your water temperature guage would probably never know the difference, at least not before your engine is toast (there is a difference between "overheating" and "undercooling"). To combat this, you need an EGT guage that tells you how hot your exhaust is. Much above 1250 for too long and you'll be buying another engine as an overtemped diesel is usually scrap.

I'm not trying to scare you off here, just wanted to stress the importance of having the correct prop. I don't have an egt on my boat. Since mine's underpropped for the amount of power it puts out, I'm not taking advantage of the extra power, and since it's a factory installed tune/engine, it's not a hot enough tune to have a meltdown (at least in its current underpropped state). What I am saying here is that if you get the 180 tune and start playing around with props, you may need to install an EGT guage downstream of your turbo.

Rob the airplane mechanic
 
One other thing to consider if you 'chip' the engine concerns the manufacturer's warranty. For the warranty to not be an issue the 'chipped' engine must be Yanmar certified.

I have 'chipped' my 2012 Volvo XC70 T6 (300 HP to 327 HP and more torque). It was done by Polestar in Sweden and is fully backed by Volvo and I ordered the car through a Volvo dealership with the Polestar upgrade as an officially blessed Volvo option... so warranty stayed intact. 🙂
 
I wonder how we could find out if this would work, after all, we do have marinized BMW engines. This could give you about 215 HP.

http://www.superchips.co.uk/search?make ... riant=2337

Even if it worked right the first time, it'd still be expensive. Chip, EGT, prop change. Could you imagine cruising in the mid 20's on plane? I'm perfectly happy going slow most of the time, but you know what it's like when it's time to get to the fishing grounds....
 
Status
Not open for further replies.
Back
Top