geeviam Posted February 24, 2019 Report Share Posted February 24, 2019 HoneyB, The upgrade sounds like a blast, and if it was available for my 115 SHO, I would probably go for it as well. However, looking at the Yamaha specs, none of the 4.2L models from 200 hp to 300 hp have a maximum RPM range above 6000. And the fuel spec for the 300 hp is 89 octane. If you're able reach 6400 to 6700 RPM, the ECU flash must have removed the rev limiter all together. Just food for thought... Link to comment Share on other sites More sharing options...
Nag Juice Posted February 24, 2019 Report Share Posted February 24, 2019 I was thinking that too. 6400-6700 is screaming for that motor. I’d be concerned with getting them down below 6k so the piston rings don’t burn up or the crank doesn’t let go. Link to comment Share on other sites More sharing options...
dcathey Posted February 24, 2019 Report Share Posted February 24, 2019 I called last year to one of the companies about it and the rev limiter stayed the same. I think it was Simons Motorsport Link to comment Share on other sites More sharing options...
fishmanjj Posted February 24, 2019 Report Share Posted February 24, 2019 11 hours ago, HewesYourDaddy said: Well dang. We should have a meet-up with all of us Georgia guys. My vote would be lunch at the Sunbury Crab Co., since its about halfway between everyone, and then we could hit the sandbar just up the river to talk boats, try props, speed runs, and a lot of other BS! Is that down there where the “ Shrimp Boat “ restaurant was a few years back ? A few hundred yards down from Sunberry Landing ? Link to comment Share on other sites More sharing options...
linesider 159 Posted February 24, 2019 Report Share Posted February 24, 2019 Depending on the flash, you can either remove the rev limiter or keep it the same. The flashed sho I have run had the rev limiter removed and was a blast. Spun it to 6500 rpm, but best speed was gained bringing it back down around 6000. Sounded like a jet engine at 6500 Need to be running 89 minimum Link to comment Share on other sites More sharing options...
HoneyB Posted February 24, 2019 Author Report Share Posted February 24, 2019 In responce to a few questions and concerns. Simon performance did the flash. Turn around is about as fast as you want to pay for shipping. I had to go out of town last week so I did not pay for fast return shipping. Yes there is no way I would hold this motor at 6700 rpm for long runs. As a matter of fact I knew I would never run this 19 pitch prop again. The limiter was supposed to stay. One company recommends moving the limiter up, Simon told me they left it alone. I have to follow up on that on Monday. Looking back at others flash threads the some people say run them close to 7000 rpm. No thank you. Regardless I am already looking for props to get me down to 6200 rpm at WOT. i realize the requirement on octaine for the 250 and 300 hp motors is 89. I had 87 in the boat and was not going to look for 89 octaine to add to it for 1 hour of test runs. If 89 changes the data I will update the post. Link to comment Share on other sites More sharing options...
linesider 159 Posted February 24, 2019 Report Share Posted February 24, 2019 The good news is when you switch to 89 you should see a performance gain. Your results may be even better than you initially thought! Link to comment Share on other sites More sharing options...
HoneyB Posted February 24, 2019 Author Report Share Posted February 24, 2019 3 hours ago, linesider 159 said: The good news is when you switch to 89 you should see a performance gain. Your results may be even better than you initially thought! I fully expect to see more gains. But I did not seek out 89 on my last few fill ups. I am sure with raising the octain and getting proped to get the rpm’s down to 61 or 62 I will have some different results. Link to comment Share on other sites More sharing options...
dcathey Posted February 24, 2019 Report Share Posted February 24, 2019 Down here, our fuel company sells 90 octane rec fuel. I keep 100 gallons at my shop. I’m ready to see what you end up with after dialing her in Link to comment Share on other sites More sharing options...
HoneyB Posted February 24, 2019 Author Report Share Posted February 24, 2019 Lol maybe I just need to stop by ur shop in the middle of the night! i just rode and looked the Sunoco up the road has 90 octaine marine. So I’m in business. Now to work out the prop Link to comment Share on other sites More sharing options...
linesider 159 Posted February 24, 2019 Report Share Posted February 24, 2019 Personally, I'd prop for right at 6k. Seems to be best range for top speed.....if that is the goal of course Link to comment Share on other sites More sharing options...
BradM Posted February 24, 2019 Report Share Posted February 24, 2019 A stock SHO will run at 6200 rpm, and if the prop surfaces, they can hit 6400 for a split second before they come down. You guys should see what some of the bass boat guys are doing...8k rpm all day. They say the have run them to 14,000 - FOURTEEN THOUSAND rpm, but they don’t like it, and come apart up there. Furthermore, if you you look at the dyno chart for the Nizpro tune, the horsepower falls down fast around 6k and the torque starts falling around 5k. The extra revs are just for speed...I would guess you would be able to turn a lot more wheel with 130 more HP, HoneyB! Link to comment Share on other sites More sharing options...
HewesYourDaddy Posted February 24, 2019 Report Share Posted February 24, 2019 7 hours ago, fishmanjj said: Is that down there where the “ Shrimp Boat “ restaurant was a few years back ? A few hundred yards down from Sunberry Landing ? Close. That was the old "Shrimp Docks" restaurant. Next door is a newer restaurant with a large dock facility and concrete walkway. Lots of dock space . The Crab Co is a pretty cool place. Link to comment Share on other sites More sharing options...
Capt. Troy Posted February 24, 2019 Report Share Posted February 24, 2019 7 hours ago, HoneyB said: In responce to a few questions and concerns. Simon performance did the flash. Turn around is about as fast as you want to pay for shipping. I had to go out of town last week so I did not pay for fast return shipping. Yes there is no way I would hold this motor at 6700 rpm for long runs. As a matter of fact I knew I would never run this 19 pitch prop again. The limiter was supposed to stay. One company recommends moving the limiter up, Simon told me they left it alone. I have to follow up on that on Monday. Looking back at others flash threads the some people say run them close to 7000 rpm. No thank you. Regardless I am already looking for props to get me down to 6200 rpm at WOT. i realize the requirement on octaine for the 250 and 300 hp motors is 89. I had 87 in the boat and was not going to look for 89 octaine to add to it for 1 hour of test runs. If 89 changes the data I will update the post. It's 4.2 liter and agree the mapping is the HP difference. 200 to 300 hundred in the same block with mapping, fuel and timing delivery. Same block all day. The turning over the RPM limiter is just what it is. Can the increase of prop size support the torque of over 300 HP on the drive system? Defeating the max RPM limits and turning 7 K is asking for it from block to the gear case. Doing it on a boat that was never intended to do such speed and stresses is asking for trouble. There is a member on here with a long history that is in the insurance business and has responded to the over HP threads in the past. I suggest you listen to him. If you can afford to tweak engines to exceed the limits of the boat I would suspect you may have something to lose or just like to gamble on the reliability of your engine or your assets. Those on here posting the known and proposed over powering of their vessels may not understand the power of the internet. Your comments have been made duly noted for ever! Link to comment Share on other sites More sharing options...
Capt. Troy Posted February 24, 2019 Report Share Posted February 24, 2019 20 hours ago, HoneyB said: Capt Troy ... they can’t sell only 300 hp motors.. not all boats are rated for 300hp. Mine isn’t either by the way.. Just as I stated and you posted for the world to know. Not trying to bust anyone's chops here but the liability in today's world is very real. This quote I just posted indicates you have knowingly over HP a vessel. I know it *** to say such but I have seen the results of the the unlucky. Lot's of folks have been burned on technicalities that had no play in the outcome of the incident. They got burned on the technical side and were not at fault for the most part. The numbers you posted are impressive none the less Link to comment Share on other sites More sharing options...
linesider 159 Posted February 24, 2019 Report Share Posted February 24, 2019 As long as its over 20 foot Allstate insurance had no problem with me exceeding the 250 rating on my lake and bay. They cared about the check in the mail and were willing to offer liability insurance Link to comment Share on other sites More sharing options...
Capt. Troy Posted February 24, 2019 Report Share Posted February 24, 2019 1 hour ago, linesider 159 said: As long as its over 20 foot Allstate insurance had no problem with me exceeding the 250 rating on my lake and bay. They cared about the check in the mail and were willing to offer liability insurance Knowing negligence and performing the act can lead to a punitive damage claim. I thought you were in law school. Not a insurance company in the world covers punitive damage claims and you better be a lawyer to read the fine print of your policy as you speak.. Lets let forum member Commocean speak to this or a lawyer versed in this subject. Lets just say that I have seen first hand, been disposed and got to watch the system work on known negligent acts. It wasn't very pretty for someone that had something to lose, and they did despite all kinds of insurance. That was a civil case. In a criminal case who knows and I don't. I just would not want to be the one doing 70 MPH and smash another boat or a person in the water in a boat with over the recommended HP and speed. These things will be discovered in today's world much easier than years ago. Much easier if you put the info on the WWW. Link to comment Share on other sites More sharing options...
HoneyB Posted February 25, 2019 Author Report Share Posted February 25, 2019 I would love for this thread not to turn into debate about if a person should or should not flash to higher hp. My boat was 50 under the recommended horse power now it is 50 over. I am ok with that. I did confirm the performance shop , they will return it to factory settings if I decide to with no charge involved. Link to comment Share on other sites More sharing options...
NCTribute Posted February 25, 2019 Report Share Posted February 25, 2019 I would like to know the apples to apples comparison of the stock 250 hp tune versus the Nizpro 250 hp tune, or any other power rating versus stock. Just curious if there is much difference. Obviously if you increase the power you will see performance differences, but how does the tune perform versus the stock tune of the same power rating. Link to comment Share on other sites More sharing options...
geeviam Posted February 25, 2019 Report Share Posted February 25, 2019 3 minutes ago, NCTribute said: I would like to know the apples to apples comparison of the stock 250 hp tune versus the Nizpro 250 hp tune, or any other power rating versus stock. Just curious if there is much difference. Obviously if you increase the power you will see performance differences, but how does the tune perform versus the stock tune of the same power rating. Good question! And at the same RPM range as stock. Link to comment Share on other sites More sharing options...
Capt. Troy Posted February 25, 2019 Report Share Posted February 25, 2019 4 minutes ago, NCTribute said: I would like to know the apples to apples comparison of the stock 250 hp tune versus the Nizpro 250 hp tune, or any other power rating versus stock. Just curious if there is much difference. Obviously if you increase the power you will see performance differences, but how does the tune perform versus the stock tune of the same power rating. If you dyno the engine and get HP it is HP. The rated HP could be be plus or minus from the OEM a % allowed to be the rated HP. A 250 going from that to 300 HP if true is just that. 300HP. RPM will equate to a prop at the shaft at x amount of RPM the prop spins and moves the boat, a variable that comes from pitch and the engines ability to spin it. The prop math including slip is fairly straight forward. a 19 pitch prop at 5500 rpm will not drive a boat but a certain speed. Increase that RPM to 6500 and the same boat will go faster if the HP allows it to reach the higher RPM on the same prop and same hull until other dynamics come into play to reduce drag and so on. It's all fun stuff but at what cost to reliability and the overall end result is what I question. Not trying to rain on anyone's parade. I like to go fast as most know. The only mods I have done on anything were on my many diesel trucks. It technically made them illegal to drive per the EPA, and tended to make me drive them like I stole them thus breaking and wearing out all the related components of the HP to the ground I produced. Link to comment Share on other sites More sharing options...
NCTribute Posted February 25, 2019 Report Share Posted February 25, 2019 7 minutes ago, Capt. Troy said: If you dyno the engine and get HP it is HP. The rated HP could be be plus or minus from the OEM a % allowed to be the rated HP. A 250 going from that to 300 HP if true is just that. 300HP. RPM will equate to a prop at the shaft at x amount of RPM the prop spins and moves the boat, a variable that comes from pitch and the engines ability to spin it. The prop math including slip is fairly straight forward. a 19 pitch prop at 5500 rpm will not drive a boat but a certain speed. Increase that RPM to 6500 and the same boat will go faster if the HP allows it to reach the higher RPM on the same prop and same hull until other dynamics come into play to reduce drag and so on. It's all fun stuff but at what cost to reliability and the overall end result is what I question. Not trying to rain on anyone's parade. I like to go fast as most know. The only mods I have done on anything were on my many diesel trucks. It technically made them illegal to drive per the EPA, and tended to make me drive them like I stole them thus breaking and wearing out all the related components of the HP to the ground I produced. Sort of, the shape of the torque curve makes a big difference on the feel and responsiveness of the engine. Also, are the power ratings at the same rpm? Again can make a significant difference. I have been designing powertrains for 35 years, so have a little understanding of it. Top speed is just one characteristic, but how you get to the top speed is what defines the ‘feel’ of the engine/prop combination. Link to comment Share on other sites More sharing options...
BradM Posted February 25, 2019 Report Share Posted February 25, 2019 NC, it goes (no matter the 4.2 liter SHO) to 330 h.p., Nizpro markets and advertisers at 320 h.p. The horsepower, as I stated above, starts falling around 5,700 rpm or so. The torque curve on this tune is what really got me excited about it. It comes in a little sooner and a little higher than stock. But, the stock torque curve falls off pretty sharply around 3,000-3,500 rpm (I may be off a little here). With the Nizpro tune, the torque curve stutters right around where stock falls off, but then climbs back up and is table top flat from 3,2-3,300 rpm up to around 4,700 rpm. It’s pretty impressive and the more interesting of the two numbers to me. I have a PDF of the torque curve that Simon, of Nizpro, sent me. I’ll send it to you tomorrow. One of the bass fishermen was able to dyno his power head after the Nizpro tune was flashed onto his ECU, he reported 354 h.p. @ 7,000 rpm, at the crank. I started the Nizpro thread a while back on this forum, and Simon ended up chiming in. I recall that of the hundreds and hundreds of hours he’s logged on STOCK Yamaha SHO motors with his super charger kit, they’ve never seen a failure on the Yamaha side of things. That super charger pushes these things to 450 h.p. and they’ve seen over 550 h.p. I don’t think horsepower is the killer here, but excessive rpm, which is true with any rotating mass, including the tires on your truck. **edit** With forced induction, you will find he weak spot within the accepted rpm range. This discussion, from my opinion, is solely based on natural aspiration. Link to comment Share on other sites More sharing options...
HewesYourDaddy Posted February 25, 2019 Report Share Posted February 25, 2019 I've got a friend that is interested in doing a tune on his 2003 Yamaha F150. I'm not sure if his engine could be flashed, but I will send a link to this thread. Pretty cool stuff. Link to comment Share on other sites More sharing options...
NCTribute Posted February 25, 2019 Report Share Posted February 25, 2019 12 hours ago, BradM said: NC, it goes (no matter the 4.2 liter SHO) to 330 h.p., Nizpro markets and advertisers at 320 h.p. The horsepower, as I stated above, starts falling around 5,700 rpm or so. The torque curve on this tune is what really got me excited about it. It comes in a little sooner and a little higher than stock. But, the stock torque curve falls off pretty sharply around 3,000-3,500 rpm (I may be off a little here). With the Nizpro tune, the torque curve stutters right around where stock falls off, but then climbs back up and is table top flat from 3,2-3,300 rpm up to around 4,700 rpm. It’s pretty impressive and the more interesting of the two numbers to me. I have a PDF of the torque curve that Simon, of Nizpro, sent me. I’ll send it to you tomorrow. One of the bass fishermen was able to dyno his power head after the Nizpro tune was flashed onto his ECU, he reported 354 h.p. @ 7,000 rpm, at the crank. I started the Nizpro thread a while back on this forum, and Simon ended up chiming in. I recall that of the hundreds and hundreds of hours he’s logged on STOCK Yamaha SHO motors with his super charger kit, they’ve never seen a failure on the Yamaha side of things. That super charger pushes these things to 450 h.p. and they’ve seen over 550 h.p. I don’t think horsepower is the killer here, but excessive rpm, which is true with any rotating mass, including the tires on your truck. **edit** With forced induction, you will find he weak spot within the accepted rpm range. This discussion, from my opinion, is solely based on natural aspiration. I asked Simon in the other thread if they had a 200 hp and 250 hp tune and he replied that they did. My interest was in the tuner you can buy from them and you store the stock tune on it. So you can go back and forth yourself. I have no desire for 330 hp. But am curious if their 200 hp and 250 hp tunes are much different than the stock tunes. You can meet the power at whatever rpm spec, but playing with the torque curve you can have a ‘power bulge’ at other rpm points that can make the acceleration feel totally different. I work with ‘yellow’ engines, you can have the same power spec at x rpm, but it can have a genset torque curve, an over the road torque curve or an construction vehicle torque curve, for example. They all will perform differently. 12 hours ago, BradM said: Link to comment Share on other sites More sharing options...
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