Engine ECU remapping

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TomTom
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Engine ECU remapping

Post by TomTom »

Does anyone have any experience/ know anything about this?

Apparently certain engines where they are a detuned engine on a block for a bigger one can get some pretty substantial power gains? Or is it all mumbo jumbo?

Just curious.

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BarraMan
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Re: Engine ECU remapping

Post by BarraMan »

I have heard that you can get 400 hp by remapping a Yammie 250 Vmax SHO like mine! 8O :help:

My fishing mate, who I respect greatly, says, “Don’t you dare”!

He hates remapping with a passion! :lol:

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Re: Engine ECU remapping

Post by TomTom »

I bet your eyes light up when you hear that your 250 could be a 400 …. Of course you would never use it at full throttle right 😂😂

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Jaysen
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Re: Engine ECU remapping

Post by Jaysen »

My experience is with automobiles but the problems are the same…

Modern engines run nearly every function though the damn computer. The computer makes deviations in timing, fuel ratios, etc based on sensors. The sensors are selected/specified based on specific operating expectations. So if you remap a 250 to the file ratios of a 400 then you need to know the code pecked O2 readings of a 400 and update the O2 map. You also need to know that the o2 sensor can operate ACCURATELY in the new map range. If you change the o2 sensor then you need to recalculate the map on the specific values that o2 sensor will output. Now repeat that for every debris attached to the ECU.

There is a reason I avoid new motors in anything. All my old crap just needs a screw turned here and there and done. Unless it’s a mercury motor… if it’s a mercury the only fix I seem to be able to do is sink it in the ocean.
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TomW1
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Re: Engine ECU remapping

Post by TomW1 »

Jaysen you are totally correct, to remap you need new sensors and changes to the computer. Barraman your 250 is included in the 4-cylider group of Yamaha motors which go to 300HP, I doubt you could get it to 400 without a rebore and total change of computers. Very, very expensive. 8O Yamaha has a 425HP but it is a V8.

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BarraMan
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Re: Engine ECU remapping

Post by BarraMan »

TomW1 wrote: Sat Feb 12, 2022 5:53 pm Jaysen you are totally correct, to remap you need new sensors and changes to the computer. Barraman your 250 is included in the 4-cylider group of Yamaha motors which go to 300HP, I doubt you could get it to 400 without a rebore and total change of computers. Very, very expensive. 8O Yamaha has a 425HP but it is a V8.
Tom
My motor is a 4.0 L, 24-Valve, DOHC, 60° V6!

It will remap to 400 hp and I am acquainted with one that has been done as its owner has encouraged me to do mine. Not going to happen, as I am NOT motivated to do 100 mph up the Hinchinbrook Channel! :help:
Last edited by BarraMan on Sat Feb 12, 2022 10:44 pm, edited 1 time in total.

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Jaysen
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Re: Engine ECU remapping

Post by Jaysen »

Doooo iiiiit!!!

The key is to delete all emissions and pull sensors (remove from system and pug holes, terminate harness connections with appropriate resistors, remove throttle body limiters) with the exception of MAF and fuel system.

Oh… and you need to beef up the cooling system.

Problem is that you will 100% violating all environmental standards and safety limiters. It is amazing to watch a heavily tuned stock-ish motor explode. Always fun looking for block pieces on a trail… Could be a new use for that fancy sidescan you have.

Just make you get video!
My already completed 'Lil Bit'. A Martens Goosen V12 set up to sail me to the fishing holes.
Currently working on making a Helms 24 our coastal cruiser.
“Mark Twain/Samuel Clemens” wrote:Eat a live frog first thing in the morning and nothing worse will happen to you the rest of the day.
Jaysen wrote: Mon Apr 29, 2019 3:44 pm I tried to say something but God thought I was wrong and filled my mouth with saltwater. I kept my pie hole shut after that.

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OrangeQuest
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Re: Engine ECU remapping

Post by OrangeQuest »

For production purposes a lot of the same short blocks are used on production motors and that could include valvetrains, intake systems and exhaust systems with a lot of de-tuning with the programming of the ECU. With everything being controlled by a processor from fuel injector duration, timing, fuel pressure, intake air. Engineers can do a lot of things up and down a performance curve. Mechanical injected diesels had mechanical governors on them to regulate hp and rpms, new diesels use electronic controlled injection systems that control hp and rpms. They also control turbo boosts too so power can be increased with a little re-programming. That 4.0L DOHC V6 in a production-built Ranger that can only do 5800-6000 RPMs is the same one in the race trucks that are turning out 9000-10000 RPMs. Most of it is done at the ECU.

Motors built for marine use are some of the strongest built motors made outside of racing or aircraft and if they are controlled by a processor then they can be "tuned".
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Matt Gent
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Re: Engine ECU remapping

Post by Matt Gent »

BarraMan wrote: Sat Feb 12, 2022 6:38 pm
TomW1 wrote: Sat Feb 12, 2022 5:53 pm Jaysen you are totally correct, to remap you need new sensors and changes to the computer. Barraman your 250 is included in the 4-cylider group of Yamaha motors which go to 300HP, I doubt you could get it to 400 without a rebore and total change of computers. Very, very expensive. 8O Yamaha has a 425HP but it is a V8.
Tom
My motor is a 4.0 L, 24-Valve, DOHC, 60° V6!
Hydrotec will flash a Yamaha 250 to 325 for under a grand. That is cheap horsepower.

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Re: Engine ECU remapping

Post by piperdown »

Not much to add beyond what Jaysen, OQ and Matt said but, yes, it's a thing.
I knew guys in the past that would immediately head straight for a tuning shop after purchasing new diesel trucks.
I know other guys buying cars that did the same thing.

Before tuning, if you wanted to build extra horsepower or torque, you had to match up all the right components. Cam, lifters, overbore pistons, rod length and crankshaft depending on the compression you wanted, intake, carb, timing, etc. Way more expensive and the tolerances had to be triple checked. Back in '90 when I rebuilt my Ford Bronco motor for low end torque (trail riding in Idaho) I put $1500, which doesn't sound like much, but that was 1990. To do the same thing today would be anywhere from 3-5k.

So I find the whole tuning "thing" fascinating, that a proper tuning shop can take your engine, not do a whole lot, and boost HP and TQ from reprograming.
Eric (aka, piperdown)

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