Outboard ECU remap

[ROBMH]

HI All,
Does anybody remap outboard engines for extra HP like you can for cars? My friend has a 75hp Tohatsu which looks to be the same as a 115.
Thanks in advance
Rob

 

[[165042]]

You won't get a 53% increase from an ECU remap alone.

 

[Hot Property]

I had a 200 hp verado and that could be re-mapped to 340 HP - apparently...

if the CC of the 75 is the same as the 115 then it maybe a possibility. Tohatsu at that size are Honda made. I have the BF100 which is the same as the 75 in terms of cc.

Thinking about it, most makes of 115 HP use bigger blocks - Honda again have a 115, 135 and 150 - all the same cc.

Maybe check on a Tohatsu forum?

 

[[165042]]

Some engines share the same cc and are remapped alongside other changes - supercharger pulley on the Verado - injectors - cooling etc. You don't get huge hp increases just from changing fueling curves.

 

[ROBMH]

Thanks for all your help

 

[Alicatt]

Some engines share the same cc and are remapped alongside other changes - supercharger pulley on the Verado - injectors - cooling etc. You don't get huge hp increases just from changing fueling curves.

Exhaust restrictors and inlet restrictors are also used I know Suzuki and Yamaha both use those to restrict some engines as well as a remapped ECU to suit the restriction.

My Yamaha motorbike engine was restricted to 80kW where the full power model had 120kW done via restrictor plates in the inlet manifolds and a different ECU.
The restricted inlet manifolds, the whole teardrop shaped centre is open in the unrestricted manifolds.



It's been done for a long time, 1980s DT125 for the UK has max 12bhp but removing the restrictor plate in the exhaust gives you 17bhp, takes a bit more work with the variable exhaust port timing, which was not fitted to the UK DT-125 it's fixed, you can get 21bhp out of it.

The small Suzuki outboards DF9.9B with the removal of the restrictor becomes the DF-15, and then adding the ECU off the DF-20 you get the full power 20hp.

 

[ChromeDome]

If going down that road be aware that quite many "we'll send you a plug-in-box" tuners simply insert digital features to trick the sensor values to be understood differently by the ECU, then to feed way more fuel and tweak timings, pushing performance until the absolute limit. As always, turbo engine gain is far higher than naturally aspirated.

Commonly without any thought for the engine internals, they are relying on the manufacturer's built-in safety measures to intervene when values exceed max. limits. And pollution will skyrocket.

I've seen it on cars - diesel and petrol. A proff readout from the OBD port while driving the car clearly showed that sensor signals were completely different and way over the default.
At full throttle it went crazy, mitigated by the system's safety.

That said, if you find the right people and pay the price, you can have a true remapping that, together with special parts, will change performance. On cars this takes a lot of time, experiments and dyno testing. Not many have outboard dynos, though.

Of course, the removal of restrictors is a different game all togehter.