Bigger Headers on 2.5

[Paul Bryant]

There's a lot of "interesting" opinions stated here.
We built a header for the 2.5, had it tuned properly, 215 crank HP. That's a 35% increase over stock.

No other mods.
So for those who say "just a header won't make much difference" you're way off base.

 

[Taz]

So what was at the wheel? I am willing to invest somewhat in my R3R but I just don't want to go down a big rabbit hole where I p!ss away money like there is no tomorrow. Did you do a remap of the ECU? It seems like a Penner Tune or BT Moto picks up a lot of HP even on a stock bike.

I am trying to understand how much more the header might net me.

 

[Paul Bryant]

So what was at the wheel? I am willing to invest somewhat in my R3R but I just don't want to go down a big rabbit hole where I p!ss away money like there is no tomorrow. Did you do a remap of the ECU? It seems like a Penner Tune or BT Moto picks up a lot of HP even on a stock bike.

I am trying to understand how much more the header might net me.

182.5 RWHP.
The bike MUST BE Dyno tuned to suit.

 

[Taz]

Thanks. So about another 7-10% more than just a tune on its own to the extent you can try to compare different dynos.

 

[dougl]

182.5 RWHP.
The bike MUST BE Dyno tuned to suit.

Richard Albans posted a video here in which he said the stock headers were the biggest restriction.

How did you dyno tune it? Power Commander or directly with Tuneecu? Not everyone has access to dyno tuners. Can you offer your tune as an accessory to your hardware?

 

[2023R3GT]

There's a lot of "interesting" opinions stated here.
We built a header for the 2.5, had it tuned properly, 215 crank HP. That's a 35% increase over stock.

No other mods.
So for those who say "just a header won't make much difference" you're way off base.

Interesting. where did you find an engine bench to measure crank numbers?

 

[Paul Bryant]

Interesting. where did you find an engine bench to measure crank numbers?

General concensus is there,s between 10-15% power loss through the drive train, depending who you talk to.
So by taking the real world rear wheel HP and calculating back by that % figure you get the crank figure.

 

[sunny]

There's a lot of "interesting" opinions stated here.
We built a header for the 2.5, had it tuned properly, 215 crank HP. That's a 35% increase over stock.

No other mods.
So for those who say "just a header won't make much difference" you're way off base.

do you still have stock air filter and is o2 sensor still on that exhaust?

 

[2023R3GT]

General concensus is there,s between 10-15% power loss through the drive train, depending who you talk to.
So by taking the real world rear wheel HP and calculating back by that % figure you get the crank figure.

general consensus on motorcycle shaftdrive losses is 20-25% - chain and belt have 10-15% losses

 

[Paul Bryant]

general consensus on motorcycle shaftdrive losses is 20-25% - chain and belt have 10-15% losses

Using the figure of 25% loss that makes the real world RWHP of 182.5, 250 HP at the crank. Do ya think ?
A 20% loss would mean that RWHP of 182.5 would be 230 HP at the crank.

Choose your own numbers.
What ever the crank HP is, the RWHP as done at BRM Tuning in Paeroa, NZ was 182.5