10hp+ Gains for Gen1 With New BT Velocity Stacks

[Belco100]

Bren Tuning have just released their new drop-in Velocity Stacks and it seems to give massive top end power gains  :

"As some may notice, BMW has changed the airbox several times over the past decade and offered a racing airbox for their HP4 Race series and WBSK bikes.  Some of these changes were introduced for more midrange, top-end, race use and so on. After studying the differences of all these units, before and after data, and dyno data logging, we were able to create a scalable solution for use with the factory airbox."



It looks to me that the mid-range is what you would expect with a full system fitted as well, so probably a few other tweaks on this bike?

These are for Gen1 only at the moment, Gen2 in development apparently.

 

[Mareng1]

IIRC long stacks for midrange, short stacks for top-end power?

Surprising that they don't show any distinct reduction in mid-range for that increase at the top.

Were there not some bikes of ???? make which had 2 short and 2 long stacks - for the best of both worlds?

Or was that a common configuration?

[drmichelin]

Yeah cuban rider just posted an install vid and a run or two with it installed.  Looks like it pulls just like my ducati did at high rpm. I think its what the Gen 2 is lacking.

[Belco100]

The install actually looks a little awkward. Hard work just getting the airbox off   

[Winger]

Hmmmm well it’s interesting and the A/F is very good, i’d Like to see the a vid of the bike pulling from 20 mph in 6th...everyone assuming they are prepared to make the effort and spend their hard earned has an agenda, mine was getting rid of the poxy TUV glitch at 4250 and not having the ECU running around in circles chasing impossible, having more on the top end is not to be sneezed at but certainly wasn’t top of my agenda, and as every tuner knows there’s no such thing as a free lunch when it comes to HP.

[bazzer]

I am running the variable stack airbox from an RR, so its the best of both worlds.

[Madmax]

Originally Posted by bazzer

I am running the variable stack airbox from an RR, so its the best of both worlds.

Any idea what kind of gains you got from this swap?

[bazzer]

I don't have the graphs to tell you to be honest.

But runs were done with them up and down to work out the best place to switch them. I don't have copies of those runs.

The gains are all at high revs though, will be more useful with an RR head with titanium valves and harder valve springs, that way we can rev it higher and get more from it :-)

It's all a bit of a project really :-) Not sure its actually any more useful on the road :-)

[Madmax]

Originally Posted by bazzer

I don't have the graphs to tell you to be honest.

But runs were done with them up and down to work out the best place to switch them. I don't have copies of those runs.

The gains are all at high revs though, will be more useful with an RR head with titanium valves and harder valve springs, that way we can rev it higher and get more from it :-)

It's all a bit of a project really :-) Not sure its actually any more useful on the road :-)

When you got it dynod what fuel management / tuner did you use or did you just flash the ecu?  Any chance you remember which position made more power? Im planning things out so I can do all mods at once and just Dyno once and trying to decide between potentially doing  this and or brentune velocity stacks. Or if either is worth it.

[bazzer]

Where the dip is at the top end thats where its opening, As you can see its useful at really high revs. It's opening at 11K