S1000xr gen 2 velocity stacks brentuning

[Saeeddxb]

I have recently purchased the new velocity stacks by brentuning for my s1000xr 2021 which has a sprint air filter and akra headers which was tuned by my local tuner and had 171 Whp before installing the stacks , as adverstised by BT said that i would gain 25 hp out of stacks and lose no power on mid range , after installing the stacks and retuning my bike i was shocked with the results bike was way slower at mid range and had 5 WHP loss on top range have anyone tried those stacks please let me know

165 whp after velocity stacks installation
170 whp before installing and huge difference in mid range about 20 whp

[smithy]

Whoever told you that you'd get 25hp out of anything on a basically stock motor is telling you a load of bollocks.

Depending on the dyno and dyno operator, a stock XR makes mid 150's rwhp...a decent set of Akra or Arrow headers and a good tune will bring it close to mid 160's RWHP.... Mine made 153.9 stock and a tad over 164rwhp after headers and decent Rapid Bike Evo tuning.... Longer velocity stacks will normally give better mid-range at the expense of top end...

Without major modification, you'll never get +25hp or ~180rwhp out of a stock XR.

JMHO.

Smithy.

[Saeeddxb]

Yap i knew it was not true that i would get that much hp out of stacks though it would at least give 5hp maybe but still i fixed them and lost alot of whp through out the whole rpm range

[smithy]

Originally Posted by Saeeddxb

Yap i knew it was not true that i would get that much hp out of stacks though it would at least give 5hp maybe but still i fixed them and lost alot of whp through out the whole rpm range

The only way to get those sorts of HP readings out of an XR is to fit an RR engine...or a hybrid of it...Jason Willoughby has done this and it works very well. I've been tossing the idea around, (inspired by Jason), but I don't believe I'll have my current XR for too much longer.

Smithy.

[Saeeddxb]

I had this idea too but couldn’t find the parts that will suite the gen 2 bike since the gen 2 rr runs on variable timing cam

[bazzer]

Smithy, don't forget the Gen 1 closes the throttle at high revs as standard (maybe to de-tune it vs the RR) You can get this flashed out and it does pick up some high rpm power there.

I don't know if the Gen 2 does this.


I have had mine mapped by Phil Crowe same as Jason. I have the variable stacks etc from the RR. Mine made 174bhp at the rear if you trust Phil's Dyno (I think I do)

I am looking for some cams, valves and springs from an RR. I have a stock XR engine spare to rebuild to RR spec once I source the bits. Trouble is I am tight so don't want to pay too much money for them :-)

[Antares]

Originally Posted by bazzer

Smithy, don't forget the Gen 1 closes the throttle at high revs as standard (maybe to de-tune it vs the RR) You can get this flashed out and it does pick up some high rpm power there.

I don't know if the Gen 2 does this.


I have had mine mapped by Phil Crowe same as Jason. I have the variable stacks etc from the RR. Mine made 174bhp at the rear if you trust Phil's Dyno (I think I do)

I am looking for some cams, valves and springs from an RR. I have a stock XR engine spare to rebuild to RR spec once I source the bits. Trouble is I am tight so don't want to pay too much money for them :-)

How much do Crowe performance want for a tune?

[bazzer]

I can't honestly remember, its similar to a brentune etc, but obviously its bespoke to your bike.

I had the launch control and audible traction control activated as well.

Give them a call, I think they do deals this time of year now the race season is over.