Do I need a Remap or ECU flash

[R6I6Z6A]

2010 s1krr with AR decat, the bike feels lumpy and sometimes jerks forward at around 3k rpm when off the power, when I installed the AR the garage advised me not to get a remap and all in all it has been ok BUT I got a K&N to try and alleviate the jerking sensation (now play nice boys), and help it breath better so fingers crossed.

My questions is with a decat AR and a K&N will I need a Remap?.?

Thanks in advance.

 

[bananaman]

100% remap... I've always been told that OE filter is better than after market

 

[alex]

OEM Filters will filtrate better, period. But, most of us don't drive through the desert (excluding some GSA owners on here!). OEM's have to keep the filtration levels very high to avoid issues.

I think the K&N will be fine from a filtration perspective, K&N will argue there's zero impact, if you maintain it well - clean and oil once a year minimum. However if you improve the engine's volumetric efficiency too much then yes a remap is required. The Decat will have a bigger impact than the filter. Fitting the filter will make the OEM map feel worse.

Remap or piggyback, up to you but definitely I feel you need do something.

 

[R6I6Z6A]

Thanks for your feedback guys, PC are around 3-400 spankers! that's a lot to get a little light kick ironed out, I understand where your coming form as a PC I could get loads more powerzzz etc but its a bloody beast anyway I never get to fully turn the taps on anyway, I need to think about a PC, but your saying a K&N would make it worse... can you elaborate? I assumed k&n would help it breath better? its not a Race kn its just a road filter upgrade.

I do appreciate your feed back and I believe 100% a PC/Bazzaz would be the way I would go but I don't have that sort of cash to drop on a whim, so trying to get a better understanding of the problem/cure to expand my knowledge of why this is happening...

 

[pof]

I ran my 2014 with k&n and ar system for a few weeks and like you it felt lumpy and hunted badly on idle. Just putting a pc5 and generic map really didnt help either. Had it custom mapped on dyno and was night and day better. Not what you want to hear i know but you will need the price of a pc5 and dyno work to smooth things out. I picked up pc5 on ebay for 180 i think plus 140 for mapping and dyno

 

[alex]

Hilltop (and others) can remap the OEM ECU on the dyno, but I believe it invalidates any BMW warranty.
BMW sell a "Power" ECU which is effectively mapped for a decat and filter, and it invalidates your BMW warranty. If you have one.
The PC5 and Bazzaz can be removed and don't invalidate the warranty AFAIK.

You pays your money and takes your choice, an ECU remap can release far more than a piggyback. Rider modes to suit you and more driveability.

Why will the K&N make it worse...with the decat you removed a blockage/backpressure and allowed the engine to breathe better. More fresh air can be sucked into the engine per 720degree revolution of the crank (Suck+Squeeze=360, Bang+Blow=360). As you add more fresh air you need to maintain the correct air:fuel ratio and the right timing to achieve maximum burn efficiency. At idle if you had an AFR gauge you'd see 14.7:1 (14.7parts air to 1 part fuel) . At full power I think engines that are not forced induction aim for 13.3:1 under load, turbo engines on the other hand aim for 11.7's to be safe.

Makes no odds but basically by decatting you've changed the air:fuel balance and it's all groovy at WOT (Wide Open Throttle), BMW will have put in a load of head room for safety's sake, you'll lean it off a little but probably make more peak power for that (too much fuel dulls power but add safety through lubrication and cooling to avoiding detonation). Every OE (see VW) does tricks to get their engine maps to pass emissions and MPG tests with flying colours. Want less pollutants in the tail pipe put in less fuel. They put a 'hole' in the fueling at 4-6,000rpm etc under light throttle, the timing is dulled and this is the magic people get back after a remap, a mapper doesn't have to pass emissions tests he just whacks in timing advance and fuel. Voila it all feels great.

The K&N, has bigger physical holes for air to get through than a stock paper filter, there is less resistance to the high negative pressure suck of the engine...and at truly high speeds, the ram effect of that direct intake. More air in...decat...more air in K&N = further moving away from the ideal air:fuel required by the engine to work optimally.

So that's why... hope that helps. If you're not asleep.
(Apologies in advance for typo's I expect a few)

 

[R6I6Z6A]

Alex you are a Legend.... that was spot on and thanks for your time and effort in your explanation

I guess I'm going to have to save a few bob and get it mapped correctly, I will try the k&n just to see the effects, I can always revert back if needed, but that helps a lot on my decision. I will post back in a few days with updates...

Thanks all.

 

[Loupe]

+1 for that explanation. Not something that I've considered doing yet but very informative.

 

[alex]

Cool glad it's helped. I doubt the K&N will make as much difference as the decat.
I personally have just fitted a K&N (not run it yet) but I don't have a decat. I'll report back any change.

But to summarise more succinctly. More air in/out without fueling and timing changes can lead to poor running.

 

[alex]

Actually this image perfectly explains the stock vs tuned experience. The leaner the mix the higher the x axis number. You can see how the stock map goes lean mid range and rich beyond that. With a Decat and filter you make it leaner across the board (by how much I do not know).
Too lean can make for poor ignition and lumpiness. Too Rich just quells power. Looks like 13:1 is the ideal, and even this Bazzaz mapping isn't that spot on. You can see how a small change in the AFR ratio improves the midrange power significantly.

 

[Navio]

I think the Bazzaz is a good solution to assemble and tune to 13.0

 

[R6I6Z6A]

Alex = Legend! :emmersed:

 

[R6I6Z6A]

Anyone got a graph to show de cat + k&n without PC/Bazzaz then with? that would be a good graph...

 

[alex]

The hardware doesn't matter. Its the tuner that does. I'd find a tuner you're happy to deal with and do what they recommend.

 

[R6I6Z6A]

Local garage said they will fit and supply Bazzaz (as they think it is superior) for ?280?? that good?

oh and map for another ?50

 

[alex]

Seems ok to me. But I've done zero research as I'm not in the market presently.

 

[fast_ryan]

Mapping

If it's a generic downloadable map then no. I would expect to be paying a lot more than that for full mapping on a Dyno.

 

[R6I6Z6A]

The garage has a Dyno so he will be putting it on that.. well that's what he said he would do for another ?50 if he fits and installs Bazzaz?

 

[alex]

The garage has a Dyno so he will be putting it on that.. well that's what he said he would do for another ?50 if he fits and installs Bazzaz?

I expect it will be a case of using a DL'd generic map and then making sure that is working/tweaking it for your specific bike. The thing is, the ECU template maps are pretty good as the engines have little variance so I can imagine in 3-5 runs it will be done.

 

[fast_ryan]

Mapping

You just need to be sure as to what service you are getting as full mapping will normally take several hours to be done properly by a reputable tuner. Furthermore before any work is done you need to request that a baseline power run is completed in order to identify where any issues are; particularly with the A/F Ratio.