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F800R 15....4.5k revs flat spot or is it just me?

20K views 65 replies 21 participants last post by  Taipan 
#1 ·
Hi all, I'm new to the forum and a new owner too. (Been on bikes for many years though)


Ok, so I'm quite pleased with the bike and so won't bore you all with my biking history expect to say I've owned/ridden most types of bikes.


So, this is the second F800R I've ridden and this time i bought it....but........With the standard exhaust/set-up I do find when throttling on there's a flat-spot around the 4/4,500 rev area and this "feels" like an exhaust/fueling thing that that is overcome by the engine and at around 5-5,500 revs.


Bike's got 350 miles on the clock and was bought from a BMW dealer as pre-registered with 14 months warranty left on it.

Will an Akro/SC-project/Arrow or whatever iron this "strangulated" sensation / flat-spot out?


Thanks for reading and any advice or opinion is very much appreciated.


Darren
 
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#3 ·
Hi, I'm from Brazil and purchased a brand new '15 F800R ... I feel the same flat spot... I'm on the 3rd tank of gas.. using only 102RON (95IAD) premium gas...

I do think is something in the tune... My bike is mounted here in brazil, so I don't know if BMW made some change in the tune...
what I do know is i rode a F800GS (okay.. not exactly the same engine..) that was fitted with a dyno tunned piggyback and the engine response was amazing (no flat spot on 5k)...
I'm waiting the 1.000km service to tune my... When I do I can post de results...
 
#5 ·
Thanks chaps.

Neek; not sure old fuel is the issue, they topped her up with new petrol when I picked her up.

Smartbear; it feels like it's being held back by an inability to exhaust / breath......not quite like an engine config issue....if that's what you mean?


I've had plenty of bikes in stock form and I suppose I'm already of the opinion I need the baffling can out the way....just wanted opinions on any other issues it could be....so thank you guys.
 
#56 ·
Thanks chaps.

Neek; not sure old fuel is the issue, they topped her up with new petrol when I picked her up.

Smartbear; it feels like it's being held back by an inability to exhaust / breath......not quite like an engine config issue....if that's what you mean?

I've had plenty of bikes in stock form and I suppose I'm already of the opinion I need the baffling can out the way....just wanted opinions on any other issues it could be....so thank you guys.
The standard silencer is very efficient, just heavy, so isn't the issue. Fitting an Akrapovic or similar will make it sound (a little) better, but doesn't improve performance. The F800 seems to have good torque at low revs, and flattens a little around 4-4,500 before picking up again at higher revs. The "flat spot" isn't really a flat spot but breaks the more linear curve and is generally accepted to be due to engine mapping to meet emission regulations. There are lots of supposed solutions, a remap/dyno tune at Hilltop Garage being mentioned a lot for UK riders.
 
#7 ·
I hear what you're saying; however I'm suggesting putting an alternative performance can on the end.

Lighter, more open......the EFI & sensors and ECU usually have enough scope to make the most of the aftermarket slip-on available....why else would they be able to support improved figures?

BMW themselves have a marriage of sorts with Akro; branding part of the "HP" upgrades.

I was wondering though, this flat spot I'm experiencing, it feels like it's more obvious than is acceptable....this is a big-ish twin. My previous bike; MT--07 was crisp and linear on the acceleration.

Admittedly; after 5,500 the f800 feels more hairy chested....which is very nice :)
 
#8 ·
all the f800 family historically suffers of a light flat spot around 4000/4500, exactly as you are experiencing .
The fact that you found it on the new '15 f800r just tells they did not correct the "problem" (it's just how they tuned the ECU) .
 
#10 ·
Thanks Nano, much appreciated.

Couple of questions if I may.....

1) Regarding the 4.5k flatty.......can the ECU on these be easily altered? Are there standard replacement maps that accompany certain exhaust manufacturers? For exaample, when I had a KTM Superduke 990, the dealer had an Akropovic Map to hand to compliment the Evo's fitted...this was super cheap at at around 20 Euros.

2) Sluggish pull-away from standstill........is this also mapping or maybe the tank-venting issue I've read about?


Basically I just want to sort a couple of niggles with tuning and then leave well alone and just concern myself with the usual biking stuff like tyres and brake-pads every so often. I'm an all year, all weather commuter that doesn't enjoy tinkering...but that just can't abide poor fuelling and running.


Many thanks

Darren
 
#11 ·
Hello Darren

I've got a GPR Powercone slip-on on a 2015 F800R and I haven't noticed any flat spot. It might be there but it's I haven't had the bike longer to enough to detect a flat spot.

Sluggish pull-away from standstill does not seem normal. The 2015 has shorter gearing for 1st and 2nd gears and take off seems damn quick to me.

I'm grasping at straws here but maybe you're over doing the throttle or clutch release on take off and the ASC, if you have it, is interferring? Do you see the ASC light come on when you try take off quickly?

Cheers
 
#12 ·
Hi Richard,

The flat spot seems to be fairly common....spoke to a service technician at my dealers yesterday....seems to be down to emissions laws and the way the bikes been set up to cater for it.

Pull away is more about being unable raw away with high revs...it like the bike's been configured somehow to hold back until it's on the move.......I too was wondering if it's the ASC?

I've read the manual but can't seem to see how I know if the ASC is on or off? Once you hold the button the light comes on and stays on....does that means it's off or on?

Very confused.....been riding 26 years and never had all this electrickery before :)
 
#15 ·
None of the slip on cans make, or claim to make, a noticeable difference in power or torque, but they sound a bit better and are lighter.

F800s do have a dip in the torque curve around 4-4,500 RPM as many dyno graphs illustrate. I think the F800 makes better power and torque than the MT-07 but there is a flattening off in the 4-4.5k region so it won't feel quite as linear but it will be quicker than an MT-07. Certainly the 2015MY have a lower 1st and 2nd gear, and slightly lower overall gearing than earlier models and so it should pull away quite well. Difficult to know if your bike has a problem without riding back to back with another, the BMW dealer should have a new F800 demo you can try.

You might be able to improve it with a power commander or other remap, I haven't tried one because I don't want to void the warranty.

For what it's worth the engine will probably get a little better with more miles, and you'll subconsciously start to adapt to the characteristics and the issue will be less noticeable. If it still bugs you in 5,000 miles you'll need to change to another bike as it seems that it's a characteristic of the engine which is difficult if not impossible to eradicate.
 
#16 ·
None of the slip on cans make, or claim to make, a noticeable difference in power or torque, but they sound a bit better and are lighter.

F800s do have a dip in the torque curve around 4-4,500 RPM as many dyno graphs illustrate. I think the F800 makes better power and torque than the MT-07 but there is a flattening off in the 4-4.5k region so it won't feel quite as linear but it will be quicker than an MT-07. Certainly the 2015MY have a lower 1st and 2nd gear, and slightly lower overall gearing than earlier models and so it should pull away quite well. Difficult to know if your bike has a problem without riding back to back with another, the BMW dealer should have a new F800 demo you can try.

You might be able to improve it with a power commander or other remap, I haven't tried one because I don't want to void the warranty.

For what it's worth the engine will probably get a little better with more miles, and you'll subconsciously start to adapt to the characteristics and the issue will be less noticeable. If it still bugs you in 5,000 miles you'll need to change to another bike as it seems that it's a characteristic of the engine which is difficult if not impossible to eradicate.
Thanks Kev, great post, makes a lot of sense.

As it happens, riding in to work this morning the flat spot didn't feel so evident and I do feel like it's me (hence the title of the thread [:)] )

Basically I think you're spot on...the bike is faster, it's just more refined than the MT in certain ways and feels less direct than the MT. Having said that the F8 handles brilliantly....far better than the MT with it's budget suspension.

I do feel I am adjusting to the bike....another example is take-off.....The F8 is just way smoother.....it creates a sense of less urgency but when I look at the speedo (Something I tend not to do) I can see the F8 is propelling me very nicely indeed.

Like you, I'm reluctant to mod the bike as the warranty is important to me. In 14 months when it runs out, I might be tempted by re-map or PC...and fettle the air intake and change the exhaust. After all, these "adjustments" are fairly common and always work on other bikes so i can't see why it wouldn't work on the F800R? I still feel that the bike has quite a bit of untapped potential.....I've not been after brutal power and speed for years, I just like that "crisp" feel when throttling on....You all know what i mean I'm sure :)

Bottom line; I now think the flatty is mainly me, after coming from a lighter MT-07 with a full SC-Project system.....but the F800 is faster, not that I bought the BMW for that.....The MT's just too budget in my opinion and was eroding way too quickly for my liking so I chopped it in while the going was still ok.

I'm really enjoying the bike, never had anything quite like it and I honestly think this one's a keeper...well, longer than the 16 months I had the MT anyway.

Many thanks

Darren
 
#17 ·
As others have said - yes it's a BMW set up to comply with where the bikes are emissions tested under EU regs - speak to a UK dyno guy and he'll point out any more bikes have dip around 4500rpm.

I judged the F800R engine as pretty reliable so went "sod it" regards the warranty for the engine and got mine (2014 new purchase) fitted with Power Commander and dynoed after decatting the bike by changing to an Arrow race header system. The silencer actually makes her enough no difference to the F800R performance as the OE one is so good (if heavy and cumbersome looking). This makes it miles more tractable and much much more fun to ride on B roads BUT will cost $$$ that probably isn't worth throwing at the bike if your honest.
 
#18 ·
Thanks for the info, much appreciated.

I've also thrown money at power commanders and dyno time in the past (Benelli 1130 TNT....I know, don't)

I've seen Hilltop tuning mentioned a few times...aren't they able to flash the ECU rather than putting a PC in the mix?

I'm going to leave the bike standard for a while, I tend to get a few thousand on the clocks before meddling......especially as the bike's new-ish having less than 500 miles on the clock at this time.

Eventually I really would like the bike breathing (in and out) better....for want of a better expression.

I'm not at all after more power or pseudo figures ....just smoother, linear delivery of what's currently available.

As I said a post back, I'm quite happy for the time being, I'm getting used to the bike and low-end delivery is decent enough.
 
#19 · (Edited)
North Oxford BMW use and recommend Hilltop though I didn't go that route and I don't know if Hilltop have worked on an F800R twin. They do for the GS's etc.

I went the dyno and exhaust route and used PDQ for the dyno work and then a PC, which eliminated flat spots and made the engine much more tractable and nicer to ride, which is what you're wanting.

Absolute power gains won't happen (I got 3-4 hp more for all the money it cost) as the airbox is so restrictive and the OE BMW filter is as good at flow as a K&N and a Pipercross (dyno proved it). If you take off the airbox & snorkel you'll get 3hp gain everywhere straightaway ( we tried it) but clearly you won't run without an air filter!

The dyno guy also explained how good standard modern BMW silencers are - the std is made by Lanfranconi - that they don't give extra HP despite what Akra fans claim....the difference comes from junking the headers for catless ones. Doing that without a PC WILL make an improvement in torque and the flat spots WITHOUT using a PC.

Sorting the fuelling WITH a PC after that will just make it even better as BMW set them up to run very lean for emissions, which is what causes the issues.

The sluggish pull away from standstill is the emissions flat spot at 1.5k rpm or so too.
 
#20 ·
Pete, thanks for that last post........great info mate.....I'm most grateful.

Given this.....IF Hilltop have a map or can create a decent custom one for the ECU and I opted to chop out the whole exhaust system from the headers....do you think this COULD yield the same or better results than a PC? Also, which do you think would be the cheaper option.....ECU map or PC?

My experience of PC's is limited, are these pretty much fit and forget these days? The one I had on my Benelli was only fitted a short while and I sold the bike....Had enough of the dam thing :)


Thank again

Darren
 
#21 ·
Hi Dazzor - A PowerCommander V will cost around 300 and is fit and forget under the "tank". The dyno time will be about 150-200 to sort the fuelling with somebody who knows their onions. Plus cost of exhaust & filter (but the OE BMW is perfectly ok - the only advantage is you can reuse a K&N!)

USA types on here swear that the booster plugs do just as good a job as a PCV in sorting the flat spot. Dunno, I went a different route.

I don't know how much Hilltop will charge but I would wager that the results would be the same. Cheaper? Only a phone call will find out!

And for exhausts, I'd give this guy a ring. http://www.osmc.co.uk/index.htm
He'd need the bike for a day or so but he laughed when I told him how much Akra and Arrow silencers cost.
He could do a complete custom stainless polished system to your exact noise/style for about £500. Cat or no cat, legal or ahem, "race"... against £285 for Arrow Race Headers plus whatever silencer you use.
He's in Stafford and used to do race systems for BSB and race bikes. I've used him, he's a genius.

I've got the dyno charts and the parts guy at SBW in Welwyn should have a copy of them too, as he took a copy when I had my bike serviced - to show the stock BMW filter and silencer was pretty efficient! (if a bit heavy and not so stylish)
 
#22 ·
agree with Pete ; I cannot bring proof because I still have mine in on a shelf (I will mount it this spring), but many say that a simple booster plug works well with the low-rpm jerkiness of the f800 .
It's worth a try before anything else, it's like 20-50€ (if you find it 2°hand) against more than 1000€ for power commander, dyno test etc.

What surprises me is that..at least for me, I don't have urgency to mount it because in truth I feel my f800 is so smooth already..! I don't know, maybe it's personal tastes and different experiences with previous bikes.
 
#23 ·
Pete; Thanks again, invaluable info.

I've made some "inquiries " and think that when I'm ready I'll be flashing the ECU. I don't want say too much here but suffice to say it should do the trick I'm after.

Emanuele:

Yes mate, I honestly do think the bike is smooth.....just not crisp and linear enough compared to other bikes I've had also as good as I firmly suspect the bike can be. it's been mentioned numerous times that the emissions regulations are putting a spanner (feel more like a sock) in the works.


It will be a wee while before I undertake the work but in order I am likely to have the ECU flashed and later replace the full exhaust system. This, according to my maths WILL be cheaper than the PC/Dyno-time route....will it be as effective? Who knows....but I am confident it will iron out flat-spots and make the drive of the engine and subsequently the ride a better one.


Thanks to all on here for contributing, great bunch and a pleasure to be a member on here.


Darren
 
#24 ·
Fuel injection on bikes has been the norm for about 15 years now and you hear a lot of complaints about flat spots, jerkiness and basic fueling problems, none of this existed with a properly setup carburettor system, in fact if you jump back on a bike with carbs the first thing you notice is how good the fueling is, a well set up old school bike with carbs is a joy to behold!
 
#25 ·
Yes, I hear what you're saying but there's also a lot of well sorted bikes out there that are EFI machines.

I think it's 6 of one half a dozen of the other....I've been riding 26 years so remember plenty of carb'd bikes....personally I'd rather have FI any day.....my old P-reg Ninja and semi-regular need to "balance" the carbs.

Efficiency's another point, isn't EFI, if done well, going to return better mpg's?
 
#27 ·
Hi Darren, I asked a similar question on this forum when I got my 15 model a few months ago. I really notice the dip in torque at that Rev range. Like you said you hardly noticed the flat spot in the morning. This may be due to the cooler conditions and once the temp picks up the fuel ratio is adjusted and the bike runs leaner. I'm going to try a booster plug as it tricks the ECU to thinking it's several degrees colder than the actual air temp and adds more fuel the the mix.
 
#28 ·
Thanks......I'd be very keen to know how you get on with the booster plug....Certainly a cost-effective option if it does the trick.

As I've said numerous times, I'm really not after inflating the bikes outright performance, just a more crisp and linear delivery.

Just to be clear, if I grab the bike by the scuff of the neck and rag it early-on in each gear, I can effectively by-pass the 5,000rpm flatty and the bike will move at a grin-inducing rate.......I don't want to have to do that tough.

I don't know about others but for me, ragging the berries off a bike is in-line 4 fodder....I stick with twins because I like, use and want "lazy" "usable" readily available power in the real-world rev-range of everyday riding. Hitting an annoying flat-spot slap-bang in the middle of the bikes rev-range kind of defeats a massive part of why I buy twins for public road duties.

If I wanted top-end power I'd have bought a 4 cylinder bike, I gravitate towards twins for the engine performance that we know is synonymous with them

Rant over, I feel better now.
 
#31 ·
Dazzor

I disagree that a can doesn't help linear power delivery. Check out Avboden's (from memory) exhaust round up on here and see the graphs yourself. You can see the Remus usefully fills in the 4.5k dip plus a couple of ponies at the top end. This isn't earth shattering performance but you a never going to get this from an F8 without spending a fortune.

The PC, all in one exhaust system may get you the step change that you'd want with say +10hp and solid torque everywhere. But it would wipe out the fuel economy and cost a lot I suspect, you may as well flog your bike and get something inherently more performant.

I can recommend that you look for a Remus on eBay. Mine was less than 100 quid and it does the job with no penalty on fuel consumption, nice noise and less weight. The booster plug (equivalent) I found online for around 30 quid I recall. Its benefits are less obvious on the 09 model but my 06 bike definitely felt gruntier with it.

I would have thought these two and lower gearing will give a lot of punch for reasonable outlay.
 
#32 ·
Dazzor

I disagree that a can doesn't help linear power delivery. Check out Avboden's (from memory) exhaust round up on here and see the graphs yourself. You can see the Remus usefully fills in the 4.5k dip plus a couple of ponies at the top end. This isn't earth shattering performance but you a never going to get this from an F8 without spending a fortune.

The PC, all in one exhaust system may get you the step change that you'd want with say +10hp and solid torque everywhere. But it would wipe out the fuel economy and cost a lot I suspect, you may as well flog your bike and get something inherently more performant.

I can recommend that you look for a Remus on eBay. Mine was less than 100 quid and it does the job with no penalty on fuel consumption, nice noise and less weight. The booster plug (equivalent) I found online for around 30 quid I recall. Its benefits are less obvious on the 09 model but my 06 bike definitely felt gruntier with it.

I would have thought these two and lower gearing will give a lot of punch for reasonable outlay.
Thanks Simon, it's nice to get varying input on threads like this.

I can't comment with impunity as I've no empirical findings of my own with this particular bike; but....I never said an end can doesn't help, just that bigger gains are said to be made with fuelling. I'd very much want a deeper, more prominent sound for filtering if nothing else so please, if you have link for that Remus please post it up......had a Remus on my old ZX6R....loved that bike (I was 24 and thought I was invincible...oh how wrong was I)

Still, some great info for me to consider.

I do find it slightly frustrating when it's suggested I've bought the wrong bike.....I've had many many bikes and my fireblade, superduke days are dusted. I've just come from a MT-07 and I only sold that because of build quality and questioned its longevity as each winter took its toll.

I'm after making an 800cc twin pull cleanly as natively that's what big twins should do....I don't want more power, just realised potential of the bike before OTT emissions regulations got involved. I don't see mpg dropping ostensibly just because a full system and fuelling is tweaked....I guess it depends on rider input more than anything:)

Thanks again for your input.....a link for the cheap booster plug would much appreciated if you have it?

Cheers

Darren
 
#34 ·
It's called the "Accelerator Module".(Do a search, it'll pop up) I've got one on my '13 F8R. It was recommended by someone on this forum. It stopped the stalling problem on my bike and as an added bonus, seemed to make it have more grunt as well. For $54.00 (US) delivered to my door, it was a bargain. Takes about 5 minutes to install, 10 maybe, if you're not handy with a torx bit. I give it two thumbs up. BTW, overall fuel economy has not changed since installation , 53 mpg (US)

RB
Brilliant!

Found it, £40 delivered!

Worth a shot I think. That and a reasonably priced end-can could be enough for me.

Thanks!
 
#36 ·
You only need the compact/short/cheapest version @ 35 euros plus postage. I can pm you the link if you cannot find it.

I think you'll notice the difference. I recall the Avboden torque/power curves showing a big jump (relatively) over stock with the Remus. It came out the best of all the cans. Its all on here if you can find it.

I still think you'll get all the punch you need especially of you drop a tooth on the front or add several on the back.

Sounds like you have arrived at the right bike if you're not after more power. I came to mine via a Fireblade and I still find it stops, handles and goes really well indeed and only find it lacking on the track where it runs out of puff. I've had mine longer than any other bike and whilst a change would be nice, I'd be reluctant to let this bike go as its so good. I recently rode an MT09 tracer. Its a lot quicker but my F8 stops and steers loads better, is far more neutral and doesn't have a torture instrument for a seat like the Yam.

I'd be interested to hear about PCs and maps and all that stuff and whether you can get a real benefit at reasonable cost. I recall seeing that you can make it go really well but at the expense of the fuel economy which is a main attraction on these bikes.
 
#38 ·
hello from a serial bike tinkerer and someone who keeps their machines a long time - hope you don't mind me blundering in on the 'R' forum.

when I got my 'S' I felt that as I exited a 30mph limit in third, the bike felt like it had more go if I hooked it up to fourth and then opened it up rather than accelerating away in third.

for about the last five years I've been running a full Arrow system and a PCIII with dyno'd custom map and I'm well happy. And the legendary F8 fuel economy doesn't have to be trashed by all this... not all the time anyway.

I run a map switch and also a switch in the O2 sensor circuit and when I want that F8 economy I switch over to a 'zero' map and put the O2 sensor back online. Usually I only do this if I've got a load of boring motorway miles to cover or need to stretch a tankful, but I've also done it when running in the mountains so the mixture gets sorted a bit better - my near sea level custom map does get a bit rich when running a few thousand metres up on the Continent.

I still get over 200 miles between fill-ups when two-up and loaded in what I call 'driveability' mode but have had the light come on after only 120 or so from brimmed when on track.


nicko
 
#40 ·
hello from a serial bike tinkerer and someone who keeps their machines a long time - hope you don't mind me blundering in on the 'R' forum.

when I got my 'S' I felt that as I exited a 30mph limit in third, the bike felt like it had more go if I hooked it up to fourth and then opened it up rather than accelerating away in third.

for about the last five years I've been running a full Arrow system and a PCIII with dyno'd custom map and I'm well happy. And the legendary F8 fuel economy doesn't have to be trashed by all this... not all the time anyway.

I run a map switch and also a switch in the O2 sensor circuit and when I want that F8 economy I switch over to a 'zero' map and put the O2 sensor back online. Usually I only do this if I've got a load of boring motorway miles to cover or need to stretch a tankful, but I've also done it when running in the mountains so the mixture gets sorted a bit better - my near sea level custom map does get a bit rich when running a few thousand metres up on the Continent.

I still get over 200 miles between fill-ups when two-up and loaded in what I call 'driveability' mode but have had the light come on after only 120 or so from brimmed when on track.

nicko
Nicko

This is very interesting is like to know more. Can you give or point to more details of your set up and results please?
 
#39 ·
Thanks Simon, I'll check that thread out.

Nicking; wow, great post, thank you.

Bottom line; I'm very keen on Hilltop's ECU "upgrade". My limited understanding is is a bit more than a basic remap. .....that and a full system from the headers.

Now I know about the mixture/temp sensor trickery I may try this first as its a much cheaper option.....having said that, I love my f8r and if I get a "premium" uplift on the ride with a decent ECU software upgrade and full system for £7-800 then I'd be happy as I genuinely think this bike is a keeper.

I also think fuel economy wouldn't be too heavily affected in a negative sense.


Must say chaps, I'm really starting to appreciate the bike.....its a blossoming relationship as it's that sort of bike. Had bikes I instantly loved but the f8 has more about it as an everyday bike. The MT-07 was a cracking little machine but it was just too budget for a daily ride for my purposes.
 
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