Running lean???

[Sickpack]

Hi all,
Having just excitedly raved on about my new mods, ie, full akro and BMC filter (dealer supplied and fitted), i've had a response from adam to say its probably running too lean.
Has anyone else got this set up and if so, is it gonna cuase me grief? Do i need a power commander?
Please help, i don't want to wreck my lovely new GSA

 

[Duchess]

Please help, i don't want to wreck my lovely new GSA

Yep, first stop .... going to move your thread over to the right section for you where I think you'll get a better response.

 

[Schtum]

If this is on an '08 or '09 bike then I suspect that Adam (is this Abel we're talking about?) could well be right.

I got away with a full Remus system on my '04 and '07 bikes although it was evident that the '07 was a fair bit leaner but I've only installed the can on my '09 until I fit the Power Commander and headers and have it mapped on the dyno.

At the very least, I'd get your bike on a local dyno and have the air/fuel ratios checked out.

 

[pathfinder]

Hi all,
Having just excitedly raved on about my new mods, ie, full akro and BMC filter (dealer supplied and fitted), i've had a response from adam to say its probably running too lean.
Has anyone else got this set up and if so, is it gonna cuase me grief? Do i need a power commander?
Please help, i don't want to wreck my lovely new GSA

The 08 runs very lean,leave the cat fitted,it is a free flowing unit,add the akro end can for the nice noise it makes.

 

[Schtum]

The 08 runs very lean,leave the cat fitted,it is a free flowing unit,add the akro end can for the nice noise it makes.

It might well be a relatively free flowing unit but on the basis that it's exactly the same as the one fitted to earlier bikes, it stifles the performance quite notably.

Fitting a can alone provides next to no improvement in performance whereas binning the OE pipes and cat/collector in favour of a set of aftermarket headers certainly does liberate a fair bit more performance.

A set of headers + a Power Commander and custom map is the way to go.

 

[pathfinder]

It might well be a relatively free flowing unit but on the basis that it's exactly the same as the one fitted to earlier bikes, it stifles the performance quite notably.

Fitting a can alone provides next to no improvement in performance whereas binning the OE pipes and cat/collector in favour of a set of aftermarket headers certainly does liberate a fair bit more performance.

A set of headers + a Power Commander and custom map is the way to go.

Exactly,the 08 runs very lean so leave all alone until ya get the the mapping sorted and the end can makes little difference bar the noise,just to repeat myself.

 

[LBL]

mines ok

Hi all,
Having just excitedly raved on about my new mods, ie, full akro and BMC filter (dealer supplied and fitted),

So the dealer fitted it knowing its going to be running lean, if its a new bike and you have problems take it back, if they supplied and installed them without advising it may run lean they should be responsible.

I have a full remus system supplied by BMW on my 09 GSA from new and i specifically asked at the first first if it was running lean, they assured me it wasnt. good enough for me.

 

[elevensies]

the first difficulty for the power commander is the canbus system, we know it hates being fetteld with

yes, normally when you open the exhaust and add a filter it does make the bike run lean without the respective chip in the ecu, but again can this work with the canbus electrics???

typically when running open pipe and filter, it will run correct on open full throttle only, the rest of the time its very lean, possibly dangerously lean.

 

[Schtum]

the first difficulty for the power commander is the canbus system, we know it hates being fetteld with

There is a Power Commander which works with the R1200GS. In fact, I have one sitting here. There are also a number of other fuel map modifying devices which do the same thing. The bike's CAN-bus system isn't an issue.

 

[Sgt Bilco]

The latest bikes run very lean to get emissions as low as possible and to conform to European law.

Fitting new decatted headers and an end can will not bother the bike because the lamda sensors sort out the fuelling with no problems. The bikes run best with decatted headers and standard can in my opinion.

However, I always advise anyone fitting our Keihan headers and an aftermarket end can is, if you go to the next stage of BMC or K&N filter to get it at least checked on a dyno to see if it's running within it's fuelling tolerances.

It's my own belief that when you have gone that far to squeeze more power out of the engine, a Power Commander or Wunderlich Power Controller is an option which would be well worth the money.

 

[Schtum]

Fitting new decatted headers and an end can will not bother the bike because the lamda sensors sort out the fuelling with no problems. The bikes run best with decatted headers and standard can in my opinion.

This will only happen when the injection system is operating in closed-loop mode. The lambda sensors aren't wide-band and therefore the system only operates in closed-loop for a restricted part of the rev range / throttle position. Even then the fuelling will only be adjusted within the parameters of the existing fuel map in the ECU. It won't cope with any requirements outside those parameters.

Can I again ask if you've run an '08 and/or '09 bike, fitted with Keihan headers, on the dyno to establish AFR's? If not, I think it would be a good idea to do so. You might also want to publish the dyno charts to give customers an indication of what sort of power and torque gains they might typically expect.

 

[Sgt Bilco]

This will only happen when the injection system is operating in closed-loop mode. The lambda sensors aren't wide-band and therefore the system only operates in closed-loop for a restricted part of the rev range / throttle position. Even then the fuelling will only be adjusted within the parameters of the existing fuel map in the ECU. It won't cope with any requirements outside those parameters.

Can I again ask if you've run an '08 and/or '09 bike, fitted with Keihan headers, on the dyno to establish AFR's? If not, I think it would be a good idea to do so. You might also want to publish the dyno charts to give customers an indication of what sort of power and torque gains they might typically expect.

Not yet but if someone wants to offer up an 08 bike as a test bed we'll do it no problem.

 

[Monty]

Not yet but if someone wants to offer up an 08 bike as a test bed we'll do it no problem.

I am happy to offer up my 09 bike for a reasonable discount.

 

[Beemerman59]

I have an '08 GSA you can try - I'm looking at buying the headers anyway. I have a standard can and an Akrapovic which would be two common solutions. PM me if you want to go ahead and set something up.

 

[Sickpack]

Well thanks for a great response. I'll get on to BMW headquarters and see what they say too. I've re-checked with the dealer mechanic, who still maintains it's fine. Heck it's all waranted, think i'll go thrash the nuts off it, and take it back if it breaks!!
And have another Guinness. Seems to solve most problems. Maybe i'll drop a bit in the tank too
By the way, anyone know a GOOD dyno operator in the midlands?

 

[wadham]

I dyno'd my 08 GSA with Remus headers and end can only. I posted the dyno graph on this site last year, use search button.

It was running way too lean which the dyno proved with Air fuel ratio. I also suffered a melting no plate and extremly hot Remus end can. Hot running is a symptom of a lean engine.

I removed the end can and flogged it.

Runs ok now.

BMW dealers do not dyno their bikes and are still selling exhaust systems expecting the engine management to sort thing out as it always used to in pre 08 bikes. I explained to a dealer my dyno results and they were unaware of the leaner running issue but welcomed the info. Over to them.

My advice if you want it, is to get the GS dyno'd or just fit either headers or end can but not both without a PC. Your GS might run different to mine and be ok.

Your warranty when you change the exhaust may not be with BMW anymore. Will your dealer take the hit for burnt valves/pistons etc. I am interested to find that out.

 

[harry]

I accept that there is a large element of truth in all the above posts..But I've

never heard of a 12engine blowing up, or melting down, due to running too

lean. I'm not saying it can't happen....just I've not heard of it.

I had the same Remus headers on three 12's, with the same Uni air filter, all bi

kes did about 18k miles, all ridden hard......with no engine probs.

I think you should ride it and forget about it

 

[wadham]

Harry

You are right, many people including me have done thousands of miles on GS with altered exhausts.

However were any of your bikes 08 or 09 models with the extra hp or other GS models.??

These have been built to run much leaner than previous GS models in order to get the extra hp out of the engine. It is only these models that seem to run so lean and therefore are the subject of this thread.

 

[929bladerunner]

Following this thread with interest........

I have an '09 GSA with Akrapovic can and toying with either Keihan (£290) or Akra (£408) headers to free the bike up in the mid-range which either should do.

Standard air filter and no PC fitted.

 

[Yonkyo]

I fitted Remus headers and Akra Can to my 09 GSA when I bought it. However, I found that the bike was running very lean and hot.

So for the last 8500miles I have run it with just the Remus headers and standard Can combo, with no problems at all.

I have a Wonderlich PC from my old 1200GS, which I’m gonna send away to be upgraded for use on my GSA. Then I might try running it with full exhaust and Green Filter.