BHP differences

daviedevs · Jun 18, 2019

A colleague took his bike in to be re mapped..2016 GS 1200..and the initial BHP output was 106.5...which increased to 116 after the work was done.

I took mine in..2016 1200GSA and the initial BHP was 98.3 which increased to 113 after the remap.

Are all engines this different? Or could it be different tyres on the rolling road?

I'm not a mechanic so was just curious to know why such a difference in the initial outputs.

Tractors are go · Jun 18, 2019

Technically, there is a compensation for differences in temp and barometric pressure, also unless it is the same dyno too.

Having said that, I've seen 5-8bhp of a difference between rr being dynod one after the other.

Some bikes are closer to optimum tolerances than others.

Don't get hung up on numbers, it is how it picks up and drives that counts for more.

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daviedevs · Jun 18, 2019

Tractors are go said:
Technically, there is a compensation for differences in temp and barometric pressure, also unless it is the same dyno too.

Having said that, I've seen 5-8bhp of a difference between rr being dynod one after the other.

Some bikes are closer to optimum tolerances than others.

Don't get hung up on numbers, it is how it picks up and drives that counts for more.

Sent from my SM-G925F using Tapatalk

Cheers for that. It was on the same dyno..but not the same day, so weather and temps could of been different.

spoonz · Jun 18, 2019

Factor in that dyno operators want you to see decent gains so u go away and tell your mates etc, so sometimes the pre map run is less than it could be. To me 98 - 113 which is about 10% is debatable for just a remap.

But as said focus on how it rides after, dyno graphs alone are really a total waste of time and money for the most part.

er-minio · Jun 18, 2019

Factor in that dyno operators want you to see decent gains so u go away and tell your mates etc

This.
Some claimed bhp increases with just a remap are a bit hard to believe. But, hey, the owners are happy with it.

Or could it be different tyres on the rolling road?

LOL - no.

Warlord · Jun 18, 2019

daviedevs said:
A colleague took his bike in to be re mapped..2016 GS 1200..and the initial BHP output was 106.5...which increased to 116 after the work was done.

I took mine in..2016 1200GSA and the initial BHP was 98.3 which increased to 113 after the remap.

Are all engines this different? Or could it be different tyres on the rolling road?

I'm not a mechanic so was just curious to know why such a difference in the initial outputs.

Another consideration on power output is the state of your cam alignment and timing.

If you're mate's cam alignment, timing and valve adjustments are better, that may be the reason he's getting better power.

Have you had your Cam's aligned properly recently, as most are out of alignment and timing is poor.

In addition to that, is your mate using a higher octane fuel. 97 RON, instead of your Supermarket 95 RON shite.

daviedevs · Jun 18, 2019

Im thinking not. I just ride the bike.

tbh its perfect for my needs..i was just curious as to the differences.

Alan R · Jun 18, 2019

Warlord said:
Have you had your Cam's aligned properly recently, as most are out of alignment and timing is poor.

Just a minor point - is this statement true? :nenau

It seems like a gross generalization and is based upon what sample size? Your statement may be accurate in that cam alignment has a bearing on engine performance, but most are out of alignment? Really? Do BMW know?
Alan R

Tractors are go · Jun 18, 2019

Alan R said:
Just a minor point - is this statement true? It seems like a gross generalization and is based upon what sample size? Your statement may be accurate in that cam alignment has a bearing on engine performance, but most are out of alignment? Really? Do BMW know?
Alan R

It is probably more accurate to say that the cams are not at their optimum position, this can be from manufacturing/assembly defect or just wear in either the cam lobes themselves or that the cam chain is eith not tensioned correctly due to wrong oil !!! Or the cam chain has stretched. What about the valve clearances, if they're incorrect what impact does that have on the timing ?

Now, if all of these occur, how close to design spec do you think it is ?

Then there's issue of how a bike was run in, how new the oil is, I saw a 4bhp increase just through changing to a different oil, what about if it is 95ron compared to 97ron.

There are so many variables.

So conclusion, yes the majority do have their cams out, so maybe a +ve effect others -ve.

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Deleted account 191119001 · Jun 18, 2019

Always makes me chuckle

upload picture

fred_jb · Jun 18, 2019

Tractors are go said:
It is probably more accurate to say that the cams are not at their optimum position, this can be from manufacturing/assembly defect or just wear in either the cam lobes themselves or that the cam chain is eith not tensioned correctly due to wrong oil !!! Or the cam chain has stretched. What about the valve clearances, if they're incorrect what impact does that have on the timing ?

I would say that if you have enough wear on the cam lobes to affect the timing - then they are not fit for purpose and need replacing.

Tractors are go · Jun 18, 2019

fred_jb said:
I would say that if you have enough wear on the cam lobes to affect the timing - then they are not fit for purpose and need replacing.

I'd agree, but it does happen.

Ducati kindly replaced a pair on the 749. Faulty batch with case hardening problem, still ran ok though.

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beaver · Jun 18, 2019

Warlord said:
Another consideration on power output is the state of your cam alignment and timing.

If you're mate's cam alignment, timing and valve adjustments are better, that may be the reason he's getting better power.

Have you had your Cam's aligned properly recently, as most are out of alignment and timing is poor.

In addition to that, is your mate using a higher octane fuel. 97 RON, instead of your Supermarket 95 RON shite.

could be his mates are out.. and his are spot on?.. you can make a huge change to the engine by messing with cams even a few deg... depends how BM set them for straight running or acceleration.. always a compromise unless you have variable cams... now there's an idea??

karlp · Jun 18, 2019

Since bhp is a calculated figure not a direct readout you need to know what conversion figures were used on the day

Neil W · Jun 19, 2019

daviedevs said:
A colleague took his bike in to be re mapped..2016 GS 1200..and the initial BHP output was 106.5...which increased to 116 after the work was done.

I took mine in..2016 1200GSA and the initial BHP was 98.3 which increased to 113 after the remap.

Are all engines this different? Or could it be different tyres on the rolling road?

I'm not a mechanic so was just curious to know why such a difference in the initial outputs.

Was it the same company involved ,the same dyno, the same dyno operator, the same atmospheric conditions all of these can make a big difference.

As for seemingly identical vehicles having different base bhp figures a lot can be down to its running in procedure............ at work we would regularly get batches of identical vehicles , the rural used ones always ended up faster than those run in in the cities and vans run in by certain drivers (ie properly) always ended up the quickest.

Finally it is not unknown or indeed rare in car tuning circles for a punter to take in a vehicle for a remap a pay for a 10% power hike and lo and behold the initial base bhp run is low and the post remapped figures are high.

We went to a dyno day and all of the cars previously tuned by the company that was running the dyno day produced bhp figures well in excess of standard non tuned or tuned vehicles from rival companies. Yet on the track and road said vehicles producing higher bhp figures were appreciably slower than remapped companies from rival tuners !!!!!!!!!!!!!

BHP differences

daviedevs

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Tractors are go

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spoonz

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er-minio

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Warlord

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daviedevs

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Alan R

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Tractors are go

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Deleted account 191119001

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fred_jb

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