Making a Gen II faster (swap middle drive from Gen I ?)

[Cosmin]

Dear all,

For some time I felt the need for change regarding my bike and that was coming mainly from some extra power need. I even suspected some power loss but after a recent inspection (valves, spark plugs replacement etc) and after riding a similar Gen II FJR I realised it was just a false alarm and I just needed a power upgrade (especially that 99% of the time I ride with my wife and heavily loaded with luggage).
So the bike (2006 built but first taken on the road in 2009 from showroom) runs great (72.000 flawless miles so far) and the main reason for potential change would be some additional power. Unfortunatelly the stubborn japanese didn't touch the engine on the newer FJR versions (minor changes like ride-by-wire but zero increase in torque/power) so I was looking at the GT1600 from BMW. The difference in power and especially torque is visible (tested it already) but so is the difference in costs. And I'm not refferring to the initial purchase costs only but also to maintenance: the FJR is very easy to maintain by yourself while for BMW everything is more complicated. Unlike the previous models, on the new GT they even firewalled the diagnosis socket so the famous GS911 diag-tool is not so useful anymore; so this means significant cost increase in maintenance also

Going back to the options, I was evaluating keeping the FJR and investing some money for some upgrades:

1) replace the middle drive gears with a pair from Gen I in order to obtain a slightly shorter gear. I am interested especially in top-gear roll-on times and taking into account also some older european bike magazines tests, the top-gear roll-on figures look significantly better for Gen I compared to Gen II. I think there is a general consensus also between owners that Gen I definetly feels faster than Gen II. Is the gear ratio the only reason or Gen II feels slower also due to additional fuel restrictions etc to meet higher pollution standards?

2) Power commander installation - how efficient is it without replacing fully the exhaust system (and removing the catalysts etc)?!

3) rear shock replacement (OEM one is awful).


I feel I would make a mistake to part from a bike running so great, that's why I'm evaluating some upgrades for it in order to come closer to my needs. I installed from the beginning some stuff for increased confort (heated handlebars, laminar-lip, heated seat for wife etc), so confort difference wouldn't be a decision factor for the upgrade. Ok, BMW has the ESA but I didn't feel so often the need to adjust suspension settings - I felt indeed that the rear shock is under-dimensioned, that's why I was planning an after-market one.

I'm asking those who had both models (Gen I and Gen II) how significant is the difference between them in a sporty ride. Also any feedback on PC installation would be welcome.

Thanks.

 

[Fred W]

Although the rear wheel torque difference is measurable, and somewhat tangible in roll-ons, I think you would be disappointed in the small difference that the lower gearing makes. Perhaps the best way to get a good feel for the actual difference would be to find a local 1st Gen FJR rider and swap bikes for a little while. Both engines make about the same power, so the only big difference power wise is the gearing.

The Power Commander will smooth out the power delivery, but it will not give you more power.

I would suggest that your money would be best spent on upgrading the suspension, which at 72k miles is surely very tired. Improving the bike's suspension will feel radically better both just cruising along, and when you are playing in the curves. You won't give the bike any more straight line acceleration, but will find that you can carry what speed you have better through the corners, and that can make the bike a lot more fun to own.

 

[RossKean]

^^^ +1

I have no direct Gen I experience but agree with Fred - essentially the same power but slightly different gearing. Difference in acceleration is unlikely to be dramatic. There is very little you can do to make a significant improvement in actual power to the wheel. Power commander won't do much for you.

My first thought was wondering if you had a problem with timing after your recent service work but you mentioned that you compared it to another Gen II machine and didn't see any difference.

 

[08FJR4ME]

Where is that thread that Useless pickles did. He tried everything I believe to get more power.

Dave

 

[Cosmin]

Thanks for replies. For Power Commander it's clear now, I knew about smoothness but after all sorts of workarounds (zero slack in throttle cables, springs removal, throttle cam filing etc) this isn't such an issue anymore. I think I read about Useless Pickles attempts - I think in the end the results were not breath-taking...

Going back to the lower gearing - I took into account the modification since I also face some (not very disturbing) roughness in gear shifting (3rd and 4th mainly) and I was evaluating at the next service (if I keep the bike) to solve these issues - even it involves splitting the cases, replacing gear wheel/fork shifts etc. I thought it might be a good opportunity to change the middle gears in order to bring also this not very significant power increase feel.

And yes, if I decide to keep the bike the rear shock upgrade is on my list; when I replaced the fork seals I also installed Wilbers progressive springs and the difference was visible. The main issue suspension related is reffering to dragging parts (pegs/sidestand/central stand) - this was partially solved by changing dog-bones. But the root cause is the insufficient tensioning/adjustment of the rear shock (now on sporty riding on curves I have that disturbing pumping effect of the rear suspension) - I suppose the improvement over curvy roads will be huge with an after-market shock (including height adjustment capabilities).

 

[PJ4863]

I think if you truely want more power, the only way to do it efficiently is to add either nitrous or a turbo charger. you could be the trailblazer... i'm sure a lot of guys would like to see how that works out!

 

[Ignacio]

Unfortunatelly the stubborn japanese didn't touch the engine on the newer FJR versions (minor changes like ride-by-wire but zero increase in torque/power)

That's inaccurate. 2013 did have a change in both bhp and torque. It wasn't large, but was definitely not "zero". HP was up from 141.5 to 144.2 and torque from 99.1 to 102 between the 2012 and 2013 model years.

I think there is a general consensus also between owners that Gen I definetly feels faster than Gen II. Is the gear ratio the only reason or Gen II feels slower also due to additional fuel restrictions etc to meet higher pollution standards?

I don't think there's "consensus" either--at least as generally as you suggest for all Gen 1 vs. all Gen 2...nor speculation about fuel restrictions. Probably the biggest X in the equation is weight. A 2003 is claimed to be 521 pounds. A 2013 claim is 637 pounds. You want a fast FJR....go buy a 2003 without all the stuff they've added in the decade following. They're cheap too.

All my numbers are from the spreadsheet I've built over the past decade plus.

 

[BugR]

I hate to point out but the bike does rev north of 9K.

More revs = more power, the Clutch & Shifter on the left and the Throttle will help you find it.

If you have ever hit the rev limiter in third you will understand.

Chris

 

[Fred W]

Probably the biggest X in the equation is weight. A 2003 is claimed to be 521 pounds. A 2013 claim is 637 pounds. You want a fast FJR....go buy a 2003 without all the stuff they've added in the decade following.

Not saying that is not true, but don't forget that the published specs were "dry weight" prior to 2009, so you'll want to add at least 60 lbs for the actual curb weight. Plus the bags. FWIW I've measured my 2014's axle weights at 314.4 Front, 346.2 Rear for a total of 660.6 lbs. The claimed weight is 644 lbs. Not sure what the 15 lb difference is. Maybe tank bag and a few things in a side bag? Or my bathroom scale wasn't accurate at over 300 lbs?

In any case, I'm not real sure how much the small differences in these bikes' weight over the years will matter to someone who rides 2-up "99% of the time". Dropping ~150 lbs onto the back will definitely make the bike slower.

 

[Cosmin]

Thanks all for the replies and details.
I remembered from some reviews that the measurements for 2013 model showed similar specs in terms of power/torque (even measured at the rear wheel) with previous model, that's why I thought the figures between Gen II and Gen III are identical. And regarding Gen I versus Gen II there were some comparison tests in which the top gear roll-ons were much better in a Gen I (same for 0-100; 0-140 and 0-200km/h times).
And yes, my wife's 120lbs are immediately sensed by the FJR but still not as much as the previous 600cc sport bike. That's why I wanted a high torque bike after all

 

[Mr. BR]

The difference between the GEN1 and GEN2/3 gearing is only about 2.7% in top gear... that's barely a difference of 100 revs/min. per mile.

That's not much change considering the work req'd to swap out gears.

Primary x 5th x Secondary Reductions (middle gear x bevel gear x FD) x 834

GEN1: 1.563 x 0.929 x 2.772 (35/36 x 21/27 x 33/9) x 834= 3357 engine revs per mile.

GEN2/3: 1.563 x 0.929 x 2.698 (35/37 x 21/27 x 33/9) x 834= 3267 engine revs per mile (that’s the well-known ~2.7% difference from GEN1).

Mr. BR

 

[Ignacio]

Not saying that is not true, but don't forget that the published specs were "dry weight" prior to 2009,

I knew that and provided a link to notes on that exact point. I was going with the largest possible delta to illustrate a point that I believe still remains salient. You start on the the journey of adding amenities like glove boxes, ABS, upgraded side stands that don't fall over, longer drive shafts, and myriad other details...the form factor has porked up at a faster rate than engine performance.

To throw fuel back on the speculation fire...there was discussion years ago that 2004 non ABS was actually fastest and 2005 was slower because of fuel map changes that bounced from t

2013 model showed similar spec

Exactly. I thought it important to point out it's not the same as "zero increase".

 

[lele]

my GEN1 is a lot faster than a friend of mine GEN3. I think is the less weight not the gearing

 

[redneckj]

GYTR slip on's with a properly mapped ECU on a GEN 2 will get you about 3 HP at the rear tire. But the bike will be sooooooo much smoother. If you want more power go buy a Busa or Zx14.

 

[escapefjrtist]

<<Big Snippage>> I suppose the improvement over curvy roads will be huge with an after-market shock (including height adjustment capabilities).

Packing double (even with a flyweight SO!) with stock suspenders will put a damper on curvy road fun. Upgrade to your favorite aftermarket shock, get the ride height / steering geometry back on the sporty side and you'll love your "new" bike. Best bang-for-the-buck $$$ you can spend!

Just my $.02!

--G

 

[Bustanut joker]

Back before I had pubic hair, Chris "Bugar" here was working on a swap with a VMax..

I don't know if or how it worked out. But I suspect it, like your Idea




Is a waste of time.

 

[audiowize]

In what way(s) would you like your bike to be faster?

In a straight line? From a stop? While rolling?

Through the corners?

I think a lot of what you want may come from freshening the suspension and using the power the bike already has.

 

[Cosmin]

Conclusions so far: (early) Gen I was faster than later Gen I which is a little faster than Gen II which also is a little faster than Gen III (5 gear model). I found some comparison data for top gear roll-ons (in km/h) and starts from standing performed by a famous German bike magazine (Motorrad) which is quite appreciated in Europe, I'll try to insert somehow the table here...

My real feel for additional torque/power happens mainly in top gear roll-on and in overtaking. This is the most difficult to solve; making it faster on curvy will be solved with an after-market shock...

 

[BugR]

Back before I had pubic hair, Chris "Bugar" here was working on a swap with a VMax..I don't know if or how it worked out. But I suspect it, like your Idea

Is a waste of time.

I still have that final drive that project is going no where now I have the 16. Any offers?

Chris