I'd always considered getting a Power Commander fitted to my old Speedmaster, as I wanted a bit more juice from it, but instead I upgraded to the 1700 Commander. Whilst whilst the new bike much more 'fruity' than the ol' speedy, after a year, I inevitably wanted more anyway. I couldn't find much/any info on others fitting a Power Commander to a TBird Commander, and was nervous about shelling out the £500-600 needed to get it done. Anyway, I took the plunge and had it done by Race Engineering in Dunmow, they did it great job, and the bike has made conservative-to-reasonable gains according to the dyno sheet, but it really does feel a lot better. I wondered if I'd really notice a few extra horses here or there, but it does genuinely pick up faster and feel perkier. Attached is the dyno sheet on the day. Power has increased by 6.5% (87.5 to 93.2 hp) at peak, and torque has increased about 5% (103.9 to 19.2 ft-lbs) at peak. I'm no expert, but looking at the dyno sheet, I notice 2 very positive things on top of the raw numbers, power and torque in the very low rev range is substantially improved, for this kind of bike, that's great since you do tend to poodle around at low revs, and now when you twist your right wrist, it picks up much better. Second, across the entire range, there's been no trade-offs, the new curve is always higher than the old, which I guess is to be expected, but is nice nonetheless. Finally, another point the tech himself raised, is that he didn't expect the dyno sheet itself to show much improvement, since the dyno sheet shows a fun only a wide open throttle. He said that my bike (as most triumphs do) tended to fuel pretty well at WOT, so at 1/4 and 1/2 throttle, the the torque/power gains will be propoportionally higher than what the dyno sheet shows. So all in all, whilst it's not a cheap thing to do, I'm pleased that I have. P.S. I already have had fitted the triumph aftermarket pipes, and the washable (slightly higher flow) air filter. So I'm guessing this is about as good as I'll ever now get with my Commander, since any performance parts for standard TBirds (or Storms), don't fit the Commander/LT. Perhaps removing the cat might help (with a redyno/retune from Race Engineering), but from what I've read, it also may certainly not help!
The dip between 2thou 3thou rpms is ignition related, you could gut out the airbox and remove catalytic converters then retune!! I did on my 2009 America, I gained 7 hp & around 6 ft/lbs more torque, thats about the same gains as you but from a motor 1/2 the capacity as yours, you have more gains in there if it can breathe better both in and out !! I have 904cc big bore kit and a ported/polished inlet/exhaust cylinder head worked. Still std cams and valves! Gained another 10/15 hp. Not had the retuning done yet just added 10/15% more fuel ! I tow a 115 kg(empty) camper trailer (loaded 180/200 kg) with ease now.
Thanks for the advice, yes I had noticed (and wondered about) the flat. I think I've heard (conversationally) that it's a 'feature' of most modern bikes due to that being the rev range that the euro noise and efficiency tests are done at, so the engine eases of around that rev range. Don't know if that's true or not. Thanks for the pointers though. I had read a previous thread about removing the cat, seems some people saying that it makes the bike sound amazing, but actually reduces torque and power - certainly until it's re-tuned, but even then, it sounds like it's more a restoration of original power, not so much of an increase - but again, I'm happy to be wrong! Where did you go to get your engine worked on? I'd certainly consider a port/polish, I'd imagine this isn't cheap though, what sort of money did you pay? Cheers, Dave
Hi Dave, The port and polish cost me the purchase price of the Air/Die grinder and two Cutting bits !!! About $100 odd , the big bore kit cost me $1200 odd plus $400 to rebore the barrels. The porting I did was "doing the obvious" as there was a definite"hump" in the Inlet tract ! I took this out smoothed the flow line in...! I only cleaned out the exhaust tract. If you do the port work yourself you are only up for a head gasket, plus the cost of the strip down/rebuild if you get a shop to do that part. As doing the Porting only requires cylinder head removal, it doesn't involve much more work than doing Valve adjustment, just going bit deeper undoing the head bolts. the engine now breathes much better at low and higher rpms...! It has changed the induction noise hugely from 5500/6000 rpm up, its higher pitched and much louder. the throttle response has improved markedly at all rpms, I expect it to get better still with a proper run on a dyno and the appropriate adjustments to fuel and hopefully to Ignition TOO !! You are right about the dip being Euro Noise emissions related ! It is a feature on all bikes , be they super sports - too cruisers ! Cheers capt
