Some Progress In Finding More Engine Performance

[ChrisAnglophile]

Explanation...The Thruxton R. has 97 hp at just 6850 rpm. 8 more than the Scrambler at 7400 rpm. The easiest way to increase the R hp would be to raise the revs but it’s ECU closes the throttles 15 % at 7000 rpm then shuts off at 7400. Modifications to the tune are severely restricted by Triumphs decision to disallow any entry by the aftermarket into the the computer which has a key or entry code that Triumph will not divulge.My point was if we install the Scrambler ECU on the R we should gain an easy 8 hp or so .Both engines are the same but the Scrambler exhaust is obviously very restricting to the point of lowering the hp from 97 to the low eighties, not good. Answer, turn it up an extra 550 rpm to get it up to 89 and tell the comrades they moved the power band down for more low end torque. When in fact the rpm has moved up. Marketing Rules The World!

If only it was that simple, just a software change.
The exhaust is a tunes pipe and its length for a fixed pipe diameter determines that pipes rpm for peak torque.
The Camshaft's timing , plays a big part in the torque output through the range.
Advancing Inlet timing for low down torque and retarding the Exhaust for higher RPM. Applies for a single Camshaft engine.
When two Camshafts are separate by design , then the Overlap is another factor.
Its been used in Superbike and Supersport racing for the last 30 years or so ,by race teams by slotting the Camshain Sprocket bolts to get these engines to Rev higher.
The sports regulations have been stating what can be done in Catch Up Mode for a long time.
The fuel injection is just a Air to Fuel mixing device.
But its easy to restrict an engines output , by retarding the ignition as the revs go up.
That way , it just won't produce any power high up.
Its a lousy way to run an engine.
But there maybe sound reasons, is. Engine Longliveity.!
If one wants to check a exhaust for restrictions, take any sensors out of it, the push a Camera up the exhaust.
Silencers, generally won't allow this , as they move the gas around by Magic, truly amazing pieces of engineering.
Chris

 

[SDNoon]

I did check them out. Looks good!

Good, glad to be useful

 

[SDNoon]

I agree Brooke. For those of you that are only interested in eliminating the easily and inexpensive HP restrictions removing the cat, a power commander, and removing the top section of the intake are the way to go. If you like the V&H mufflers you can lose a little weight and get a throatier sound but they DO NOT ADD HP & TQ at this level of modification (particularly if you leave the sound pligs in). The stock mufflers perform as well until you get over 98 to 100 rear wheel HP. We found this in dyno testing when both exhaust systems are properly tuned. Raisch in Germany found the same thing and that is the reason they do not include aftermarket mufflers in their performance kits for the Thruxton R. I bought and tested Arrow head pipes which are larger than the stock Triumph head pipes and they eliminate the cat & the need for a X pipe. This DID NOT increase HP & TQ in fact it reduced power. The Arrow head pipes appear in the advertising to have a crossover pipe but in fact it is just two pieces of tubing welded to the outside of the Arrow head pipes with a slip fitting in the middle. We drilled out the inside of the Arrow crossover and then the bigger Arrow head pipes performed better than the stock head pipes. Why is this? The answer is that the inlet size of the stock mufflers or any aftermarket set of mufflers are to restrictive and you need a crossover pipe ahead of the mufflers to allow the engine to use both mufflers. This is particularly true if you use the rev extend feature on the power commander to raise the rev limit on the motor.

Hi, can you tell me what diameter the arrow headers are?

 

[SDNoon]

I agree Brooke. For those of you that are only interested in eliminating the easily and inexpensive HP restrictions removing the cat, a power commander, and removing the top section of the intake are the way to go. If you like the V&H mufflers you can lose a little weight and get a throatier sound but they DO NOT ADD HP & TQ at this level of modification (particularly if you leave the sound pligs in). The stock mufflers perform as well until you get over 98 to 100 rear wheel HP. We found this in dyno testing when both exhaust systems are properly tuned. Raisch in Germany found the same thing and that is the reason they do not include aftermarket mufflers in their performance kits for the Thruxton R. I bought and tested Arrow head pipes which are larger than the stock Triumph head pipes and they eliminate the cat & the need for a X pipe. This DID NOT increase HP & TQ in fact it reduced power. The Arrow head pipes appear in the advertising to have a crossover pipe but in fact it is just two pieces of tubing welded to the outside of the Arrow head pipes with a slip fitting in the middle. We drilled out the inside of the Arrow crossover and then the bigger Arrow head pipes performed better than the stock head pipes. Why is this? The answer is that the inlet size of the stock mufflers or any aftermarket set of mufflers are to restrictive and you need a crossover pipe ahead of the mufflers to allow the engine to use both mufflers. This is particularly true if you use the rev extend feature on the power commander to raise the rev limit on the motor.

Hi Dynajohn, great work you have done - inspirational to me. I have just installed arrow headers, thanks for the tip on drilling out the blanks on the ballance pipe (why didn't arrow do this?) and a pair of shortie silencers, what you are saying here is very interesting, I was wondering if it is worth while cutting out the restricted pipe length on the arrows, which allow them to fit on the stock silencers and having a corresponding larger diameter swaged and slit pipe TIG welded onto the silencer to remove the restriction. In your opinion would it make any appreciable difference? Considering the expense? Bike is booked in for a dyno run and ECU reflash to get the A/F correct for all the changes, be interesting to see how much difference all the changes have made? Hoping that Tune ECU will allow the re-map, if not I have a PCV. To summarise changes TEC cam, DNA air filter, intake snorkel removed, Arrow headers and Cone shorties. It certainly feels a lot livelier.

 

[brooke]

No reply so far to my request for further details on the flash.

Just got an email from my neighbour containing a video of a 2020 765 Owner using tune ECU to remap the Tune . He mentioned DNK Key Tune Works so I found the site . They are doing all 2016 WC twins , af ratio , rpm limit , throttle restriction , etc . Have only had one on the dyno , the Thruxton R and the graph is there . 98.5 HP and close to 8000 rpm ?

 

[SDNoon]

Just got an email from my neighbour containing a video of a 2020 765 Owner using tune ECU to remap the Tune . He mentioned DNK Key Tune Works so I found the site . They are doing all 2016 WC twins , af ratio , rpm limit , throttle restriction , etc . Have only had one on the dyno , the Thruxton R and the graph is there . 98.5 HP and close to 8000 rpm ?

Was that a standard engine, or was there any mods!

 

[brooke]

Was that a standard engine, or was there any mods!

Just checked that on the JT Cycle site , they are an authorized dealer obviously , which states it was with an x pipe , slip ons and air filter . Only turned a bit over 7 k rpm with no dip in power at the where the throttle would normally close partially . Guess my main point was that the programme has been opened and with that we should see tuners getting interested in the big twins now that the restrictions have been overcome .

 

[SDNoon]

Got the bike back from the Dyno yesterday 98.75bhp and 84.68ft/lb torque so not bad was hoping to break 100bhp but better than the standard 87bhp