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Discussion Starter #1
OK - I have been reading and so far not really come up with much geeky detail for my restless mind.
We know the 790D is a Euro4 bike - and so will be "made to comply".

We know that Coober/AR and others have solutions. We know these solutions may improve things.

But I am missing a something - I don't know what it is, but I "know" it's there. And I have been seeing through smoke and mirrors my whole lifetime.

Like 99% of tuners - most tune at WOT (Wide Open Throttle). This is fine if this is how you ride. I'd guess though that most of us simply do not have the occasion to do so often. I'm not impressed.

I stumbled (again) across https://www.790dukeforum.com/forum/97-2018-ktm-790-duke-news/34-ktm-790-duke-dyno-tested.html#post52 - a post on here from May 2018.

The first curve is a typical Dyno chart


The above torque curve looks flat - but there is a very notable dip in torque on the road. The second set of curves is far more interesting. It is the power produced at a fixed (not WOT) throttle opening in all 4 modes. iirc 30% throttle.



I ask you to examine this and ask yourself. Why is there such an enormous dip in the power curves at 30% throttle? - I am pretty sure I know, but has anybody else realised. Note it is there independent of the ride mode employed. Even TRACK.

I would love to see that second set of tests repeated with ATOM, COOBER, PCV whatever. Because - That's where we'll really see what they do.

I'd also like to see a full mapping of AFR, torque, tps (or better still MAP) and rpm. I've looked and will keep doing so - but if anybody has them - PLEASE POST THEM. Because it is driving me potty.

I have seen this dip effect on other bikes that have been "made to comply". In one case an additional 30% of extra torque was retrieved from a similar dip very easily. Yes THIRTY PERCENT.

I wish I could get my mate Rob to take an interest in the 790. But he's dedicated to getting really silly bhp out of Triumph Rockets.
 

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Like 99% of tuners - most tune at WOT (Wide Open Throttle).

The key is to find the 1% who do not do it WOT.
I have coober ecu on my 790 installed, my dealer told me to use it and most of the guys i know have it also installed. I call them few times, they told me exact the same story as you wrote it in your post.
99% of tuning companies do it WOT, this is the most unrealistic tuning that you can do.
A serious setup take days and the most important thing is, you can't do it on the bike. You can confirm your setup on the bike, you you need the engine out of the bike on a dyno, to be able to make a setup.
 

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About that fixed throttle chart. Could it be related to the rpm range that sound checks are done for compliance? Dropping the torque for a few hundred rpm might give lower sound readings there so that they can can have a more open exhaust system for the rest of the rpm range.
 

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Discussion Starter #4 (Edited)
About that fixed throttle chart. Could it be related to the rpm range that sound checks are done for compliance? Dropping the torque for a few hundred rpm might give lower sound readings there so that they can can have a more open exhaust system for the rest of the rpm range.
That is almost certainly part of the reason. My guess is for Swiss noise laws. But it does then beg the question - why is it like that in track mode?


Interestingly I was just on the COOBER site. This is their published graph. Almost certainly Rear Wheel values. And WOT.




Notice anything? - the dip is still there. Something to do with Lambda Delta values at play I think. Also in the fixed throttle charts - the jump at 8K is "interesting". I have a theory and it is based on Euro5 and the rumour mill 890 engine (Which my dealer expects detailed order conformation of in October).
 

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If you have one of those "autotune" setups it'll adjust for any throttle, rpm, and load. Adds a wideband O2 sensor in the exhaust and will adjust fueling to the target ratios while you ride. The trick is to find out what target AF ratio is right for your bike and how you ride. I run an FTECU ActiveTune setup on my FZ07 and a Power Commander Autotune on my WR250R. Works very well although I've never had any smoothness or part-throttle issues with a standard reflash or map from a reputable tuner.

The 790 tuners seem to stay very quiet about a lot of stuff. Rottweiler hasn't figured out the whole "PC5 check engine light" thing yet but show that they flatten out the "dip" in the curve. Coober confuses me. They have stated the decat is pretty much the worst thing you can do to our engines yet have an "EVO" map available and have shown a nice increase in power after they tuned for one. Their site doesn't offer much info either.

I'm attempting to tackle this on my own and find out more info. I feel as though the 790 has good power for me but I want to smooth out the delivery and "tune out" the emissions and/or noise regulation dips in the curve.
 

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I'm attempting to tackle this on my own and find out more info. I feel as though the 790 has good power for me but I want to smooth out the delivery and "tune out" the emissions and/or noise regulation dips in the curve.
EXACTLY my thoughts as well.

I'm spoiled now as the last few bikes I've had was a short trip to my tuner away from seeing major increases in power, ridability, and peace of mind knowing the A/F ratio was bang on so I'm not crazy lean (like the 790 is down low as we get them stock). My '17 Gix1000 went from 159hp to 173hp with just a flash/tune then up 185hp with a full Yosh system - I'm not hoping for a 25 pony bump but even 5-7hp, the emissions dip removed, and a nice flat torque curve would be amazing.

I wish more tuners tackled these bikes and offered multiple packages other than just Rottweiler who offers a PCV for your bike in one of three modes - oem pipe, slip on, and full system.

I'd personally through on a cat delete, air filter, and PCV if any North American tune company offered a proven set up that didn't leave the check engine light on, showed solid/moderate power gains and a nice level 13:1 AF ratio.
 

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Discussion Starter #7
What is "interesting" is that Coober now basically only sells a complete solution for one "pipe": Wings. As little a 2 weeks ago they listed other pipes. They are really clear on the gains. And from the numbers it is right in that dip. 10bhp at 5500/6000rpms more or less. The pipe plays a part in this - they even quote the dB killer removal gains - which are not a lot.

A grand is a lot imo for the gains. It does not mean 100% that I won't will not be getting it, but that depends on how I fare with the 790 over the winter. After all I've not had it a month yet.

tbh If I decide I really want TORQUE/POWER - I'll buy a used 1290. I doubt I will.

OK they have an AKRA EVO solution - but we're talking a track pipe and that tbh needs individual Dynoing anyway. On a track bike the warning light won't be worrying most folk.

A full blown PCV with dual band Autotune and the POD display (which ime is worth every penny) is a grand without a pipe. A decent decat race pipe - close to 2 grand. I am reluctant to say the price-performance benefits are there.


Maybe the boosterplug really is the solution for 95% of road bikes.


The geeky part of me still wants to know WHY though :wink:
 

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What is "interesting" is that Coober now basically only sells a complete solution for one "pipe": Wings. As little a 2 weeks ago they listed other pipes. They are really clear on the gains. And from the numbers it is right in that dip. 10bhp at 5500/6000rpms more or less. The pipe plays a part in this - they even quote the dB killer removal gains - which are not a lot.

A grand is a lot imo for the gains. It does not mean 100% that I won't will not be getting it, but that depends on how I fare with the 790 over the winter. After all I've not had it a month yet.

tbh If I decide I really want TORQUE/POWER - I'll buy a used 1290. I doubt I will.

OK they have an AKRA EVO solution - but we're talking a track pipe and that tbh needs individual Dynoing anyway. On a track bike the warning light won't be worrying most folk.

A full blown PCV with dual band Autotune and the POD display (which ime is worth every penny) is a grand without a pipe. A decent decat race pipe - close to 2 grand. I am reluctant to say the price-performance benefits are there.


Maybe the boosterplug really is the solution for 95% of road bikes.


The geeky part of me still wants to know WHY though :wink:

i have their ECU installed out of the Power Kit setup
it comes with Stock, Wings, Akra and few other maps installed. You can clearly feel how it switch the map when you replace the wings to akra or stock to wings.
Akra muffler feels most powerful for me.
 

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Discussion Starter #9
Now here's something.

It's almost certain given date references etc that most if not all the performance packs were measured against the 2018 OEM map. As I purchased my Duke used a month ago - and it was coming up for a year old - I took it for a KTM dealer service last Thursday. It now rides VERY differently.

The torque curve certainly "feels" different, the quickshifter is "different" (it's not better or worse - just different). Fuelling is far smoother and there is something new in the ignition timing. Tickover is smoother. Downside is it also apparently "sounds" less.

Would be interested if anybody has Dyno results pre/post KTM ECU upgrades or we can find PreKTM vs Coober and PostKTM vs Coober.

imo the Coober probably offers other benefits, though they seem to be quite poor at explaining it. One is the mapping granularity.
But It is almost certainly a predictive model - which however may not be that great for those riding in wildly varying altitude, unless they Dynoed at varying MAP.

If I get a bit of time this week - I will write to COOBER with some very concrete technical questions - which I'll get my mate Rob who maps ECU's from scratch to proof read as well. Maybe he'll add ultra techie stuff.
 
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