O2 Eliminators / De-Cat Headers

[Rasher]

Just fitted some O2 eliminators, waiting for fog to clear up to go and test them.

Also got some De-Cat Headers on the way

Funny how emmisions ruin modern bikes differently, with the GS they pop and bang and lurch about at low speeds. The Tenere actually feels far more refined but has a slight stumble or hesitation just off idle and is restricted at low revs in lower gears.

De-catted headers certainly improved the bottom-mid range on my GS, and an accelerator module helped the fuelling.

The clutch switch mod on the Tenere has removed the stumble and low down restrictions, and from the Dyno I know it runs fairly rich, so I am hoping this will allow the fuelling to still be good with the new headers.

The O2 eliminators in theory will improve part throttle response, at under £30 off E-Bay it seems a worthwhile gamble.

I know a remap is the ultimate "fix" but as they cost around £400 if a £5 switch can remove the throttle body restrictions and a pair of £30 O2 sensors sort out the crap fuelling I am about £350 up.

I am also wondering if the eliminators on their own may fix the stumble

Results to follow.... some sunshine

 

[streaky]

Just fitted some O2 eliminators, waiting for fog to clear up to go and test them.

Also got some De-Cat Headers on the way

Funny how emmisions ruin modern bikes differently, with the GS they pop and bang and lurch about at low speeds. The Tenere actually feels far more refined but has a slight stumble or hesitation just off idle and is restricted at low revs in lower gears.

De-catted headers certainly improved the bottom-mid range on my GS, and an accelerator module helped the fuelling.

The clutch switch mod on the Tenere has removed the stumble and low down restrictions, and from the Dyno I know it runs fairly rich, so I am hoping this will allow the fuelling to still be good with the new headers.

The O2 eliminators in theory will improve part throttle response, at under £30 off E-Bay it seems a worthwhile gamble.

I know a remap is the ultimate "fix" but as they cost around £400 if a £5 switch can remove the throttle body restrictions and a pair of £30 O2 sensors sort out the crap fuelling I am about £350 up.

I am also wondering if the eliminators on their own may fix the stumble

Results to follow.... some sunshine

My bike ran very well with ecu flash and full system, but you need a pcv to finish the job properly, And you will be very suprised at the end result

 

[Ban_6]

Fair play to ya man, I am a little lazy sometimes re goingthe extra hog with modification.

Sounds like you're well happy.

As I am only running in the S10 i'll see how I go after that. But I'll p[rob leave it stock

Will it impact your mpg ? ( if it does I am sure you're not worried )

 

[streaky]

Fair play to ya man, I am a little lazy sometimes re goingthe extra hog with modification.

Sounds like you're well happy.

As I am only running in the S10 i'll see how I go after that. But I'll p[rob leave it stock

Will it impact your mpg ? ( if it does I am sure you're not worried )

Hi it will still do 52 mpg on a run

 

[Rasher]

Did an hour on Saturday solo and a few hours Sunday two-up.

I "think" it may have been 1-2 mpg down on my solo blat (45.5mpg where I "normally get 46-47 on a gentle Saturday ride) and maybe 2-3 mpg down on a gentle Sunday run two-up on country lanes (47mpg where I would expcet 49-50mpg) So hard to tell over such a short test distance, but I am certain it has not improved MPG.

The throttle response is much better from down low, so much so I am probably using barely more than half the throttle openings I did before and shifting a few hundred rpm less to achieve the same pace.

In sports (or clutch mod mode) the throttle response is very agressive, it makes the engine feel far stronger, although in reality it is just giving more grunt for less throttle opening so if you really yank the throttle it is not any different, but when riding steadily (probably normally for most folks) it feels stronger and smoother.

The other effect it does have though is making the top end seem a shade flatter as using more revs / throttle gives less of a gain than before.

It definately has not removed the stumble, I spent time turning the clutch mod off and on, and when pulling away the stumble is still there but I am sure it is not as bad as it is without the eliminators, but I still prefer the clutch switch mod turned on.

Touring mode is also noticeably better, I always hated it before, but it now feels a shade more useable and when on very narrow lanes today (almost mud tracks) it was handy to use and did not feel as lethargic as previously, may also be useable for me when "touring" or at least pottering around towns, or stuck on the motorway.

Definately need a weekend away to really see the fuel difference, but I think @2-3 mpg is the penalty for this mod, well worth trying for yourself at the price if you do want a bit more low down grunt / better throttle response.

If you spend most your time at more than 40% throttle or above 5,000rpm it will make probably make little or no odds to the fuel consumption and for anyone who just tends to use the bike for thrashing about this is likely to make you very happy.

Hoping it will feel even better with the de-cat headers, I already know from the last dyno outing it runs rich up top, and with the clutch mod also runs rich down low so hoping that the fuelling will be better with the headers fitted - intend to get them fitted and then run it up on the dyno again to check fuelling and power.

 

[Ban_6]

Thats a fairly accurate run down on how its all working out. Sounds all good to me, maybe in the future.

The very slight loss of mpg is nothing so it seems to work well.

 

[Rasher]

Headers have arrived, so hope to try them at the weekend

 

[Rasher]

Initial tests are all good, went for a brief spin after fitting the headers, hard to gauge exactly what is going on as I only did a few miles with the O2 eliminators last week and am not sure how much of the current feel is the eliminators and how much the downpipes.

I "think" it has added a bit more ooomph everywhere, but can't be certain as the low down response with the O2 eliminators was pretty impressive, but it has certainly not got slower off the bottom end !

Up top it has definately gained, cannot be sure about actual peak power increases, my instinct tells me there is noticeably more power, what I know is it definately hangs on to the power longer, whereas it felt flat past 7k before,as if power was tailing off it now pulls harder and into the red.

It also was upsetting TC1 on full throttle in second which I have not noticed before - but it was only 7c and up until now the weather has been much warmer, so it could be down to a bit less grip.

It also seems to run nicely, it will hold 2k in 4th (30mph) nicely and pull smoothly from there, crusing at higher speeds also felt good, only did a handful of miles so will have to see if anything odd happens over time.

The decat headers seem to make a much bigger difference to this bike than they did the GS, and the O2 eliminators have more of an effect than the Accelerator module did on the GS.

The bike always had a better bottom and and midrange than my '08 GS (And I also though the twin-cam GS was behind until about 6k, but had a much better top end) and with the clutch mod, O2 Eliminators and De-Cat headers I reckon it is now way more grunty through the low - mid range than the twin cam GS, and now probably has a top end that is similar - just in time for the WC one to turn up and piss on my bonfire

If you want a bit more from your Tenere start with the clutch mod (10p) and then progress to O2 eliminators (£30) and you will be amazed at the difference.

Will get back down the dyno as soon as I can to check it all out, and try to get some longer runs to see if I am gonna need to buy into some oil stocks.

 

[Rasher]

Did some more miles today and got a quick dyno session in, overall the bike still feels very resonsive with the current setup.

Did another 70 odd miles with a mix of A-Roads, narrow mud splattered back lanes and a bit of town work, on the way out with mainly A-Road and quite a bit of traffic holding my speed down I managed a 50mpg. The faster return Journey was 47mpg (both seem very close to what I would have expected pre-mod)

I definately like the T mode a lot more with the eliminators, it is now far more useful for town work and gentle cruising.

The dyno pretty much confirmed what I had hoped for, the over-rich top end is now about spot-on with the motor breathing a bit more freely, and with the clutch mod the low down fuelling is also pretty good on full-bore.

Seemed little point doing loads of part throttle runs as the dyno man said your unlikely to be way off to the point of damaging a motor with an exhaust change - but he did some part throttle tests - seemed OK. If I plug the O2 sensors back in he is fairly certain it will just revert to the horribly weak running the emmisions tests dictate.

One thing I did not do last time was a high gear run, it seems 5th gear makes more power than 3rd and more power than the clutch mod mode. This is what i have seen elsewhere, it looks as if power is slightly held back in 1st - 3rd with a little more power in each gear, then 4th - top is about the same.

Overall I gained about 4 BHP, with the before and after 3rd gear runs (with clutch mod) showing 86.9 (Stock pipes) and 91.0 (Arrows) with a gains from around 3,000rpm and a good extra dollop of power from 6k upwards (it feels quicker up top on the road too) this is the 3rd gear comparison of stock headers Vs arrow headers with the clutch mod

Below is a 3rd gear run and 5th gear run (no clutch mod) and a 3rd gear run with the clutch mod, another thing I noticed is there is an even bigger gain with the clutch mod now, on OE pipes the power went from 41BHP to 49BHP at 40 in 4th, it now jumps to about 53BHP.

5th Gear is giving a respectable 96BHP - More than any twin cam GS, with the exception of tweaked press bikes The midrange was very good before, but it now feels less lethargic up top.

This also shows the clutch mod is off limited value if your cranking along in upper gears (making a switch even more handy) you can use the switch in slower stuff when your up and down the gears, but if your able to keep the motor above 5k rpm or not drop below 4th gear the switch can be turned off.

I could have spent all day there doing runs in each gear, and each mode, with switch, without switch etc. etc. but I now know the bike is running fine, both by seat of the pants, and on the dyno.

If I am concerned about mpg I may go back to running the O2 sensors, as these operate at up to 40% throttle and 5000rpm (basically any cruising speed up to a ton is in the closed loop area) but I am not so sure the mpg is much worse now, and as I am struggling to work out if it has worsened, it obviously cannot be a lot worse - and probably not enough for me to want to lose the rather sharp throttle response I now have.

An end can may add another 3-4BHP (Arrow claim 2BHP for a can alone and 8BHP for the full system) but as I don't like noisy pipes as they annoy me when cruising I may not bother.

I am sure an end can and / or a good remap (Or ECU Flash) would make the bike even better, but I have gained power across the rev range, lost the annoying low gear / low rpm flat spot and considerably improved throttle response for under £200 (and saved some weight)

The flash will probably happen at some point, but for now the bike is pretty sweet