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2018 Street Scrambler with TEC cam not performing as expected

20K views 93 replies 29 participants last post by  JoeDuc 
#1 ·
Hi all,



It's been a couple of months since i've had the TEC cam places in my Street Scrambler after I saw the convincing video of TEC that claimed the top-end RPM to become usable while the lower-end RPM would stay in tact.

After trying many things I have to say that i'm disappointed in the results. The image below shows the comparison of a stock bike with mine (TEC cam, V&H full exhaust, K&N filter, snorkel removed, booster plug). After there "upgrades" it went from 81NM at 2900 rpm to 75NM (5 less) at 4200 rpm and 65/70 at 2900 rpm. HP has increased, but only with around 4HP, while there's 15 HP being claimed when you only swap the cam. The only part that is true to the claims is the torque being available until 7000 rpm, but I've trading in a lot for that gain.

People are talking about off-road tunes, but after a lot of research I found out that this tune is no longer available for Street Scramblers since medio 2017 and I haven't found any dealer to help me out and get it on my bike some other way (even the dutch importer wouldn't).

This situation got me stuck between the dealer claiming that everything went right while installing and TEC claiming that it might be the exhaust or bad cam timing. But I can't see how that's possible with this cam and using the right tools.

My last resort is the Power Commander, but i'm getting quite sceptical with this. Is this really going to give me my low-end torque back and bridge the min 10HP gap? Especially the low-end torque is the thing I'm missing the most on the bike.

What would your next step be? I just want the bike to perform as claimed on the videos.
 

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#2 ·
Never believe everything that is claimed, just throwing in a hot cam and claiming to get another 15 hp is a big claim, there is more to that than just throwing in a bigger cam, some cams work better mid range and the hotter ones work best at top of the range but for hot cams to really work other work needs to be done, there is head work that is needed, tunes for the new cam, the exhaust system, air flow etc etc, just throwing in cam and expect it to perform might work but at what cost losing torque down the lower RPMs.

Ashley
 
#5 ·
I tend to think the dealer screwed up the timing. The cam chain can ‘bunch’ or ‘kink’ unless pressure is kept on it to keep it taut. Took me three attempts to get it spot on. Very happy with the results of my cam, no loss of low down or midrange and it keeps pulling where the stock cam fell off a cliff.

It’s not a big job to re-check the timing and I would certainly do that before getting into the potential nightmare of a power commander.
 
#6 · (Edited)
I tend to think the dealer screwed up the timing. The cam chain can ‘bunch’ or ‘kink’ unless pressure is kept on it to keep it taut. Took me three attempts to get it spot on. Very happy with the results of my cam, no loss of low down or midrange and it keeps pulling where the stock cam fell off a cliff.



It’s not a big job to re-check the timing and I would certainly do that before getting into the potential nightmare of a power commander.
Did you use a timing tool from Triumph to keep the cam in place? I'm not having the right tools so I might have to go and ask the dealer to open it up again. Hopefully not at too much costs.

Verstuurd vanaf mijn CLT-L29 met Tapatalk
 
#9 ·
Fine. Your prerogative. I, personally, am delighted with the performance boost their cam has given my 900. Absolutely delighted. It’s gone from a machine I was looking forward to selling to one I want to keep.

With regard to the original poster, I wonder if the dealer re-set the valve clearances properly? All 8 of mine were tight (mind you, 6 were tight before I started - I don’t have a lot of faith in Triumph’s assembly workers anymore). If the valves are tight it’s never going to perform properly.
 
#11 ·
Also. What's this booster plug supposed to do . I've never fitted one or touched the ECU and all seems fine. Im told the ECU self maps and adjusts if your trying to fool it with interference devices maybe it's constantly trying to adjust the interference out. Others who know more about fuel injection please answer

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#12 ·
Also. What's this booster plug supposed to do . I've never fitted one or touched the ECU and all seems fine. Im told the ECU self maps and adjusts if your trying to fool it with interference devices maybe it's constantly trying to adjust the interference out. Others who know more about fuel injection please answer
The booster plug simply tells the ECU that the incoming air is colder than it actually is, so the ECU compensates by injecting more fuel to make the mixture richer.
 
#15 ·
It has been my experience that many Dyno's give different results so when TEC did their test it might have been on a more generous Dyno in perfect weather conditions etc, than yours, also I don't know anything about the V & H exhaust on a scrambler or if the Cat is removed but on theirs I bet it is which would probably pad their numbers, also the booster plug won't add any power it just smooths out the throttle response, and it wouldn't surprise me that they had access to a different tune that probably isn't available anymore.
 
#16 ·
You're right about the off road tune. George had it on his bike. But is that going to make a 15NM @ 2900rpm and 10 HP @ 6500 rpm difference?

The chart in my first post has a comparison between stock and mine just like George has on his video.

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#18 ·
Btw does anyone know if the latest high output ST tune can be uploaded to the early low output model and if anyone has done it and seen a difference. Also has anyone got the triumph part numbers for the can between the old and new model to see if it's changed. If it has it might be a fit into the old model instead of a Tec cam. We need a friendly dealer to have a mess around with an old bike and new parts [emoji3]

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#29 ·
While you can do valve clearances without removing the stator cover, I think you’ll struggle to get the timing spot on unless you can lock the crankshaft. That requires removal of the stator cover to get it right. You can find top dead centre by resting something on the piston top through the spark plug hole an watch for it to stop moving but it has too much margin to guarantee you’ve got it right. Others may have a different view but in my opinion it’s too important to fudge.
 
#30 ·
@CanberraR3 is right. You need to positively locate the crank or you’ll just be guessing - and wasting your time.

This is what you need and need to know..

alternator cover gasket* - T1268765
CAM screws T40 head* - T3053005
Cam tensioner O rings - T3600199 +*T3601276
Tightening torques
Cam sprocket screws 22 NM
camshaft bearing carriers 10Nm
Head top cover 14Nm
Alternator cover bolts 10Nm
Cam tensioner* 16NM

I have the Triumph crank location tool and you’re welcome to use it.
Good luck.
 
#32 ·
I’m no mechanic but have always worked on my cars and bikes. I admit fitting the cam was a little intimidating and I did have one heart stopping moment, but I got a huge sense of satisfaction out of doing it myself. It is, however, a job that can become a catastrophic disaster if you get a key thing wrong, such as dropping something into the engine or getting the timing way out.

George is very unclear in the video about how to reset the cam chain tensioner and this caused me to pause for a couple of hours while I tried to find out how to do it. Otherwise, if you follow his process step by step you should be OK. He also glosses over how to move the wiring harness and what to unplug. There’s a tricky part to that that needs care and a little bit of knowledge and/or problem solving ability. Refitting the alternator cover can also be a bit tricky.

You perhaps shouldn’t use this exercise to learn how to set timing and valve clearances.

Its very doable but if you’re in doubt, my advice would be to get someone with expertise to do it.
 
#33 ·
So after installing the cam in my 2016 street twin, I’m beginning to wonder how much power this cam has actually added, there’s plenty of people raving on here about it but I feel like the results are similer to the OP, big loss of immediate torque.. and on my bike anyway.. hesitation low down, torque and power picks up midrange and builds up to the higher rev range... but, to me it really doesn’t feel like a big gain in power.
I would absolutely love to see a genuine before and after cam change Dyno run on the same bike.
 
#34 ·
You should have got one done! And nothing stopping you doing one now to see how the curves look at least.
Don’t forget the power increase is at higher revs and biggest at the red line, largely because you are able to rev higher. If yours isn’t feeling right low down and is hesitating then something isn’t right with the install such as timing or clearances. You also need to ride about 500kms to “run it in”. You will notice an improvement over time. If anything mine feels a little stronger low down now after 3,000km and certainly no weaker at any point, all the way to 6,500-7,000rpm. No one has claimed the cam gives a surge of power. It absolutely doesn’t; your 900 will not become a 1200, so if that’s what you were after these cams won’t deliver it.
Did you ensure you have the updated map loaded?
 
#36 ·
it does feel quicker higher up the rev range, I am just re-invigorating the question by the original poster.. has it only added 5hp extra... or the 15hp that tec claims?
my timing is spot on, done myself so i know its completly correct, checked it for about 20 minutes, so i know it cant be a timing issue, I have booked in for a map update, solent triumph is fully booked up so im having to wait till 29th august to get it in, done 200miles now, by then I should have done over 500.. and then once the map is checked/updtated I will report back.
as for the power, im happy for a little extra, like i said just questioning the claims. I had a T120 from 2016 for 2 years but i prefer the street twin, just trying to unlock more performance at the top end, and I feel this cam has done this but at the moment it does'nt feel right lower down.. this is my take on it at the moment, I hope its fuelling and an update will fix it.. fingers crossed!
 
#37 ·
My bike has 5 hp more instead of the claimed 15 by TEC.

As for the map update. I hope you can get the off-road map for your Street Twin. That will open things up for you. Unfortunately, the Street Scrambler can't get this map uploaded anymore.

Please let me know if the old lower end torque is present again when you have the off road map.

Verstuurd vanaf mijn CLT-L29 met Tapatalk
 
#39 ·
“Fast is fine - but accuracy is everything”. (Wyatt Earp). :grin2:

There was snow on the ground when I did my cam swap and I was in no rush, Davey. My background is with Isle of Man race bikes and you don’t hurry through preparing those.

It looks like most folks who have fitted the TEC cam are happy, but there’s a couple who are disappointed and I still don’t think that tearing into it is the right way for most.
 
#47 ·
Update

So after finally getting my bike in to triumph to check the map, they’ve confirmed I already had the latest map for my bike, and no charge for checking ?

So now I’ve had the cam in about 350miles It’s feeling a lot better than at first, I do believe though it’s a bit more fussy when it’s cold, the hesitation and surging comes back a bit but once it’s warmed up it all seems good

I think there is a loss of low down torque but it really does build power better than it did, defiantly feels faster now
 
#48 ·
I have a 2017 Street Cup that is at the dealer as we speak, getting the TEC cam fitted, valves checked, etc. I already had the bike put on the dyno prior to this. I had the K&N Air filter already, snorkel removed, gutted stock cans, TEC x-pipe, etc...

Here is the baseline run. Looking at the AFR, I don't see how it could possibly be optimized for this new cam. I expect I will have to get a PC-V and retune it, despite the claims of TEC that it "runs just fine on the stock map"... We shall see. But here is my baseline of all the mods before the cam, and I will have the same dyno operator do a run after the cam install. And if we have to tune it, we will then have a 3rd dyno run of the final results.
 

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#49 ·
I can say with 4500 miles of use that the Tec cam runs fine without any additional fuel devices. Make sure after fitting you follow through the process of letting the bike idle for 15 minutes and then more untill the fan come on before touching the throttle. My bike has no issues at any point in the rev range right up to the limiter. Other changes are limited to straight through headers mounted to standard silencers and cutting down the air filter snorkal

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#50 ·
Yeah, I have already talked to the mechanic and he knows to reset adaptives and let it do the 12 minute tune, etc... They did the cam on a couple Bobbers recently and those did require both fueling and timing changes with a PC-V, but that was because they removed the airbox and installed pod filters, plus that 1200 cam was made for Thruxton, not the Bobber motor...
 
#51 ·
So an update. Rode the bike about 125 miles after my cam work was done today. It works.

I don’t have the dyno chart yet, but here is what we found. We did my before run, on a different dyno. The one used was a dynojet... same one all the magazines use... the dealer has a Factory Pro which measures power differently, and is typically about 15% lower than what a dynojet reads...

So on the dynojet, I had 51hp and 60tq, rounded to the nearest value. On the Factory Pro, I measured 55hp and 54tq. If we add 15% we get 63hp and 62tq.

What we also found is that it runs ok with the stock map, but there are absolutely rich spots down low, and lean areas up top. Not dangerously so, but there is absolutely room for improvement with a power commander and a tune. Better fueling, a pod style air filter, a little ignition advance and he feels wee will he flirting with the 70hp mark.

It feels great. I never hit the rev limiter before. The bike would be wheezing and losing power long before it ever got there... now, it pulls hard right to the limiter... bounced off it a few times today, for the first time ever.

It’s making a solid 12hp more in the 5000rpm to redline area, and with some tuning and tweaks we should be able to bump that up to a 15-18hp gain.

At that point, I will take it to the same dyno I did the baseline run on and get a true before and after chart for you guys, same dyno and operator...

But right now, a 12hp increase and being able to use all the revs... this cam is the real deal.
 
#52 ·
Pretty much how the rest of us feel. I would give it at least 1000 miles before adding any piggy back device. Firstly you will find now you can rev the motor it will free up considerably also give the stock ECU time to adapt to your new style of riding as it constantly adapts apparently. Looking through this forum a lot of people using piggy back devices seam to have continued tune problems. I promise you mine at 6000 miles hits the limiter in top and revs cleanly with no flat spots idling issues or popping. It just feels like it's lost a little right at the bottom but that could be me now riding it differently.

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