Tec 202 Camshaft - Street Twin 900

Being pretty much IT incompetent I would have no idea how to alter the mapping for an ideal fuel and ignition map even if I wanted to. I can appreciate that the engine electronics were never designed to compensate for significant changes, such as a camshaft swop. Why would they be? I doubt Triumph expected many, if any, owners to start messing around with serious bits of engine, Triumph would probably assume they would buy a more powerful bike.

I know the ST engine runs lean, you can feel it on start-up, but generally I'm happy with the way the bike runs (except for throttle snatch, which is annoying, especially when compared to my three 30yr old Hondas, which are sooo smooth).

However, if it can be improved with not much effort or cost I would be interested.

 

If your bike has a fly by wire throttle the answer is probably yes. My son’s Panigale had the same problem, evidently they are known for it, there is a kit consisting of some small spacers that need to be fitted into the twist grip. TMF did a video on sorting his Panigale out, worth a watch.

Also when son sorted his out he had to borrow my set of security bits to disassemble the throttle housing as the screw heads have a triform “slot” not hex or Torx or cruciform. So ensure you have the right tools to do the job.

 

I actually meant improving the bike's running by changing the mapping. But thanks for that suggestion, I shall look into it. Anything that can make the throttle smoother is welcome.

 

Yes I must finish the install. I also just remembered I did get a custom tuning map file two years ago from a member of these forums (the one posting the Triumph Rat thread below). So will try that too.

I found this thread interesting. Havent read it all, but I will

https://www.triumphrat.net/threads/...hs.995617/?post_id=2004315272#post-2004315272

 

My 2 penneth worth...

My ST has the the stage 1 cam, decat, baffle-less V&H and dna filter less snorkel and it runs beautifully. BUT it's a waste of time unless you do the suspension and brakes - all of that is serious money. Assuming you do everything yourself, about £1400-£1500 quid (inc brakes and suspension - 10mm over Hagon 2820 in stainless was my option for the rear). My 17000 mile ST is quick, agile and looks a picture. It averages 64mpg too - but I do regular 200mile trips on her to visit my very old Mum!

To me, it is worth every penny. I love the early ST looks and prefer it to all of the 900 and 1200 classics. I love it's comparatively low weight. I love the tubeless tyres. I love playing with this simple and accessible machine. I did the mods over time and that made it affordable to me.

I run a standard ECU map and have no issues. I will be putting it on a dyno next year to investigate the fuel/air ratio.

I think most would go for a 1200 Speed Twin and it would be a good bet. I'm very proud of my little 900 however. To me that is worth double what I have spent on it and it is probably unique - my vanity likes that thought!

 

I am not sure what you mean with it's a waste of time unless do suspension and brakes
It's not exactly a high performance sport bike, and it never will be. I think it rides and brakes OK.
I have had a few bikes with 120-170 hp, but I really don't need that anymore. I am pleased with my ST, just a few more ponies and it's perfect.

Anyway I bought YSS rear shocks, they have good reviews. Not tried them yet, and I probably will not do so until May next year (since I am living well north of the arctic circle and the season is over).

My mum is also rather old, turns 95 next spring. But at the time being we live in the same house, so no trips necessary

 

Agreed. Like you, I come from a back ground of high performing bikes. 2x Speed Triples, ZXR and, before my ST, a significantly lightened 955i Sprint RS. That said, I'm not tempted by the state 2 cam. I'm getting 'high 60's (bhp) at the real wheel with great midrange torque - plenty for this bike.

I think the brakes on a ST are not as bad as some would suggest. My problem is I'm a fat bastard - over 17st - and my beautiful wife is over 12st. At speed and on some road surfaces, the suspension would pogo and the bike could sometimes became a handful. 8.5n/mm linear springs and a set of bespoke Hagon 2820 shocks cured these tendencies. Basically, my ST is running Street Cup geometry and works very well.

I have had YSS stuff and I rate it. As you say, the ST is no R1 and, inmho, the YSS brand delivers a real performance upgrade at a reasonable cost.

I think we all want the ST to be a 'roadster', an all-rounder. The gen1 from the factory was nearly there. Another £1500 and you have it. Is being another bike a better option? For most probably. It has been fun to do however

 

I think that is e actly right mate. There are not many bikes out there that you can modify for the best. Most are too advanced/difficult or too good standard to make it worth it. The Street Twin is different. For those who may have the skills, tools and the money you can genuinely improve it without destroying its many good points. I love mine and it can do most things reasonably well. Regards, Steve Rat

 

Not really a cam shaft topic but linked....

I am recovering from a hernia op, bored and sore and I just had a weird thought....

How would a 900 LC Trumpet react to breathing through a couple of smoothbore carbs (instead of the EFI)?

I know some will slap me down and suggest the thought is ridiculous and they love the Street Twin as it is etc BUT, just for fun and theoretically how would performance be effected? What would the trade offs be? If you were building a track bike would there be a positive argument to the proposal?

Just for fun guys.

(By the way I am happy with mine and not seriously thinking of changing it!)