Triumph Rat Motorcycle Forums banner

1 - 13 of 13 Posts

·
Premium Member
Joined
·
514 Posts
Discussion Starter #1
I ride an 09 Bonnie SE with the following performance related mods:
BC Sleeper exhaust
Airbox Eliminated, K&N filters
SAI Eliminated
O2 Sensors blanked off
TuneECU tune flashed

I have never had the bike on a dyno but she seems to be running quite nicely. I have been looking at lots of other performance mods like the 813 Cam or a 904 bore or high compression pistons, etc. I am perfectly happy with the top speed of the Bonnie, I don't take it to the track or anything. I would love to get some more low and mid-range grunt though. What do you all suggest I consider if pulling the front wheel up under hard acceleration is my goal and not having the fastest bonneville in the Pacific Northwest?
 

·
Registered
Joined
·
3,271 Posts
I ride an 09 Bonnie SE with the following performance related mods:
BC Sleeper exhaust
Airbox Eliminated, K&N filters
SAI Eliminated
O2 Sensors blanked off
TuneECU tune flashed

I have never had the bike on a dyno but she seems to be running quite nicely. I have been looking at lots of other performance mods like the 813 Cam or a 904 bore or high compression pistons, etc. I am perfectly happy with the top speed of the Bonnie, I don't take it to the track or anything. I would love to get some more low and mid-range grunt though. What do you all suggest I consider if pulling the front wheel up under hard acceleration is my goal and not having the fastest bonneville in the Pacific Northwest?
I have more or less the same mods as you except that I decided to keep the airbox with a DNA filter, and I have the Arrow 2-2. I have also been contemplating the 904 at sometime in the future.

For your requirements though, I believe that a change in final drive ratio might give you a bit more grunt, perhaps by going down a tooth on the gearbox sprocket and up a couple of teeth on the rear. Cheap and cheerful mod but if the top end is adequate for you it might be worth doing.
 

·
Premium Member
Joined
·
514 Posts
Discussion Starter #4
I have more or less the same mods as you except that I decided to keep the airbox with a DNA filter, and I have the Arrow 2-2. I have also been contemplating the 904 at sometime in the future.

For your requirements though, I believe that a change in final drive ratio might give you a bit more grunt, perhaps by going down a tooth on the gearbox sprocket and up a couple of teeth on the rear. Cheap and cheerful mod but if the top end is adequate for you it might be worth doing.
I have been thinking of doing just that. I have an 18T sprocket installed now and have used a 19T before. I may have to try 17T and see how I like it.
 

·
Registered
Joined
·
3,885 Posts
There's no replacement for displacement. A 904 kit w/o head work will give you more torque. You'll stilll need to regear to loft the front wheel...17/45 should just about do it.

Cheers,

--Rich
 

·
Registered
Joined
·
8,872 Posts
If your looking to be able to power wheelie you will need alot more then gear change or even a 904.It takes around 70 ft/lbs to do that on these bikes .So you will need a 988 ,994 or a 1087 with head work cams and so on.
 

·
Registered
Joined
·
141 Posts
Maybe a turbo kit? I remember reading an article about one a few years back that was pretty impressive.

Sent from my DROID RAZR using Motorcycle.com Free App
 

·
Registered
Joined
·
775 Posts
Sit as far back on the seat as possible.

I'm pretty certain Mike has hit the nail on the head, more CC's. My 1100GS has a lot more grunt than the Bonnie and I could only imagine that by increasing the displacement, you'd increase the low-end grunt.

Back when I'd R&D for Ford's small blocks, if you set the same cylinder heads on more cubes, you'd only gain marginal hp up top but gain a much broader, earlier and over all higher torque curve.

Go for the 1087 and be done with it.
 

·
Registered
Joined
·
3,885 Posts
Thanks for all of the advice. Out of curiosity, what does the 813 cam do to your power and torque curves?
Compared to 865 cams I assume? You gain both torque and RWHP. You need to move the rev limiter up in order to fully realize the top end with the 813 cams...on my bike, I hit my 8,500 rpm limit and was still building power.

YMMV,

--Rich
 

·
Registered
Joined
·
566 Posts
I ran a 17/45 for quite a while, definitely a lot more fun over stock - it works out near enough the same as running a 16 on front with the stock 43 on the back :)

Unfortunately it brought out too much of the hooligan in me so I dropped a 19 on the front to bring things back into line.
 

·
Registered
Joined
·
8,872 Posts
Thanks for all of the advice. Out of curiosity, what does the 813 cam do to your power and torque curves?
They help both from 4500 rpms on to redline.You wont loose anything below 4500 rpms ether.813s are not crazy race cams they still idle good just a tad better sound at idle.The stock shim over bucket cam set up limits how big of cam you can run the 813s are the max you can run with stock shim over bucket set up.
 
1 - 13 of 13 Posts
Top