Will The Bonnie Work For Me?

[Cat Daddy]

Originally Posted by B02S4

Holy shit, that is nice!

Thank you for the kind words.

[sargev55]

Originally Posted by SomethingClever

Some people are talking hp and some people are talking rwhp which is making this discussion confusing. Let me see if I can clarify.

The stock Bonnies claim 67hp, but that is measured at the crank. At the rear wheel (as measured on a dyno) they tend to pull 54-55 rwhp out of the box.

I believe the author of that post was saying his bike went from low 50s rwhp to 70 rwhp, which is just on the edge of believability. It is also odd that he said he only gained a few pounds of torque... most gain more than that. It's possible that the Arrow pipes he's using are built to emphasize HP and don't give as much torque gain.

My bike was dyno tested in stock form at 53 rwhp. After airbox removal and new pipes (less free flowing than his Arrow system AFAIK), I had it tested again and found I was getting 63 rwhp, but I was a little lean. After richening up I believe I am getting 65 rwhp but I have not had it tested a third time. I also gained 10 ft/lbs of torque between stock and new pipes/airbox.

That's close to 20%.

Regardless, I don't believe I've seen anyone quite hit 70 rwhp with just airbox and pipes... to crack that number you would need to do something more expensive... like bigger carbs, hotter cams or a big bore kit... in addition to pipes/airbox (or mapping for EFI guys).

There are a couple guys that have gotten 110 rwhp out of these bikes but it is VERY expensive to get there.

my harley 1200 roadster went from the stock 58whp/72tq to 72whp/76tq with rejet/air filter/and slip on muffler. thats a bike that has a stated crank rating of 70hp/80tq, but thats at the crank.

my buddies triumph went from low to mid 50's to close to 70whp and torque went up just a few pounds. that was with tuning/full arrow exhaust/ and whatever hi-flo air filter triumph sells. i just have slip-ons on my harley, he had the arrow exhaust from the header back. that was a mean little bike.

both the sporty and bonnie are way undertuned for EPA reasons from the factory.

[sargev55]

Originally Posted by jon_l

Well I'd certainly buy the bike going from 65 HP up to 70 with jetting, air & exhaust, but not 70 from the low 50's.

Regardless, I have not ridden a loaded for travel Bonnie, but with just me, they seem to have enough power.

thats because you dont own a bike that has a carb. even the the newer EFI ones are the same way, its for noise and pollution control so they meet the EPA standards.

the bonneville and sportster are incredibly lean and corked up from the factory, you richen it up, let it breath, and bam, you just got a crazy gain.

well your DR probably has a carb, but still, different sort of ball game.

with the harleys, the basic upgrades are called 'the harley tax,' because all it does is get the bike to where it should be from the factory, but isnt allowed...i guess with the classic style triumphs its the same. both bikes are pretty boring stock, then you 'pay the tax,' and its a different story.

[ARGary]

I don't really care if you believe or not, but here are the facts.

Low 50's stock hp to 75+ modified is common with fully modified carbed 790cc T100s. Mine tested at 81.3 rwhp. Here's the full list:

All emissions stuff eliminated totally,
Airbox eliminated,
One K&N per carb,
Toga mufflers (like early 60's Bonnevilles straight-through, glasspacked, also gives retro look and sound),
The idle and main jets both get bumped, and spacers need to be added to the needle.

The needed change in size of the main jets after the mods is really astounding. As I recall, the stock main jets are about 25s, and a fully modded T100 will easily pull 55 mains, and that's almost a 500% in flow (keep in mind that jet size is diameter and a 55 is 4.84 times as large as a 25 in circumference). Mine will pull 57.5s without any bogging when the throttle is whacked wide open when in final gear (the best test for a main jet that's too big, but 60s will bog on my bike); however, I run 52.5s in mine, which is still 440% more flow than 25s. The key to gaining horsepower is knowing how to tune an engine (including balancing the carbs on a multi-carb bike); most people either don't really open up the airflow at both ends, or they don't know how to properly jet a carb.

The downside of the mods I made are 1) much more difficult cold starting (cold meaning, sitting for more than a full week - the airbox does make a difference here), and 2) significant decline in gas mileage (you can't flow 400%+ more and keep the same mileage).

However, you gain 1) a huge bump in hp and acceleration (makes very fast shifting a necessary skill), 2) awesome sound of Togas at all speeds, 3) equally awesome intake honk at high rpms, 4) great retro look and 5) ability to leap around anyone on anything other than a crotch rocket. The bike will pull very hard and very quickly to redline and then keep pulling hard all the way to the rev limiter (even with the windscreen).

By the way, on a dyno, lightening the bike doesn't get you more rwhp and I don't really know of any other way to accurately measure rwhp.

Some of my other Bonnie mods:

Lowers on front forks custom chromed.
Triumph chrome fork uppers,
Triumph chrome headlight mounts,
Triumph roadster screen,
Garmin GPS,
Triumph eggcrate vintage tank badges,
Triumph chrome engine guards,
Triumph chrome cam cover,
Triumph chrome chain guard,
Triumph security alarm system,
Chrome rear luggage rack,
Triumph leather saddlebags, and
Sheepskin seat cover.

I have entered the bike in numerous shows and have won or placed in top 3 overall in all shows.

[SomethingClever]

Originally Posted by ARGary

I don't really care if you believe or not, but here are the facts.

Low 50's stock hp to 75+ modified is common with fully modified carbed 790cc T100s. Mine tested at 81.3 rwhp. Here's the full list:

All emissions stuff eliminated totally,
Airbox eliminated,
One K&N per carb,
Toga mufflers (like early 60's Bonnevilles straight-through, glasspacked, also gives retro look and sound),
The idle and main jets both get bumped, and spacers need to be added to the needle.

I have almost the exact same mods. Norman Hyde Togas, airbox gone (K&N style pods fitted), emissions gone and I'm running 150 mains, 42 pilots and a little over 2 turns out on the D screw.

Originally Posted by ARGary

The needed change in size of the main jets after the mods is really astounding. As I recall, the stock main jets are about 25s, and a fully modded T100 will easily pull 55 mains, and that's almost a 500% in flow (keep in mind that jet size is diameter and a 55 is 4.84 times as large as a 25 in circumference). Mine will pull 57.5s without any bogging when the throttle is whacked wide open when in final gear (the best test for a main jet that's too big, but 60s will bog on my bike); however, I run 52.5s in mine, which is still 440% more flow than 25s. The key to gaining horsepower is knowing how to tune an engine (including balancing the carbs on a multi-carb bike); most people either don't really open up the airflow at both ends, or they don't know how to properly jet a carb.

I think the stock jets are even smaller than 125s. I think they're 110 or 115 tbh.

Originally Posted by ARGary

The downside of the mods I made are 1) much more difficult cold starting (cold meaning, sitting for more than a full week - the airbox does make a difference here), and 2) significant decline in gas mileage (you can't flow 400%+ more and keep the same mileage).

I have rarely let my bike sit for a week, but I have noticed that it is much easier to start in cold weather than before the mods. Three pushes of the starter at most in freezing weather, and that's if it has sat for a few days.

Originally Posted by ARGary

However, you gain 1) a huge bump in hp and acceleration (makes very fast shifting a necessary skill), 2) awesome sound of Togas at all speeds, 3) equally awesome intake honk at high rpms, 4) great retro look and 5) ability to leap around anyone on anything other than a crotch rocket. The bike will pull very hard and very quickly to redline and then keep pulling hard all the way to the rev limiter (even with the windscreen).

Agree with all but #5. Although I'm only getting 65rwhp... maybe if I had 15 more horsies I'd think differently

I'm surprised your results are so different than mine... although I do have the 865 CC engine which supposedly has worse cams than your 790.

[jon_l]

Well there are enough folks with dyno results that I am obviously incorrect. I'm impressed that relatively inexpensive mods can yield such gains.

[B02S4]

Originally Posted by SomethingClever

... although I do have the 865 CC engine which supposedly has worse cams than your 790.

Not supposed, it's verified. The 865 cams SUCK/BLOW. And not in a good way.

Try a set of TPUSA 813's and prepare to be impressed.

[mjs3800]

ARGary says .... I don't really care if you believe or not, but here are the facts.

Low 50's stock hp to 75+ modified is common with fully modified carbed 790cc T100s. Mine tested at 81.3 rwhp. Here's the full list:

All emissions stuff eliminated totally,
Airbox eliminated,
One K&N per carb,
Toga mufflers (like early 60's Bonnevilles straight-through, glasspacked, also gives retro look and sound),
The idle and main jets both get bumped, and spacers need to be added to the needle.

Real hard to believe. Been around these Bonnies since 01 and guys are not getting those numbers with those mods even with a 'juiced' igniter. I have seen low 70s at best. Can ya post your dyno sheet ?

[SomethingClever]

Originally Posted by B02S4

Not supposed, it's verified. The 865 cams SUCK/BLOW. And not in a good way.

Try a set of TPUSA 813's and prepare to be impressed.

If I have the money I may have the shop swap in a set of those at 24,000 miles when they are checking the valves. That kind of job is way beyond what I'll ever be able to perform myself.

However, I *think* I'm mechanically up to the challenge of replacing the stock carbs with FCR 39s, so if I ever find myself with a spare $900 again, I may do that.

[mjs3800]

Originally Posted by SomethingClever

If I have the money I may have the shop swap in a set of those at 24,000 miles when they are checking the valves. That kind of job is way beyond what I'll ever be able to perform myself.

However, I *think* I'm mechanically up to the challenge of replacing the stock carbs with FCR 39s, so if I ever find myself with a spare $900 again, I may do that.

SomethingClever you are right on target with your airbox and pipes mods. Thats a nice little jump. I was looking at posted dyno sheets over at the RAT Forum and the only way guys are getting in the mid 70s-80 HP range is with additions of 904 kits, bigger carbs, heads flowed and oversized valves. Instead of looking at cams or carbs right now you might consider getting a remapped igniter replacing the factory module. Triumph Performance USA offers up 4 options. With your mods option # 2 would be what your looking for. Raises the rev limiter and ignition timing 3 degress. Cost is a little over 200 bucks.

[SomethingClever]

Originally Posted by mjs3800

SomethingClever you are right on target with your airbox and pipes mods. Thats a nice little jump. I was looking at posted dyno sheets over at the RAT Forum and the only way guys are getting in the mid 70s-80 HP range is with additions of 904 kits, bigger carbs, heads flowed and oversized valves. Instead of looking at cams or carbs right now you might consider getting a remapped igniter replacing the factory module. Triumph Performance USA offers up 4 options. With your mods option # 2 would be what your looking for. Raises the rev limiter and ignition timing 3 degress. Cost is a little over 200 bucks.

What kind of return does that mod deliver in terms of performance? Also, do you send in your stock igniter and they mod it, or do they just send you a whole new unit?

Would be pretty tempting if they just send you a new one. I don't really want to be without the bike for a couple weeks waiting on postage... I commute on the thing.

[mjs3800]

Originally Posted by SomethingClever

What kind of return does that mod deliver in terms of performance? Also, do you send in your stock igniter and they mod it, or do they just send you a whole new unit?

Would be pretty tempting if they just send you a new one. I don't really want to be without the bike for a couple weeks waiting on postage... I commute on the thing.

Really dont know the HP numbers but there are gains. As you can tell these Bonnies can hit the 7400 rev limit pretty fast and strangle them as they are coming on the cam. The rev limit is raised to 8500 with a igniten advance at 3500. There is a core exchange... you send yours and they send you one back. Here is the USA dist. Talk to Carlos.


http://www.triumphperformanceusa.com/

[B02S4]

Originally Posted by ARGary

...Mine tested at 81.3 rwhp. Here's the full list:

All emissions stuff eliminated totally,
Airbox eliminated,
One K&N per carb,
Toga mufflers (like early 60's Bonnevilles straight-through, glasspacked, also gives retro look and sound),
The idle and main jets both get bumped, and spacers need to be added to the needle...

Let's see the dyno sheet, correction factor, & smoothing factor.




You do have it, right?

[conchscooter]

Originally Posted by EetsOK

Why are you bashing Triumph? Ted Simon rode a push rod Triumph around the world. He wrote a book called Jupiters Travels.
If they sucked so bad, how'd he make the trip?

Youneed to stop bashing Triumphs. Just becase you don't like them don't mena they are crap. If they were such rubbish, why did they sell so many and why were people so eager to see Triumph reborn?

Haters gonna hate.

If you read Jupiter's Travels you will find Simon's Daytona was constantly breaking down and he was fixing it, which worked for him. Personally with 60,000 trouble free miles on my POS 2007 Bonneville I cannot imagine taking off with spare pistons in my luggage. And oh yes I have a couple of Iron Butts under my belt on my POS modern Bonneville with the standard seat. The beauty of these machines is that whatever you dislike you can change, exhausts, seats, handlebars, and improve performance if that matters to you. A modern Bonneville is a blank slate to do with as you will.

Old Triumphs were superbikes, until Honda CB750s hit the scene then Triumphs died an agonizing, under funded death. When clean reliable boring Japanese bikes appeared the wild oily vibrators disappeared. They were reborn because the Triumph name has a glorious history and John Bloor had the billions to bring them back right. I am glad I own one.

In an effort to avoid a POS old Bonneville I bought a Benelli Tornado 650 in 1970 something ( I lived in Italy). It didn't leak but when it wasn't tearing my eyeballs out from rip snorting acceleration the electrics were failing. Vibration is an issue for much more than rider comfort as any old timer will tell you. Engine vibration breaks wiring, kills light bulbs, loosens all manner of fasteners, frequently most unexpectedly, numbs fingers and makes long distance riding hell. I remember, I was there. Modern bikes are lovely.

[Beaverboy]

I don't understand all of the hate from the classic Triumph owners. Nor do I understand how people can claim the new bikes don't have character. I feel like my bike has loads of character compared to most modern bikes. But then, the only Bonneville I've ridden is my own. True, from the showroom it's a bit of a blank canvas, but that's why it's so much fun to own.



I had no problems doing the ton like that. Actually, I went up a tooth up front after that trip because it was screaming at 70mph despite making plenty of torque. One of my three complaints about the bike from the factory is that it really could use a 6th gear with the 865cc engine. The other two are the pathetically thin mag wheel bike's seat and the truck-like rear shocks. I replaced the shocks (with Thruxton-length Ikons) before I took my next big trip on the bike (a 1200mi weekend) and things were dramatically better. I replaced the awesome stock Metzelers with some numb sport-touring tires and have been regretting that decision ever since. The truth is, as much as I enjoyed the idea of touring on the Bonnie, I couldn't bring myself to install a windshield. I bought a used Tiger 1050 for touring and have begun slowly transforming the Bonneville into a street fighter.

First up: custom baffled exhaust:

http://www.youtube.com/watch?v=YkYBhAQJRDw

Yet to come: a 17T front sprocket, some real sticky tires, rear fender elliminator, front fork emulators, some taller & wider bars and an airbox removal

Originally Posted by Tripped1

With that displacement you are going to hit a wall around 90hp air-cooled, just by the nature of the motor. Likewise the 270* crank timing doesn't help, it definitely smooths the motor, but there is a lot of wasted torque because by nature you simply aren't "hitting" the crank at as close to 90* as possible and that wastes a lot of torque that could otherwise be put into power.

The Bonneville, T100 & Thruxton all have the same 865cc, 180* crank engine. The Speedmaster, America and Scrambler all have 270* cranks.

As for your "hitting" the crank at as close to 90* comment.. well, you seem confused about what '270* crank' means... or I'm completely missing your intended meaning.