Triumphrat

meatwagon · 11-26-2005, 12:20 AM

I had new pipes put on 1000 miles ago.I loved the performance increase and wondered how much horse power boost I got and if messing with the needles or shimming could help.Took it in for a dyno run today to see where things stood.05 Bonne Black stock airbox and filter(the original filter!) TJ Wassell Pipes 115 mains 42 pilots.....64.22 hp at rear wheel,47.65 pounds torque. Very linear power increase curve,no flat spots at all really.I will stay away from the carbs,maybe go with a K+n filter.

Cornelis · 11-26-2005, 04:38 AM

Healthy figures indeed! Have you also seen the Air/Fuel ratio across the rev range?

FattRat · 11-26-2005, 09:04 AM

'05 Black Bonnie' here too: 61.0 hp & 48.9 torque

D&D pipes
130 Main jets
42 Low speed jets
Two shims each side
Gutted air box, sans snorkel
K&N air filter

The weather was still a bit on the warm side when the run was taken. My air/fuel starts to dip toward "11" at 2000 rpm, bottoming out at 2700 rpm. It then rides between "13" & "13.8" from 3500 rpm to 5000 rpm, where it dips again to "12" from 5500 to 6800 rpm.

You can see a distinct fall-off in power at these rich spots, but at 6500 rpm the power starts to come on like gangbusters! The guy performing the Dyno run commented that if there was no rev' limiter, he wouldn't be surprised if it put out 80 hp at the rear wheel!!

With regard to the rich dips, he said that a guy could mess with the needles, but the dips may actually move themselves to another part on the power curve. BUT.... that was the advantage of a carbureted engine, a guy has more flexibility than with fuel injection.

I was advised by the gentleman who did the jetting to take one shim outa both sides in an attempt to lean it out a bit at the rich spots. I've chosen to ride instead......

For the gurus of the board, I then ask:
Have I gotten the correct impression that the Thruxton needles seem to be the hot set up? And if I were to install some Thruxton needles, what size would you advise????

[ This message was edited by: FattRat on 2005-11-26 07:07 ]

B02S4 · 11-26-2005, 09:22 AM

Quote:

On 2005-11-26 07:04, FattRat wrote:
...D&D pipes
130 Main jets
42 Low speed jets
Two shims each side
Gutted air box, sans snorkel
K&N air filter
...

Pat, is there a reason you kept the airbox instead of running pods?

billstokes · 11-26-2005, 09:23 AM

Pat - I've now got about 4500 miles on Thruxton needles. No official dyno runs, however, only the butt dyno. Midrange felt noticbly better. As far as I know, the Thruxton needles only come in one size. They cost about $7.00 each. My set up is: Unifilter (NARK coming soon), Norman Hyde pipes, snorkle out, AI removed, 42 primary jets, mixture screws one turn out, 18T front sprocket. Main jets are stock (110). The Thruxton needles are both thinner and more tapered than the stock Bonnie needles, I am may be a touch rich at top end. Since I plan too install a NARK over the winter, I expect I'll need to increase main jet size. If I were not going to do this, then I'd probably go one jet size smaller than stcok. Altitude is 1500 to 2000 feet.

Bill

meatwagon · 11-26-2005, 01:31 PM

Cornelis ,for some reason the counter guy said he could not give me the fuel air ratio printout for a roll on type test..don't know why..he did say that at idle I was rather lean.I went back to my dealer and showed him the results..he adjusted the mixture screws and said he tests with a CO method,not the way the dyno folks do.
A while ago I read an interesting post on the NTBF delphi forum about the design and tuning of the stock airbox...it helps make up for midrange dip,etc .Wish I could find that again..I think the Triumph engineers were spot on ;maybe thier design does not make max hp but it is tuned well across the range.There is a VERY slight dip at 4600rpm,not enough to do any thing about.Power peaks at 3400 ,dips about 2 lbs at 4600 then right back up and flat across to rev limit.I think power would keep right on climbing if not for the limiter.
Keep in mind Jenks' chart showing which carb parts affect each section of the rev range..Pat you may be able to come DOWN on your mains to get a little top end hp..IF you feel like doing anything at all,those are good numbers!I also considered the Thrux needles but wanted to see how things stood before doing anything.
I will also add that these are just numbers;I loved my bike before the new pipes;loved the boost before I had the dyno run and we are not talking about Speed triple figures here,just a nice Bonneville. :-D
If you "tuners" are curious,why not throw down a few bucks for a test?

ChuckofTahoe · 11-26-2005, 10:27 PM

Here is mine. I think the jets and shims are noted on the chart. These tests were done at elevation 4500 feet. The steady and constant slope of the torque and power curves are very appealing and make the Bonneville very predictable and progressive in nature.

FattRat · 11-26-2005, 11:44 PM

B02S4,

Wish I could pretend to be knowledgeable 'bout this stuff, I'm no mechanic though.... I bought the bike from a buddy
who owns an automotive repair business, and has jetted a few Harleys in his day. He set it up.

Steve didn't own my BonnieBlack for any longer than a month and a half, putting no more than 800 miles on it.
He did all the mechanical mod's including his choice to gut the air box and stick in a giant K&N.

I accept that it's not like the 110 hp Sprint RS I courted trouble on, nor does the Bonnie' have the pull my 80 hp
BMW had. I would however like to find out from the biggest, baddest, most knowledgeable Bonneville Guru
around, what the best intake & exhaust for my standard 790cc "Black" is.

I was given the impression that a two-into-one exhaust was the best way to go.... back in the day. But since cross-over
pipes are commonly used on two-into-two configurations nowadays, maybe that's not the case (???). I wrote, via a
link provided here, some outfit in Germany about their fancy two-into-one exhaust. It's huge, but the claims seem to be
extraordinary...... unfortunately they sent me a Dyno run of Thunderbird, and a picture of a Bonneville with the can.....
I still don't know how my 790cc would respond to it. And I do in fact wonder if individual pods are better than a box,
or if the factory designed ("constrictive") system may in fact be better (albeit for best mid-range). I like to wind my
engines out, but I can appreciate the better "drivability" of an engine with respectable/STRONG mid-range.

My current set-up is cool, but it's lacking...... and sometimes when I blip the throttle before a spirited downshift,
I happen onto it's rich flat spot.... and it doesn't rev' for me; frustrating when you wanna get the rev's up
before clicking down a gear.

So..... 'Guru' out there, somewhere.
I'm all ears, but I'm know'n that I can't make a Speed Triple outa my BonnieBlack.....!

[ This message was edited by: FattRat on 2005-11-26 21:46 ]

meatwagon · 11-27-2005, 12:10 AM

Chuck wow wotta gain you got there.Says alot for the British Customs products and Freedom Cycle's tuning.I hope I'm not outta line for saying this but..I'd like to ride your bike! :-D :-D

ChuckofTahoe · 11-27-2005, 12:43 AM

20% gain. I think the good products such as the D&D packages, Bub, Mototwin etc. are in this ballpark as well. When I was shopping for pipes I spoke for some time with Brad Yuil who owns the Triumph franchise here in Reno. He is just a super guy, a great race tuner and and I completely respect him haveing gotten to know him and his operation.

They had basically put on and tuned the most popular American exhaust systems that are made for Triumphs: Bub, D&D, BC (though I think the British Customs guys actually get their exhausts made in Britain) plus all the factory stuff. So Brad tells me that of everything they have put on, the British Customs stuff produces the biggest increases and nicest power bands.

I asked him about Staintunes, Thunderbike and Togas and they were just were not familiar with these products. At least from a hands on point of view. I really like the look of the Staintunes but I decided to go with what these guys know best. I am pretty happy with the bike right now.

Quote:

On 2005-11-26 22:10, meatwagon wrote:
Chuck wow wotta gain you got there.Says alot for the British Customs products and Freedom Cycle's tuning.I hope I'm not outta line for saying this but..I'd like to ride your bike! :-D :-D