[crosstie]

<deactivates lurking device>

Back when I did this to my bike, a few people were curious how much power difference it made from my previous set up. Short answer, not much :???:

I was running:
40 pilots
120 mains
Factory Pro needles (4th clip I think)
Airbox w/ 5x 1.5" holes
TORs

Dyno said 74.1 RWHP - a nice jump from stock

Now running:
same pilots & needles
130 mains
pod filters (no airbox)
custom 3-1 pipe

Dyno says: 74.87 RWHP - gaining a whopping .76 over the previous set up. Sigh.

However, I am no longer too rich at low throttle, and I have a significant lean spot between 4-5k rpm... which I *think* means the needles need to come up a notch - more gas earlier.

On the upside, the pod filters do just fine in pouring rain... as I found out on the ride home
:razz:

I still have some s3 cams to drop in as well. I'll let you all know when the next dyno run comes around...

[ This message was edited by: crosstie on 2007-03-12 12:48 ]

 

[Spooner]

Don't you think you're overdoing the pilot size a little? :-D

My experence is the same...on my last dyno I got 78 hp rear wheel
and 80 NM of torque. I was still rich though so I can probably get slightly
better figures now that I've leaned her out :hihi:

Edit: In the words of my dyno guru "These CV vaccum carbs respond poorly to "unrestricted" airflow". Sure, you might get half an extra pony but the hassle of getting
it exactly right won't be worth it. He did however continue to say that "Give me 6000 bucks and I'll whip some 130 hp out this little baby."
Ofcourse my eyes and heart went "BLING" :idea: at this...but my wallet instantly jumped up and told me off.

[ This message was edited by: Spooner on 2007-02-09 01:35 ]

 

[jimmyj900]

Put it in perspective guys.

Mutato produced 60 RWHP stock. Mutato after mods produces 72 RWHP.

((72-60)/60) x 100 = 20%

I find a 20% increase in peak horsepower is quite satisfactory... at this point. :-D

Jim

 

[Rhinoe]

Thanks for the update Crosstie. Tuning info is always appreciated.

Did you get any torque numbers?

btw - What size are your pilots - really?

 

[TBSstunta]

Did you notice an increase, decrease, or relocation of the flat spot with the bigger mains? Did you put the pods on and run with the smaller mains before rejetting? How did that feel?

[ This message was edited by: TBSstunta on 2007-02-10 09:04 ]

 

[crosstie]

Don't you think you're overdoing the pilot size a little? :-D

No way! Those huge pilot jets are the secret to my power! :razz:

OK, how about 40 pilots, up from the stock 38s... I blame cut-&-paste for the error.

Jim, you're absolutely right - as are all the people who keep pointing out the bike has more than enough power already. :wink: It was more just surprise that there was so little difference between a drilled airbox and 120s, and pod filters w/ 130s. It just goes to show I guess that there's only so much extra hp to be coaxed from jetting and airbox mods.

On 2007-02-10 08:26, TBSstunta wrote:
Did you notice an increase, decrease, or relocation of the flat spot with the bigger mains? Did you put the pods on and run with the smaller mains before rejetting? How did that feel?

The flat spot got bigger (leaner) - from about 15 to about 16.5... and it moved lower on the powerband - it now peaks at 4600rpm instead of 5500. Remember though that I also added pod filters and a new exhaust to the equation.

The air/fuel ratio is pretty even everywhere else, right at 13.5, though it climbs back to 15 at wide-open throttle. I could maybe use 132s or something, but I'm not sure it's worth the hassle.

I hope to eliminate (or at least reduce) the flat spot by raising the needles one notch - hopefully that won't make me too rich at 6000rpm.

So I've been reading up on the green cam swap, and I'm feeling a bit intimidated. It looks like there may be some valve adjustment involved, and a gasket or two to replace. As far as adjusting the valves, it looks like I might need new shims... where does one find such a thing? Anybody? Are they universal, or bike-specific? Where do people go for gaskets these days?

I'm afraid of getting the engine apart and then having to wait 6 weeks while the dealer tracks down the bits I need...

 

[denny]

Honda bikes
The models are: 1979 thru 1983 CB 750 K,F&C
CB 900 F&C
CB 1000 C
CB 1100 F
CB 750 SC

Yamaha V4 models - Vmax and Royal Star with the V4

Some Suzuki's and Kawasaki's also use the same shims.

Even some Honda automobiles use them.

they are 25mm diameter valve shims.

There is a Kawasaki/Suzuki dealer near me and I always go to the service department to get them. The parts guys are pretty brain dead if you can't give them a specific bike model number, etc.



[ This message was edited by: denny on 2007-02-10 15:50 ]

 

[BadMouth]

Dropped mine off to be dyno'd this morning.
:-D

I just did a 955 cam install with no prior experience (and a lot of research). It probably took me 10 times as long as it would have a mechanic, but I got it done and learned a lot.

If you are due for a valve clearance check and have to swap out shims yourself without the special triumph tool, you'll actually have the cams out anyway, so you might as well use the opportunity to install the ones you want. That was my justification.

This Article came in handy as well as the threads in this forum.

I'm sure that I paid too much for them, but I ordered Triumph shims from bike-bandit. They had the oddball sizes that I needed to get towards the middle of spec. The dealer didn't. They also have the gaskets if you don't have (or like) a local dealer. AMA members get a little bit of a discount.

The cam cover gasket is pretty thick rubber and can be reused. You will need a crankshaft cover gasket, a timing chain tensioner gasket though. I found it easier to work on with the coolant outlet unhooked, so you might want to get a gasket for that also.

 

[jimmyj900]

It was more just surprise that there was so little difference between a drilled airbox and 120s, and pod filters w/ 130s. It just goes to show I guess that there's only so much extra hp to be coaxed from jetting and airbox mods.

Yep! :-D

The problem is that peak horsepower is calculated at high rpm, so opening up the airbox has the potential for high horsepower but the reality is that you run afoul of the airflow restrictions in the exhaust system.

Jim

 

[crosstie]

The problem is that peak horsepower is calculated at high rpm, so opening up the airbox has the potential for high horsepower but the reality is that you run afoul of the airflow restrictions in the exhaust system.

So what you're saying is, if I just removed the exhaust altogether... :-D

Denny, BadMouth, thanks for the info! Very helpful. BM, did you re-use the spark plug tower seals as well?

Rhinoe, I did get torque #s this time, but I didn't the first time so I have no baseline comparison. It was pretty well flat: It jumped between 45-50 ft-lbs up to 4800K, and then it's at 52 ft-lbs the rest of the way out. I don't know what stock is offhand, but since hp is just torque x rpm, I expect it's up by the same %.

Cheers all.

 

[BadMouth]

On 2007-02-11 13:45, crosstie wrote:

BM, did you re-use the spark plug tower seals as well?

Yes, they are actually part of the cam cover gasket. They are all linked together by narrow strips of the same material.
It made it kind of hard to keep all the parts of the gasket in place when reinstalling the cover. It helps to "glue" the gasket into place with RTV before installing the cover.

The problem is that peak horsepower is calculated at high rpm, so opening up the airbox has the potential for high horsepower but the reality is that you run afoul of the airflow restrictions in the exhaust system.

I pretty much copied what Saigon5 has, only I have a D&D 3>3 versus his Thunderbike 3>1. He dyno'd 92hp with a nice torque curve. : :bow: : Saigon5 Dyno Thread

I'm anxious to see what difference the 3>3 makes. I'm hoping that it doesn't cost me my low end torque.
When I told the guy at the dyno shop that I was shooting for 90hp without sacrificing rideability, he looked at me like "yeah right". I told them I wasn't in a hurry, so it may be a couple weeks before I find out anything.


Saigon5 also used a Trophy airbox versus my stock airbox with the back hacked out, but I believe that either (or pods) would be capable of flowing the maximum amount of air demanded by the engine.

 

[crosstie]

Cool cool. Thanks again for the info and the links. Good luck w/ the 3->3...