Triumph Rat Motorcycle Forums banner

1 - 20 of 26 Posts

·
Registered
Joined
·
1,185 Posts
Discussion Starter #1
Edited per popular demand and technical correction...

I just put the K&N in my Sprint and was a bit disappointed in the fit. The groove that fits to the lower airbox is a little wider than that on the OEM filter. However all seemed to fit fine once I realized that I had not transplanted the OEM o-ring to the K&N. Note to self: Read the instructions!


I also noticed that the OEM filter was dirty only in a small central oval. The picture below shows the filter after running a partially shortened snorkel for a while. The dirty area was originally smaller.


On closer observation it seems that the intake snorkel protrudes into the airbox nearly up to the filter surface. There isn't much room for the airflow to fan out to the perimeter of the filter. I would think this makes the OEM setup a bit restrictive.


I mail ordered another snorkel just to have a stock piece and proceeded to cut my original piece just inboard of the airbox.


My next observation was that the resonator protruded far enough into the snorkel to choke off a good portion of the right hand cross section. I trimmed the nose of the resonator such that it fits flush with the inside of the snorkel. Of course this raises the frequency of the resonator since the airmass in the tube resonates with the enclosure volume.
This was after trimming the resonator snout. The snorkel was nearly closed off in this area by protrusion of the resonator.


So...
Steady state airflow should be improved. The resonator (and snorkel) are tuned to higher frequencies. Intake cross section should be increased. I am running a TOR pipe and the 20107 tune. My head pipe has the US spec precat which is fine as I have no heat complaints now with the TOR.

Bonus photo in case the thread still loads too fast.
T595.net has a link in the Performance Tips forum titled secondary air injection. There is a link to photos of CNC'd SAI plates.
He wants $100 shipped for them, probably 3x a reasonable price.
They aren't needed as SAI hardware can be disabled with rubber caps.
I bought them anyway.


Now of course the standard disclaimer.
Mess with your bike at your own risk.
If *you* mess up *your* bike, warranty etc... Remember it was *your* doing. I will not accept *your* responsibility, feel bad or even particularly care.

Sorry about that.

[ This message was edited by: CLB on 2006-11-19 12:11 ]
 

·
Registered
Joined
·
259 Posts
I am running a TOR pipe and the 20107 tune. My head pipe still has the US spec precat and I would prefer to keep it as the heat issue is solved.
CLB:

How does the bike run on that tune? Did you install it from the Tune-Boy? I just added the TOR can and have not yet had the Triumph Off-Road map uploaded. I'm trying to decide whether to buy the Tune-Boy or have the dealer just add the standard TOR map.
 

·
Registered
Joined
·
1,185 Posts
Discussion Starter #6
The bike felt about the same with TOR and original tune to me.

The tune seemed to make more difference than the TOR. That difference is mostly felt at low throttle settings. The bike felt like it hunted and surged a bit through town at low speeds with everything set to original.

Some time back I imported 20104 (original) and 20107 into Excel and did a matrix subtraction to see the differences. From memory:
The low throttle (>6%) map was richened 5~10%.
A small area in the midrange was actually leaned 5% or less. At the time I figured this would not affect mileage as the throttle settings were a bit above steady state cruise.
The very high end was richened 2~3%
Timing was bumped a couple degrees but I don't remember how much or where.

I posted the results at the time so I am fairly sure it is still on the board. Take a look. there should be more and better information there.

Bottom line is that I felt the TOR had more to do with sound than power.
I felt the 20107 tune had more to do with low throttle manners than power.
And of course the disclaimer that I wouldn't be able to tell 123hp from 130 without a dyno anyway. The bike has spent precious few seconds in the upper quarter of the tack so far.
 

·
Registered
Joined
·
1,185 Posts
Discussion Starter #7
Original post corrected...

[ This message was edited by: CLB on 2006-11-18 14:27 ]
 

·
Registered
Joined
·
259 Posts
On 2006-11-17 23:20, CLB wrote:
Edited per popular demand and technical correction...

THere is a link to photos of CNC'd SAI plates.
They aren't needed because 20107 shuts off SAI with software.
CLB:
I had the 20107 loaded today also running TOR pipe. I rode the bike home from the shop, SAI gear still in place, with it doing it's usual burbling and popping.

As soon as I got back, I added block off plates to all the SAI valves, and took the bike for a ride. Noise on decel was completely gone, vanished, not there. Bike ran fine, but no more noise.

The tech at the shop told me the SAI is "normally open" with power controlling the closed function, no the open function. I doubted him, but I now think he was correct.

So, while the 20107 does "turn off" the SAI, air obviously continues to flow freely through the SAI in this state.

Bottom line: block off plates, caps, whatever are required to stop the air flow through the SAI system. Simply loading the 20107 does not appear to do it, and in fact probably increases the air flow as there is no longer a power on state to interrupt the flow.

Thoughts?.
 

·
Registered
Joined
·
1,185 Posts
Discussion Starter #9
On 2006-11-19 00:06, Yimm wrote:


CLB:
I had the 20107 loaded today also running TOR pipe. I rode the bike home from the shop, SAI gear still in place, with it doing it's usual burbling and popping.

As soon as I got back, I added block off plates to all the SAI valves, and took the bike for a ride. Noise on decel was completely gone, vanished, not there. Bike ran fine, but no more noise.

The tech at the shop told me the SAI is "normally open" with power controlling the closed function, no the open function. I doubted him, but I now think he was correct.

So, while the 20107 does "turn off" the SAI, air obviously continues to flow freely through the SAI in this state.

Bottom line: block off plates, caps, whatever are required to stop the air flow through the SAI system. Simply loading the 20107 does not appear to do it, and in fact probably increases the air flow as there is no longer a power on state to interrupt the flow.

Thoughts?.
This was easy to check as my SAI hardware has been relocated for easy access.

The valve is normally open. It snaps shut with application of power and promptly springs open when power is removed.
The coil draws 0.61 amp at 13.2 Vdc.

I could reach the SAI connector on the bike so I plugged the valve back in with a DVM connected to the valve leads.
With the 20107 tune the bike does not applt power to the valve.

Your dealer is correct.
Now off to correct thet part of my post above.
 

·
Registered
Joined
·
18 Posts
Do these alterations that you've made change the sound of the air intake? Mine sounds like it's sucking air througha straw, I've been meaing to get in there and do similar alterations after I get the 20107 tune installed.
 

·
Registered
Joined
·
259 Posts
CLB:

Coupla questions about the airbox mods. Will shortening the snorkel protrusion into the airbox have any effect on the resonant frequency of the box?

And, why not remove the resonator altogether? I think it's fair to assume the snorkel can deliver way more air than the engine could ever use, and all the resonator does is reduce induction noise.

I think the correct resonant frequency for air delivery is controlled in the airbox (volume, shape, bellmouth configs) and that under typical circumstances the snork and resonator have virtually no effect on this.

What do you think?
 

·
Registered
Joined
·
1,185 Posts
Discussion Starter #12
On 2006-11-23 10:22, Yimm wrote:
CLB:

Coupla questions about the airbox mods. Will shortening the snorkel protrusion into the airbox have any effect on the resonant frequency of the box?
Resonant frequency had to increase somewhat.

f=(.5*c/pi)*(S/(L*V))^.5

c is speed of sound (1120 ft/s), so the first term is just a constant.
S is snorkel area. ft^2
L is snorkel length. ft
V is airbox volume. ft^3


This mod trades some snorkel length for airbox volume. The snorkel looses a greater percentage of its length than the airbox gains in volume, so resonant frequency increases a bit.

And, why not remove the resonator altogether? I think it's fair to assume the snorkel can deliver way more air than the engine could ever use, and all the resonator does is reduce induction noise.
It was the best fitting plug I had. My only concern was that the resonator snout closed off a good percentage of the snorkel area. I should have taken a before picture.

I think the correct resonant frequency for air delivery is controlled in the airbox (volume, shape, bellmouth configs) and that under typical circumstances the snork and resonator have virtually no effect on this.

What do you think?
The snorkel has a large effect. The inertial mass of air in the snorkel is resonating with the "airspring" of the box.
The resonator probably has minimal effect. It resonates out of phase with the airbox at the same frequency. It provided the pulsating flow so that the noisy snorkel mouth does not have to. It probably lowers the Q of the resonance a little.

I don't know that this is really worth doing but it provided some amusement. If I was confident that things were improved I probably wouldn't have a stock snorkel sitting on my shelf. You might see some very small gain if combined with a dyno tune. If anyone plans on that, post your before & after plots.

I don't know what effect this has had on intake noise either. It's been raining hard and my other vehicle has this marvelous thing called a roof. You can't hear much above the primary gear whine at idle.



[ This message was edited by: CLB on 2006-11-23 19:32 ]
 

·
Registered
Joined
·
658 Posts
The tech at the shop told me the SAI is "normally open" with power controlling the closed function, no the open function. I doubted him, but I now think he was correct.

So, while the 20107 does "turn off" the SAI, air obviously continues to flow freely through the SAI in this state.

Bottom line: block off plates, caps, whatever are required to stop the air flow through the SAI system. Simply loading the 20107 does not appear to do it, and in fact probably increases the air flow as there is no longer a power on state to interrupt the flow.

Thoughts?.
Just a note on the above (which is correct).

If you run the TOR can and you have not get rid of the SAI hardware or blocked the SAI tubes, the correct tune to run is 20106, not 20107. The 20106 tune will behave exactly as the stock tune with regards to the SAI valve (i.e it will restore power to the SAI valve and open it only on idle and closed throttle running), but in every other respect is similar to the 20107.
 

·
Registered
Joined
·
259 Posts
On 2006-11-24 00:00, NikosR wrote:

Just a note on the above (which is correct).

If you run the TOR can and you have not get rid of the SAI hardware or blocked the SAI tubes, the correct tune to run is 20106, not 20107. The 20106 tune will behave exactly as the stock tune with regards to the SAI valve (i.e it will restore power to the SAI valve and open it only on idle and closed throttle running), but in every other respect is similar to the 20107.
SAI is a good thing under normal circumstances. But in my case minimizing the heat is important. The SAI's effect on prolonging exhaust gas combustion into the header creates lots of unnecessary heat. That was the reason for my decision to remove it.
 

·
Registered
Joined
·
45 Posts
This post started me thinking again. I did this mod on my Ducati 907ie some 12yrs ago before the intro to cold air boxes. Looked at cutting down the inlet tube but this reduces the RAM tube effect. All I did was give the air box more efficiency by adding 2off 60mm tubes. I cut down the resonator as well.
The idle actually picked up so to me a better flow had already started. When riding no real difference until after 60km/h. Roll on throttle response was a little different and the computer litre per km had gained.
 

·
Registered
Joined
·
1,499 Posts
The snorkel hits the filter for a reason. It's so it creates a vacuum effect when the throttle bodies are open. You are now loosing bhp and fuel mileage.

If you were such a good engineer, how come you don't work for Triumph?
 

·
Registered
Joined
·
1,185 Posts
Discussion Starter #17
On 2006-12-02 15:22, triumphite wrote:
The snorkel hits the filter for a reason. It's so it creates a vacuum effect when the throttle bodies are open. You are now loosing bhp and fuel mileage.
Thank you for your most helpful quantitative analysis. I agree with the first part of your statement.
Let me explain my goals. What I am after here is a "pressure" effect when the throttle bodies are open.

If you were such a good engineer, how come you don't work for Triumph?
I really don't see the relevance of this question to the matter at hand, but I am (present tense) in fact a good engineer. I don't work for Triumph for a number of reasons. One of the more significant reasons being that would rather play with toys than design them.
That is what I am doing here, playing with my toys. Don't like it? Leave the x-acto saw in your toolbox.
 

·
Registered
Joined
·
314 Posts
I just removed the K&N filter to clean it. I installed it at 6,000 miles, mileage now is 14,500. Same centered area with concentrations of dirt/debris as I saw on the OEM filter. I cut the snorkel, cleaned the filter and installed iridium spark plugs. I don't agree that I have lost power from this change for 2 reasons. By looking at the filter it is obvious that since all the dust/dirt/debris is concentrated to a small area, the filter looses flow, Also I don't think 2 inches less length changes the volume of air being introduced the air box, and the bike runs great. I will be tuning on the dyno soon and post results.
 

·
Registered
Joined
·
1,499 Posts
CLB,

Your touchy. :sad:

Dyno it, and give us the huge number increase!!!!

My stock Sprint dyno'd at 111.4 at the wheels.

Then, when you get the 30 bhp increase, I'll cut mine too!! :-D
 

·
Registered
Joined
·
259 Posts
'Tis better to have tried and failed than to make errant presumptions that Triumph's engineers had best airflow in mind when placing the snorkel outlet so close to the filter. Maybe it was just a batch of snorks left over from an over-run on another model. Or it was an effort to control noise, or a mis-manufactured batch of parts. God knows, they've made enough other mistakes. Who knows? These are secrets only the dyno knows for sure. So what do you say CLB, off to the dyno?
 
1 - 20 of 26 Posts
Top