This sounds somewhat like an afterburner in a jet engine. On a jet engine, additional fuel is intentionally introduced AFTER the combustion chamber to produce extra thrust out of the exhaust. I know, on a bike it's just more air to burn fuel residue, but nevertheless, there's more burning involved which means more combustion. As far as I can tell, whenever there is combustion, there is a pressure change in the system. Now, we all know a bike's performance is related to the amount of flow in the exhaust system. Hence, getting rid of the muffler increases performance. It also increases loudness, but that's just a byproduct.

I am not trying to be disagreeable here, but I have a difficult time believing that a "combustion" in the exhaust system has "zero affect" on performance. It is a thermodynamic fact in analyzing engine performances that temperatures and pressures at exhausts affect engine performance. More burning simply means more temperature. More combustion means pressure change. To my amazement, a guy actually wrapped his headers (i.e. exhaust system) http://www.rogueracing.org/satoexhaust.htm to improve performance on his CBR. From an engineering perspective, that wrapping business is a technically sound approach to affecting engine performance. Notice, the guy had to perform custom mapping.

Sure, the effects of Pair Mod may not be noticeable in some situations, but in combination with other mods, that effect may become more pronounce.

 

Your trying to over think things , and me trying to explain things to you is apparently waising my time.

Next.

 

If you read the begining of the 4th paragraph under "dyno runs" @ Hooligan bike tech you will see that the first thing they did after running the bike bone stock was clamp off the pair valve. He states that "the bike gained 1.3 hp and 1ft lb of tq" Maby because it's robbing air from the engine, maby because combustion in the exaust port. I don't know why, but is was proven on a dyno.http://hooliganbiketech.dynup.net/ho...frameindex.htm

 

1 hp on a dyno is the difference in a few degrees in tire temp
as tires get hotter they gain psi
higher psi on a rear tire will cause a hp increase to be read

 

bornluckee13:

I checked out the URL you provided about the "Dyno Runs". This is amazing because MgA_ODEN and others on this thread seem to think that you had to disconnect the Pair in order to properly do a dyno run. Never having done a dyno run myself, I just took their word for it. I guess they didn't have the whole story afterall.

In any case, thanks for the link. It clears up a lot of smoke. The results make a lot of sense. If anything, I figured the removal of the Pair system would increase performance. I mean, how can you argue with actual test runs. Although, I would guess some may still have few words to add.

 

you do not have to disconnect the Pair to do a run

you do have to disconnect the pair to get an accurrate air fuel reading

 

Read , try to comprehend , then comment.

Or do yourself a favor and say nothing.

 

Oooo..you're angry!!

What MgA_ODEN said is rite.. A P.A.I.R valve removal or clamping off will not add any hp BUT WILL HELP TO GIVE AN ACCURATE AIR/FUEL RATIO READING which is very essential to a very good custom map!! A PAIR valve work by supplying air(oxygen) to the exhaust port thus turning harmful CO into CO2. In layman terms turning harmful emission into harmless emission.

Pls don't put others down when you know nuts..Read up, ask around and understand the physics before posting. [8D]

 

I don't get angry at people on forums [&:]

I was just stating fact.

 

In my original comment, I said nothing about airflow reading. I was interested in a dyno performance run between 100% stock verses 100% stock minus Flapper. Since I didn't know what was required in a DYNO RUN, I took what MgA_ODEN and others said about clamping off the PAIR.

Regardless, I was still interested in seeing the DIFFERENCE BETWEEN 100% STOCK AND 100% STOCK MINUS FLAPPER.

This is my only point. I don't care about airflow readings.

If you think it is not possible to do a dyno run WITHOUT clamping off the PAIR, just say so.

In that case, what is this about:

Apparently, somebody out there did "Dyno Runs" that compared 100% stock verses 100% stock minus Flapper. THIS IS ALL I AM INTERESTED IN.