Tune questions from Germany

[Scholle]

Hi to all of you,

I`m a german Rocket rider since 2005 and I registered in this Forum a couple of years ago. Since then I am reading here constantly with high pleasure. I`m especially interested in the TB discussion. I have the TB and my Rocket still has the stock cat box with the following mods: TOR pipes, K&N under tank, secondaries full open etc.

I`m planning to open the cat box, eliminating the cat and afterwards put back it to the bike. Hope to get better performance and lower fuel consumption.
Right now I`m looking for the best Tune. When studying this forum, there are a lot of different descriptions for various tunes that I don`t understand probably due to my restricted english konwledge. For example: no catalyst, cat box removed, with cat bypass, with empty cat converter, with cat converter removed, cat box removed etc.
Can somebody explain what the differences are?
And, if possible, what would be the best tune for my bike? Could it be tune # 20228? The fuel consumption should not increase significantly, due to extremely high fuel prices in Germany.
Many thanks in advance and sorry for my bad english.
Georg

 

[saboteur]

Scholle, someone will surely correct me if I'm wrong, but if you ride an '05, then the catbox is basically empty, without the converter. That's the way I remember it.
I can't help with the tune as I'm still running stock.

 

[Pig9r]

That is correct. In some locations the cat converter box was empty for the 05's. There is a mark on it which I believe is N for no catalysts and C for catalysts. If the description says cat box remove that would mean that the bypass has been installed. No catalysts means the cat box is there, it is just empty.

 

[Scholle]

Many thanks for your quick answers. My Rocket is a 2004 model. I guess, all over Western Europe, especially in the EU, Rockets do generally have a cat. I`ve learned, that for the US, except those for California, the cat box is empty. Today I opened my cat box and removed the cat. Now it is empty
Question: What is a cat eliminator, what does it mean?
Can anybody give a recommandation for the perfect tune?
Regards, Georg

 

[RatBoy]

The 'cat eliminator' was an aftermarket part that one could buy to replace the stock catalytic converter.

The purpose was to remove the restriction caused by a 'full catalytic converter'.

Since you have removed the insides of your stock converter, you have essentially made your own 'cat eliminator.'

As far as 'what's the best tune for your setup', I'm afraid that I'm not the right person to ask.

 

[dougl]

The cat bypass pipe should be less restrictive than the empty cat box. However, with stock intake, this might not be significant. Who knows?

 

[Power-Tripp]

Removing the cat from the stock cat box leaves a large volume that the exhaust pulses see as an end to the system. This creates a place for the pulses to reverse, and alters when the pulses return to the exhaust valve.

Removing the box, and replacing with a pipe, allows the engine to have a longer collector length that better matches the needs of the engine.

This is similar to 3-2 exhaust systems compared to 3-1 systems. The 3-1 has a longer collector length, and the R3 engine tends to perform better at all engine speeds and loads as a result.

Just removing the left side pipe from a Jardine system can add a couple of hp throughout the power-band, simply because of the better tuned length of the system. This occurs even though the primary lengths of the Jardines are not what the engine wants for best output.

Increase compression, improve cam/valve events, etc., and this becomes even more important.

Something to think about.

 

[Scholle]

I installed the 20228 Tune, O2 sensor deactivated, and the increase of performance is significant . Thanks to all of you for your kind postings.

 

[atomsplitter]

I installed the 20228 Tune, O2 sensor deactivated, and the increase of performance is significant . Thanks to all of you for your kind postings.

Tell us how your fuel consumption changed post modification. Better power can also increase the fuel consumption. (Trade-Off)

 

[dougl]

Removing the cat from the stock cat box leaves a large volume that the exhaust pulses see as an end to the system. This creates a place for the pulses to reverse, and alters when the pulses return to the exhaust valve.

Removing the box, and replacing with a pipe, allows the engine to have a longer collector length that better matches the needs of the engine.

This is similar to 3-2 exhaust systems compared to 3-1 systems. The 3-1 has a longer collector length, and the R3 engine tends to perform better at all engine speeds and loads as a result.

Just removing the left side pipe from a Jardine system can add a couple of hp throughout the power-band, simply because of the better tuned length of the system. This occurs even though the primary lengths of the Jardines are not what the engine wants for best output.

Increase compression, improve cam/valve events, etc., and this becomes even more important.

Something to think about.

So for the stock header and TOR mufflers, is there any point to the left side muffler?