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Discussion Starter #1
I saw someone post about removing the secondary butterfly valves on the 04-05 zx10r...what exactly is this??? How is it done??? Advantages and disadvantages???
Anything else I need to know to do it...

Thanks
 

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Unless they were doing some sort of turbo set up I can see no advantages at all. The electronic secondaries are used to try and boost mid range torque by altering the airflow coming into the motor.
 

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sneaky said:
Unless they were doing some sort of turbo set up I can see no advantages at all. The electronic secondaries are used to try and boost mid range torque by altering the airflow coming into the motor.
Yup, it tries to keep you with the maximum volumetric efficiency possable. The point where VE max's out, is the point in your powerband where the max torque occurs. The butterflys try and change the airflow streamlines to create either presure drops, velocity change, or streamline geometry to keep the VE high during the midrange. This can get extremely complicated so I will trust that the engineers at Kawi did thier homework and found the best possable combination for our bikes.

On a side note, the VE changes when you modify intake (air filter, stacks etc) or exhaust. If you remove your butterfly's you may alter the VE for that given range that Kawi has setup for you and calculated thier stock maps in the computer for a certain VE at that point.
 

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The secondary throttle valves have bugger all to do with "constant inlet velocity"

They are plain and simple inlet noise mufflers.

They are the best way to get a bike with huge throtttle bodies, huge air bix and huge ram air tubes past a noise emmisions test.

The stepper motor does not open the valves as fast as the engine "can" rev.

If you remove them you gain mid range power.

You will need a PC and a custom map or it will be CRAP

:eek:ccasion1
 

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We over here in the US do not have to worry about inlet noise as much as the british and european markets do.

You may be able to remove them, that part will be easy but how are you going to bypass the ECM functions that are going to trip the FI light once you do pull them off of the TB's?

Until I see someone reputable do a before and after dyno run with the normal A/F and DB readings then with some custom mapping then I am going to continue to think that the Kawasaki engineers know what the heck they are doing.

I am not in the hunt for all out top end hp, the best part of having the 10 is the awesome mid range punch it has, the take the secondary TB out and lose that would prob sacrafice some low to mid range TQ and take some of the fun of this bike away from it.
 

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This is exactly the same setup as in the GSXR's.

You can fool the TPS to thinking the valves are still there... or you can just unscrew the valves and remove them.

If you leave the rod etc alone then the ECU doesn't know the plates are gone.

I have entirely removed them (rod and all) in my GSXR and once you get the fueling right again you don't need a dyno to tell you it's quicker.

I really couldn't be bothered chasing up before and after dyno runs and crap to post on the net but the gains are quite good.

The biggest fueling problem on te GSXR is acually about 3500 - 4000 rpm when you remove the 2nd throttle valves. The custom map fixes it.

You get more power - EVERYWHERE

This is not a one off. It also applies to the 04-05 Yamaha R1 as well.

The R1 likes them removed even more than the Gixxer.

As I said, they are mufflers.

Kawasaki, Suzuki, Yamaha engineers know best ? Well they have to pass noise and emmissions test, I don't.

Why do you think Yoshimura sell kits to remove them and/or lock them open ?

:thefinger
 

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Discussion Starter #7
zx10r butterfly removal??

Anyone done this on the zx10r???
I am going to do the mod just need instructions on what I need to remove and if I need to wire anything in or out to keep the FI light off...

LMK
THanks
 

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Have to admit I'm curious myself. Besides, I like mods that work and I don't have to buy anything!
 

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Ok...one of the guys who comes to this forum once in a while had the secondary throttle bodies removed, buttons machined and put in the holes, and a custom map made with a PC III with a full exhaust system...

The results...he has 164 HP and I have 157 HP...I have a slip on and not tampered with the secondary T B. His bike can't idle until it gets warm..he has to fiddle with the idle adusting screw until then...

Yes, you can remove them...yes you can get more power...yes, it is a hassle...it is up to you...
 

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If he has a full system and you only have a slip on can. That in itself would account for his extra power. Now had it been the other way around it would have been impressive.
 

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I had 162 rwhp custom mapped with a slip on. The bike was sold to "Hired Jockey". He put a full system on it and custom mapped the bike. The bike "may" have had a small amount more top end but I think it was more due to it being slammed (areodynamics) than the throttle bodies. The bike suffered compared to other 10's down low. It had a bad dip around 4k-5k rpm that HJ got mostly tuned out but it still didn't launch as hard as other 10's. HJ would run them down on the big end, but he is light and a good rider. As OG said above you lose your fast idle control. I had a solution to that. Not too big a deal. but I choose to keep my secondarys in on my 2nd 10. If you live at WOT and are looking for every last tiny bit, go for it. otherwise i frmly believe you'll slow the bike down and affect ridability overall.

...just from one coonass' experience...
 
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