Header and Torque

[Steve Northrop]

I'll go with Rob Muzzy on this one. The plates will stay air tight until the 
back pressure and heat from the exhaust blow the gaskets out. Leaving the 
reed valves in will prevent this. I'm happier with my result.

Steve in Western NY
'96 GPZ1100
'08 KLR 650
'08 Tuono Factory
"You Can't Fix Stupid", Ron White

----- Original Message ----- 
From: "John Soliday" <johnsoliday at msn.com>
To: "'GPZ List'" <gpzlist at micapeak.com>
Sent: Tuesday, June 08, 2010 7:27 PM
Subject: RE: Header and Torque


>I guess it really doesn't make much difference if the block off plates are
> air tight.  I figured since the instruction said to remove them I would, 
> as
> the whole exercise was to remove all the smog/exhaust weight and I'm happy
> with the result.
>
> -----Original Message-----
> From: gpzlist-bounces at micapeak.com [mailto:gpzlist-bounces at micapeak.com] 
> On
> Behalf Of Steve Northrop
> Sent: Tuesday, June 08, 2010 3:13 PM
> To: GPZ List
> Subject: Re: Header and Torque
>
> The instructions with my Muzzy plates said to leave them in.
>
> Steve in Western NY
> '96 GPZ1100
> '08 KLR 650
> '08 Tuono Factory
> "You Can't Fix Stupid", Ron White
>
> ----- Original Message ----- 
> From: "John Soliday" <johnsoliday at msn.com>
> To: "'GPZ List'" <gpzlist at micapeak.com>
> Sent: Tuesday, June 08, 2010 1:09 PM
> Subject: RE: Header and Torque
>
>
>> Actually my instructions said to remove the reed valves.  I checked on 
>> the
>> ZX11 list and people said water vapor condenses inside if you leave the
>> valves in as I guess a bit of hot exhaust weeps past the closed valve and
>> then water condenses on top of the valve but under the block off plate.
>>
>> -----Original Message-----
>> From: gpzlist-bounces at micapeak.com [mailto:gpzlist-bounces at micapeak.com]
>> On
>> Behalf Of Steve Northrop
>> Sent: Saturday, May 29, 2010 8:14 AM
>> To: GPZ List
>> Subject: Re: Header and Torque
>>
>>>>I can tell you there is pulses going through my bypass system, as you 
>>>>can
>>>>actually hear...
>>
>> That's why they tell you not to take out the reed valves..........
>>
>> Steve in Western NY
>> '96 GPZ1100
>> '08 KLR 650
>> '08 Tuono Factory
>> "You Can't Fix Stupid", Ron White
>>
>> ----- Original Message ----- 
>> From: "John Soliday" <johnsoliday at msn.com>
>> To: "'GPZ List'" <gpzlist at micapeak.com>
>> Sent: Friday, May 28, 2010 10:53 PM
>> Subject: RE: Header and Torque
>>
>>
>>>I took out the reed valves, otherwise I agree with your analysis.  So now
>>> the exhaust pulses from cylinders 1/2 and 3/4 can see the entire exhaust
>>> system, so you have a lower pressure that any one cylinder sees.  I can
>>> tell
>>> you there is pulses going through my bypass system, as you can actually
>>> hear
>>> it pretty clearly...sounds nice, louder than the header from my position
>>> on
>>> the bike!
>>>
>>> -----Original Message-----
>>> From: gpzlist-bounces at micapeak.com [mailto:gpzlist-bounces at micapeak.com]
>>> On
>>> Behalf Of Steve Northrop
>>> Sent: Friday, May 28, 2010 2:23 PM
>>> To: GPZ List
>>> Subject: Re: Header and Torque
>>>
>>> It's a passive system that does absolutely nothing performance wise
>>> whether
>>> (or how) it's blocked off or not. The reed valves under the plates act 
>>> as
>>> one-way valves so air can  be drawn into the exhaust system. The reed
>>> valves
>>>
>>> prevented exhaust reversion pulses from feeding back through the system
>>> and
>>> into the airbox. Better get your ass dyno recalibrated ;^)
>>>
>>> Steve in Western NY
>>> '96 GPZ1100
>>> '08 KLR 650
>>> '08 Tuono Factory
>>> "You Can't Fix Stupid", Ron White
>>> ----- Original Message ----- 
>>> From: "John Soliday" <johnsoliday at msn.com>
>>> To: "'GPZ List'" <gpzlist at micapeak.com>
>>> Sent: Friday, May 28, 2010 10:55 AM
>>> Subject: Header and Torque
>>>
>>>
>>>> So I've been riding the GPZ a lot since rejetting, air box mods and
>>>> adding
>>>> the Jardin header and thought I'd throw this out to the group.  I
>>>> noticed,
>>>> as would be expected that the low end grunt (torque) was reduced
>>>> somewhat
>>>> after these changes, but liked the sound, high end power, and much
>>>> reduced
>>>> weight.  Initially I put block off plates on the air injection ports 
>>>> but
>>>> then started thinking (that's always dangerous!).  I took off the block
>>>> off
>>>> plates and put the air injection hoses back on and connected the two
>>>> sides
>>>> together with a 1/2" piece of PVC to act as a crossover pipe like I 
>>>> have
>>>> on
>>>> my '73 Nova SS, except on the car it's after the header collectors.  It
>>>> "feels" like I gained back some or all of the low end power of the 
>>>> stock
>>>> pipe!  Maybe I'm imagining things but I'm thinking it's working in a
>>>> similar
>>>> way.  Thoughts???
>>>>
>>>>
>>>>
>>>> Happy Memorial Day, Remember our Veterans,
>>>>
>>>>
>>>>
>>>> John
>>>>
>>>
>>>
>>
>>
>
>