Weber 48 IDA stack height vs HP@RPM

[John Fitzpatrick]

Primary pipe length formula #27165 - Mon Dec 15 2003 04:42 PM

This thread has some great information on the effect of various exhaust pipe parameters on performance, and the resonance effect. I'm wondering if anyone has studied the effect of varying velocity stack length on performance. I would assume that shorter stacks would resonate at a higher RPM, but is the difference worth obsessing over?
John

 

Hi John, That looks like an interesting post, i have searched and searched but can't locate it,just doesn't come up with it, could you please post a link to it.

Best Regards
GraemeS

 

Tested back to back on dyno std and shorter stack,basically the same in power but move the torque higher (370@4900 vs 370@5250),

 

[John Fitzpatrick]

[ QUOTE ]
Hi John, That looks like an interesting post, i have searched and searched but can't locate it,just doesn't come up with it, could you please post a link to it.

Best Regards
GraemeS

[/ QUOTE ]

Sorry, I can't get the link to show in the post. I'm doing something wrong... If you search on "pipe length formula" (with quotes) you'll see the thread. Go to the oldest entry, #27165 - Mon Dec 15 2003 04:42 PM, to start.
John

 

[John Fitzpatrick]

[ QUOTE ]
Tested back to back on dyno std and shorter stack,basically the same in power but move the torque higher (370@4900 vs 370@5250),

[/ QUOTE ]
That's really interesting--could you give a bit more info on your engine configuration and the lengths of the stacks you tested?
And anybody know what's up with the wierd tags in the quotation?
John

 

Hi John , Thanks for the help,very interesting articles, heres the link for those of you who would like to have a look. http://www.gt40s.com/ubbthreads/showflat...=true#Post27165

Regards
GraemeS

 

2.37/1.00
Engine specs:289
4.020 bore
2.87 stroke
11.0 CR
5.506 tit rod
C6FE GT 40 head,1.88/1.625 tit valves
Custom flat tappet cam 265/264 @0.50,107.0@105 intake centerline