making a exhaust work !!

[bud firebolt]

hi,

i'm looking for some formula's for exhaust lenght ( 2 in 1 ) and optimal diameters for my mate's drag xb
for drag use ( 6000-7800 rpm power )

@ the moment the exhaust is not good enuf to reach the max ( hp ) out off the engine
the 60 feet time's are good ( 1.4- 1.5 )
but the topspeed is still staying behind, still under 200 km/h ( 124 mph )
we need to get it over 200 to get under the 10 seconds.

i have seen the nightrider formula's but i would like to see more off theme,
i did some reading about savaging and intake track lenght, but i would like to put it into real numbers so we can see where the restriktion is

thanks, bud

[Uncledaddy]

This may give you some direction.

http://www.rbracing-rsr.com/exhausttech.htm

[aswracing]

Bud ... I'm not willing to share my formulas and algorithms, but if you give me bore, stroke, and exhaust open event timing, I'll work up numbers for you.

[bud firebolt]

thanks, uncledaddy, good reading

thanks aaron,
the numbers bore 3-13/16 & stroke 3-13/16, Redshift 624's ( exhaust open 62 deg. , closeing 22 deg. duration 264/ 48 overlap )
we are running a little longer than usual intake lenght!

easy ( driver/owner ) & me are still learning about all the motordynamics involved for dragracing, but the feeling the used pipes are wrong ( to big ) to help the carb in the upper regions

gr, bud