valin
Active member
I am wondering if anyone has any thoughts or opinions as to why the power goes flat at 8000 rpm to about 8600 rpm. With these pipes (Bender 835 pipes), the power should peak at about 8500. For some reason, I have one hell of a dip. I watched the servo motor during one of the runs, and it seems to be staying open. We ran 40.5mm carbs / 38mm carbs, boost bottle / no boost bottle, airbox / no airbox, and this dip is consistant in all runs.
Sled specs:
780cc, lake race ported
case porting
11 to 11.5:1 CR
Bender Big Bore 835 pipes
38mm carbs
V-Force 2's
Stock ignition and timing
Also, for those interested, running the boost bottle builds 5 hp less on my motor.
Sled specs:
780cc, lake race ported
case porting
11 to 11.5:1 CR
Bender Big Bore 835 pipes
38mm carbs
V-Force 2's
Stock ignition and timing
Also, for those interested, running the boost bottle builds 5 hp less on my motor.
Attachments
Last edited:
maybe compression ,squish or squish angle valin....my own opinion......
bufalobob
Member
ryan:
if you recall when we were @ the dyno i said your pipes look different than mine. i went home & looked @ mine & they are not the same. i'm going to the shop soon & i will check another ser & let you know. take some measurements: header length, center section length, stinger length & diameter.
bob
if you recall when we were @ the dyno i said your pipes look different than mine. i went home & looked @ mine & they are not the same. i'm going to the shop soon & i will check another ser & let you know. take some measurements: header length, center section length, stinger length & diameter.
bob
valin
Active member
Will do, Bob.
valin
Active member
ARgh..........camera battery is dead. Give me a few to charge it 
I'll get pictures and measurements of the pipes up.
I'll get pictures and measurements of the pipes up.
valin
Active member
Ok. Here's some pictures and dimensions of the pipes.
Header to center section: 24" long
Center Section: 17" diameter, 7.5" long
Cone from Center section to stinger: 10.5"
Stinger outside diameter: 1.25" (the pipes are a real pain in the *** to get back into the stingers, so I did not take them apart).
Header to center section: 24" long
Center Section: 17" diameter, 7.5" long
Cone from Center section to stinger: 10.5"
Stinger outside diameter: 1.25" (the pipes are a real pain in the *** to get back into the stingers, so I did not take them apart).
Attachments
bufalobob
Member
ryan:
my pipes:
header to center - 21 1/4"
center section - 16 5/8", 8" long
cone from center to stinger - 11"
stinger outside diameter - 1.38"
header circumfirence - 6.5"
bob
my pipes:
header to center - 21 1/4"
center section - 16 5/8", 8" long
cone from center to stinger - 11"
stinger outside diameter - 1.38"
header circumfirence - 6.5"
bob
toydoc
Member
Your peak trq oscilates from 7800rpm, then drops, then peaks at 8800rpm. That can be your header pipe length are not the same on all the pipes. It also peaks hp and trq at the same time, thats hard to clutch. If the header are the same (and all pipes seat all the way in at the cyl). I'd try to add some header length and see what it does. IMO, Even if you get the dip out, you want to move your peak hp away from your peak trq rpm so you have more room to clutch.
valin
Active member
Toydoc, I don't have any issues clutching it, but that is certainly something to look into.
Bob, I am going to head back down to the dyno in the spring or summer. Maybe I could try your pipes while I am down there, if it's not too much hassle. Think about it, and let me know. Also, any luck on those clamps?
Bob, I am going to head back down to the dyno in the spring or summer. Maybe I could try your pipes while I am down there, if it's not too much hassle. Think about it, and let me know. Also, any luck on those clamps?
valin said:
those pipes are way differante than the one i use to have!!
bufalobob
Member
ryan:
my center sections are 8.5" long not the 8" i previously posted.
i've got to dig thru the clamp box @ the shop & see if any left. let me know when coming back & i will pull my pipes & bring to dyno. also, bring a set of stock pipes w/ you.
bob
my center sections are 8.5" long not the 8" i previously posted.
i've got to dig thru the clamp box @ the shop & see if any left. let me know when coming back & i will pull my pipes & bring to dyno. also, bring a set of stock pipes w/ you.
bob
valin
Active member
Will do Bob.
9801srx
Member
hi, valin and bufalobob. i also have a set of these pipes on my 780, mine measure the same as yours valin. do either of you know if there was a couple variations of these pipes made ,and what there intended use was? like is one set more for lake racing and the other for drags ,if so which set is for what? thanks, Neil
valin
Active member
interesting....
Bob will have to chime in for that one. He works out of Bender's shop. That info is very easy for him to get
Bob will have to chime in for that one. He works out of Bender's shop. That info is very easy for him to get
bufalobob
Member
just one version - trail. i will go to the shop tomorrow & get measurements off another set.
bob
bob
valin
Active member
Thanks again, Bob.
yamalars
Member
Finally got hold of bender and they now have the bb pipes up on there webshop 
But what version (messurement vice) am i getting? Also pipes in pic. looks like viperpipes? Maybe
just wrong pic.?
http://www.benderracing.com/SRX_Big_Bore_Pipes_s/39385.htm
But what version (messurement vice) am i getting? Also pipes in pic. looks like viperpipes? Maybe
just wrong pic.?
http://www.benderracing.com/SRX_Big_Bore_Pipes_s/39385.htm
yamalars
Member
Bump... Anyone (bob,valin) have some more info about these pipes?
Thanks/Lars
Thanks/Lars
Argento102
Member
sideshowBob said:
Agreed SIDESHOW,...my 81" piped Srx had same issue. No damned clutching would end-run that issue.
yamalars
Member
Agreed,thats why i trying to get some more info before i bye these (very pricy) pipes.
Good hp. numbers isnt worth a dime if i got a flat spot somewhere with them!
Good hp. numbers isnt worth a dime if i got a flat spot somewhere with them!