It's just slightly louder with a little crisper sound. It has definitely improved power and responsiveness. I am happy with the change. I don't think it's legal to leave off the end pieces, but I am not sure. Somewhere I think I have a clip of the exhaust sound before the modification..If I find it I'll post.
I'd like to hear it accelerate thru the gears, approaching thru first and second, and going away third-fifth. That would be a test of sound. Revving it without a load is not a true test. JMO
my stock exhaust was custom cut shorties with baffles cut, my vid shows them it sounds pretty wicked just got a used vance and hines for real cheap so im selling them.
it does sound better without the end pieces. i have a 91 nighthawk 750 and i am going to try this but try a couple different things with the baffle and see whats good or bad. ill put a video up of the different sounds.
no they don't th-cam.com/video/jjPeP_Nn2B4/w-d-xo.html here's a very detailed 9 minute video by an engineer explaining why "needing backpressure" is a myth
Back pressure is a myth. Its not backpressure. Youre actually creating a lower pressure in the exhaust when it is "smaller' but designed right, this effect is called scavenging and its the flow of the exhaust pulses pulling the next one out the exhaust ports and into the exhaust
The key is to have it flow (big) enough to make good top end power, but to also still be restrictive enough to maintain the VELOCITY of the exhaust gases so that you retain the scavenging effect which helps increase flow/power in low end and mid range especially. An engine with no header has zero midrange and low end power
you got to be careful with honda's.they use backpressure combined with lean carb. jetting to get by the EPA.they are very lean to begin with.when you reduce backpressure it leans them out farther.thats why many honda's run worse than stock when you reduce stock backpressure WITHOUT increasing pilot & main jet sizes.why in the hell would anyone want a louder but slower bike without upping carb jets to compensate.its like only wiping half of your ass.
after your done messing with your factory exhaust system,put ur bike on a dyno machine and ur gonna see,you didnt improve in anything it just got louder,ive had 2 buddies put there bikes on a dyno machine after removing the pipe baffles and both bikes,lost between 1/2 to 3HP on top end and the bikes fuel economy dropped from 45MPG to 38 MPG..
I didn't/don't recommend totally removing the pipe baffles; the modification I did involves drilling a series of holes into the baffles and re-installing them. I wanted to refer you to the web page that I used as a guide, "Tim Hodge Exhaust Mod" on www.nighthawk750.com, but it appears that web page is not working at the moment... But I was able to see a cached version of the page: webcache.googleusercontent.com/search?q=cache:RtmlTDGTpecJ:www.nighthawk750.com/mods/exhaust.html+&cd=1&hl=en&ct=clnk&gl=us&
then you need to tell your friends to tale the time to rejet their carbs because after the same mod and rejeting my 1982 450 night hawk seen on a DYNO at C.W.MOTORSPORTS in effingham ill.a 7 h.p. increase at the WHEEL .that also included opening the air box with a stock replacement air filter.
Noah Billingsley actually all you have to do is possibly the jet the carb. You burn valves by running lean and engines lean out because of enhancements but usually take more than straight pipe exhaust to do that. If you deleted the stock air box and put shorty pipes on it then yah probably. But all you have to do again is re-jet.
What is the name of the inner piece? I just bought a nighthawk and the previous, previous owner removed the inner part, for me it's too noisy and I'd like to see if I can find just those parts so I can reinsert them.
i have an 84 CB700s it basically has the same exhaust. i removed the baffles but i cannot remove the mufflers buried inside the pipe is there anyway i can do this without cutting them open
4 into 1 replacement. Starts pretty quietly. Up to the power band it sounds like it wants to be seen. At 4500-8000 it has this wheeee that let's ppl know I'm passing them. If I coast in a more relaxed gear (30mph in 3rd not second) it sounds like a classic 50s muscle car BLUB BLUB BLUB.
Hello all. I'm wondering if anyone knows this : Does the 4-1 exhaust system of a CB400 Super Four fit on a 4-2 CB750 Nighthawk? I'm trying to swap the system on my 750 for a 4-1 to reduce weight and noise. Would it work? Or are there better options for this? Thank you.
Delkevic makes a CB750 4-1 exhaust that will fit. It's for the early 80's bikes but it does fit. You just have to shorten the muffler pipe a little to get the mount to line up.
@@blytheluv how many did you add one or two? Im planning on removing the baffles entirely ive read online people having great success with removing the baffles and shimming the needle jets
sounds so sick without baffles
I've always loved the mechanical sounds in the exhaust of nighthawks.
It's just slightly louder with a little crisper sound. It has definitely improved power and responsiveness. I am happy with the change. I don't think it's legal to leave off the end pieces, but I am not sure. Somewhere I think I have a clip of the exhaust sound before the modification..If I find it I'll post.
I'd like to hear it accelerate thru the gears, approaching thru first and second, and going away third-fifth. That would be a test of sound. Revving it without a load is not a true test. JMO
+Nomad Ryder The exact thing I think on every exhaust video.
yes .. i'd like to hear it on the road .. going through gears
Sounded better when you took the inner pipes out and ran it open.
modifying exhausts without increasing jet size causes a lean fuel-air mixture that could lead to burnt valves and piston faces
I drilled four 3/8" holes of each side. It has been working great.
make a video !! lets hear it ! :)
Did you have to do any re jetting
Sounds like shit should left the baffles out.
my stock exhaust was custom cut shorties with baffles cut, my vid shows them it sounds pretty wicked just got a used vance and hines for real cheap so im selling them.
ill belive all those exhaust modifications n after marker pipes give u more power,when i see a before n after dyno performence sheet.
I did this after watching video, no differences sounds the same.
but it's possible your engine might perform better?
it does sound better without the end pieces. i have a 91 nighthawk 750 and i am going to try this but try a couple different things with the baffle and see whats good or bad. ill put a video up of the different sounds.
@lynzack No carb work needed with four 3/8's holes on each funnel.
Well done
Louder is not the same as more low and mid-range power. Back pressure is important, too.
no they don't
th-cam.com/video/jjPeP_Nn2B4/w-d-xo.html
here's a very detailed 9 minute video by an engineer explaining why "needing backpressure" is a myth
Back pressure is a myth. Its not backpressure. Youre actually creating a lower pressure in the exhaust when it is "smaller' but designed right, this effect is called scavenging and its the flow of the exhaust pulses pulling the next one out the exhaust ports and into the exhaust
The key is to have it flow (big) enough to make good top end power, but to also still be restrictive enough to maintain the VELOCITY of the exhaust gases so that you retain the scavenging effect which helps increase flow/power in low end and mid range especially. An engine with no header has zero midrange and low end power
I have drag pipes that sound like yours. Without the backing added back.
Great Video.. Thanks..
you got to be careful with honda's.they use backpressure combined with lean carb. jetting to get by the EPA.they are very lean to begin with.when you reduce backpressure it leans them out farther.thats why many honda's run worse than stock when you reduce stock backpressure WITHOUT increasing pilot & main jet sizes.why in the hell would anyone want a louder but slower bike without upping carb jets to compensate.its like only wiping half of your ass.
Did you do a before & after gas mileage results?I'd be interested to find out if drilling those holes increased or decreased it.It did sound better.
I need to try that carb modification.
beauty beast sound
after your done messing with your factory exhaust system,put ur bike on a dyno machine and ur gonna see,you didnt improve in anything it just got louder,ive had 2 buddies put there bikes on a dyno machine after removing the pipe baffles and both bikes,lost between 1/2 to 3HP on top end and the bikes fuel economy dropped from 45MPG to 38 MPG..
I didn't/don't recommend totally removing the pipe baffles; the modification I did involves drilling a series of holes into the baffles and re-installing them. I wanted to refer you to the web page that I used as a guide, "Tim Hodge Exhaust Mod" on www.nighthawk750.com, but it appears that web page is not working at the moment... But I was able to see a cached version of the page: webcache.googleusercontent.com/search?q=cache:RtmlTDGTpecJ:www.nighthawk750.com/mods/exhaust.html+&cd=1&hl=en&ct=clnk&gl=us&
then you need to tell your friends to tale the time to rejet their carbs because after the same mod and rejeting my 1982 450 night hawk seen on a DYNO at C.W.MOTORSPORTS in effingham ill.a 7 h.p. increase at the WHEEL .that also included opening the air box with a stock replacement air filter.
also the baffle wasn't removed it was opened up.next time watch the whole video before getting snarky.nothing worse than being arogant and wrong.
Run it without baffles and retune. Sounds way better
My baffles will not come out even with hammering the pilers as I pull. Nor did pb blaster help, I doubt you will respond but I hope you do.
I just hacked off the tube with a cutting wheel, same effect, less labor.
can i take my those out completely on my 250cc 2005 ? i need it to be louder i was almost hit by a car the other day.
If you want to burn the exhaust valve out and have to get the engine rebuilt then go right ahead. You can't take those out you lose back pressure
If you want it louder just buy custom pipes and get the bike jetted that's the proper way to do it
Noah Billingsley actually all you have to do is possibly the jet the carb. You burn valves by running lean and engines lean out because of enhancements but usually take more than straight pipe exhaust to do that. If you deleted the stock air box and put shorty pipes on it then yah probably. But all you have to do again is re-jet.
loud pipes don't save lives,smarter riding does
Ll
What is the name of the inner piece? I just bought a nighthawk and the previous, previous owner removed the inner part, for me it's too noisy and I'd like to see if I can find just those parts so I can reinsert them.
baffle
Whut u dont do to your factory pipe
would have been useful if you had the before sound
Sounds like someone lit a duck on fire
i have an 84 CB700s it basically has the same exhaust. i removed the baffles but i cannot remove the mufflers buried inside the pipe is there anyway i can do this without cutting them open
4 into 1 replacement.
Starts pretty quietly.
Up to the power band it sounds like it wants to be seen.
At 4500-8000 it has this wheeee that let's ppl know I'm passing them.
If I coast in a more relaxed gear (30mph in 3rd not second) it sounds like a classic 50s muscle car BLUB BLUB BLUB.
Hello all. I'm wondering if anyone knows this :
Does the 4-1 exhaust system of a CB400 Super Four fit on a 4-2 CB750 Nighthawk? I'm trying to swap the system on my 750 for a 4-1 to reduce weight and noise. Would it work? Or are there better options for this? Thank you.
Delkevic makes a CB750 4-1 exhaust that will fit. It's for the early 80's bikes but it does fit. You just have to shorten the muffler pipe a little to get the mount to line up.
I have a 450 nighthawk, how did it run without the baffles? I want to take mine out completely, think it'll run good?
i think so, but some people say you may need to modify the carburation
1
I have a 650. it's not quite the same design exhaust, but is it the same concept to doing so?
probably
did any carb work need too be done? ie jetting changes
i added the small washers to needle jets
you can probably search on that (adding small washers to increase fuel flow)
@@blytheluv how many did you add one or two? Im planning on removing the baffles entirely ive read online people having great success with removing the baffles and shimming the needle jets
thanx
Remove the baffles entirely and shim the needles in thr carbs with 1 or 2 #4sae washers. Will run like a bat out of hell. Thank me later
Sounds like shit man. just run it without the baffles.
So sad