probably a silly question but, why do most drag cars run stinger (straight out) exhausts??? do they run better without the back pressure a muffler provides????
matt
matt Insano Dub Head
743 posts · joined Dec 2002 ·
stingers
Brian Officially Full-On Dubber
263 posts · joined Jun 2007 ·
define exhaust back pressure please , its always confused me😂😂
matt Insano Dub Head
743 posts · joined Dec 2002 ·
i dont know much about it i just assume a motor will run better with a bit of back pressure. back pressure is the resistance of the gasses to flow through the exhuast, some one else may explain it better
matt
matt
Brian Officially Full-On Dubber
263 posts · joined Jun 2007 ·
if all other things are equal (ie air /fuel ratio etc) the muffler will slow it down
matt Insano Dub Head
743 posts · joined Dec 2002 ·
oh ok, you learn something new every day!!!
thanks
matt
thanks
matt
chunks54 Slammed & Awesome Dubber
84 posts · joined Aug 2009 ·
Plus there's nothing like waking up in the morning at a drag strip listening to a flat four barking through a stinger 😉
Happiness is a Hot VW.
1954 Bug, 2276/Turbo
Turbo lag - that split second when the other guy thinks he has a chance
1954 Bug, 2276/Turbo
Turbo lag - that split second when the other guy thinks he has a chance
trickysimon 100km/h is only 9 seconds away
1,473 posts · joined Dec 2007 ·
Why not just have no stinger or muffler at all?
bajachris88 The international telephone dialing code for Antarctica is 6
6,661 posts · joined Apr 2005 ·
You need backpressure of some kind. But in a drag racers case, the extractor tubing alone towards the flange for the stinger is sufficient.
But i dont know if backpressure is the right term. See... from what i'm aware of, its to do with air velocity. Smaller diameter tubing with same rate of air flow has greater velocity of air going through than a larger diameter tube.
A wider diameter exhaust tube with same rate of air flow as the smaller diameter tube has larger volume, slower air flow.
By finding a 'balance' to create maximum air velocity, by manipulating tube diameter without large restriction (and too much back pressure) it results in a 'relative' vacuum at the exhaust port as the momentum of the air exiting the exhaust (due to its velocity) continues to 'suck out' exhaust gas inside the tubing as it goes the exhaust pipe.
Extractors take advantage of this, by lengthening the pipes correctly to collaborate with the timing difference of the exhaust ports. They work with the 'pulses' of the exhaust gas to maintain a continuous flow and continuous forward momentum of the exhaust gas exiting, to keep 'sucking' out the gas from the port.
Eva seen how shizzy any motor runs without any exhaust manifold at all? 👍
Its a mess. efi or carby...
Load like a tractor on the dub though haha.
its similar, but opposite to velocity stacks on a heads intake, choosing the right size for best possible air velocity. or even TVIS, taking advantage of the 'natural supercharging' effect.
But i dont know if backpressure is the right term. See... from what i'm aware of, its to do with air velocity. Smaller diameter tubing with same rate of air flow has greater velocity of air going through than a larger diameter tube.
A wider diameter exhaust tube with same rate of air flow as the smaller diameter tube has larger volume, slower air flow.
By finding a 'balance' to create maximum air velocity, by manipulating tube diameter without large restriction (and too much back pressure) it results in a 'relative' vacuum at the exhaust port as the momentum of the air exiting the exhaust (due to its velocity) continues to 'suck out' exhaust gas inside the tubing as it goes the exhaust pipe.
Extractors take advantage of this, by lengthening the pipes correctly to collaborate with the timing difference of the exhaust ports. They work with the 'pulses' of the exhaust gas to maintain a continuous flow and continuous forward momentum of the exhaust gas exiting, to keep 'sucking' out the gas from the port.
Eva seen how shizzy any motor runs without any exhaust manifold at all? 👍
Its a mess. efi or carby...
Load like a tractor on the dub though haha.
its similar, but opposite to velocity stacks on a heads intake, choosing the right size for best possible air velocity. or even TVIS, taking advantage of the 'natural supercharging' effect.
(ô_!_/ô) (ô_!_/ô)
69' baja: kombi box, thing spindles, irs, disc front, type 3 rear drums, 2 inch lift kit, 31x10 rears. 👍
New engine in process: 94mm p&bs, 74mm C/w chomol Crank, 35.5x39 SP heads, turbo. Wierd combo, hopeful torque monsta!
69' baja: kombi box, thing spindles, irs, disc front, type 3 rear drums, 2 inch lift kit, 31x10 rears. 👍
New engine in process: 94mm p&bs, 74mm C/w chomol Crank, 35.5x39 SP heads, turbo. Wierd combo, hopeful torque monsta!
colonel mustard Son of Jim - Creator of Good
2,829 posts · joined Feb 2009 ·
they make the car pretty useless for driving between o and 2k-ish but rock after that...
and they sound awesome 🙂 I got one fro my thunderbird from action day, spent 2 hours cleaning it up.. and it looks sweet... under my bed with the rest of the exhaust. 🙂 all ready for the set up!
and they sound awesome 🙂 I got one fro my thunderbird from action day, spent 2 hours cleaning it up.. and it looks sweet... under my bed with the rest of the exhaust. 🙂 all ready for the set up!
Duanepipe Learner Dubber
9 posts · joined Oct 2008 ·
I ran several runs with the stinger and several with just the open header on my drag bug. It definately ran stronger with the stinger.I think it has some sort of scavenging effect too especcially at speed.👍
fish26 Fahrvergnugen
903 posts · joined Jul 2007 ·
Best person to chime in would be Brad "westi" from Westside, but the way I see it is:
Stingers work because we need some sort of exhaust tail section after the collector to help with wave scavenging, there is less loss of velocity and would probably work even better if they were the same dimension from flange to exit as there are no expanding gasses past the collector therefore continuing velocity.
They sound great because they simply exaggerate the sound of the exhaust pulse.
Mufflers are just that, used to soften the sound and pulse of the exhaust gasses.
Think of it like running your tap to fill a cask, the water traveling through the small pipe is traveling at a fast rate and losses velocity as it fills the cask, although exiting at the same volume but a slower rate through a larger hole.
Your engine has 15 psi (1 Bar) of atmospheric pressure sitting at the inlet and another 15 psi lurking at the end of the tailpipe. The inlet stroke creates a pressure differential and the atmosphere goes rushing inward. The exhaust valve opens and there is a pressure rise in the tube followed by a strong "vacuum signal" as the gases head down the pipe. The vacuum signal or low pressure that follows an exhaust event can be used to help scavenge the cylinder during overlap when both exhaust and inlet valves are open. Conversely, during this overlap period, the increase in "backpressure" can cause these burnt gases to re-enter the combustion chamber and contaminate the inlet charge. Result...loss of power. The way to look at exhausts is to view them as a way to maintain the highest velocity that will not impede flow. As velocity increases the pressure drops and the engine can become more efficient. As bajachris88 pointed out, there's all the variables of length, diameter, rpm, collector size, etc. There is no "one answer".
Stingers work because we need some sort of exhaust tail section after the collector to help with wave scavenging, there is less loss of velocity and would probably work even better if they were the same dimension from flange to exit as there are no expanding gasses past the collector therefore continuing velocity.
They sound great because they simply exaggerate the sound of the exhaust pulse.
Mufflers are just that, used to soften the sound and pulse of the exhaust gasses.
Think of it like running your tap to fill a cask, the water traveling through the small pipe is traveling at a fast rate and losses velocity as it fills the cask, although exiting at the same volume but a slower rate through a larger hole.
Your engine has 15 psi (1 Bar) of atmospheric pressure sitting at the inlet and another 15 psi lurking at the end of the tailpipe. The inlet stroke creates a pressure differential and the atmosphere goes rushing inward. The exhaust valve opens and there is a pressure rise in the tube followed by a strong "vacuum signal" as the gases head down the pipe. The vacuum signal or low pressure that follows an exhaust event can be used to help scavenge the cylinder during overlap when both exhaust and inlet valves are open. Conversely, during this overlap period, the increase in "backpressure" can cause these burnt gases to re-enter the combustion chamber and contaminate the inlet charge. Result...loss of power. The way to look at exhausts is to view them as a way to maintain the highest velocity that will not impede flow. As velocity increases the pressure drops and the engine can become more efficient. As bajachris88 pointed out, there's all the variables of length, diameter, rpm, collector size, etc. There is no "one answer".
bitten by the bug..........several times
Duanepipe Learner Dubber
9 posts · joined Oct 2008 ·
At the end of the day they look good ,sound good, make people ask "whats that for" and people trip over them.
All good for me.👍
All good for me.👍
bajachris88 The international telephone dialing code for Antarctica is 6
6,661 posts · joined Apr 2005 ·
😂 hahah people trip ova them... lol
I definitely gotta make it to the drags then!
I definitely gotta make it to the drags then!
(ô_!_/ô) (ô_!_/ô)
69' baja: kombi box, thing spindles, irs, disc front, type 3 rear drums, 2 inch lift kit, 31x10 rears. 👍
New engine in process: 94mm p&bs, 74mm C/w chomol Crank, 35.5x39 SP heads, turbo. Wierd combo, hopeful torque monsta!
69' baja: kombi box, thing spindles, irs, disc front, type 3 rear drums, 2 inch lift kit, 31x10 rears. 👍
New engine in process: 94mm p&bs, 74mm C/w chomol Crank, 35.5x39 SP heads, turbo. Wierd combo, hopeful torque monsta!
colonel mustard Son of Jim - Creator of Good
2,829 posts · joined Feb 2009 ·
I nearly tripped over Craigs on the dray rat at action day....... don't tell him.
Awwwwwwwwwwwwww YEAH!
Pardon the messy room... lots of assignments going on. hahaha
Awwwwwwwwwwwwww YEAH!
Pardon the messy room... lots of assignments going on. hahaha
matberry Moderator Go hard or go home
8,114 posts · joined Mar 2006 ·
Couldn't have put it better....All good here too :-)Duanepipe wrote:At the end of the day they look good ,sound good, make people ask "whats that for" and people trip over them.
All good for me.👍
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
rose doin it for d girls
2,036 posts · joined Dec 2004 ·
I have one to put on Buz at Warwick but you wont trip over it as Buz isn't lowered 😂
HappyDaze Superannuated
2,887 posts · joined Jun 2009 ·
Exhaust systems are a 'Black Art' - just look at 2 strokes and their expansion chambers. In 1969 I drove a Vee, which came with 4 separate pipes, 1.25" dia. After talking with Bruce Peters of Sonic Speed Equipment (they made a VW exhaust system), I made a 4 into 1 using smaller (1.125"dia.) primary pipes, and a single 1.25" dia. tail-pipe. This gave a 4HP increase on the Dyno! That's an extra 10%!!!!!!! Bruce told me that they (Sonic) virtually threw away their books on exhaust theory, and used the Dyno to experiment with different ideas.
Cheers, Greg
Cheers, Greg
I'd rather wear a Beetle out by racing it than by polishing it!
pete wood 23 Windows of Awesome
6,828 posts · joined Jan 2004 ·
greg, doesn't surprise me, but exhaust design has come a long way since 69'. I'm sure there are a few good books you could get to help these days .
speaking of stingers on Fvees. I saw a whole bunch of Vees running stingers last weekend at Wakefield. A few were running hotdogs, but the one that got my attention was this setup...
speaking of stingers on Fvees. I saw a whole bunch of Vees running stingers last weekend at Wakefield. A few were running hotdogs, but the one that got my attention was this setup...
1 attachment · Log in to view
"stoopid is stronger than axles"
http://drivingnotpolishing.blogspot.com.au/
http://drivingnotpolishing.blogspot.com.au/
bajachris88 The international telephone dialing code for Antarctica is 6
6,661 posts · joined Apr 2005 ·
its like the dual cannon motorbike stylin kinda thing.
me likes 👍
me likes 👍
(ô_!_/ô) (ô_!_/ô)
69' baja: kombi box, thing spindles, irs, disc front, type 3 rear drums, 2 inch lift kit, 31x10 rears. 👍
New engine in process: 94mm p&bs, 74mm C/w chomol Crank, 35.5x39 SP heads, turbo. Wierd combo, hopeful torque monsta!
69' baja: kombi box, thing spindles, irs, disc front, type 3 rear drums, 2 inch lift kit, 31x10 rears. 👍
New engine in process: 94mm p&bs, 74mm C/w chomol Crank, 35.5x39 SP heads, turbo. Wierd combo, hopeful torque monsta!
fish26 Fahrvergnugen
903 posts · joined Jul 2007 ·
Best guys to learn from are engineers in F1, lots of R + D on N/A.
bitten by the bug..........several times