Jump to content
Sign in to follow this  

Great balls of fire

Recommended Posts

I just found that the DRZ-S is very good at throwing flames out the pipe ! I ride along at 50mph, press the engine kill button while keeping the throttle open wait 2 seconds and press the kill switch again and voila a thunderous bang with a two foot flame shooting out the back ! I bet it keeps the cars behind me entertained :cry: My only concern is if this will be bad for the motor ? Will the unburnt gas exploding have any effect on the valves etc ? Dont get me wrong though I love my DRZ and always take good care of it, this is not something I do often.

Share this post


Link to post
Share on other sites

I would think (without knowing) that it would be very bad for your engine :cry: My question would be WHY :cry: If you think it makes ya cool think agian, scares the crap outa people in the vicinity and contributes to some folks giving us bikers bad names..sorta like the loud straight pipes on harly's at full throttle. :cry:

Share this post


Link to post
Share on other sites

No no don't get the wrong idea :cry: The only reason I tried it was because a long time ago when I was alot younger I used to do it on my streetbike and just wanted to see if the DRZ did the same. I'm all for stealth and respecting other people. Although most people will never think any better of motorcyclists no matter what we do !

Share this post


Link to post
Share on other sites

One time my bro and i were driving down the freeway and we heard a noise from our car that sounded as if we had a flat tire so we pulled over to check it out! Well every one else around us was pulling over to check out their flat tire as well, so we thought &%$#@!? We looked over and it was a big ol army helicopter going by and the noise from the rotor sounded just like a flat tire :cry: :cry: :cry:

Share this post


Link to post
Share on other sites

I ruined a muffler on a Honda CBR doing the same thing in Baltimore a few years back. Some old guy was persistently riding my ass so I flamed him. It was pretty dramatic, and since I did it while going through a tunnel I could see the walls light up. He stopped tailgating me then :cry: Its not the kind of thing I'd do now, but I was college at the time and did a lot of dumb stuff then. Just try not to turn your muffler into a grenade :cry:

Share this post


Link to post
Share on other sites

Back in 79, had a 65 mustang, 289 w/ 2-fo's , centerlines, it was sweet. Anyway in stockton there was a theater on pacific ave where the line to get in ran along the sidewalk real close to the road. Id run it up to bout 50 a block away and shut off the key coast to the middle of the line, now doing about 20mph turn the key back on and PPPOOOOWWWWWWWWWWWW!!!!!!!!!! ... We didnt have drive bys back then but everone would still hit the deck!! Frigin hilarious, only damage it will cause is to your exhaust system, as it did mine. I know its all bad but sure fun to remember the good old days. Mike in Modesto AKA old and boring

Share this post


Link to post
Share on other sites

Back in my younger days I would haul ice down to the fishing boat in a U-haul box truck. Back then we called them key poppers. Turn off the ignition while in gear, give the gas peddle a couple of good pumps and them BAM. :cry: :cry: It was hell on exhausts. One time we split the muffler open like a bannana. Great fun scaring the hell out of the tourists though. :cry:

Share this post


Link to post
Share on other sites

Don't have a first hand experience but heard/read ? somewhere a while ago that the explosion could possibly open the exhaust valves and have a valve - piston contact. Don't know though... I guess one could figure out the pressure it would take to open the valves and figure out whether any muffler could hold up to that pressure. I guess this occurence be more likely with a chocked up hefty OEM muffler. :cry:

Share this post


Link to post
Share on other sites

All this talk about damaging valves is crap. You may damage your exhaust, particularly the muffler. Your valves will be fine. :cry:

somewhere a while ago that the explosion could possibly open the exhaust valves and have a valve - piston contact. Don't know though... I guess one could figure out the pressure it would take to open the valves and figure out whether any muffler could hold up to that pressure.

That "pressure calculation" is not as easy as you may think. If you want a semi-accurate number you need to spend at least $250,000 on a good computational fluid dynamics program. Assuming you can run the program yourself (they're not the bad) you need to correlate the model to the real world...and then...oh nevermind...its not worth it. Just trust me :cry:

Share this post


Link to post
Share on other sites

Lets all re live out youth and bring back the days of the key pops. Ill try it on my F-250 super duty diesel (good results not expected) and try and talk my wife into trying it with her lexus. :cry: :cry: :cry: :cry: :cry:

Share this post


Link to post
Share on other sites

I usually do it to my buds after I lead them into a tunnel. :cry: Great fun for me. They hate me though. :cry:

Mike

:cry:

Share this post


Link to post
Share on other sites

All this talk about damaging valves is crap. You may damage your exhaust, particularly the muffler. Your valves will be fine. :cry:

somewhere a while ago that the explosion could possibly open the exhaust valves and have a valve - piston contact. Don't know though... I guess one could figure out the pressure it would take to open the valves and figure out whether any muffler could hold up to that pressure.

That "pressure calculation" is not as easy as you may think. If you want a semi-accurate number you need to spend at least $250,000 on a good computational fluid dynamics program. Assuming you can run the program yourself (they're not the bad) you need to correlate the model to the real world...and then...oh nevermind...its not worth it. Just trust me :cry:

"All this talk about damaging valves is crap".

Hey they're your valves. Where's Burned when I need some back-up :cry:

Share this post


Link to post
Share on other sites

Thanks Burned. I knew someone once who used to warp the sh*t out of valves when I , oops :cry:, he was a factory test rider and playing artillary boy with the on-off switch. :cry:

Share this post


Link to post
Share on other sites

Burned have you actually damaged valves that way? If so was if from contact with the piston (valve pushed off of its seat from exhaust pressure)? Seems hard to believe to me, but if you've seen it first hand then I can't argue with that.

I've done plenty of testing on automotive engines, since one step in durability testing exhaust systems is to squirt some fuel into the exhaust and ignite it to simulate a worst case scenario. I've seen lots of split open mufflers and never seen a damaged valve.

Share this post


Link to post
Share on other sites

if it can damage the muffler,why wouldnt it be hard on the valves?

Its a matter of surface area and strength. The pressure acts on a bigger area in the muffler then on the exhaust valves.

Let's say the pressure in the exhaust during the "explosion" is 50 psi. I forget what size exhaust valves are in a drz, but lets say the area is roughly 1 square inch per valve for a total of 2 sq inches for both valves. So, 50 psi of pressure acting on 2 sq inches of surface area will give you a force of 100 (50 x 2)pounds acting on the exhaust valves. Now let's look at the outer skin of the muffler. I don't have my bike in front of me so I'm guess the surface area is roughly 165 sq inches. So 50 times 165 gives us 8250 pounds of force acting on the outer skin of the muffler :cry: That's a lot of force!

Share this post


Link to post
Share on other sites

ive seen it take chips/chunks out of the ex valve face.the only coralation i have to the cuase is the owner stating what he was doing when that cyliner quit running.

wanna take a guess what real cool idea he had?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×