interesting find??

[Spyderman]

found this last night surfing for GS bits & bobs


here's a link to the site

http://www.x-pipe.com/motorcycle.html

has anyone tried one of these they look kind interesting

[Nessism]

Archives is full of negative feedback about the "X" pipe. Do a search if you want to be educated.

[Spyderman]

Archives is full of negative feedback about the "X" pipe. Do a search if you want to be educated.

hmmm
ok thanks

[Colorado85gs550]

personally I don't think they're a bad thing......some enginuity on jetting would be required and as long as there isn't negative feedback on the company that produces them other than that, I'd say "why not"

[posplayr]

Looks to improve ground clerance, although the entire pipe would have to be removed to change oil. Centerstand might be retained. Alot of the mid 90's GSXR's has this type of dual cross over system.

If you are not racing, it might do OK. Most of the debate I remember in the old threads was like the discussion on another thread about what 4:1 was best.

What I suspect is that it will idle well and provide good mid range with a new pipe and good ground clearance. PITA for oil changes though.

[posplayr]

Look at this stock GSXR exhaust in comparison to the X pipe and see what you think.

http://cgi.ebay.com/ebaymotors/Suzuki-GSXR1100-GSX-R1100-GSXR-1100-FULL-STOCK-EXHAUST_W0QQitemZ120332477398QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item1c045fe3d6&_trksid=p4506.m20.l1116

Suzuki GSXR1100 GSX-R1100 GSXR 1100 FULL STOCK EXHAUST

I think this a water cooler exhaust even though it says 88-92
Update looked at the parts Fiche and it matches the 89-90 and 91-92 GSXR 1100!!!

[Colin Green]

Am I looking at it wrong? It appears to have cleats to bolt on to the centre stand brackets??

Also one side appears to have a much bigger dent on the inside face of the pipe at the bend next to the 4 into 2 junction

[DMorris]

At first glance, I would say that it very likely would cost you hp.
There is effectively no collector, just a square chamber for the exhaust to dump into.
A proper header system is tuned in length, diameter, collector shape and pulse rotation in the collector. This is done to return a low pressure pulse back to the exhaust port at just the right time to increase cylinder charge density.
The shape of the collector has an effect on the duration and strength of the low pressure pulse. That in conjunction with the other tuning factors determine the RPM range at which the header is most effective.
4 into 1 systems tend to be a little narrower in their effective RPM range than 4-2-1 systems which deliver a bit broader but less powerful low pressure pulse to the exhaust port.
This system looks cool and is likely inexpensive but probably counter productive in the power department.

IMHO, Don

[posplayr]

DMorris

Please contrast and compart the X pipe to the Stock 88-92 GSXR pipe. Why are they so much different?

The stock 92 1127 GSXR put out about 145 hp

[drhach]

If you look at the old threads about this. Most of the negative commentary has more to do with the guy selling them than the actual performance of the pipe. I don't recall one instance where someone actually bought one and had anything good or bad to say about the product itself.

[DMorris]

Well posplayer,
I am no expert ( I am a Numerical control and process control technician and not an automotive engineer) so I was giving my guesstimate based on what I have read and observed. With that in mind, I'll take a shot at describing the differences I see in the two systems.
As I mentioned in my previous post, the collector area in the X-pipe appears to be nothing more than a box with all the pipes dumping into it side-by-side. The lengths of the primary pipes also appear to be a little short on the X-pipe. When the exhaust valve opens at the end of the combustion cycle, a positive pressure wave or pulse starts down the pipe. When the positive pulse reaches the higher volume of the join between adjoining pipes, a negative pressure wave or pulse is reflected back up the pipes toward all the exhaust ports. If an exhaust valve is open, the pressure in the cylinder drops below ambient pressure just as the exhaust valve is closing and the intake is opening. The difference in pressure between the atmosphere and the cylinder becomes greater than what would exist just from the pumping action of the piston in the cylinder. The difference in pressure is what causes air flow in the intake tract. If every thing is timed just right, enertia of the accelerated fuel-air mass in the intake tract causes the pressure in the cylinder to be greater than atmospheric at the moment the intake valve closes. This is sort of an enertia supercharger. If you examine the collector area of a header, you will see that the pipes join into a cone shaped area. The length and rate of taper of the cone shaped area influences the sharpness or rate of change and duration of the reflected negative pressure going back to the exhaust valves. By joining 2 pipes first and then those 2 sets of 2 joining a little farthur down the pipes, the pulse duration is also lengthened (it is also reduced in intensity and rate of change). This increase in negative pulse duration increases the RPM range in which the scavenging effect is effective.
So, having said all that, if you compare the pictures of the two systems, you will see that the GSXR pipe first joins pipes 1 & 2 in a pair and 3 & 4 in a pair. You will also see that the area of the joins are curved cones with significant length and a slow taper. The 2 resultant pairs are then joined into a specifically shaped collector area and then split onto two pipes exiting into 2 mufflers. This appears to me to be a 4 into 2 into 1 that then branches into 2 mufflers. I believe this was done for a couple reasons which are both compromises. First, I believe most people like the balanced look of 2 mufflers. (marketing) Second, sound attenuation requires volume (space) and it is easier to obtain that volume in 2 canisters than in one.
The X-pipe shows none of these design considerations. It is just 4 pipes dumping into a box that is connected to 2 mufflers. I would guess that the x-pipe is a lot like the grapefruit shooter mufflers that the kids put onto their import cars -- loud and showy and nothing else --except that when the x-pipe is put in the place of a well designed factory pipe it costs hp.
It is my understanding that header pipes that were well thought out by after-market manufacturers often make a major improvement in performance on early bikes when properly jetted. The more modern the bike (at least in the performance bike group) the less dramatic the performance improvement because the manufacturers incorporated these attributes themselves. If fact, I believe that with the latest generation of bikes, weight saving is the greatest improvement associated with a change of pipes.
All that being said, the GSXR pipe appears to be a VERY carefully designed device that suffers a couple of carefully integrated compromises for marketing and noise control reasons while the x-pipe is pure flash and bling. (IMHO)
For a for a more in-depth explaination, check out Kevin Cameron's (spelling) book on sport bike performance, Gordon Jenning's two stroke tuner's handbook and any of Smokey Yanuck's books on engine tuning.

So, that's how I understand it but then I could be full of it to my eyebrows!

Best, Don

P.S. There is a performance reason for the cross connection between pipes 2&3 on the GSXR pipe but I can't remember what it is. I would have to go back to the books for that one. I can say that on V8s, the cross pipe between sides is placed after the collectors and improves mid-range.

WHEW!!

[Colin Green]

That effort deserves applause... well done.

What did it all mean Lol

[posplayr]

Don

Thanks you very much for taking the time to explain that. I have often heard of tuned exhausts and scavenging effects but never really understood what was meant.

I think you did a very good job at explaining the scavenging effect and the design factors required to broaden the tuned RPM of the pipe. At least I understand it much better now. It is clear you understand the subject well even if you don't have any first hand knowledge (i.e. you are not an automotive engineer).

From a layman's perspective, I really don't think I could do much better explaining it than you did . From an engineering perspective the electrical analogy of impedance mismatch and VSWR are the things that come to mind. Not exactly sure of how applicable it is , but in electromagnetic any time there is a change in impedance or resistance of a medium, there is a reflected wave. The change in pipe diameter from individual pipes to the collectors represents a change in that impedance. The larger the impedance change the the larger the reflected wave.

Moderating that pipe transitions, must expand delay of the reflection and hence the RPM (frequency) range. As you described it provides the broadening of the RPM range where savaging and "super charging exists". The reflected wave (after running back to the exhaust valve) actually drops the pressure at the exhaust valve prior to it closing and provides "suck" to pull in the new charge.

Now sure I added anything, but thanks again for the explanation; very well done.

As far as that cross pipe, I don't know why it helped but a cross pipe like that really helped to smooth out the low RPM drivability of my motorhome. Instead of going blap blap blap (like running on 4 cylinders) at low RPM, it turned into a nice rumble with better part throttle control.

So given teh analysis, the X-pipe might very well improve performance, but it would likely be at only one specific RPM and fall flat else where.

Pos

[posplayr]

I just refreshed my memory a bit on VSWR and standing waves.

http://en.wikipedia.org/wiki/VSWR

When an antenna and feedline do not have matching impedances, some of the electrical energy cannot be transferred from the feedline to the antenna.[2] Energy not transferred to the antenna is reflected back towards the transmitter.[3] It is the interaction of these reflected waves with forward waves which causes standing wave patterns.[2] Reflected power has three main implications in radio transmitters: Radio Frequency (RF) energy losses increase, distortion on transmetter due to reflected power from load[2] and damage to the transmitter can occur.[4]

as quoted below, in electromagnetic, there is a reflected wave off of the impedance mismatch. Because the forward wave and back ward wave are at the same frequency they add and subtract constructively/destructively in a standing wave pattern between the source and the reflection. The pattern changes with frequency. In the case of exhaust it is with RPM.

The pulsing of the exhaust pressure comes directly from the cyclic pulsing of the engine. As a function of RPM, the standing pressure wave (due to reflections) will increase or decrease at the exhaust port as a function of the standing wave pattern.

The interaction with the transmitter as described above can be a benefit on the engine as the wave is actually a pressure wave. and the drop in pressure of the pressure wave improves scavenging of flow of the input charge.

I need to confirm this with some more reading, but I don't see any reason why the phenomenology is not the same mathematically.

Nite

[Colin Green]

I think my head burst