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stainless header for gs

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TheCafeKid said:
While VH headers probably had alot of reasearch put into them they were more or less designed (at least your standard street pipe/Meg ) were made for practical performance eg Joe motorbike to toss on his machine without questioning weather or not other areas of the rpm ranges would be negatively effected. Midpipes on

Massive top end rush is the result. One pipe I have (SuperTrapp) with a large pipeset makes my 1100E take off like it was shot out of a cannon from about 6K on. The VH pipe like Joe posted up on the same bike tuned to it resulted in a very punchy midrange ( really nice for standard street riding) but ultimately next to no rush up top. Very flat.
The difference is remarkable and a bit unsettling if you're not planning for it.
Click to expand...

The V&H Mega I thought was made to combat the flatspot "can" headers have.

I know I don't do alot of topend hi rev riding on the street so I like the pipe. I would be interested to know the dyno numbers on two pipes since from '86 on the pipes are all smaller down pipes. For the gsxrs anyway.

I would question the "MASSIVE RUSH" which is why a dyno run would be good. I don't know of any gains like that from a pipe alone but could be wrong. The dyno runs on my kats are in the low to mid 130's hp and are anything but flat between 7 and 10k. I can't imagine bolting on a different header and experiencing a massive increase from what is there now.

Of course this is just my opinion. No numbers to back it up.

I was talking to a header guy recently and he was telling me the 4-1 pipe creates a scavenging effect sucking exhaust through the pipe where as the 4-2-1 does not. Anyone heard of that?
 
katman said:
The V&H Mega I thought was made to combat the flatspot "can" headers have.

I know I don't do alot of topend hi rev riding on the street so I like the pipe. I would be interested to know the dyno numbers on two pipes since from '86 on the pipes are all smaller down pipes. For the gsxrs anyway.

I would question the "MASSIVE RUSH" which is why a dyno run would be good. I don't know of any gains like that from a pipe alone but could be wrong. The dyno runs on my kats are in the low to mid 130's hp and are anything but flat between 7 and 10k. I can't imagine bolting on a different header and experiencing a massive increase from what is there now.

Of course this is just my opinion. No numbers to back it up.

I was talking to a header guy recently and he was telling me the 4-1 pipe creates a scavenging effect sucking exhaust through the pipe where as the 4-2-1 does not. Anyone heard of that?
Click to expand...

Rob,
There was a discussion on here a while back about exhaust. I did a little research as well and here is what I surmised.

The engine firing of a 4 cycle engine represents a series of pulses (pressure) which is oscillating up and down and to more or lesser extent can be represented by sinusoidal pressure variations.

When a wave of pressure (part of a pulse) hits a change in impedance, there is a tendency for that wave to bounce off of the impedance . This will primary physically occur when 4 pipes join into a single as this is a big change in flow. After the pulse hits the collector a portion goes through and the rest bounces back to the exhaust side of the head. Basically what sets up is a standing wave of pressure variation. The more of a mismatch you have (like going from 4 down to 1) the bigger the reflection and the larger the standing wave ratio.

At some RPM's the standing wave (which is a function of RPM) causes the pressure at the exhaust valve to be at a minimum (pressure) which causes a savaging effect pulling more intake charge than would normally occur. Of course there is an RPM (1/2 of that) where that pressure at the exhaust valve is maximum :o. In other words just when the exhaust valve is opening the wave that ran down the pipe hit the 4:1 collector is now arriving at maximum pressure just as the exhaust valve is opening. This clearly will inhibit power. So in nominal terms if you want peak scavenging effect and hp at 10K RPM, you will put a flat spot at 5K rpm.

This is described and there are comparison dyno charts in Kevin Cameron,s "Sportbike Performance Handbook". It shows a 93 GSXR 750 with a 4:1 and another chart showing a 97 GSXR 600 with 4:2:1. The 4:2:1 produces a much more linear flow (rising hp with RPM).

I would see the 4:1 as basically a great idea to get racing performance increase from 7-12K rpm above. After all when do racers lug at 5K rpm?

On the other hand 5K RPM his right in the middle of the torque band for street riding.

The following is just my conjecture.

If you think about the problem as "impedance matching", then in order to get the high pressure at the exhaust port to equalize with the atmospheric pressure at the outlet, the "megaphone" shape makes sense as it is gradually transitioning from the small diameter of the collector out to as big as practical to reduce the pressure down to 1 atm.

By providing the more gradual pressure transition, there is a lessor standing wave and more linear power gain with RPM (better for street).
 
posplayr said:
Rob,
There was a discussion on here a while back about exhaust. I did a little research as well and here is what I surmised.

The engine firing of a 4 cycle engine represents a series of pulses (pressure) which is oscillating up and down and to more or lesser extent can be represented by sinusoidal pressure variations.

When a wave of pressure (part of a pulse) hits a change in impedance, there is a tendency for that wave to bounce off of the impedance . This will primary physically occur when 4 pipes join into a single as this is a big change in flow. After the pulse hits the collector a portion goes through and the rest bounces back to the exhaust side of the head. Basically what sets up is a standing wave of pressure variation. The more of a mismatch you have (like going from 4 down to 1) the bigger the reflection and the larger the standing wave ratio.

At some RPM's the standing wave (which is a function of RPM) causes the pressure at the exhaust valve to be at a minimum (pressure) which causes a savaging effect pulling more intake charge than would normally occur. Of course there is an RPM (1/2 of that) where that pressure at the exhaust valve is maximum :o. In other words just when the exhaust valve is opening the wave that ran down the pipe hit the 4:1 collector is now arriving at maximum pressure just as the exhaust valve is opening. This clearly will inhibit power. So in nominal terms if you want peak scavenging effect and hp at 10K RPM, you will put a flat spot at 5K rpm.

This is described and there are comparison dyno charts in Kevin Cameron,s "Sportbike Performance Handbook". It shows a 93 GSXR 750 with a 4:1 and another chart showing a 97 GSXR 600 with 4:2:1. The 4:2:1 produces a much more linear flow (rising hp with RPM).

I would see the 4:1 as basically a great idea to get racing performance increase from 7-12K rpm above. After all when do racers lug at 5K rpm?

On the other hand 5K RPM his right in the middle of the torque band for street riding.

The following is just my conjecture.

If you think about the problem as "impedance matching", then in order to get the high pressure at the exhaust port to equalize with the atmospheric pressure at the outlet, the "megaphone" shape makes sense as it is gradually transitioning from the small diameter of the collector out to as big as practical to reduce the pressure down to 1 atm.

By providing the more gradual pressure transition, there is a lessor standing wave and more linear power gain with RPM (better for street).
Click to expand...

Exactly what I was thinking...
 
I just made a deal on this Micro Stainless 4:2:1.
It will need some modification to fit the GS, but looks alot like the Yoshi
 
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Good thread and interesting idea. I like the idea of a stainless system but like most, I can't see really justifying the high cost.

The project 82 Kat 750 came with a stainless Yosh system that has held up extremely well for all those years. Really rusty down pipes that have cleaned up nicely to unpitted solid metal. The chromed can is a bit discoloured but not pitted and still useable, so for longevity they can't be beat.

Now if I'm keeping a bike for 25+ years $1000 to $1,500 wouldn't be a bad investment but if I'm horsetrading, as many of us do, then its not money well spent.

I've been diligently searching for at least a 4 into 1 setup for the GS750 but haven't found anything other than Macs in the last 2 years. At a price point of between $300 and $400 it would be something I can swallow but I'd rather have something else as lets face it, Macs are cheaply constructed.

I think one of the early comments about ceramic coated mild steel systems might make more sense, economically. If you could produce a quality piece maybe slightly higher than the Mac stuff then I think we'd be lining up on your front porch to get a copy or two.

I appreciate your interest in trying to solve this problem for us. Its got to be one of the most frustrating things for owners of old bikes. I know it frustrates the hell out of me.

Cheers,
Spyug
 
so last night i was surfing for pipes just to see what is out there and i ran across this
http://translate.google.ca/translate?hl=en&sl=ja&u=http://www.autoparts-ksy.co.jp/cgi-bin/autopartsksy/siteup.cgi%3Fcategory%3D1%26page%3D3&ei=tBxMS-KOJ47UNdOYqfsM&sa=X&oi=translate&ct=result&resnum=1&ved=0CAgQ7gEwAA&prev=/search%3Fq%3Dhttp://www.autoparts-ksy.co.jp/cgi-bin/autopartsksy/siteup.cgi%253Fcategory%253D1%2526page%253D3%26hl%3Den%26sa%3DG

they list pipes for a GSX1100 sword i'm assuming that it is the same as our 4 valve 1100's by the look of the pic on the header it seems to be a cross of a 1000 S and an 1100 they look like good pipes yoshi knock offs for a reasonable price shipping may be an issue
there is a link to contact them perhaps a few can get together and get a better deal you never know it might be worth looking into perhaps some of you have seen these before perhaps not i just thought i'd post it for all to see
 
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Spyderman said:
so last night i was surfing for pipes just to see what is out there and i ran across this
http://translate.google.ca/translat...teup.cgi%3Fcategory%3D1%26page%3D3&hl=en&sa=G

they list pipes for a GSX1100 sword i'm assuming that it is the same as our 4 valve 1100's by the look of the pic on the header it seems to be a cross of a 1000 S and an 1100 they look like good pipes yoshi knock offs for a reasonable price shipping may be an issue
there is a link to contact them perhaps a few can get together and get a better deal you never know it might be worth looking into perhaps some of you have seen these before perhaps not i just thought i'd post it for all to see
Click to expand...

hmm..shipping may be as much as the pipe, but you may be on to something there.
 
+1. They had a new GS1100 pipe listed on the Japanese Yahoo auction site about a year ago, and I emailed them for a shipping quote, but got no reply.:-s
 
Mysuzyq said:
+1. They had a new GS1100 pipe listed on the Japanese Yahoo auction site about a year ago, and I emailed them for a shipping quote, but got no reply.:-s
Click to expand...

I have been led to believe there are aftermarket parts galore for these bikes in Japan. We need somebody on the inside to be a reseller. I don't think most of them will ship here, plus the language barrier.
 
Yes, the Youtube Japanese clips show a lot of trick parts, esp. on the Kats....there are professional re-shippers that will forward the items, but their fees effectively add about 70 to 80%, making them stupidly expensive.:(
 
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