Complete race pipe K6-K9 GSX-R600

[FROSTY]

Hey guys Ive got a track use only GSXR600 K7 fitted with a Lovely looking and sounding Leo Vince system.
At High RPM she pulls like a schoolboy but theres a massive hole in the midrange.
Mr tuner is well reputed and has told me the pipe is the cause of the hole.
So Im looking for a Yosh or similar race pipe Ie a complete system for the K8-L1 600
Im hoping that with the K7 being "old hat" someone will have something lying around.
Ive edited to remove any price indication

[mossy1200]

GSXR600 K7

Run it with a db killer and check the midrange. Sounds like a lack of back pressure.
If its better sleeve the mid pipe down a bit at the muffler end and remove the db killer again.

If you post the internal size of the muffler inlet someone will have a db killer the correct size.

[FROSTY]

what the heck is a DB killer?

[Gremlin]

https://www.google.com/search?q=db+killer&tbm=isch&tbo=u&source=univ&sa=X&ved=0CB0QsARqFQoTCNyM7JjYsccCFWXopgodukQCtw&biw=1920&bih=938

Removable baffle.

[FROSTY]

Thanks guys but I do want to get a K8-L1 full system

[mossy1200]

Thanks guys but I do want to get a K8-L1 full system

So when you said Leo Vance System you meant Leo Vance Muffler?

I would have thought going even bigger bore and flow exhaust system is going to make the midrange worse instead of better.

[oohook]

PM me if you're interested in selling the LeoVince. Cheers :)

[FROSTY]

So when you said Leo Vance System you meant Leo Vance Muffler?

I would have thought going even bigger bore and flow exhaust system is going to make the midrange worse instead of better.
To be honest mate --I don't know and don't personally have the time to think about it.
mr Clee says.--"Put a Yosh K8-L1 race system on" So I bows down and goes yessum massa.--given he has a "bit" of experience tuning this sort of bike I figure he knows what he's talking about.

[mossy1200]

To be honest mate --I don't know and don't personally have the time to think about it.
mr Clee says.--"Put a Yosh K8-L1 race system on" So I bows down and goes yessum massa.--given he has a "bit" of experience tuning this sort of bike I figure he knows what he's talking about.

These systems new are 2.2k landed including gst. Your going to need be very lucky to find a second hand race set for sale cheap.

[FROSTY]

These systems new are 2.2k landed including gst. Your going to need be very lucky to find a second hand race set for sale cheap.
Ohh well 2.2k it must be then

[Drew]

Run it with a db killer and check the midrange. Sounds like a lack of back pressure.
If its better sleeve the mid pipe down a bit at the muffler end and remove the db killer again.

If you post the internal size of the muffler inlet someone will have a db killer the correct size.

'Back pressure' is a really misleading and counter productive term. People need to stop saying it.

It's all about pipe length and size, creating the much needed 'correct' velocity to maximise the gains from valve overlap. Play with yer cam timing, and you're doing half the job. Play with the exhaust dimensions and you are usually making more noise and little else.

[mossy1200]

'Back pressure' is a really misleading and counter productive term. People need to stop saying it.

It's all about pipe length and size, creating the much needed 'correct' velocity to maximise the gains from valve overlap. Play with yer cam timing, and you're doing half the job. Play with the exhaust dimensions and you are usually making more noise and little else.

So your saying Leo make system incorrectly or its a system not designed for the bike.
Goes back to trial with db killer at back of midpipe in front of muffler and sleeve midpipe down if the fault goes away discarding the db killer. I am picking the midpipe is a little fat. With a $400 budget its the only way to find out without committing mega monies.

Or buy a tuned system you know is correct but they are not cheap.
Idd like a new system for mine but they are priced the same as many new lams bikes.

[Grumph]

So your saying Leo make system incorrectly or its a system not designed for the bike.
Goes back to trial with db killer at back of midpipe in front of muffler and sleeve midpipe down if the fault goes away discarding the db killer. I am picking the midpipe is a little fat. With a $400 budget its the only way to find out without committing mega monies.

Or buy a tuned system you know is correct but they are not cheap.
Idd like a new system for mine but they are priced the same as many new lams bikes.

what he is saying is 1/ believe your engine builder as he knows more than a random poster on KB...
and 2/ The leo vince system doesn't work with that cam/head combo but the yosh one does....

My own very limited experience of leo vince systems pointed to the same thing, not a bad road system but change the camming and there were problems...

[mossy1200]

what he is saying is 1/ believe your engine builder as he knows more than a random poster on KB...
and 2/ The leo vince system doesn't work with that cam/head combo but the yosh one does....

My own very limited experience of leo vince systems pointed to the same thing, not a bad road system but change the camming and there were problems...

Don't doubt you but OP original post has a $400 budget. Bet he wasn't told he would find a complete Yoshi system in some ones back yard for that price.
Racing perfect bikes doesn't leave any room for a budget. $400 is 2/3rd of the price of a set of slicks.
Does Frosty want to win or turn up. If its win then pay 2.2k for a system that his tuner is asking for. That's cool. I know how to spend money racing bikes.

[Gremlin]

Aftermarket exhaust systems have been proven in the past to often provide very little gains, sometimes even being worse than stock. Others can yield good gain.

Obviously that varies from brand to brand, but is one major reason why the likes of akra, yoshi etc cost more than the cheap systems. A lot more R&D has gone into design.

FWIW, when I had a Racefit, with baffle in, there was a hole the tuner couldn't correct, that was easily solved with the baffle removed.

Essentially as Drew said, trust the engine tuner/builder over others eh?

[mossy1200]

Aftermarket exhaust systems have been proven in the past to often provide very little gains, sometimes even being worse than stock. Others can yield good gain.

Obviously that varies from brand to brand, but is one major reason why the likes of akra, yoshi etc cost more than the cheap systems. A lot more R&D has gone into design.

FWIW, when I had a Racefit, with baffle in, there was a hole the tuner couldn't correct, that was easily solved with the baffle removed.

Essentially as Drew said, trust the engine tuner/builder over others eh?

And open up wallet to match expectations.

[Grumph]

And open up wallet to match expectations.

Another reason I like building classic and post classic race bikes - I build the pipe myself to match just what I've done to the motor.
Generally cheaper for the customer too. Not a lot of genuine period race pipes floating around....

[mossy1200]

Another reason I like building classic and post classic race bikes - I build the pipe myself to match just what I've done to the motor.
Generally cheaper for the customer too. Not a lot of genuine period race pipes floating around....

Same had cycleworks build a midpipe and muffler to extend a Yoshi header on the posty then bought and tuned new flatslides and 1040 kit plus headwork to suit the lack of exup system after wasting thousands trying to match things up.

My point was always if the budget is $400 then perfection cant be high on the list. Someone trying to find a perfect lap time is going out on new rubber every race day at 600-700 so 2.2k on a pipe isn't that much.
You cant have a perfect bike on a budget. Unless you have bought some one else's perfect bike that doesn't need changed.

[Drew]

I wasn't having a dig at all Steve. Just pointing out that 'back pressure' is a misleading term that's often misunderstood. Interesting that you mention cycle works. A mate's bike has a full system from there...it's bloody terrible. Has two 90° bends that are incredibly tight, joined straight together.

The wise and knowledgeable Grumph kindly gave me the details of the pipe he made for the same motor. This $1500 costom system is oversized in length and diameter from the head to the muffler. The result is a hole at 8K. A shit of a spot to not have power on tap on an old CBR600.

[Shaun Harris]

Frosty, contact Suzuki NZ Direct! for a complete Yoshi System man, and I will take your one off you. And well said Drew

[mossy1200]

Theres more info that would be handy.

Is Frosty racing competitively?
Is the bike a successful F2 bike that hes purchased that's had its good system removed.

I don't know Frosty or how he rides but is it possible hes riding in a rev range the previous owned never spent any time in.
Its hard if your asking a tuner to fill a hole that was put in a bike to obtain top end power.
Has Frosty ridden the bike often enough to be riding it in its power band all the time or is this tuning repairs after one or two outings?

A full description of what is on Frosty's bike would be good and maybe even who raced it prior.
Has anyone else ridden it lately?

I spent money dyno tuning and had some impressive numbers only to find out the bike had no control under part throttle. It was either throttle on or off. Tuning is frustrating and costly. Does Frosty have someone that can do some laps to give him a run down of how the bike compares to others if its Frosty's first F2 bike.

[Drew]

Frosty is older now, than when he was mid pack in F3.

Ray Clee is the builder. So his word is pretty solid on what it needs. If the previous owner was a demon and could keep it on song, there's every chance Tony won't.

[mossy1200]

Frosty is older now, than when he was mid pack in F3.

Ray Clee is the builder. So his word is pretty solid on what it needs. If the previous owner was a demon and could keep it on song, there's every chance Tony won't.

Ray would be one of the best but it would be nice to know on the track where the hole is and how big. I left a hole in mine deliberately to gain more up top but left it low enough down to only go through it once off the start line. The joys of exup removal.

It is a problem trying to solve issues to perfection without a very open wallet.
Wonder if Frosty has done enough laps yet to start the spend or has the frustration of knowing he could be faster than hes circulating at the moment. Maybe slightly bigger rear sprocket until lapping quicker and then another gearing change might miss the hole.

Has the transition been from a bike with good midrange to a peak power bike.

Just alternative ideas not intended as instructions.

[Shaun Harris]

'Back pressure' is a really misleading and counter productive term. People need to stop saying it.

It's all about pipe length and size, creating the much needed 'correct' velocity to maximise the gains from valve overlap. Play with yer cam timing, and you're doing half the job. Play with the exhaust dimensions and you are usually making more noise and little else.


To add to your comments here Drew

"It depends on where you want power. If you want maximum power at high rpms only you want low back pressure, think top fuel dragster. If you want a certain power characteristic, you want back pressure. More specifically you want a timed high pressure pulse to arrive at the exhaust valve at a specific time to push unburned gasses back into the cylinder to improve combustion, or to help pull spent gasses out of the cylinder after combustion.

It isn't the back pressure as much as wave timing and resonance to optimize the burn.

[Shaun Harris]

Ray would be one of the best but it would be nice to know on the track where the hole is and how big. I left a hole in mine deliberately to gain more up top but left it low enough down to only go through it once off the start line. The joys of exup removal.

It is a problem trying to solve issues to perfection without a very open wallet.
Wonder if Frosty has done enough laps yet to start the spend or has the frustration of knowing he could be faster than hes circulating at the moment. Maybe slightly bigger rear sprocket until lapping quicker and then another gearing change might miss the hole.

Has the transition been from a bike with good midrange to a peak power bike.

Just alternative ideas not intended as instructions.


I know the bike and Frosty's problem. The motor is standard and has never been raced. Bike now has Yoshi ECU with fuel mapping by Ray Clee. The Dyno chart shows a big hole at around 8 RPM, and it is a big hole to ride through

[FROSTY]

Hey Mossy --sorry dude I'll try again.
The bike was a road bike pretty well standard before I bought it.
Plan was to build a 450 triple for F3 but do a shed load of laps with it in standard form before ripping the head off.
So suspenders are race ready,The engine has been gone over but not tweaked at all. It was fitted with a Yosh ECU now and a full Leo Viince exhaust. Basicly legally speaking it could go out and race at national level.
Ive owned/ridden other K7 gixxers so know how even in stock form they should make power.
This bike has a MASSIVE hole in the power curve.Yes I can and do ride around it by getting revs up higher and using the clutch more.
But it needs to have as much midrange as I can give it so when it goes to 450 Its actually rideable-The 450 leaves it low on midrange.
Ray said the K7 isn't particularly strong at that rev range but mine is really bad. he said the exhaust was the cause and a yosh system would work on the bike.
Simple fact is that its not fun to ride
The $400 was just a number in a box.-maybe I shoulda put $1 and noted the lack of any budget issues.

[mossy1200]

Hey Mossy --..... of any budget issues.


All good. I like to fish around in the thread until I have the full story.
Its safer than joining Ashley Madison.


You may find an end can as the insurance companies have been selling surface scratched parts on trade me. Then you would just need the front and midpipe.

I got a Yoshi headers set for my race bike second hand from US for 60 plus another 60 freight a long time ago but it was from a fzr1000 site and not ebay and it was bash damaged with splits that needed shaped and welded.
I found a front back system for yours within 10 mins when I first looked which was $1800 plus you would get the 15% gst and incoming cost of another $50 approx.

Chance of a second hand system in NZ would be low but I put it on my quick search daily on tardme.
If one comes up I would say 10 people will all want it and it will hit half its new price quickly.

http://www.trademe.co.nz/motors/motorbikes/parts-for-sale/exhaust/auction-937239302.htm

Theres the back bit if you don't mind ss