Jets vs Exhaust

[mlinder]

Have you done anything to it, so far?

 

[tkent02]

Took most of it apart, put some of it back together, derusted the tank, painted the frame, scrounged up a lot of parts, including a 650 top end, removed about 17 lbs of leaves, muck and slime. Adjusted the valves, cleaned the carbs, cussed out the PO. Fixed a few leaks. Same old stuff they all need.
It hasn't run in decades.
Yet.
And yours?

 

[mlinder]

Oh, runs fine after 10 years of not running. Better after rejetting, etc...
All of em, actually.

My question was to see if you had a running one. I think you'd be surprised. I was going to send you main jets and have you run your bike against them with stock jetting and airbox, and then after deristriction and rejetting. The difference really is extraordinary on the 550. Most responsive bike I have/have had to such changes.

 

[tkent02]

The difference really is extraordinary on the 550. Most responsive bike I have/have had to such changes.

Cool, I believe that part, and I can't wait. But I'll have to wait, doing a bit of traveling. I'll get it going in a couple months. What size jets did you end up with?

 

[mlinder]

You're going straight to a 650 top end. Different story for you.

I run 110's with stock airbox and filter, with the box-top removed.

 

[posplayr]

If you research exhaust systems like you did regulators you could know what kind of HP you should have.

apparently you are excessively qualified at making unqualified statements on subjects for which you are not qualified.

 

[Graham]

apparently you are excessively qualified at making unqualified statements on subjects for which you are not qualified.

Yea, not qualified after 27 years of motorcycle repair. What is your qualification?

 

[posplayr]

Yea, not qualified after 27 years of motorcycle repair. What is your qualification?

Here is another idea; Instead of us sending you high school report card, Why don't you qualify your statement so it has a shred of validity?

 

[tkent02]

Why don't you qualify your statement so it has a shred of validity?

How on Earth would you qualify a 25% gain?

 

[posplayr]

How on Earth would you qualify a 25% gain?

Assuming Graham has learned something in "27 years of motorcycle repair" (yet another one of his unqualified statements) ,

then there is probably (a qualification of my thesis) some rational reason for his statement. I think I know what it is; the question is does he know what it is and can he articulate it? :-\\\

 

[tkent02]

Maybe it's 27 years of selling pipes with bogus claims about horsepower increases.

 

[Guest]

Wuh Whoa here we go

 

[Graham]

Here is another idea; Instead of us sending you high school report card, Why don't you qualify your statement so it has a shred of validity?

I remember back in the day, a GS1100 on the dyno pushing 127hp stock with a Yoshimura header. A stock GPZ750 turbo running 130hp with a Kerker system. My stock 77 KZ650 ran 78hp with a Mac and a missing air filter. Back in the 80s aftermarket exhaust manufactures claimed 15 to 20% increase in hp (witch was true). The other 5% I guessed from the pods increased airflow. If you don?t find any validity in my statements then don?t get a header system.

 

[Graham]

Maybe it's 27 years of selling pipes with bogus claims about horsepower increases.

Restrictive factory exhaust system changed to a free flowing system that will scavenge the exhaust gasses. More exhaust gas out means more fuel mix in which equals more CFM. Gee bigger valves and a performance cam will do that too, more CFM. Does more CFM in and out of motor equal more HP?

 

[posplayr]

I remember back in the day, a GS1100 on the dyno pushing 127hp stock with a Yoshimura header. A stock GPZ750 turbo running 130hp with a Kerker system. My stock 77 KZ650 ran 78hp with a Mac and a missing air filter. Back in the 80s aftermarket exhaust manufactures claimed 15 to 20% increase in hp (witch was true). The other 5% I guessed from the pods increased airflow. If you don’t find any validity in my statements then don’t get a header system.

I think something must be fading ....................

Here is a thread that will give you an idea of what it takes to add 25% to a stock 1100. It is alot more than a Yoshi pipe.


http://www.thegsresources.com/_forum/showthread.php?t=137631

So do you still claim that just a Yoshi pipe will give 15% increasein hp????

 

[tkent02]

So do you still claim that just a Yoshi pipe will give 15% increasein hp????

No, he never claimed 15% increase, he claimed 25%.

Restrictive factory exhaust system changed to a free flowing system that will scavenge the exhaust gasses. More exhaust gas out means more fuel mix in which equals more CFM. Gee bigger valves and a performance cam will do that too, more CFM. Does more CFM in and out of motor equal more HP?

All true, that's how it works. I have put pipes on a lot of my bikes, they usually go a little better.

Pods too, sure a little better on top once the jetting is figured out. I never said I didn't like them. I just said it's not going to get 25% more.

 

[posplayr]

No, he never claimed 15% increase, he claimed 25%.


.

I know but he obvioulsy can't even begin to explain 25% so maybe 15%. That (15%) would only be over three times normal for just a stock motor

 

[Graham]

I think something must be fading ....................

Here is a thread that will give you an idea of what it takes to add 25% to a stock 1100. It is alot more than a Yoshi pipe.


http://www.thegsresources.com/_forum/showthread.php?t=137631

So do you still claim that just a Yoshi pipe will give 15% increasein hp????

15 to 20% over stock with the right jetting. The bike in the thread is not stock and as should know one mod can take away from another.
If you read back I first said about 25% for header + pods + jetting. I also said I guessed at 5% for the airflow incraese of the pod filter which left about 20% for the header.
Now if you or tkent02 are unable to get about 25% from your good header + good pods + jetting on a stock GS you just bring it down here to Florida and I'll show you how.
The nitpicking is getting no where.

 

[tkent02]

Surely in 27 years someone has put one of these bikes on a dyno, before and after? 6%, maybe 8%?
Maybe 10% gain from opening up a real corked up dog?
That's all we need. Some dyno results.
Real numbers on a real bike.
Let's see it.

 

[Graham]

Surely in 27 years someone has put one of these bikes on a dyno, before and after? 6%, maybe 8%?
Maybe 10% gain from opening up a real corked up dog?
That's all we need. Some dyno results.
Real numbers on a real bike.
Let's see it.

That was like 84 or 85 and by 87 the stock exhaust was getting so close to aftermarket header performance you could no longer get double digit %HP from a header. The GS, KZ, CB and XJ were the last to get the big HP from the header.