Author Topic: Going for the Goldstar Exhaust ! (Read 7041 times)

chanderjeet · **on:** August 06, 2009, 03:10:00 pm

Hello,

So I read about and I saw it online. With my minuscule understanding of mechanics and everything else, I have decided to go for the Goldstar muffler on my AVL 500.

I need your suggestions about everything related to it and things that can go wrong and things that can go right.

I thought to change the pipe only because I like the way it look, I later got to know that there's lot more to exhaust than just farting.

Help,
Chanderjeet

Thumper · **Reply #1 on:** August 06, 2009, 06:26:26 pm

There's also a version of my notes at:

http://members.verizon.net/allofusmorrows/PerfUpgrade.htm

Matt

UncleErnie · **Reply #2 on:** August 07, 2009, 02:05:45 am

If it has a baffle and everything else is stock, I'd just run it as is and see how it works out. If the performance seems to be affected in a bad way, then it's time to diagnose a problem.

REpozer · **Reply #3 on:** August 07, 2009, 04:10:34 am

straight pipe- Is an exhaust pipe with no baffles,or fiberglass. Just a pipe or a straight piece of pipe fitted to exhaust out to the rear .Or a simple pipe.

1Blackwolf1 · **Reply #4 on:** August 07, 2009, 04:38:47 am

Also considered to be obnoxiously loud, like wake the dead loud. And usually reduces exhaust back pressure enough to choke off engine performance. Generally loved by the law enforcement community. Will.

Rick Sperko · **Reply #5 on:** August 07, 2009, 02:00:21 pm

Quote from: chanderjeet on August 07, 2009, 04:02:10 am

Hello,

So to be honest, everything on my bike is still stock and came with a BS29 factory fitted carb. I'm not sure about the pilot and main jet sizes. Whats a straight pipe, I know not, im posting a pic of my bike thinking you can figure out much more from the pic that asking me. Coz i dont know much :stupidme

That is a pretty cool pack-mule you have there. Looks like a fun adventure. Sorry, no AVL advice from me.

-Rick

ace.cafe · **Reply #6 on:** August 07, 2009, 02:31:41 pm

I use a Gold Star exhaust system on my Iron Bullet.

It's louder than stock, but I don't find it objectionable at all, and I've never had anyone complain about it. And I run it without any baffle, straight open. The small baffle is removable, so you can easily have the baffle in or out, whichever way you prefer.

I also have no problems from any reduced backpressure, and have my carb jetted to suit it, and it gives a good performance increase. But the carb jetting must accommodate it, or you will have problems.

One thing that you will notice is that it makes a "chirping sound" when you close the throttle on deceleration, which is a characteristic of the original Gold Star(BSA) system, and they faithfully achieved that sound on this copy. So, it will "chirp" just like a BSA Gold Star DBD34 does, on deceleration.
Some people like that, and others might not like that.

I like my Gold Star exhaust system, and when the time comes to replace it, I'll buy another one.

UncleErnie · **Reply #7 on:** August 07, 2009, 03:56:16 pm

Assuming he keeps the air delivery stock, what jet changes do you recommend?

ace.cafe · **Reply #8 on:** August 07, 2009, 04:03:50 pm

Quote from: UncleErnie on August 07, 2009, 03:56:16 pm

Assuming he keeps the air delivery stock, what jet changes do you recommend?

I have no idea.
The AVL uses a completely different carb design, and different jets, than what I have.
That will be a question for those with AVLs, who have experimented with rejetting.
All I can say is that it is likely to need richer jetting.

UK-Classics · **Reply #9 on:** August 08, 2009, 09:35:37 am

Not seen anyone running goldie with standard setup - most uk guys tend to either stick with the stock avl or go down the route of removing pav system, straight pipe, carb upgrade etc. I can't see the any probs putting the goldie on current setup - I understand (from others) that the cv carb is fairly forgiving, you may get away without jet change - you could run it for a few miles & check it's not running too lean - if it is then you need to go up a jet size or two!

Another thought! Is the Indian home model the same as our export avl?

chanderjeet · **Reply #10 on:** August 10, 2009, 04:02:48 am

This is the same as export model AVL.

1Blackwolf1 · **Reply #11 on:** August 10, 2009, 12:21:26 pm

I removed the PAV, opened the air system with a K & N, and installed a cocktail shaker on my wifes' Electra. Went to a 20/125 jet set-up and all is well. Wouldn't have got away without rejetting. Will.

chanderjeet · **Reply #12 on:** August 11, 2009, 03:56:17 am

Whats a PAV ?

Thumper · **Reply #13 on:** August 11, 2009, 12:24:12 pm

Quote from: chanderjeet on August 11, 2009, 03:56:17 am

Whats a PAV ?

Pulsed Air Valve

Rudimentary emissions stuff.
From the early days of emissions control - the 70's.

It pumps air back into the sytem to burn unspent gases in the exhaust. I think.

Matt

chanderjeet · **Reply #14 on:** August 11, 2009, 01:03:01 pm

You guys gave all the info needed to do all sorts of mods on an RE.
I've been reading a lot about jets and carbs and drilling holes and what not.
I think i understand most of it but Im a bit reluctant to do it all myself till I truly understand what am I doing. (i.e. which screw do i open and which part i pull out , yes, I am a numbskull mech)

Thanks, there isnt a step by step (pictorial) thread for rejetting a BS29, is there?

Cabo Cruz · **Reply #15 on:** August 20, 2009, 11:51:01 pm

That's a very cool looking Bullet, Br. Bong!!! I also have the Gold Star header pipe and muffler on Perla (Pearl in Spanish), which is of the Iron Lung variety. (The PAV went into the trash can!!!)

chanderjeet · **Reply #16 on:** September 07, 2009, 02:04:33 pm

Great looking bike. I have been thinking of white tires. They look so kool.
Where'd get those from?

soulforge · **Reply #17 on:** September 07, 2009, 05:00:26 pm

Quote from: chanderjeet on September 07, 2009, 02:04:33 pm

Great looking bike. I have been thinking of white tires. They look so kool.
Where'd get those from?

My white walls are MAXXIS tires. They are a Taiwanese brand.
I believe it can be possible to obtain through web search.

chanderjeet · **Reply #18 on:** September 12, 2009, 04:37:56 pm

I did it.

Changed the stock long exhaust to a Chennai Megaphone otherwise known as the Goldstar.

Observations:

The low end torque has gone for a toss.
I have to throttle a lot.
The sound is anti-social. The extra decibels will only get me in trouble. (sweet)
It does feel like its going a bit faster but then im throttling a lot more.

I got it checked from the mech and he confirmed my doubts. I need a new set of clutch plates.

I will post again once the clutch plates have been changed.

BTW, could tightening up clutch do this ? By this I mean, it seems like the engine is churning good power but its not reaching the final drive.

1Blackwolf1 · **Reply #19 on:** September 12, 2009, 06:12:44 pm

It's called clutch slip. And you can lose a lot of power/torque to the rear wheel since the clutch isn't completely engaging/or the discs (friction material) is glazed. Will.

ace.cafe · **Reply #20 on:** September 12, 2009, 11:02:02 pm

Quote from: chanderjeet on September 12, 2009, 04:37:56 pm

I did it.

Changed the stock long exhaust to a Chennai Megaphone otherwise known as the Goldstar.

Observations:

The low end torque has gone for a toss.
I have to throttle a lot.
The sound is anti-social. The extra decibels will only get me in trouble. (sweet)
It does feel like its going a bit faster but then im throttling a lot more.

I got it checked from the mech and he confirmed my doubts. I need a new set of clutch plates.

I will post again once the clutch plates have been changed.

BTW, could tightening up clutch do this ? By this I mean, it seems like the engine is churning good power but its not reaching the final drive.

It's not just the clutch.
The Goldstar exhaust is designed for hp at higher revs, and not for low end torque.

You may have clutch slip too.
But in the Iron Barrel Bullet, the Goldstar system raises the torque peak by 500 rpm.
The low end is not as reinforced by the Goldstar system.
It may likely have similar effects for the AVL.

I like the sound. I run mine with no baffle at all. Straight thru.

chanderjeet · **Reply #21 on:** September 13, 2009, 05:55:11 pm

For Mr Ace.Cafe,

So you are saying that I have lost the low end torque forever?
There must be something that can be done to get it pulling as usual apart from pulling out the carb and making the jet changes. I don't know how to do that. Not sure even if we can find the jets for the size needed here.

~Chanderjeet

Cabo Cruz · **Reply #22 on:** September 13, 2009, 06:01:09 pm

"I like the sound. I run mine with no baffle at all. Straight thru." ace.cafe

Amen, amen and amen!!!

chanderjeet · **Reply #23 on:** October 02, 2009, 07:13:09 pm

Got 'er done.

She sounds anti-social now. Envy of the neighbourhood.

Cabo Cruz · **Reply #24 on:** October 03, 2009, 01:55:29 am

Looking good, Br. Bong!!!

chanderjeet · **Reply #25 on:** October 03, 2009, 03:14:03 pm

And today I got the clutch loosened. I should really learn these little things so im self dependent. But its running much more better. Good response. A little (very little) response lag but nothing too worrying.

chanderjeet · **Reply #26 on:** October 04, 2009, 01:23:15 pm

So what should I do? Check the plug for black soot?

ace.cafe · **Reply #27 on:** October 04, 2009, 04:20:23 pm

Quote from: chanderjeet on September 13, 2009, 05:55:11 pm

For Mr Ace.Cafe,

So you are saying that I have lost the low end torque forever?
There must be something that can be done to get it pulling as usual apart from pulling out the carb and making the jet changes. I don't know how to do that. Not sure even if we can find the jets for the size needed here.

~Chanderjeet

No, you haven't lost the low end torque forever.

Normally, at least in the Iron Bullets, the Goldstar pipe has a larger inside diameter than the stock pipe. The GS pipe is thinner walled, and bigger inside.
This moves the torque peak up the rpm range by about 400 rpm.

I'm not certain if this diameter change is present on the AVL Goldstar pipe, but it might be.
In any case, next time you have it off, you can compare the inside diameter to the stock pipe. If the stock pipe is smaller I.D. then you can find a piece of suitable thin tubing to slightly sleeve-down the inside diameter of your Goldstar pipe(where it joins the head, and as far out toward the bend as you can), and that will help to bring down the rpm at which you reach torque peak.