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Sat Jul 16, 2016 10:03 am

Looking to up my header size to 1-5/8" on my 2109

Cant decide between the CB with my Bugpack hideaway muffler
http://www.cbperformance.com/product-p/3658.htm

Or the AA system that comes with a muffler
http://aapistons.com/collections/sidewinders/products/aa-sidewinder-ex-system-1-5-8-w-muffler

I've heard the AA system is loud

My current set up is a Berg 1-1/2", I like the sound I just think 1-5/8" will perform better

Sat Jul 16, 2016 11:05 am

You have to tell us whether you're after performace or sound. For performance, the best way to know FOR SURE is to either dyno test or invest in a wideband. The wideband will let you know if the exhaust is more efficient or not for your particular engine combination. No one can actually tell you what exhaust works best unless they actually have or had the same combo as you and have tested.

Weld a bung onto your current system, tune it, pull the exhaust off and install your new system with an O2 sensor bung, test that one. If you need to richen up certain areas, it flows better. If your jetting is too rich, put your old one back on.

Sat Jul 16, 2016 11:16 am

The AA is "louder" cause it has a performance type muffler. Your running a quiet pack style muffler that is well....quiet..... Its not a performance muffler in any way.

If you like the Hide-A-Way style, I would spend $50 more then that AA setup you mentioned and get the same thing in Stainless from Carcraft:

http://carcraftstore.com/sidewinder158exhaustsystem.aspx

You will definitely notice a difference in power from what you have now. For $50 more, you get something that doesn't rust and turn to crap. Its so much nicer to work with. $350 for a complete stainless system is a great deal.

Sat Jul 16, 2016 11:42 am

[quote="jpaull"Your running a quiet pack style muffler that is well....quiet..... Its not a performance muffler in any way. [/quote]
That's a generalization that's not true for every quiet pack.

Gene Berg GB-933S 1-5/8" merged, GB-971A-2M dual muffler

This was on for less than a day. It was loud, obnoxious and had less bottom end than the dual QPs.

Sat Jul 16, 2016 12:10 pm

Not a fair comparison that your making. You have TWO quiet packs. Once you give your exhaust that much space to flow its not much of a restriction.

Force all your exhaust through ONE quiet pack and my statement is true, its not a performance muffler.

Jeff

Glenn wrote: [quote="jpaull"Your running a quiet pack style muffler that is well....quiet..... Its not a performance muffler in any way.
That's a generalization that's not true for every quiet pack.

Gene Berg GB-933S 1-5/8" merged, GB-971A-2M dual muffler

This was on for less than a day. It was loud, obnoxious and had less bottom end than the dual QPs.
[/quote]

Sat Jul 16, 2016 12:55 pm

jpaull wrote: Not a fair comparison that your making. You have TWO quiet packs. Once you give your exhaust that much space to flow its not much of a restriction.

Force all your exhaust through ONE quiet pack and my statement is true, its not a performance muffler.

Jeff

1776 dual 36 Dells, ported heads 40x35 single HD springs, all balanced with a single QP.

It ran great for 87,000 miles.

Sat Jul 16, 2016 1:37 pm

Very cool Glenn. Always good to see people put some real miles on their Vw's. (You woulda had more power with your dual quiet packs or anything else then that single though) :D

Glenn wrote: jpaull wrote: Not a fair comparison that your making. You have TWO quiet packs. Once you give your exhaust that much space to flow its not much of a restriction.

Force all your exhaust through ONE quiet pack and my statement is true, its not a performance muffler.

Jeff

1776 dual 36 Dells, ported heads 40x35 single HD springs, all balanced with a single QP.

It ran great for 87,000 miles.

Sat Jul 16, 2016 2:19 pm

jpaull wrote: Very cool Glenn. Always good to see people put some real miles on their Vw's. (You woulda had more power with your dual quiet packs or anything else then that single though) :D

Glenn wrote: jpaull wrote: Not a fair comparison that your making. You have TWO quiet packs. Once you give your exhaust that much space to flow its not much of a restriction.

Force all your exhaust through ONE quiet pack and my statement is true, its not a performance muffler.

Jeff

1776 dual 36 Dells, ported heads 40x35 single HD springs, all balanced with a single QP.

It ran great for 87,000 miles.

I disagree. You need back pressure. Too much flow hurts power.

Sat Jul 16, 2016 3:42 pm

Once your exhaust gets to the muffler flange its met all the backpressure it needs providing your header is proper size. This is why someone can run a open stinger on a vw. Annoying as hell but they work.

I ran 5 exhausts an a 1600 stock but dual carbs and lowest restriction had the most power. The single quiet pack was the slowest. Experience is king, if you tried them all and more restriction works for you then great.

[/quote]
I disagree. You need back pressure. Too much flow hurts power.[/quote]

Sat Jul 16, 2016 4:19 pm

If you want to use the same merged hideaway muffler then just get a Berg 1 5/8" since the flanges will match up. Al's headers make them so you can look for that.

If you are looking for something different and to make power look at a Mohr stepped header with muffler set up..
http://www.mohrprf.com/products/stepheader.htm

Sat Jul 16, 2016 5:07 pm

jpaull wrote: Once your exhaust gets to the muffler flange its met all the backpressure it needs providing your header is proper size. This is why someone can run a open stinger on a vw. Annoying as hell but they work.

I ran 5 exhausts an a 1600 stock but dual carbs and lowest restriction had the most power. The single quiet pack was the slowest. Experience is king, if you tried them all and more restriction works for you then great.

I disagree. You need back pressure. Too much flow hurts power.[/quote][/quote]

So you're saying a header with a stinger gives enough back pressure for street use?

You've just lost the debate.

Sat Jul 16, 2016 6:01 pm

Glenn wrote: jpaull wrote: Once your exhaust gets to the muffler flange its met all the backpressure it needs providing your header is proper size. This is why someone can run a open stinger on a vw. Annoying as hell but they work.

I ran 5 exhausts an a 1600 stock but dual carbs and lowest restriction had the most power. The single quiet pack was the slowest. Experience is king, if you tried them all and more restriction works for you then great.

I disagree. You need back pressure. Too much flow hurts power. [/quote]

So you're saying a header with a stinger gives enough back pressure for street use?

You've just lost the debate.[/quote]

I have to say that I disagree with your statement. I once believed that, because that's what everyone said, just like almost everything in our hobby. The more reading I did (Four Stroke Performance Tuning, several David Vizard books, How To Build Horsepower, The Design And Tuning Of Competition Engines, several online write-ups and articles), the more I truly believe that engines need high gas velocity/low backpressure. What your preaching is a myth, unless you can find some current literature to back your belief.

Sat Jul 16, 2016 6:23 pm

In one David Vizard book I read, he went so far as to say ZERO back pressure is ideal. The main goal for best performance is to scavenge so well in the engine's operating range that intake charge is pulled in before the exhaust valve fully closes.

Sat Jul 16, 2016 6:29 pm

Ah the back pressure myth again.

I agree with high velocity with as little back pressure as possible. A restrictive muffler can cause reversion and hurt performance. Its true that anything beyond the collector is just for sound reduction. If the header design, primary tube size/length is optimized for the engine a stinger will work both on the track and street. If a muffler offers little to no back pressure you will not loose power.

On the other hand if the header is too large for the power band a restrictive muffler will make it feel better but its just a bandaid for poor planning.

Sat Jul 16, 2016 7:14 pm

I don't see the difference. old guys call it backpressure, and new guys call it high velocity. So what, i don't think there has been any progress.

Anyhow, your muffler sucks. The tube between the header and muffler is bigger than both, ans that's your main problem.
If you describe heads and cam of this engine I might be able to guess more

Sat Jul 16, 2016 7:21 pm

Quote: So you're saying a header with a stinger gives enough back pressure for street use?

You've just lost the debate.

Yeah I disagree as well, I couldn't tell any performance difference between a stinger and single quiet pack. We need a dyno chart to see the difference throughout the rpms, my bet is the muffler will perform better at low rpm, lower than where most of your driving is.

Sat Jul 16, 2016 7:23 pm

modok wrote:

Anyhow, your muffler sucks. The tube between the header and muffler is bigger than both, ans that's your main problem.
If you describe heads and cam of this engine I might be able to guess more

Cool I was thinking the same thing. Leaning toward the sidewinder anyways.

Sat Jul 16, 2016 7:50 pm

bugguy1967 wrote: I have to say that I disagree with your statement. I once believed that, because that's what everyone said, just like almost everything in our hobby. The more reading I did (Four Stroke Performance Tuning, several David Vizard books, How To Build Horsepower, The Design And Tuning Of Competition Engines, several online write-ups and articles), the more I truly believe that engines need high gas velocity/low backpressure. What your preaching is a myth, unless you can find some current literature to back your belief.
Are we talking race or street engines?

Because using a stinger on the street sucks below 3000rpm.

Sat Jul 16, 2016 9:57 pm

I don't know, I love running a stinger, but it's just too loud to run. I feel more power up top and hit the rev limiter easier, I don't really feel the loss at lower revs, at least not enough to miss. Can still putt around and climb hills. I'd run it more often but it's just too loud, and can be a hazard (I park on the street often).

Stan

Sat Jul 16, 2016 10:17 pm

I'm leaning towards I have no clue.
one way to guess at it: 35.5mm exhaust valve try sidewinder, 37.5mm then stay with classic design header (short tubes)

In either case, the mufflers can be improved. IMO, if you can live with the dragging, then the hideaway is a great layout, but, one size muffler does not fit all, so to get best performance you may need to go muffler hunting.