What size header do I need?

[andy198712]

Hello,

I'm looking to replace my temporary empi quiet pack in next few months with something more fitting (although surprisingly it fits very well) currently it's 1 3/8 I believe.

The spec is
2110 (90.5x82)
044 heads 40x35.5
86b
Will be gsxr ITBs In a 72beetle


I'm looking pretty much at sidewinders due to the sleeper look and the ground clearance, 1 outer spline down in the rear and the current quiet pack catches certain speed bump on the mufflers seam. And that's with it making full use of the bump stops
I don't think a mondo style would very well here....

So is 1 1/2 going to be ok or do I need 1 5/8 or.....?

Thanks

Andy

[Zach Gomulka]

As a rule of thumb you correspond the header size to the exhaust valve, 35.5 exhaust would use a 1 1/2" header. In this case you have quite a bit of displacement so a 1 5/8" would be my choice. Either one is ok, smaller exhaust may give you a little more torque, larger may give you a little more HP.

[Iryanu]

My engine is pretty much the same as yours, except you have a much bigger cam. I run a 1 5/8" stainless vwspeedshop sidewinder, which is currently for sale in the for sale section. So I reccomend that exact one.  

84x90.5 2161cc
Web 111 camshaft (276° 0.476" lift)
Ported & polished heads by RNJ Motorsport 40x35.5 valves
Dual 44IDF
VW speedshop 1 5/8" stainless sidewinder exhaust and muffler

Was recommended it by stateside who did all the machining / balancing, and Rob at RNJ who put it all together had no objections.

Ryan

[andy198712]

As a rule of thumb you correspond the header size to the exhaust valve, 35.5 exhaust would use a 1 1/2" header. In this case you have quite a bit of displacement so a 1 5/8" would be my choice. Either one is ok, smaller exhaust may give you a little more torque, larger may give you a little more HP.

Cheers bud, here's a question, is the exhaust sizing ID or OD?
Lime bug said there header was 1 9/16 ID....
Thanks

[andy198712]

My engine is pretty much the same as yours, except you have a much bigger cam. I run a 1 5/8" stainless vwspeedshop sidewinder, which is currently for sale in the for sale section. So I reccomend that exact one.  

84x90.5 2161cc
Web 111 camshaft (276° 0.476" lift)
Ported & polished heads by RNJ Motorsport 40x35.5 valves
Dual 44IDF
VW speedshop 1 5/8" stainless sidewinder exhaust and muffler

Was recommended it by stateside who did all the machining / balancing, and Rob at RNJ who put it all together had no objections.

Ryan

I have looked at your for sale thread lovingly many times!
I'm pretty tempted by the ones that poke the muffler tip away from the car though for dust kick up and sound in the car? Although the speed shop item would be very high quality.
But having just paid off my credit card I need to wait a month or two to recover!

[Udo]

42 mm outside diameter ,do not know in inches right now

Udo

[andy198712]

42 mm outside diameter ,do not know in inches right now

Udo

1 5/8 is 41.2mm so probably that. Thanks Udo

[Iryanu]

42 mm outside diameter ,do not know in inches right now

Udo

1 5/8    = 1.6250"    = 41.2750mm 

[Iryanu]

I have looked at your for sale thread lovingly many times!
I'm pretty tempted by the ones that poke the muffler tip away from the car though for dust kick up and sound in the car? Although the speed shop item would be very high quality.
But having just paid off my credit card I need to wait a month or two to recover!

Can't say I noticed it too much, but without knowing the difference, maybe it does do that. What over the straight cut cam gears and the solid mounted engine and gearbox / no soundproofing it's not been an issue. Haha!

Ryan

[Zach Gomulka]

As a rule of thumb you correspond the header size to the exhaust valve, 35.5 exhaust would use a 1 1/2" header. In this case you have quite a bit of displacement so a 1 5/8" would be my choice. Either one is ok, smaller exhaust may give you a little more torque, larger may give you a little more HP.

Cheers bud, here's a question, is the exhaust sizing ID or OD?
Lime bug said there header was 1 9/16 ID....
Thanks

It is measured by OD.

[andy198712]

As a rule of thumb you correspond the header size to the exhaust valve, 35.5 exhaust would use a 1 1/2" header. In this case you have quite a bit of displacement so a 1 5/8" would be my choice. Either one is ok, smaller exhaust may give you a little more torque, larger may give you a little more HP.

Cheers bud, here's a question, is the exhaust sizing ID or OD?
Lime bug said there header was 1 9/16 ID....
Thanks

It is measured by OD.

Thanks Buddy

[andy198712]

I have looked at your for sale thread lovingly many times!
I'm pretty tempted by the ones that poke the muffler tip away from the car though for dust kick up and sound in the car? Although the speed shop item would be very high quality.
But having just paid off my credit card I need to wait a month or two to recover!

Can't say I noticed it too much, but without knowing the difference, maybe it does do that. What over the straight cut cam gears and the solid mounted engine and gearbox / no soundproofing it's not been an issue. Haha!

Ryan

 

[Sarge]

As a rule of thumb you correspond the header size to the exhaust valve, 35.5 exhaust would use a 1 1/2" header. In this case you have quite a bit of displacement so a 1 5/8" would be my choice. Either one is ok, smaller exhaust may give you a little more torque, larger may give you a little more HP.

Try something different and use BOTH sizes; stepped... more torque AND more power!!  Having had an 1 5/8" in both a conventional and a sidewinder then remembering Fumio's 1 1/2" advice from years ago,
I had A-1 build a stepped header to try.  My engine is small compared to most; a 2017 with an Engle 125 cam and 35.5X40mm valves.  The stepped header works out well for a mid-size motor.

[Jeff68]

Andy...my experience - I think you need to go to a 1 5/8 header, and a step header would be best.  My 2110 with 42 X 37.5 valved ported heads has a 1 5/8 header and it's too small. Considering your valve size is a step smaller I think you would need the next step larger header, a 1 5/8. I too am in the market for a new header, I need a 1 7/8 but I will go with a step header. Just have to save some $$ and buy one.

[Joel Mohr]

Pic of my 3 step....I found it's best to stay with a "conventional" primary. Yes, you can "over scavenge" the chamber. For yours, I would use a 1 1/2 primary 3 step, or a 1 5/8ths 2 step...and the dyno proves it...more torque and more power than even a sidewinder. And much better than a conventional merge with a "Fat Boy".....

[andy198712]

Would be cool but I've not seen them for sale in the uk?
That last one looks nice and tucked up too

I'm still swinging towards sidewinder due to fitting up in the valance and availability in stainless...? But 1 5/8 is going to be the size to go for it seems

[Joel Mohr]

Made in California...I can ship....550 raw, 750 in black ceramic...

[Sarge]

    "I'm still swinging towards a sidewinder...."

You really need to spend some time in a car with a sidewinder before committing to actually owning one.
My car ran hotter and had more vibration and noise in the cabin... it DID look nice though!

[andy198712]

    "I'm still swinging towards a sidewinder...."

You really need to spend some time in a car with a sidewinder before committing to actually owning one.
My car ran hotter and had more vibration and noise in the cabin... it DID look nice though!

Did it have the short turn down end pipe?

[andy198712]

Made in California...I can ship....550 raw, 750 in black ceramic...

Getting out of my price range a bit sadly, thanks though!

[robkong]

Joel,   Will your header fit a ghia?

[cedric]

I am running a-1 lowdown,pretty good,engine cooler,but to loud for me..still tinking wich mufler i need for me..or cut mine open and put more stuff in it...

[Sarge]

   ...."Did it have the short turn down end pipe?"

Yep, here's a pic.   Exhaust noise and rumble seemed amplified by exiting inside the fender-well.  I thought about modifying that but it would have ruined the "look."
Another thing to consider was having to space the traction bar down about an inch to clear the primary pipes.  It's never easy; good luck!

[andy198712]

That's cool, completely hidden,
Something that's playing in my mind is make my own muffler setup maybe with a winder header... I know it's never easy but for me the enjoyment is making stuff.
Manga flow muffler or something....

[Joel Mohr]

Yes, my header also fits Ghias...