BTB Zone 6 branch fitted !

[M5pilot]

i got a full exhaust system made by BTB for GUG. the gains are impressive to say the least, here are a few snaps before i put the system on about a month ago... single bore system now replaces the standard dual system...







quality outfit, big thanks to sal for helping me out with this system!

No worries dude,

The GUG deserved it, standard manifold on that engine would never had released the potential.

I've fitted this setup to a 325i and the result was the most amazing noises I have ever heard from an M20 engine.

Get a sound clip up if you can.

Sal

[Templ8e30]

Iain,

what did you have them do to your cylinder head? Im almost ready to get mine sorted and im wondering if i should use these guys, their web site looks like they know what they are doing....

Cheers

Tom

Hi Tom, they did a lot of work to the head.

My head used to belong to a zoner who did some experimentation with it for his 2.7 but never completed it.

They had to cut out quite a bit of corrosion from the water jacket on the inlet side of the head and weld it over, skim and pressure test it, fit new valve guides, recut the valve seats and throats for the bigger valves, reshape the ports to match the new valves and cut the valves and seats to 2 angles for better flow.

They also modded the combustion chambers to un-mask the valves as best they could.

Top quality work though,

Before
http://img137.imageshack.us/img137/889/pict0002dh8.jpg

After
http://img151.imageshack.us/img151/8969/pict0002im9.jpg
http://img137.imageshack.us/img137/2512/pict0004mb0.jpg

Cheers,

Iain T[/url]

[tomson]

Iain,

what did you have them do to your cylinder head? Im almost ready to get mine sorted and im wondering if i should use these guys, their web site looks like they know what they are doing....

Cheers

Tom

Hi Tom, they did a lot of work to the head.

My head used to belong to a zoner who did some experimentation with it for his 2.7 but never completed it.

They had to cut out quite a bit of corrosion from the water jacket on the inlet side of the head and weld it over, skim and pressure test it, fit new valve guides, recut the valve seats and throats for the bigger valves, reshape the ports to match the new valves and cut the valves and seats to 2 angles for better flow.

They also modded the combustion chambers to un-mask the valves as best they could.

Top quality work though,

Before
http://img137.imageshack.us/img137/889/pict0002dh8.jpg

After
http://img151.imageshack.us/img151/8969/pict0002im9.jpg
http://img137.imageshack.us/img137/2512/pict0004mb0.jpg

Cheers,

Iain T[/url]

I see, so what head was it originally?
Ive got a late 2.5 for mine.

Cheers

Tom

[Templ8e30]

Originally it was a standard 731 casting 320i head.

Cheers,

Iain T

[reggid]

Does anyone know what are the ID of the openings of the 6 branch is? Are they the same as the gasket bore?

I am going to match the exhaust ports of my head to match the BTB 6 branch that will arrive a a couple of months and wanted to know before hand what size it is. The stock exhaust ports of a 885 casting head are approx 31.5mm.