Exhaust Shop

[Captain_Stealth]

Hi All

need some help here

So on a e36 325i (will be upgraded to m50b30). I want to do a custom exhaust.

I want a Single pipe running from the headers

So I am still researching if I should go 63mm or 70mm

I have contacted an exhaust shop and got the following prices

Stainless Steel with TNT Branches - R6500
Mild Steel with TNT Branches - R5800

Isnt the price of the mild steel system a bit high ? , if so which shop can I try ?

Here is an example

here is the site I got the pics from if anyone is interested

You ask why basically my Idea

is to build a fast NA m50b30 e36 and badge it as a 316, hence why I want the single exhaust

any input will be appreciated

Thanks

 

[Maljan]

Not sure that the single pipe is a good idea. BMW must have gone with the dual pipes for a reason.

If you want the naughty stealth look of a single pipe, why not just join them up at the back with an oval tailpipe or something like that?

The exhaust note will give the game away, in any case.

 

[Ralf*]

At my shop 63 mm mild steel is the maximum we can do whilst still on a budget, after that size it gets a lot more expensive because of the cost of 70mm tubing, and because our pipe bending machine cannot accommodate anything greater than 63mm

those prices you mentioned for mild steel seem to be a bit of a robbery

 

[Maljan]

Just the one silencer box? Not even a very big one? :skit:

A system like this will be loud. Really, really, really loud.

People three blocks away will know you have a six under the bonnet. That 316i badge will be of no consequence.

 

[328ii]

I had the same question a while ago and was advised by a performance
exhaust shop that 63mm should be good - they did 'some' dyno testing
so i could not assume anything wrong with their answer..?

The inside diameter of the pipe is what is important as this is what
determines the 'flow' area. Considering 1mm wall thickness, you are going
to need ~73mm diameter to match the 2x 52mm pipes.

Inner Area = PI() * inner radius ^ 2 - same for outer

You will however, gain some weight advantage of around 42%.

If i am not mistaken the way pipe sizes are measured in industry varies
quite a bit, so be sure what you are dealing with - inner or outer diameter,
wall thickness, material weight etc.

A smaller flow area could have advantages as the gasses will have higher
speed and you can take better advantage of cylinder scavenging. You may
even gain with 'better/suitable' cams.

Best way to do this (imo) is to do dyno test before and after to see
what effect your changes has had on power and torque curves.

good luck anyways...hope it sound good after all is done

8?>

 

[moranor@axis]

cross section area of a pipe is only part of the flow capacity a single pipe with a smaller total cross section will flow more than two pipes with a larger combined section because there is less wall contact

for a NA 2.5l I would go mandrel bent 63mm single Stainless

 

[Kimeran]

Go visit Philip from Kontrol Freaks, his number is 076 037 7518.
The best workmanship you will ever lay your eyes on! :thumbs:

 

[Captain_Stealth]

At my shop 63 mm mild steel is the maximum we can do whilst still on a budget, after that size it gets a lot more expensive because of the cost of 70mm tubing, and because our pipe bending machine cannot accommodate anything greater than 63mm

those prices you mentioned for mild steel seem to be a bit of a robbery

Ok thanks I thought so, are you in JHB ?

Just the one silencer box? Not even a very big one? :skit:

A system like this will be loud. Really, really, really loud.

People three blocks away will know you have a six under the bonnet. That 316i badge will be of no consequence.

Haha I know had it on my toyota, never again lol
I am gonna go with the 2 box setup

I had the same question a while ago and was advised by a performance
exhaust shop that 63mm should be good - they did 'some' dyno testing
so i could not assume anything wrong with their answer..?

The inside diameter of the pipe is what is important as this is what
determines the 'flow' area. Considering 1mm wall thickness, you are going
to need ~73mm diameter to match the 2x 52mm pipes.

Inner Area = PI() * inner radius ^ 2 - same for outer

You will however, gain some weight advantage of around 42%.

If i am not mistaken the way pipe sizes are measured in industry varies
quite a bit, so be sure what you are dealing with - inner or outer diameter,
wall thickness, material weight etc.

A smaller flow area could have advantages as the gasses will have higher
speed and you can take better advantage of cylinder scavenging. You may
even gain with 'better/suitable' cams.

Best way to do this (imo) is to do dyno test before and after to see
what effect your changes has had on power and torque curves.

good luck anyways...hope it sound good after all is done

8?>

Yeah this was my thoughts originally, for some odd reason read up that there is a different sound you get when fitting a mild vs stainless steel exhaust

cross section area of a pipe is only part of the flow capacity a single pipe with a smaller total cross section will flow more than two pipes with a larger combined section because there is less wall contact

for a NA 2.5l I would go mandrel bent 63mm single Stainless

I found this post on the net giving specs for the hp to exhaust sizes

But since I am going to a 3.0l conversion I would like something bigger

Go visit Philip from Kontrol Freaks, his number is 076 037 7518.
The best workmanship you will ever lay your eyes on! :thumbs:

Cool thanks, will give him a call

 

[Ralf*]

At my shop 63 mm mild steel is the maximum we can do whilst still on a budget, after that size it gets a lot more expensive because of the cost of 70mm tubing, and because our pipe bending machine cannot accommodate anything greater than 63mm

those prices you mentioned for mild steel seem to be a bit of a robbery

Ok thanks I thought so, are you in JHB ?

Kempton Park

 

[moranor@axis]

If you going 3l some head work you could see around 200kw in this case a 70mm pipe might be a better choice

 

[Captain_Stealth]

If you going 3l some head work you could see around 200kw in this case a 70mm pipe might be a better choice

My plan for the motor in the future is the following...

Rebore Throttle Body
Port and Polish
Bigger Valves - must do some research if this is possible
Dual Valve Springs
van der linde cams
m5430 bottom end
86mm Pistons
Balanced Crank

Dont expect this soon thou lol

 

[moranor@axis]

then go with the 70mm pipe but this will be poinless if in mild steel as you will need to replace it again

if going mild steel just get 63mm for now and change to 70mm when you do the other mods

 

[Yuben]

How did this 3.0 conversion materialise?