cat back exhaust system m52tu 2.5ltr

[eef48 0]

If I throw off the exhaust from cats and run a twin system back to rear how much H/P would I gain and is it worth it.

the engine is the M52tu 2.5ltr 170bhp.

I read that there is cats in the headers but i carn't see any thing that looks like cats there.Its just 2 seperate headers that run straight down to the twin cats at the bottom and then expands to like a big single pipe all the way back to the twin outlet exhaust.

[smiddy 76]

If I throw off the exhaust from cats and run a twin system back to rear how much H/P would I gain and is it worth it.

the engine is the M52tu 2.5ltr 170bhp.

I read that there is cats in the headers but i carn't see any thing that looks like cats there.Its just 2 seperate headers that run straight down to the twin cats at the bottom and then expands to like a big single pipe all the way back to the twin outlet exhaust.

Hi Beam, happy new year.

I have a E46 328 which i am awaiting delivery of OEM mount 304 SS headers, these are equal length units tig welded, unlike the standard stepped units on our cars which are restrictive.

I will fit these headers to my vehicle and replace centre section post cats [2into 1] this area is restrictive and effects top end power.

If all is good I will import units which the manufacture

is developing for our Jap import fittment for a wide range of Bimmers.

[eef48 0]

Hi Beam, happy new year.

I have a E46 328 which i am awaiting delivery of OEM mount 304 SS headers, these are equal length units tig welded, unlike the standard stepped units on our cars which are restrictive.

I will fit these headers to my vehicle and replace centre section post cats [2into 1] this area is restrictive and effects top end power.

If all is good I will import units which the manufacture

is developing for our Jap import fittment for a wide range of Bimmers.

[eef48 0]

Happy new year to you as well.

It will be interesting to see the results when your 328 is fitted out.I was wondering how you get around the problem of taking the oxygen sensors out of the exhaust system with out causing grief to the engine managment system?

[smiddy 76]

Happy new year to you as well.

It will be interesting to see the results when your 328 is fitted out.I was wondering how you get around the problem of taking the oxygen sensors out of the exhaust system with out causing grief to the engine managment system?

Hi Beam, oxy sensors post cats are retained in new pipe config, headers have OEM sensor fittment.

[eef48 0]

Cat back exhaust mods are largely cosmetic/ Aural - you may gain a kilowatt or two and some sounds - I got 2 on my 328 contrast that with 12kW from doing real headers for the same money??

What would you pay for a set of headers and can you buy them local or do you have to buy from the UK? looking at sites on the USA is probably a waste of time as everything will be for left hand drive.There would't be many sets kicking around second hand here.

[smiddy 76]

You can get European made stubbies for around 2 grand that are for a right hand drive and will give you 5 to 8 kilowatts.

I went for second hand M3 headers they are just the bollocks - also fitted M3 mid and rear section all up for less than the cost of stubbies.

Stubbies wont give you as much low down / mid range torque as the M3 headers because the primaries are not as long.

As stated earlier on this forum I will have RHD stubbies, OEM mount and long tube, all tig and 304 stainless in about a month.

Will have units for all beamers, E30,36,46, E39, Z3 and Z4 318 also, price around $500.

[mr E34 11]

As stated earlier on this forum I will have RHD stubbies, OEM mount and long tube, all tig and 304 stainless in about a month.

Will have units for all beamers, E30,36,46, E39, Z3 and Z4 318 also, price around $500.

E34 535i?

[smiddy 76]

E34 535i?

Not to sure, if head bolt pattern conforms, should be ok, maybe down pipe flange mod needed.

[mr E34 11]

Not to sure, if head bolt pattern conforms, should be ok, maybe down pipe flange mod needed.

Let me know when you have some, thanks.