Custom exhaust options? (Merc Cosworth)

[JOEPRO]

Another option is this -

2.5 16v Cosworth Cat Back Stainless Steel Exhaust for Mercedes 190 (W201)

Stainless steel cat back exhaust system for the Mercedes 190 (W201) 2.5 16v Cosworth. Made entirely from T304 stainless steel so will not rust or corrode and should last the lifetime of the car. Lifetime guarantee. Made from OEM pattern so fit's straight on to the car with no modifications...

www.190parts.co.uk

So a new purpose made stainless "cat back" system and I make good the bad pipe section on the output of the old 1st muffler / resonator and patch it up as the 1st part also has at least one rust hole in it.


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Update -

I went ahead and ordered the above system. Its made for this model so in terms of a restoration is the best solution IMO. A custom place is OK too but they could mess it up sound wise and back to square one!

So I will repair, VHT paint and remake the pipes from the original first section of exhaust to connect to this new system like original spec.

 

[Munkul]

The Merc Cosworth development is more complex than that! Note there were full blown DTM 190E race cars back in the day. These were 400hp roughly from memory with the same engine.

Then as part of the DTM racing rules, Mercedes had to produce road going versions. They were given the standard KE jetronic injection and the head ports reduced slightly to detune them down to circa 200hp for the 2.5L.

The race car likely had a totally different exhuast granted but this is what the "Introduction to service" manuals say regarding the exhaust on the road going Cosworths:

granted, the headers do look like a proper bit of kit, nicely designed and made. That's the most important part anyway, where you'll get the most "area under the graph" if done properly.

All I'm saying is, it's pretty easy for aftermarket exhaust makers to improve on the rest of the system, as that's always the part they make the most compromises on.
The important part is where the 2 into 1 goes, as this will affect the rev range where torque peaks. If you move this position, it will move the torque peak, possibly improving it, possibly making it worse.
The rest of the system is just about balancing flow with a small amount of backpressure - again, the bigger the pipe, the further you tweak the torque rise.

 

[Turbo]

I always think this thought is hilarious no offence meant, I'll justify my reasoning -
sure, the intention is there, but the reality with mass produced cars is, they get something that gives "enough" power whilst being a. Quiet, b. Cheap, and c. Not spending time and money on development.

If you think the Cosworth badge means they spent loads on development, you'd be mistaken. There's just an ounce more of thought gone into it than would have otherwise.
Great cars, great engines, don't get me wrong, but the exhaust is absolutely utterly NEVER going to be a perfectly optimised part. It's the easiest part to cheap out on.

This is hardly a mass produced car. As @JOEPRO said, these were an homologation special produced in very limited numbers. I can't get an exact figure for the numbers but I'm sure Joe has already researched how many of his model were built.

Chances are the special tuning parts were fitted off the production line.

This is not a Sierra Cosworth which was a mass produced car.

 

[Blobber]

I think its clear that Cosworth made/designed the manifold which is lovely and then Mercedes made the exhaust which looks poorly designed and restrictive to me

 

[JOEPRO]

granted, the headers do look like a proper bit of kit, nicely designed and made. That's the most important part anyway, where you'll get the most "area under the graph" if done properly.

All I'm saying is, it's pretty easy for aftermarket exhaust makers to improve on the rest of the system, as that's always the part they make the most compromises on.
The important part is where the 2 into 1 goes, as this will affect the rev range where torque peaks. If you move this position, it will move the torque peak, possibly improving it, possibly making it worse.
The rest of the system is just about balancing flow with a small amount of backpressure - again, the bigger the pipe, the further you tweak the torque rise.

This is hardly a mass produced car. As @JOEPRO said, these were an homologation special produced in very limited numbers. I can't get an exact figure for the numbers but I'm sure Joe has already researched how many of his model were built.

Chances are the special tuning parts were fitted off the production line.

This is not a Sierra Cosworth which was a mass produced car.

I think its clear that Cosworth made/designed the manifold which is lovely and then Mercedes made the exhaust which looks poorly designed and restrictive to me

I think with it being a production car there was obviously a balance Mercedes had to make with with noise, Drivability and longevity/ reliability.

So I agree that yes the manifold is tasty on the engine and the exhaust whilst clearly upgraded in the factory documentation, it would have been a balance of the above factors and would therefore not necessarily be the best / highest performance solution.

But for a mere mortal like me who doesn't want to dyno or abuse a classic car I will never know how many improvements could be made here HP or Torque wise.

My goal is a sensible, long lasting system to replace the old rusted out parts whilst not making the car sound "rorty and cheap" or reducing performance.

 

[Blobber]

I think with it being a production car there was obviously a balance Mercedes had to make with with noise, Drivability and longevity/ reliability.

So I agree that yes the manifold is tasty on the engine and the exhaust whilst clearly upgraded in the factory documentation, it would have been a balance of the above factors and would therefore not necessarily be the best / highest performance solution.

But for a mere mortal like me who doesn't want to dyno or abuse a classic car I will never know how many improvements could be made here HP or Torque wise.

My goal is a sensible, long lasting system to replace the old rusted out parts whilst not making the car sound "rorty and cheap" or reducing performance.

Mercedes must have got some younger engineers now, have you heard some of their modern stuff? They sound like an old Deltic starting on a cold morning