W126 Exhaust Performance Upgrades

[Oversize]

Looks like I’ll have to build my own if I wish to follow this path!

 

[c107]

Looks like I’ll have to build my own if I wish to follow this path!

I was quite impressed with the home build on the 500SLC. How are you stainless steel welding skills?

 

[motec 6.9]

Most decent exhaust shops can build you a very decent performance exhaust. Find out were the racing or drag guys go would be a good place to start or the show car guys as they are very picky.

 

[Oversize]

Yes I think I’ll just be sourcing the parts and having them weld it together. Not full stainless either. Probably just downpipes and mufflers.

 

[Oversize]

Interesting that the Benz firing order is the same as the Mustang 5.0 & Buick Nailhead! And yet the Benz Tri Y design is rather unique...

 

[motec 6.9]

Mark this is what i did with 6.9 exhaust it is duel 2.5 inch with x pipe hotdogs and rear resonator that is duel in duel out . You know about the custom extractors and how they are set up for correct firing order

 

[Oversize]

Yes that’s my point. The other engines have the same firing order yet the manufacturers have not done anything special with their exhausts. So is the unique design not worth the effort??

Great job BTW Geoff!

 

[motec 6.9]

Exhaust and extractors were worth around 25hp at the rear wheels. How much is down to either the extractors or exhaust is down to conjecture.

 

[Oversize]

Based on an exhaust port of 39.5mm (AMG 500, std 500/560 is 37mm), the minimum exhaust internal diameter (ID) is:

2.75” (69.85mm) single,
2.25” (57.15mm) dual.

However these are for a dead straight pipe with no additional resistance (ie no mufflers) so the diameter should be increased to compensate....

 

[Oversize]

What I found strange is the valves are all 39.10mm. To me the AMG porting out to 39.5mm is pointless since the valve is smaller than the port and that doesn’t even account for the valve stem!! So the exhaust valve is the biggest restriction in this area.

 

[c107]

Yes that’s my point. The other engines have the same firing order yet the manufacturers have not done anything special with their exhausts. So is the unique design not worth the effort??

Great job BTW Geoff!

May be cost related? Benz sold their cars for a much higher price so had more room to work in terms of the specification and still providing room for a profit....

Its the old story like the Rover SD1. Engineers wanted to do a IRS instead of live rear axle, but BL vetoed it that buyers wouldn't spend the extra $50 or whatever it would have been.

 

[motec 6.9]

A Holden executive in the 90's boasted that they had never spent more than 2 dollars on their car stereo speakers even in high end models. Says it all really.

 

[c107]

I just had the exhaust done on my SEL. Somebody had replaced the kidneys and done a terrible job. You couldn’t get the hangers to line up and it was scraping the drive shaft. I replaced it with a stainless system sans kidneys. I can feel the increase in performance and you get a better sound under hard acceleration but it is nice and quiet around town.

 

[Patrick_R]

Lovely looking system Bryce.

 

[Oversize]

Looks great! I’m still sceptical about the X pipes, so I’ll try something different next time.

 

[Oversize]

This is a mates SEC...

 

[c107]

Looks great! I’m still sceptical about the X pipes, so I’ll try something different next time.

This is my Aussie SEL, so that was mostly for the O2 sensor.
When I eventually do the SEC, it doesn't need an O2 sensor and would probably go with something more aggressive.

 

[Oversize]

Geez I think I may have to get the verniers out onto Doras exhaust! I have a feeling it has 2 x 2.5” pipes... Interesting that hot dogs reduce drone & are therefore totally worthwhile.

 

[Oversize]

Here’s an original AMG setup...

 

[c107]

Other than the o2 sensor, looks pretty similar to the one I have on my 560SEL. Cool.