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I’m on the fence whether to go ahead with dropping the engine to put turbo back downpipes. I can’t find any substantial research that this mod is worth the trouble. Other option would be a cat delete downpipe and leave the OEM bridge pipe in place?
hardly anyone even makes them.. which leads me to think that the mod isn’t worth the cost of parts/labor.
I have not made that mod but there is tons of chatter about it on these forums... rule of thumb is the downpipe mod is not needed unless you've already done stage 1 tune and your ready for stage 2...
I'm sure others with more experience will chime in
I have not made that mod but there is tons of chatter about it on these forums... rule of thumb is the downpipe mod is not needed unless you've already done stage 1 tune and your ready for stage 2...
I'm sure others with more experience will chime in
The thing is that it’s all chatter, and no evidence. I’ve heard from a reliable source that once u make high HP (eg. 600) that turbo back pipe can drop power because of no back pressure.
Do some searching, from what i remember it was good for 50-60 hp... and was the biggest restriction if you wanted to go further than stage 1... hopefully the folks who have the dyno's will pop in... or do more searching
The thing is that it’s all chatter, and no evidence. I’ve heard from a reliable source that once u make high HP (eg. 600) that turbo back pipe can drop power because of no back pressure.
I have stage 2 renntech tune,
reducing back pressure can sometimes lower HP on supercharged engines, not turbo'd. reducing back pressure on turbos is a good thing as it lets them spool faster. if you want more power...and you already have a tune....the next logical step is to make your exhaust more efficient (and then tune for it, of course). and, on these cars, the best way to do that is catless downpipes. its definitely not 'all chatter'. its about as tried and true as it gets with turbocharged engines...
I’m on the fence whether to go ahead with dropping the engine to put turbo back downpipes. I can’t find any substantial research that this mod is worth the trouble. Other option would be a cat delete downpipe and leave the OEM bridge pipe in place?
hardly anyone even makes them.. which leads me to think that the mod isn’t worth the cost of parts/labor.
anyone try both and tested?
hardly anyone makes them because there's not a huge market of folks that want to deal with the gas smell that you get from removing the cats on a mercedes. or...they feel that 500+ hp is sufficient in their luxury vehicle.
and im really having problems understanding the nomenclature (not singling you out as i've seen a lot of folks use it)...but i was always taught that ALL downpipes are turbo back. you either get catless downpipes or catted downpipes. getting catted downpipes doesnt really make a ton of sense as you still have the restrictive catalytic converter in place....although, they will probably come with a higher flow version. the gains will be marginal unless the stock downpipes are just ****. that isnt really worth the price, imo.
hardly anyone makes them because there's not a huge market of folks that want to deal with the gas smell that you get from removing the cats on a mercedes. or...they feel that 500+ hp is sufficient in their luxury vehicle.
and im really having problems understanding the nomenclature (not singling you out as i've seen a lot of folks use it)...but i was always taught that ALL downpipes are turbo back. you either get catless downpipes or catted downpipes. getting catted downpipes doesnt really make a ton of sense as you still have the restrictive catalytic converter in place....although, they will probably come with a higher flow version. the gains will be marginal unless the stock downpipes are just ****. that isnt really worth the price, imo.
It’s been a learning process for me too. For the m157 and m278 there’s downpipes that start below the bridge pipe, which is the piece that is bolted directly to the turbo. This piece has the cat attached.
Then there’s turbo back pipes, which replace the squished looking bridge pipe and lower portion all together. However, for the 4matics these would require dropping the engine.
It’s been a learning process for me too. For the m157 and m278 there’s downpipes that start below the bridge pipe, which is the piece that is bolted directly to the turbo. This piece has the cat attached.
Then there’s turbo back pipes, which replace the squished looking bridge pipe and lower portion all together. However, for the 4matics these would require dropping the engine.
the first option would still remove the cats
Vs
so there are DP's that bolt directly to the squished stock pipe? that seems really....dumb? is that the bridge pipe that everyone is talking about? that seems to be a pretty big restriction to over come by opening up the diameter AFTER it. i havent really looked into DP's because of the aforementioned smell. thanks for teaching me something new.
but yeah...if you want more power....i'd get rid of the flattened piece. hahahaha
so there are DP's that bolt directly to the squished stock pipe? that seems really....dumb? is that the bridge pipe that everyone is talking about? that seems to be a pretty big restriction to over come by opening up the diameter AFTER it. i havent really looked into DP's because of the aforementioned smell. thanks for teaching me something new.
but yeah...if you want more power....i'd get rid of the flattened piece. hahahaha
Well yea I want more power but I have to be honest with myself.. it’s just a 550 not an AMG. And some of those bridge replacement pipes costs around 5k because it includes modified engine mounts to fit them. And also the engine should be removed for proper install since I’m 4matic. That is a lot of labor to drop the motor so the cost adds up quick for maybe ???? HP? I can’t find many resources that can give me a projected HP/TQ number. And Don’t forget the retune . If I had an AMG I would do it though
Last edited by Raptorpower700; Aug 16, 2019 at 09:06 PM.
Reason: Changed numbers
power increase is very minimal, if anythings its just more responsive on the low end tq. the car sounds more throaty a deeper exhaust note. power wise its all BS. I didn't do a dyno after just the downpipes. but I have done several runs on the drag strip and there was no change in the times or mph. not even a mili sec change. if you were to gain any power, you'd be incredibly lucky to get 50hp, but realistically expect 10-20hp nothing more.
the bridge pipe does need to be replaced with a wider diameter pipe to remove the airflow restriction. essentially all downpipes do is let a larger volume of air leave the engine faster. Turbo engines do need a certain level of back pressure to keep power levels up but you do lose power on top end.
I don't believe the engine needs to be dropped to do the bridge pipe, I will double check with my installer
I have video of the sound from my installer ill post up here when I find it
Last edited by fusion2007; Aug 28, 2019 at 12:53 AM.
power increase is very minimal, if anythings its just more responsive on the low end tq. the car sounds more throaty a deeper exhaust note. power wise its all BS. I didn't do a dyno after just the downpipes. but I have done several runs on the drag strip and there was no change in the times or mph. not even a mili sec change. if you were to gain any power, you'd be incredibly lucky to get 50hp, but realistically expect 10-20hp nothing more.
the bridge pipe does need to be replaced with a wider diameter pipe to remove the airflow restriction. essentially all downpipes do is let a larger volume of air leave the engine faster. Turbo engines do need a certain level of back pressure to keep power levels up but you do lose power on top end.
I have video of the sound from my installer ill post up here when I find it
Thanks, I'd love to hear it that clip. I imagine the cat-delete downpipes (sans bridge pipe swap) are all going to provide relatively similar exhaust notes, is that correct? Any other factors to take into account like coatings or anything? Asking because between the Kooks E63 from World Motorsports, VRP Racing's downpipes, Kleeman's downpipes, MBH's downpipes, etc etc - the range of prices can very. And then there's folks who just get them made. I'm trying to figure the best approach.
power increase is very minimal, if anythings its just more responsive on the low end tq. the car sounds more throaty a deeper exhaust note. power wise its all BS. I didn't do a dyno after just the downpipes. but I have done several runs on the drag strip and there was no change in the times or mph. not even a mili sec change. if you were to gain any power, you'd be incredibly lucky to get 50hp, but realistically expect 10-20hp nothing more.
the bridge pipe does need to be replaced with a wider diameter pipe to remove the airflow restriction. essentially all downpipes do is let a larger volume of air leave the engine faster. Turbo engines do need a certain level of back pressure to keep power levels up but you do lose power on top end.
I don't believe the engine needs to be dropped to do the bridge pipe, I will double check with my installer
I have video of the sound from my installer ill post up here when I find it
So you’re saying there’s not much to gain from doing the turbo back downpipe (replacing the OEM bridge pipe) vs a downpipe that starts below the bridge pipe and only deletes the cats?
figuring out how to upload the clip here without going through youtube.
seve3en that is correct not much difference at all in sound. do you mean the finish? theres really only 2, titanium or stainless steel.( those are primarily for lightness) ideally id go with a name brand, just for that piece of mind that you got a good quality product. but performance wise there would be almost 0 difference. Most likely you would notice the welds and shine from different manufacturers.
raptorpower700 that is correct. Remember the motor is tuned only to move a certain amount of air with the power its producing. even when the ecu "adapts" it won't push enough to fill that area before its able to escape .
figuring out how to upload the clip here without going through youtube.
seve3en that is correct not much difference at all in sound. do you mean the finish? theres really only 2, titanium or stainless steel.( those are primarily for lightness) ideally id go with a name brand, just for that piece of mind that you got a good quality product. but performance wise there would be almost 0 difference. Most likely you would notice the welds and shine from different manufacturers.
raptorpower700 that is correct. Remember the motor is tuned only to move a certain amount of air with the power its producing. even when the ecu "adapts" it won't push enough to fill that area before its able to escape .
It can be a pain to link pics and videos for some reason.. takes me some trial and error before it works.
Are you saying that after a re-tune for turbo backs that it’s hardly noticeable?
I understand what you’re saying.. however, wouldn’t you need to re-tune for the increased air flow from the turbo in order to maximize on the gains?
I would assume the gains would be minimal if I would just slap on the turbo backs if the car is tuned for a more restrictive (back-pressure) setup?
It can be a pain to link pics and videos for some reason.. takes me some trial and error before it works.
Are you saying that after a re-tune for turbo backs that it’s hardly noticeable?
I understand what you’re saying.. however, wouldn’t you need to re-tune for the increased air flow from the turbo in order to maximize on the gains?
I would assume the gains would be minimal if I would just slap on the turbo backs if the car is tuned for a more restrictive (back-pressure) setup?
the Mercedes ecu has some adapting capabilities when it reads sensors. correct it does need to be retuned to get best results... but the car still has stock turbos only soo much it can do.
The weistec turbo back system is nice. Unfortunately weistec system was knocked off and is now being imported from China. If you buy the chinese knock offs and have an AWD car you have to remove the engine then have turbo back pipe modified to fit the AWD car. Not only that but Mercedes along the way swapped mounting bracket locations. It just happens to be that the turbo back downpipes when they were copied had the original exhaust hanger locations. This mean if you have 2014+ (not actually sure of the year) your exhaust hanger location is different of that from 2012-13. So for a lot of unknowing people they have their turbo back downpipes being held up my the turbo flange and the factory resonator. This is because the exhaust hanger locations are not correct.
With a standard downpipe, the install is less than an hour. If you need to swap back to stock, again install is under an hour. With a turbo back system what the R&R time on a engine? Then potential fab work on top of that? The install time and shop labor rate will maybe be more than the cost of the downpipes.
I’m on the fence whether to go ahead with dropping the engine to put turbo back downpipes. I can’t find any substantial research that this mod is worth the trouble. Other option would be a cat delete downpipe and leave the OEM bridge pipe in place?
hardly anyone even makes them.. which leads me to think that the mod isn’t worth the cost of parts/labor.
anyone try both and tested?
Guys,
For some reason I cannot justify spending $3000 plus for just downpipes/ stage 2 for an additional, say 30hp max, except I have the money to stage 4 and get at least 300hp plus. Go all in or nothing.
Appreciate all the input you guys have put towards this topic.
After some consideration, that extra upfront cost and disassembly isn't worth it to me for my M278 stock turbo CLS 550. When / if I decide on a turbo upgrade, that'll be when some fab-work / bridge pipe sourcing comes into play, and i'll already have the downpipes necessary.
For now, gonna keep my costs well under 2k and enjoy that exhaust note and throttle response.
Appreciate all the input you guys have put towards this topic.
After some consideration, that extra upfront cost and disassembly isn't worth it to me for my M278 stock turbo CLS 550. When / if I decide on a turbo upgrade, that'll be when some fab-work / bridge pipe sourcing comes into play, and i'll already have the downpipes necessary.
For now, gonna keep my costs well under 2k and enjoy that exhaust note and throttle response.
Good call. remember if it is just for crazy sounds you are going for, you can just straight pipe your car for under $500 and get a pretty good throat sound
the Mercedes ecu has some adapting capabilities when it reads sensors. correct it does need to be retuned to get best results... but the car still has stock turbos only soo much it can do.
Wow!!! I hope non of you are listening to this guy~ I know this is an old thread but reading this man's comments are just so ridiculous!!
Expect 50-60 up increase over stock after tune with a down pipe install
if you're on RWD and want the 20whp sure. otherwise I would only do bridges with new turbos or other "engine out" service. I think the biggest gains we could make for the most impact after stage 2 is e85/eflex tune
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. If I had an AMG I would do it though
