A' La F1

Bit of a hard start on a closed road...

http://www.youtube.com/watch?v=294vflhe4pE

AMS Performance

Hello Hernan,

Any luck getting the dyno data? should be interesting to see the exact difference.

~AMS

alx

i am sorry to say that (and i dont want to rip on anybody), but 13-15rwhp out of headers is a... somewhat sad state of affair...

maybe it is customary for shorties to add that much to a n/a merc engine, but.... still...

alex
few cars

AMS Performance

15+ HP and 30+ TQ at the crank is no laughing matter. Plus furthermore, if you are to add high flow secondaries to them they make the same amount as Long Tube headers deleting primaries would make. Remember much of the gains on long tube headers are NOT from the headers themselves, its from the deletion of the primary catalytic converters.

With AMS performance headers & high flow secondary cats you can get almost the same results as a long tube header, all while keeping the headers 100% bolt on, keeping stock primary cats in place, and remaining 100% street legal. Also our headers are RHD & LHD compatible as well (most long tubes are not).

So keep those in mind, when you do the math the best choice becomes clear and obvious. thanks

~AMS~

Fast55

100% street legal? Really? What is the CARB EO number for these headers?

AMS Performance

Good point, They are 100% street legal in 49 states. Californias laws are becoming a bit too extreme and apparently they are becoming even more strict in the near future with the new administration (unfortunately for those living in California). That is still 49 states better than long tubes which are 100% illegal everywhere in the USA.

~AMS~

SLK55R

I remember my renntech shortys having a carb Eo number on a plate that was welded to the headers.

Btw the gains by the AMS headers seem to be pretty decent.

AMS Performance

Thanks SLK55R,

And it is important to remember that secondary high flow cats make roughly 10HP / 12TQ on the dyno so in conjunction with our headers that comes out to almost the same numbers as long tube headers deleting the primaries except its much more legal than the alternative and you still maintain 100% bolt on headers and keep the mid pipes as is. You do have to weld in the high flow secondaries but honestly the stock secondaries go bad anyways b/c they are ceramic cats so this can be viewed preventative maintenance as well as a performance modification all for a fraction of the cost ($300 installed, parts & labor). Thanks

~AMS~

legin

So your saying these headers plus 200 cell secondaries will make 25 rwhp. Do you have a graph showing 200 cell cats is worth 10 rwhp ?

AMS Performance

Yes of course. 300-cell metal core cats made ~10HP / 12 TQ on a stock NA 55 AMG. These naturally aspirated 5.5Ls respond very well to the high flow cats. The C32 Kompressors don't get any gains from them, it just differs from car to car but the NA 55s really respond well to the high flow cats.

Technically, you could make more than 25 rear wheel torque on low end with the combo but on older 55 AMGs (02 and older) there wasn't a true "Dyno Mode" so you can only really measure power 3500rpm+, but on the newer SLK55 & etc you can put it in dyno mode to measure as low as 2000rpm.

The AMS headers with high flow cats produce a very high quality refined exhaust note as Ala F1 has mentioned which is unique to our headers because of their design. You can view the videos posted earlier in the thread for reference.

Thanks
~AMS~

legin

OK I was aready sold on your quality of sound arguement it has been the effectiveness in power terms compared with a semi long tube like the Kleemann that I struggled with. So Kleeman with primary delete makes about 25-30 rwhp. AMS with std primary but secondary delete will be in the same ball park at 25 rwhp. Im aware the AMS makes better low end Tq but its the top end thats lacking which a 4into1 favours like kleemann although a 421 is the best n/a. For absolute clarity can you confirm "AMS with std primary and secondary delete will be in the same ball park at 25 rwhp" this is a relevation to me which sways me on my impending header selection.

AMS Performance

Yes, correct. Much of the gains from long tubes are not from the headers themselves its from the deletion of the primaries which allows for more flow directly off the heads because the 2nd cats are much further back in the exhaust system (under front seats). However, the secondaries are actually more restrictive simply due to their much larger size. Primaries are metal core and never really need to be replaced but secondaries go bad all the time (and when they do they make a horrible rattling sound). This is because they are ceramic core and fail after a few years so you might as well go ahead and replace them with high flow metal core cats anyways for longevity & reliability sake.

Yes you are also correct, That is the one downside to a shorty header, you do give up some top end, but in conjunction with the high flow 2nd cats it will give you plenty of top end so it all comes out to about the same thing. The header & high flow 2nd cat combo works very well together and the cats only add about $300 total (parts & labor) so its a very cost effective way to improve HP & sound quality on the AMGs in conjunction with the shorty bolt-on headers. In fact, it does such a good job we recommend keeping the entire back half of the stock AMG system alone (resonator & rear muffler) they are already 100% free flowing so there is no reason to change them. All the bottlenecks are in the front half of the exhaust system (headers & cats), not the rear (resonator & muffler). By addressing these bottlenecks in the system you improve the performance, and the sound while still retaining that Mercedes AMG refinement, after all we drive mercedes for a reason, more power isn't worth making your car sound like a Camaro or Mustang (no offense to either group).

Hope that helps,
~AMS~

phoung

A' La F1, what did you set your rev limit to?

phoung

A' La F1, and do you have LSD, or does the slk55 come with it? because on the video with you taking off hard, it leaves 2 tire skid marks.

AMS Performance

His rev limiter is stock. No, no LSD. Even if you have an open differential you can still leave 2 tire skids if you are going straight or close to it. If you do a burnout, then usually its only just one tire.

phoung

stock rev limiter which is 6200?

AMS Performance

Thanks Ala F1 for providing us with the data chart, here are the results at the specific rpms for a more in depth analysis of how the headers performed both before & after....

A' La F1

Phoung, sorry I have been out of touch for a bit. Work has been out of control.

It is a stock rear end (no LSD) and I don't believe that the rev limiter was altered by the Powerchip software flash. Given the car's relatively low weight and nice low end power, I rarely go past 5,500 rpm. In the video I don't think I got past 4,500 or 5,000 rpm.

A' La F1

It has been about 3 months since the install and I am still very satisfied with the results. The car seems a bit louder than the initial install, but that may be my imagination as I am now driving around with the top down more often in this nice weather. Last week I had an LAPD officer pull up next to me and comment on how nice the car sounded when I pulled away from a light. If I had long-tubes, I'm sure I would have gotten a ticket.

Fit and finish is still spot on. No leaks, no issues at all. As you can see on the increase in torque around 3k rpm above, the only issue I have is hooking up the rear tires. I have to feather in 1st and 2nd gear. I am running hard compound Toyos and need to switch to something more sticky.

I am attending the car meet this Sunday (last Sunday of every month) in Calabasas if anyone wants to see the car first hand. Exit Valley Circle off the 101 at the parking lot just south of the freeway. Huge event with 1000+ people. Need to get there by 7:30am or you will not get parking.

Yellow R1

Ill up you one on traction issues. I was driving through a tunnel @ 70 mph yesterday & decided to downshift & get on it a bit to pass some lady trying to cut me off as the lane was going to merge (besides, I was curious how loud it would be with the top down in a tunnel - it was 92F). The car slid sideways & my ESP was blinking up to ~ 85mph when I let up - I didn't even nail it. I looked at my wife and said, "Geezuz...this thing is a BEAST". She just nodded & said the lady in the car next to us had a wide eyed/surprised look as we catapulted by her Boxster.

IIIMBPIII

I want your car!!! I am thinking of doing some Kleemann mods once I get back in June no FI just yet but hopefully soon!

cdiem

A' La F1 your car is sooo sick, i'm new to this board and had a couple question to ask if you dont mind. I was wondering how i should go about putting on high flow cats on my car. do they bolt on or are they welded on? sorry if these questions are dumb. I have a Clk55 AMG and am trying to get the same goal as you in in terms of 60% the power of long-tube headers for 30% of the cost. Also where did you get the 200 cell cats?

- your help is greatly appreciated

A' La F1

Thanks much, it has been a very fun project.

I got the 200-cell cats from Ebay. Yes, the old cats need to be cut out and the new ones welded in. Best to use a higher-end performance muffler shop like the one I used. Here is a link to the full write-up.

https://mbworld.org/forums/slk55-r17...e-exhaust.html

Yellow R1

You are driving a modded SLK55 - no different than ours. In fact, I rarely find myself using all the power the car has - no need as these cars already have fantastic low end response. I think I've redlined the car 3 or 4 times?

Enjoy your SLK!

-Matt

IIIMBPIII

Yea but I am power hungry right now and the little kid in me wants more, more, MORE!!! lol We will see what happens I wont be back from school till late June but once I am there will def be some performance mods done then!