TexasEngineer

I haven’t seen a lot of product reviews or write ups lately, so I thought I would share my review of the Agency power headers and mid pipes.

Initial Inspection

When I received the headers and mid pipes everything was packaged well and nothing was damaged. The construction of the headers and mid pipes also looks topnotch. The TIG welding on these pieces really looks quality. The merge collectors seem to be very well designed. There is a velocity spike where the four primaries meet. The fit and finish of the product is really impressive overall.









Installation

We began the installation at around 10am, and thanks to the help of MBWorld members Shardul and MeKantor, we finished up a little after midnight. The stock manifolds are an incredible pain to get out. Everything is very straight forward, but it is very time consuming and can wear on you patience. You will need every 11mm socket, extension, and wrench combination you can think of. Some attempting to do this may find it beneficial to remove the heat shield for extra space. We did not do that, and it might have cost us some time. We did remove the coils and wire to make room on the driver's side. We also removed the steering shaft. When installing the headers, start with the primaries closest to the front of the car, and work your way to the rear of the car. I ended up reusing the gaskets and studs, and so far, I don't have any leaks. Do not tighten the studs all the way. Leave some play. This will make it easier to slip the collectors over the primaries. Once the primaries are on you can go back and tighten the studs down on the primary flanges. I also recommend swapping the O2 sensors while the collectors are uninstalled. The mid pipes are very easy to install and bolt up perfectly to the stock resonator using the stock clamps. New clamps are provided for the connection to the collectors. The collectors also bolt up to the bracket where the OEM primary cats/down pipe assemblies bolted up. These bolts are not included. They should be M8x1.25 bolts. I picked some up from at a local auto parts store. This is a very nice feature that helps keep everything tight and stable.





Installed product review

They are LOUD! Cold starts will startle some people. The car sounds seriously mean. I really don't think you can get a more aggressive tone without going to straight pipes or cutouts. The You Tube link below is of the very first startup after the install (at around midnight).

http://www.youtube.com/watch?v=quEIDy-ZJ00

Even though they are loud, they are very daily drivable. At cruising speeds there is absolutely no drone. There is also no vibration or rattling of the exhaust even at wide open throttle. Another plus about the Agency Power headers is that they will not set off your CEL. There is no need to have your tuner remove the CEL after the install.

Last weekend, I took the car to a Eurocharged dyno day to get the car retuned after the header install. It literally caught everyone off guard with how loud it was. It was an extremely hot and nasty day (far from ideal for dyno gains), but the car picked up about 25 rwhp over its previous baseline with just a tune.



I am very pleased the product, and I can recommend it to anyone looking for a more aggressive exhaust note and more horse power.

I hope this review was helpful. I will be posting up more videos soon. Let me know if you have any questions about the install or the headers.

novae500

headers look nice and great writeup. Where did you get the headers from/price?

Rob@vividracing

TexasEngineer - Glad you like the headers.

Novae500 - We have a few sets instock, retail is $2500. We have been selling them to board members for $2250 shipped . Give me a call if interested.

Agency-Power

Thanks for the nice review TexasEngineer! If you do get our Valvetronic Exhaust on there, it will smooth out the sound for sure.

_AMG_

Great review!!
The quality looks great. Does Agency power make a X pipe as an option if you wanna replace the straight mid pipes?
Lets see some videos.

TexasEngineer

I don't believe they have other options available for the mide pipes, but if you really wanted an x pipe, their rear exhaust has an x pipe incorparoated into it.

http://www.agency-power.com/catalog/...h52m171et0grl5

I will try to get some videos done over the weekend.

Sincity

Great writeup. Those weld beads are just beautiful!

BK63amg

Gorgeous! When my warranty is up, I'll be ordering some headers!

Rob@vividracing

Here is a quick video of my car on the dyno a few minutes ago.


http://www.youtube.com/watch?v=G0sHhxZ0tvk

shardul

iTrader: (1)

TexasEngineer's car sound very good in person. I think a X pipe and some resonators will it sound refined.

lakbum

How many labor hours would it have been to install the headers if you didn't do it yourself?

That sounded amazing btw...I'm picking mine up tomorrow and I would love to have mine sound like that.

C63newdude

The sound is great and the looks and finish is astonishing, it looks like a quality piece. Explain me something though, did you picked only 25whp after adding these headers and got it retuned? typically the long tube headers yield more power no? I am not trying to argue here I am just saying that typically you see higher gains with the addition of the LTH specially since Eurocharge now has an improved software(V3).. my 2c.

SonnyakaPig

I'm pretty sure TE was saying that he gained 25 whp with these headers over and above what his car dyoned at with the V3 tune.

So, the V3 tune was in the high 380's and, now with the headers it's at like 413 rwhp. And like he said, it wasn't the greatest weather for big dyno numbers.

Still, 25 whp gain is solid and it would definitely be more out on the open road, especially when the weather is better.

TexasEngineer

I didn't really get any quotes from shops, but I have heard others say that it could be as much as a $1,000 job. Sorry I have no idea how many hours a shop would charge for this. Hopefully someone else can chime in.

TexasEngineer

It is not uncommon to see higher gains with long tube headers. I can only speculate that the weather had a lot to do with it. The baseline in the graph I posted was done at cooler ambient temperature. As to how much cooler, I am not sure. Also, the tune I had previously on the car was very strong. I will be returning to the dyno and hopefully going to the track once the weather is better.

BAD430BENZ

wait for cooler temps if your looking for better dyno #s . the track will be the true test but i noticed the temp had a lot to do with the #s i got on my dyno run with long tubes and tune . i dynoed mine during a 97 degree day and it was windy as hell . i only put down 460 whp . i'm sure my #s will increase during a cooler day , which here in El Paso is about once a year .

congrats on your new setup

TexasEngineer

So I am finally getting around to posting up some videos. The first video is an in car shot. I wanted to show what it sounded like at wide open throttle, cruising speed, and at part throttle. I would describe the new exhaust as sounding like the OEM exhaust only much louder and slightly raspier. It is very aggressive sounding grabs a lot of attention even at part throttle.

http://www.youtube.com/watch?v=6jf8W5P21p4

http://www.youtube.com/watch?v=PUVbEjjfcIU

http://www.youtube.com/watch?v=OSSQ-7fYmp4

http://www.youtube.com/watch?v=lDvl8RRzAGs

http://www.youtube.com/watch?v=Dh7b2uBoQ8k

bushburninc63

your car sounds straight nasty. Makes me want to get a set. :o

BerBer63

that catback section looks nice...group buy?

DuaneC63

Nothing like the sound of a big V-8 with headers.

BenzoBoi

Great write up and pics!

_AMG_

Damn that's loud!!!
Thanks for the videos.

DialDforDan

Couple of questions on this, assuming you're still around on this forum

1 - Did the 14hour install cover just the headers? Or is that the full system + wiring the valvetronic gear?

2 - So aside from taking bits off to clear up some space, is there any other 'gotchas' that would save a young punter like me doing it at home?

Cheers,
Dan

mr747

Hi dan

Agency will not work on your car only ipe will work agency is Lhd only

DialDforDan

Yeah that's cool mate. More interested in the details.. Assume the process will be pretty much the same.

Who else here has done their header installs at home?