Mikevercetti

Can a dual exhaust be done without switching spare tire wells? I've got a 350 and I want to do the same. I read something about removing the secondary cats and resonator and being able to place the second muffler in place of those?

Kevwood

M-bENZ did his true dual that way, he's got a thread up with pics. He didn't use a muffler in place of the 2nd cats and resonator though, just straight pipes off the primary cats.

unitfreebie

Say, doesn't a true dual exhaust increase air flow so the engine will run lean and lose torque?

I've read that by flashing the ECU it will enrich the air/fuel mixture to regain the loss torque but then emission problems might occur?

Anyway, here's the Weitmeier's quad exhaust sytem but is pricey at $1250 !!

http://www.performanceproducts4benz....l?dept_id=5959

dynomite05

If you don't change the wheel well you won't be able to fit 2 mufflers. You could do what Andy did and delete 2nd cats/resonator/muffler and run 2 glasspacks in the middle and straight pipes to the tips.

dynomite05

For less than that you could do the actual conversion.

Kevwood

By just going from the factory exhaust to a true dual set up is not going to cause a lean condition. It will definately allow the engine to breathe easier and lean up the a/f ratios but only marginally. Some members here and on other forums have said that they feel like they lost bottom end when going to a free flowing exhaust but IIRC all of them negated those thoughts after the ECU adapted to the change.

dynomite05

Now that you mention it, my car did feel a bit sluggish on the drive home. It was about a 45 min trip and it did get a little better towards the end of the drive.

Mikevercetti

There won't be any back pressure issues by just straight piping it for the second exhaust?

And Kevwood, when you say that was negated after the ECU adapted, are you talking about the stock ECU or are you implying that it will require a new ECU tune?

Oh, and Dyno, you mentioned the muffler too? To do that, I'd have to remove the stock muffler and do straight pipes to both sides?

M-bENZ

Yup thats what I have right now.

Andy

dynomite05

If you're thinking about doing what I I'd you would have to remove your stock muffler. Once you switch the spare wheel well, you no longer have enough room on the left side for the factory muffler. You need to get 2 new ones.

Kevwood

Mike, the primary cats are still going to be in place, they restrict the exhaust flow and therefore create enough back pressure. Yes the secondary cats and stock muffler also produce restricted exhaust flow and removing them will increase the flow. I'm 100% confident that the CLK is going to be fine with the primary cats in place, I'm going to have a resonator and muffler but they will both be chamberless (highflow) and will not create restrictions (backpressure).

The stock ECU will adapt to the mild changes made to the exhaust system/flowrates. If you want to speed up the process, reset the ECU before leaving the exhaust shop, the ECU will learn the new curve from the get go, not have to adapt to the changes after it's already adapted to driving styles/habits as well. I use to do this after every dyno tune/mod.

I personally believe that way too much is being made of having to re-flash an ECU after cutting the seconday cats and muffler, it will adapt. If you were cutting everything out then it could be a different story. I was involved in engine tuning for many, many years and learned/learned with a very reputable tuner in Canada who doesn't turn many mild projects out of his shop. If I thought for a second that this exhaust mod may cause an issue - I wouldn't do it and would warn others. I'm going to do my exhaust and intake system without an ECU flash and will dyno the car with a wideband for results.

dynomite05

I'm looking for a place to dyno the car after I finish the exhaust. Haven't been able to find on close to me.

Luke_Geezy

Andy how are the performance gains from running a setup like that? i bet its LOUD as all hell too. i decided on just keeping my eisenmann race the way it is.. i was gonna start cutting tips off and make a nice dual or quad setup, but im pretty sure im just gonna leave it alone now.

M-bENZ

Loud ? lol it was before I installed the 2 glasspacks to the system but after the sounds is good now. Here is the clip for cold start,

http://s230.photobucket.com/albums/e...traighpipe.mp4

Andy

dynomite05

When are you going to post a clip giving it some gas?

M-bENZ

Probably tonite or tomorrow . Be patient lol.

Andy

Luke_Geezy

wow im retarded... i completely missed the glasspacks part... all i read was 2nd cats, res, muffler delete straight pipes to tips lol.. thats what i meant was loud as hell lol

unitfreebie

How do you reset the ECU?

Say, if you have to reflash the ECU chip, who would do it? Can the chip be reflashed for 104 Octane gas ? If so, how much HP would be gained?

dynomite05

Like KeV said, I really don't think that will be necessary. I felt the car start to adapt.

Kevwood

I know how to do it for the 500/550's but I'm not sure if it is the same for the 350's. There are a lot of ECU tuners around but the one I would recommend for a 'out of the box tune' (based on testimonials by lot's of MBWorld members) is Speedtunning USA. They have a few different tunes available depending on what mods you have.

Now, having said that, if you want to do it right (no offense to anyone with ST USA tunes), take your car to a dyno tuner after all your mods are done and have it custom tuned. From experience I can tell you that the gains and safety of doing it this way are unmatched, but, it comes at a cost.

Kevwood

You must be replying via iProduct. My iTampon always changes Kev to keV...

Fly Guy

Great Job Dynomite! That's one bad CLK!

ahmadk

still waintin for the mufflers and tips ...

dynomite05

lol, you got me. That was early morning on the can...lol




Thanks.




The mufflers arrived already, just waiting for the heat shields. The tips are already at the exhaust shop. I'm thinking I will be finished by Wednesday.

Kevwood

What did you decide on for muffs Wes? And yeah, iProduct!