E55 RUSS

Hello guys...need you advice...

I have Kleemann Style Headers, Primary Cats removed, O2 moved behind Secondary Cats and E.Race mufflers...

I am thinkinking of removing my Secondary Cats also to make my car to breathe even better, make more Power and run better at higher RPMS...but I also know that loosing to much back pressure is not good also...will loose togures etc...

Anyone knows how would E55 perform with Headers, No Cats and Freeflowing mufflers, will it run better overall ???

Will I gain or loose, why, should I do it or NOT ???


Thanks...

phatmitzu

"O2 moved behind Secondary Cats"

Got any pictures of that? Thanks

rlee02135

thats gotta be loud as HELL

dsc

I was told by Cory at Kleemann and my installer that removing the 2nd Cats would give no power increase. I have K2 with the primaries removed.

ProjectC55

Yep I was told that too. I was also told that you would probably even lose power without having at least the secondary cats on without the primaries. Bottom line ,two cats(secondaries) are better than no cats.

jangy

It all depends on how much air you are pulling in. As power gains, fatter exhaust will help. you say you are looking for top end gains. If so, I say you may wanna try it. the SS system is a prime example of no cats.
I know you will lose low end, but not sure that top end would be better? My only concern with the E55 at top end is the kompressor screw actually becoming a resistance to air flow. that's why I've learned to enjoy the E at low end instead. let us know what you do.

Roupin

Jangsta, why would he lose any low end? I know in theory that's how it should work, but practically slightly opening the exhaust on every car I've ever messed with gave better response at both low and high rpms. The Kompressor isn't a turbo and doesn't gain boost based on backpressure, but then again don't take my word for it.

I just straightpiped the 2ndaries on the E, and if anything it spins the tires more off the line. Same thing with Murtaza's SL500.

jangy

Boosted cars are different in that they need the backpressure or else the pressure differential goes backwards and all the heat stays at the source.

I was taught the concept in a funny way. I was chilling with a tech buddy smoking pot (back in high school). He used the smoke coming from my cough cough lungs as the example and made me blow using different sized tubing.

Try 3 different conditions. One with just you blowing into open air, one through a paper towel center and one through a boba straw.

Oddly, enough you'll see that it takes less effort to clear yourself with a tuned diameter. It is a wired paradigm and even wierder analogy, but somehow it stuck.

By the way, people are like forced induction engines in that we use our diaphram. The cars you have been doing it to lately are both NA and so they work differently. It isn't that they don't need some back pressure as well. Its that they simply need less, since they aren't forcing the air in on the front side.

E55 RUSS

OK...thank for you tips guy...


I wanna do it but I also dont want to risk...The car would definatetly loose some torgues and should make more power on TOP, therefore run better at higher speeds as the gases will be able to leave the exhaust system faster...

I need to test on Dyno and on the ROAD...

What I am most worried about is that...its loud already removing Secondaries would make it crazy loud and unfortable for everyday driving...

http://video.google.com/videoplay?do...35767073029946

Also my friend with SL55 Evotech has all Cats removed, as his tuner says his car is making 680 HP and he is faster on TOP the ME but rolling start I am faster till 145mph...

But I am not sure if Cats do this or his Re-programmed and re-inforced tranny...Tuners in Germany say re-porgrammed tranny make a big diff at higher speeds....



Backpressure on the exhaust on E55 definately has effect on the BOOST Pressure...installing headers with no Cats cause Boost to drop by 0.2...

Unfortuntaely I dont have a pics on O2 srelocated I've delited them, but you just need to extend you wiring and located then as close to cats as possible in order not to get SES lights...

Zod

That looked like fun

E55 RUSS

Anyone else knows more info ???

E55 RUSS

Been told from one of our expert on this board that I should gain around 10-15HP and shouldnt loose at Torgues...

What do you think guys ??? Should I go for it ???

or

1st Dyno the car withSecondary Cats and then remove them and Dyno again... more money but I we will know the truth...

What I am scared off is the SOUND LEVEL...it would be insane...too much noise...

BENZGal

I say go for it. I have the opposite set up with my sec. cats removed. I love the monster sound.

Thank you for the O2 info. I have to take my car into the DMV next week for a visual inspection.

E55 RUSS

OK...I already have a monster sound...what I dont want is more resonance at low RPMS...

Going to do it Next Saturday and try to DYNO on Sunday...hope it will work...I even read books about it and in theory I should get the benefit...