hooleyboy

I'm going to be redoing my whole exhaust and, well most of it as I think the stock muffles sound good. I know no one makes a cat for my car so im going to go with a universal primary hiflow cat system. With 2.5 inch true duel exhaust. The only thing thats impeding me from doing ASAP is finding what kind of universal cats i would need. I know all the places to look for them, Like Magaflow, and others but when i get their i don't know what i'm looking for. If anyone can help that would be killer.

BTW Off this topic, Headed back to the drags to see what the car can run with some race fuel. i will post any times that are worth posting. Pulleys working great and I've made up my power loss and then some from the heavier wheels i put on.

c32AMG-DTM

From what I remember, you can get Kleemann high-flow cats for the w203 cars... but it's probably cheaper sticking with universal.

Good luck at the drag strip - post up the results regardless of what they are! Any info to share is good info, IMHO.

rploaded

The stock cats are really pretty good albeit a bit heavy. How much more HP you think you can muscle out of that system?

For awhile I ran straight exhaust back from the primary cats, it was way too loud (sounded like a nascar) but at night you could see flickering in the tailpipes which was cool. In the end I had to tone it down a notch.

Back to your question......

You might want to look at some of the Porsche racing sites.. They should list some good racing cats that would work on the 203 platform.

My.02

hooleyboy

anything kleemann is just $$$ I thing if i got a bit cheaper i can still get were i want to be. I'm kinda feeling magnaflow but i dont know how to find out what one would be the right one. This is tricky stuff i tell ya, at least for my small brain. I'm post the times when i get back from the drags. Still a bit warm out here in AZ

||C55AMG||

Before buying any HFC, I would inquire about what substrate they use. A 100 cell substrate will flow better than 300 cell substrate HFC.

Check out this link:

http://forums.evolutionm.net/showthr...cell+substrate

Hope this helps...

hooleyboy

This is what I'm talking about. how many cells are the stockers Whats the min I can go with passing emissions or does that not matter? In a PM conversation I was told the stockers are like 400 cell??? If there was power gains from removing 2end cats than there has to be with replacing main cats with other ones.

||C55AMG||

Wow, 400 cell is pretty thick. Keep up the good work, I am liking your results!!!

Eleventeen

Knowing what I know now, I would stick with the stock AMG cats (at least the primaries), but maybe the 55 has more to gain by going aftermarket If you really want to do it, Magnaflow "Spun-cats" are a good place to start; that's what I'm currently running.

http://www.jegs.com/p/Magnaflow/763223/10002/-1

hooleyboy

Thats what im looking for but those are rated up to 5.2L and i got a 5.4L

rploaded

Yes but you have two of them!

Maybe you cut the 5.4 in half since the work is split between two cats?

Just a thought or is that wishful thinking?

hooleyboy

I never thought of that. Does it work that way? If it does i'm all over them for for $150 for both. All I need to know is how many cell the stokers are and go from their. Then comes the question of were the he11 am i going to but the o2 sensor? All I know is this is going to be fun.

drags tonight: 13.391 at 107.585mph was my best. As soon as the temps drops into the hi 70's there was no traction. everyone was spinning and fighting for the right lane as it was the better of the two evils. Car felt amazing and sounded killer. trap speed was back up from being down to 103mph. Thank God i tree'ed a Grand National as it spun out on the track, shooting an rear wheel and Axle across the track. Note: thats why you dont street race and take it to the track. If that happened on the street he could have killed himself or someone else and I would have been just as guilty for drag racing. when it gets down to 60 degrees here in AZ and i can hook up 12.9 is what I hoping for. Dragtimes.com D/A correction time would be 12.8 @ 109mph. Member "cruzinquick" had his STR-6 running 12.7's - 12.8's He was just killing it tonight. He came in second in the bracket race.

rploaded

Called my shop, I was told that the rating given to a cat is the total size engine it can handle. He said for my car having 2 cats any cat rated over 4 liters would be fine as the work load is split.

I also asked him what the rating was on the stock AMG cats.

He said he could not give me the stock specs but suspected by looking at AMG cats they have cut open in the past that the unit would be around the 200's stock. He did say though in essence YMMV.

I hope this is helpful in your quest. As far the 02 sensor I would cut one cat off and replace with O2 and test. If you get a CEL I would put that sucker right back the way it was. Emissions controls being what they are, short of a reprogram in the ECU I think you will be in a for a world of ongoing troubles.

hooleyboy

supersprint hiflow cats for a CLS55 claim that the stock main cats are 400 cell. Do i know this as fact..no. So I deff going to have to research. thanks for the good info.

Eleventeen

Correct

hooleyboy

Nice! Now I just need to know how many cell the stockers are.

Some people think that the stock main cats are high flow. This maybe true, I dont really know so i'm trying to look into that before i go cut out $1500 a piece main cats and replace them with $150 cats

timdf

are almost always 400 cell. I would expect even AMG to use 400 cell parts. If you have your old cats to hand it's quite easy to tell what they are by estimating a square inch and counting the holes !

Check this site out:

http://www.sardracing.com/products/sports_catalyzer.htm

I have replaced my OEM 400 cell cats with 100 cell cats and am told they allow my 911 TT to pass CA smog, they also have not caused any CEL problems (they have O2 sensors before and after).

You should be able to purchase after market 100 cells cats and have them welded in, but I don't know about the O2 sensor arrangements on MB's - doubtless someone else can comment.

I can say though removing restrictions in either the intake or exhaust paths is a sure way to add power, but be aware that messing with the intake side can actually reduce power if not done correctly.

Thus exhaust mods should come first :-)

hooleyboy

right now your word is gold to me All I got is a renntech airbox up front and that about as far as im going. I'm going to totally re-pipe the exhaust system. and find away to use run the o2 sensors. I feel yeah, IMO there has to be some power to gain by going with 100 cell cats and true duel exhaust. IF there was power in from removing the secondary cats than their has to be some power in reducing the cell count from 400 to 100. It just might pring out the true potential of the evosport headers i have.

good info in this thread.