Possible Supersprint Header for m44
 

http://www.supersprint.com/en/prod-c...r_oem_kat.aspx
Found this while browsing Supersprint's website. Don't know anything about it, but assume it would be better than OEM??

Not worth the money. The M42/44 has a factory header. I doubt the Supersprint header makes more than 5hp.

+1. Their catbacks are really nice, hard to find here in the states.
http://www.supersprint.com/en/prod-5...80BA___00.aspx

I have a header similar to that (not stainless) and I have not installed it for the very reason that there has been no solid information proving any substantial benefits of this design. Probably why I got it free:rolleyes:

I was looking at the one at the bottom, with the quad tips, and looks like the right are different from the left section?

What about the front pipe? Is that a test pipe, or high flow cat? Can it be installed with simulator so will not trigger cel ?

The front pipe is an adapter piece that attaches to the cat back. They did that so they could use the same cat back part on multiple vehicles and just change the length of the adapter based on the specific vehicle.

Any idea from where can I buy test pipe for ti? Or just replace the cat with mufler and simulator for the sensor?

Why would you do that? The ones sold are for race use only. There's no performance to be gained, your car will be obnoxiously loud, it's illegal and and you'd be ghettofying your car to the point that resale will suffer.

Well, ok. Why do people on this forum do any exhaust upgrades? Only for the sound? In that case I dont need a louder car. I dont wanna swap the economic engine, or pay 4 g's for blower. I just wanna make it a little more fun to drive, thats why was thinking to remove any restrictions on the exhaust, software may be. Im aware this will give me around 9 extra ponies :), but still, just to release all the potential of that 1.9 engine. If you have a better advice, am glad to hear it.

9hp, not a chance. In fact, if you remove your cat, you'll not only gain a raspy drone, but you'll probably lose a lot of low end torque. The best catback on the market might get you 1-5hp max(not even enough to notice) and yes, people here install catbacks for sound. The only real benefit besides sound is possibly a little weight reduction. The M42/M44 engines came with a really nice header from the factory. The factory muffler is much lighter than the ones used on the e36 coupes sedans and verts. I know it's hard to believe, but BMW actually got it right with these little engines. They already squeeze out a good amount of horsepower while still maintaining efficiency. Without a bore/stroke or FI setup, there's very little if any power to be gained. Sure, you could get a custom tune. However, whatever you gain on the high end, you'll likely lose on the low end. And whatever you gain in power, you'll lose on economy. If you want the car to feel sporty, get a lightweight flywheel, sport tuned suspension and some sticky tires. If you want power, suck it up and do a 6cyl swap or go FI. It's laughable that you want to keep the economical engine, but you want to remove the catalytic converter.

FWIW, we had a Stromung groupbuy a few years ago. Most people got 2 1/4" piping to match the factory cat and a few members with DASC's ordered the 2 1/2" piping for better flow. All of the DASC'd guys reported a loss in low end torque and none of the NA guys reported any performance gains that I can recall. It's a placebo effect. Just like the guys who install CAI's, they drive harder to hear the suction and then claim their car is faster. It's not really faster, they're just driving more aggressively to hear the sound.

Some people just don't want to believe that BMW designed a peppy little engine. It is what it is, no matter what you bolt onto it, it's always going to be a 1.9L.

Thank you for the clear and explanatory answer. You saved me hours of worthless reading and money not well spent. I think someone should put that to the main page, so all the new ti enthusiasts can see it. Even painfull, I admit that you myfriend say the truth. I go to this shop and the guy over there that fixes my car always tells me, why dont you put that,why dont you change that, worthless! Change the engine, suspension, brakes etc. and make it a freakin track car, as a lot of people here did, or just by an M. Have a good sleep! Atleast mine will be now.

Don't get me wrong, there are improvements to be had with these cars. Tightening up the worn bushings and suspension will probably be the most noticeable improvement in performance, but there's a ton of other stuff you could do to make the car funner to drive. A Z3 shift kit will make a noticeable improvement, as will a lightweight flywheel. A limited slip diff will wake up the rear end a little while putting better power to the road. If you have tools and experience, you could advance the cams a couple of degrees and stretch the powerband out over higher RPM's. Your engine can only suck in as much air as the MAF and throttle body will allow it to, so an intake is pointless unless you want to bore out your throttle body and run a larger butterfly. You can port match your intake and exhaust manifolds and port and polish the cylinder head. Heck, if you have the money and a good machine shop, you can increase displacement to 2.1L by over boring the cylinders, running bigger pistons, connecting rods, fuel injectors and a more aggressive crankshaft. Everything comes with a price, and part of that price is compromised reliability. The factory exhaust isn't really restrictive. In fact, it has just the right amount of backpressure. If you were to run an open header, you'd burn up your exhaust valves pretty quickly, so you need some backpressure. Plus with all these o2 and SAP simulators and stuff, you're tricking the car into running lean or rich. So it's either gonna run hot and fatigue everything or it's gonna run cold and gunk everything up with carbon.

I see. Yes, I was looking into the metric mechanic web page, prety nice stuff for a prety high price, and it gives you whole 35hp :), for around how much? 6-7 k may be. Thats crazy. And than I still have to upgrade clutch,diff, and bunch of other stuff. + dasc , because after rebuilding th engine like that you gotta FI it. I'm wondering how much that guy Marko spend on that silver ti? For that amount of money you can buy e46 in a good shape, ofcourse will be havier for autocross, but I can't imagine spending that kind of money and then some 18 year old to blow me off at the trafic light with a 335i.
I'm becoming more convinced that I should not mess with the car, till I have the time and money to make it track car. Thank you Jess for info.

Bytheway I saw a video of Jean H.318TI doing backfire while acelerating, and he has no cat. Is that the reason?