135i Turbo Engine (N54 / N55) *General Questions Thread*

[bryce]

[bryce]

weird rasp in your exhaust note? this is a great thread for answers

[BMW86]

Can you give me a close estimate on the gains I could expect from the following mods, with and without a tune.

catless downpipes
midpipes
axel back
fmic

How much total horsepower would one have with these mods.

[bryce]

Originally Posted by BMW86

Can you give me a close estimate on the gains I could expect from the following mods, with and without a tune.

catless downpipes
midpipes
axel back
fmic

How much total horsepower would one have with these mods.

how much horsepower is kind of a relative question. dyno type, weather conditions, altitude, etc etc etc can all have an effect on horsepower figures.



here's my best attempt at an estimate:

with a tune, 350-420 wheel horsepower
without a tune, 300-340 wheel horsepower



as you can see, a tune is really required to get the most from your mods. catless exhaust, intercooler, etc will net you some power at stock boost levels, but the increased capacity for higher boost really should be taken advantage of.

[BMW86]

How much horsepower can someone expect with catless downpipes on a tuned car?

Also, what about midpipes?

[bryce]

Originally Posted by BMW86

How much horsepower can someone expect with catless downpipes on a tuned car?

Also, what about midpipes?

catless downpipes, at least 25 whp on a tuned car. probably higher, actually



midpipes, not as high. i still have stock catted midpipes, i think they'd only be worth 10-15 whp at most

[BMW86]

Originally Posted by bryce

catless downpipes, at least 25 whp on a tuned car. probably higher, actually



midpipes, not as high. i still have stock catted midpipes, i think they'd only be worth 10-15 whp at most

I thought catless downpipes would be around 30whp. Maddad promises 10whp for their resonated midpipes on a stock car. Do you think for a full turbo back exhaust 40whp gains could be expected? I know there is next to nothing for the axel back section except for weight savings.

[mineo77]

Originally Posted by BMW86

I thought catless downpipes would be around 30whp. Maddad promises 10whp for their resonated midpipes on a stock car. Do you think for a full turbo back exhaust 40whp gains could be expected? I know there is next to nothing for the axel back section except for weight savings.

if you add a grocery grabber in the trunk you can get an extra 1,000 hp! hahaha. j/k

I think it really varies on how efficient your DP's run etc. The dyno test are varying out there, but maddad did get 10-15hp gains with addition to the midpipe, i have seen the dyno runs and think they are posted on the site
too. Go catless, you will feel the difference. I just switch AR catted DP's to Macht Schnell catless and it was a world of difference...no dyno yet.

[The1]

you'll see and feel a difference when going catless. unfortunatly, you'll hear it too.

the other benefit to catless and doing an axle back, huge weight loss, which you can feel too, even if there were no gains.

But i wouldn't be surprised if you did 40whp difference with a tune and catless.

running an aftermarket FMIC on stock boost is a waste of money the stock system is optimised nearly perfectly for the stock system and tune. If you swap it out, you'll maybe get 1 or 2 hp, but you'll gain 10lbs at the front of the car. and lets not forget, you're paying between 400 and $1000 to gain 1-2 hp when you aren't tuned.

[BMW86]

Originally Posted by mineo77

if you add a grocery grabber in the trunk you can get an extra 1,000 hp! hahaha. j/k

I think it really varies on how efficient your DP's run etc. The dyno test are varying out there, but maddad did get 10-15hp gains with addition to the midpipe, i have seen the dyno runs and think they are posted on the site
too. Go catless, you will feel the difference. I just switch AR catted DP's to Macht Schnell catless and it was a world of difference...no dyno yet.

Is there any particular reason you went with Macht Schnell catless instead of the AR catless? Also, what are your thoughts on the AR Resonated catless? Do you think the resonated version will sacrifice some of the horsepower gains? they have said it wouldn't but I'm skeptical as there aren't many people running the resonated version.

[mineo77]

On the 2010 135i there is no removable elbow on the charge pipe to install for meth bung application. any idea how people are handling this situation? are people removing the charge pipe and drilling if for meth bung? any remedies?

[The1]

Originally Posted by BMW86

Is there any particular reason you went with Macht Schnell catless instead of the AR catless? Also, what are your thoughts on the AR Resonated catless? Do you think the resonated version will sacrifice some of the horsepower gains? they have said it wouldn't but I'm skeptical as there aren't many people running the resonated version.

Resonators are known to sap power, but pretty minimal, and with how close they are to the turbo, maybe even less power loss as the hot gasses move much easier then cool gasses.

so their claim could be pretty accurate about no power loss. or at least minumal.

no matter what, a resonated will still produce more power output then a catted aftermarket downpipe.

only difference is, you're going catless, but don't get the volume of catless.

[mineo77]

Originally Posted by BMW86

Is there any particular reason you went with Macht Schnell catless instead of the AR catless? Also, what are your thoughts on the AR Resonated catless? Do you think the resonated version will sacrifice some of the horsepower gains? they have said it wouldn't but I'm skeptical as there aren't many people running the resonated version.

Honestly there was no reason, just swapped with another forum member. But after install I can tell you that the Macht Schnell is a much better fit. This could be that AR included cats and their catless are a better fit, but there is some fudge factor involved and the MS slide in like OEM.

Not sure about the resonated versions.

[The1]

Originally Posted by mineo77

Honestly there was no reason, just swapped with another forum member. But after install I can tell you that the Macht Schnell is a much better fit. This could be that AR included cats and their catless are a better fit, but there is some fudge factor involved and the MS slide in like OEM.

Not sure about the resonated versions.

I've heard that in comparisons by people (not direct comparisons) the build quality and gains provided by the MS are very similar to the AR designs when in the catless.

I have heard of a few people struggling to fit the catted downpipes before, but i guess you just have to wiggle around a bit and eventually they will sit properly.

MS has a slightly lower price point the AR as well.

I have the AR sitting on my living room floor, they are beautifully put together, so i don't regret my choice, but I'm certain the MS people will say the exact same thing.

I went with the AR because they seem a little easier to get your hands on. there's lots more venders carrying them. Including a local Canadian vender, which solves a few problems when avoiding the border.

[BMW86]

This is the only information I can find on the net about the AR resonated downpipes. I can't find any reviews on them or pics of them installed.

What are your thoughts on them - http://n54tech.com/forums/showthread.php?t=9805

Do you think it's possible that there may be some power loss instead of getting standard catless?

[The1]

Originally Posted by BMW86

This is the only information I can find on the net about the AR resonated downpipes. I can't find any reviews on them or pics of them installed.

What are your thoughts on them - http://n54tech.com/forums/showthread.php?t=9805

Do you think it's possible that there may be some power loss instead of getting standard catless?

in looking at the picture, the resonators are so small, i wouldn't worry too much
instead of 30whp, you might get 28 or 29, no dyno is going to pick out the difference. A catted aftermarket downpipe might be good for about 20whp, so the resonators are definitely going to be much much better then the catted version.

[The1]

one more thing to point out, catless without resonators can have a bit of a "rhasp" sound. The resonators will or should get rid of that.

another solution to consider is the resonated midpipes that i think mad dad makes... just something to think about as an alternative.

[BMW86]

Originally Posted by The1

in looking at the picture, the resonators are so small, i wouldn't worry too much
instead of 30whp, you might get 28 or 29, no dyno is going to pick out the difference. A catted aftermarket downpipe might be good for about 20whp, so the resonators are definitely going to be much much better then the catted version.

Okay cheers, that's what I thought too. It does not look like a restriction. Is the 30whp gains with a tune? Maddad are claiming 10whp for their resonated midpipes. Do you think catless downpipes + maddad midpipes is good for 40whp or am I dreaming?

[The1]

Originally Posted by BMW86

Okay cheers, that's what I thought too. It does not look like a restriction. Is the 30whp gains with a tune? Maddad are claiming 10whp for their resonated midpipes. Do you think catless downpipes + maddad midpipes is good for 40whp or am I dreaming?

it would be with tune. I don't think you'd be far off those numbers, though the only real way to find out is to do a base run with tune, then add the pipping and then do another run with the same tune.

but exhaust and tune on a turbo are the most effective power makers in my opinion, followed closely by intercooler. I don't have much experience with meth injection, but from what i've seen/heard, you're looking at another 20-30whp there.

add everything all together and you'll be looking consistently over 400whp, especially with meth, you'll be surpassing 400 with ease.

your ultimate best results would be catless, resonatorless, and mufflerless, like the AA exhaust which just has basically a sound baffle off to the side or the mad dad mufflerless axle back... which basically has resonated tips i believe.

[BMW86]

Originally Posted by The1

it would be with tune. I don't think you'd be far off those numbers, though the only real way to find out is to do a base run with tune, then add the pipping and then do another run with the same tune.

but exhaust and tune on a turbo are the most effective power makers in my opinion, followed closely by intercooler. I don't have much experience with meth injection, but from what i've seen/heard, you're looking at another 20-30whp there.

add everything all together and you'll be looking consistently over 400whp, especially with meth, you'll be surpassing 400 with ease.

your ultimate best results would be catless, resonatorless, and mufflerless, like the AA exhaust which just has basically a sound baffle off to the side or the mad dad mufflerless axle back... which basically has resonated tips i believe.

I already have the AA axel back exhaust and I really like the sound especially during WOT and downshift. There is definitely some noticeable drone between certain rpm's but it's not a deal-breaker for me. Eventually I would like to change to a quad setup at some point. Not sure about the rest though.

[mineo77]

any input on my meth question??

[The1]

Originally Posted by mineo77

any input on my meth question??

ohhh, missed that.... Bryce might have a better idea then I. I haven't really researched any Meth stuff really.

However, you could drill it, but I always fear shavings going into the intake and becoming debris stuck in the cylindars. good way to get precognition.

I would definitely recommend trying to find a way to take it off, might not be easy, but worth it in the end....

I'll try a quick search and see if anything comes up, but you should know, i suck at the internet, and am very poor at searching

I can find porn easily when i need to though!!!