Full 3" turbo back exhaust....need opinions!

[raceman]

It's dream or it would be bag of compromises.
Definitelly something will go wrong.

[BerkTechnology]

It would be really tough to get a turbo back for $1000. From an engineering standpoint, a 3" single flows LESS than a dual 2.5" or a dual 60mm. It's a lot cheaper to produce but you're actually downgrading performance with a 3" single.

[SlicktopTTZ]

3" Dual turbo-back or 3" Down-pipes to a Y and then 5" single or whatever equivalent flow is for 2 3" pipes.

[HondaGoneRogue]

Originally Posted by BerkTechnology

From an engineering standpoint, a 3" single flows LESS than a dual 2.5" or a dual 60mm. It's a lot cheaper to produce but you're actually downgrading performance with a 3" single.

Here's what AMS had to say about a single 3". Are they wrong?

Originally Posted by Eric@AMS

Now we have a great deal of turbo history. I have seen more snails within my 5 years here than I can shake a stick at. As you know the current exhaust system has a true dual system. However after examining the system we think we can build a single 3" system. Now I know some of you are going to say but the car has twin stock....true. However the turbos are so small that there is no way they can overwork a three inch exhaust pipe. Twin 2.5" pipes have greater volume but there is no way this little guys need that much. Essentially you have been paying for exhausts that the turbo's cant even use all of.


What this will enable us to do is several things:

• Develop the most straight through and least restrictive system on the market
• Allow for a more affordable exhaust
• possibly integrate sound adjustability into the system
• v-band the entire system to eliminate sloppy slip fit joints that NEVER seal correctly
• most importantly, create an exhaust that will work with our turbo kit down the road

AMS does some serious tuning, so I would like to hear both sides of this.

[ALLMuRdErEdOut]

The ONE and ONLY Custom Performance Engineering

[BerkTechnology]

Originally Posted by HondaGoneRogue

Here's what AMS had to say about a single 3". Are they wrong?


AMS does some serious tuning, so I would like to hear both sides of this.

I agree with everything they are saying, my 2 cents to their list is:

1. Least restrictive would be dual 2.5" with straight though mufflers/resonators, not a single 3". These N54's are routinely doing 350rwhp+.
2. This is probably the #1 reason for doing a 3" single vs. 2.5" dual. There is a packaging problem when using 3" a single tube vs. 2.5" dual tubes. Clearances are already very tight under the chassis brace with dual 2.5" tubes and will be even worse with a single 3" tube. Can be done, just very tight.
3. If it is a single tip exhaust then this would be easiest to do. IMO single tips don't look right on the 1er. This is all personal preference though.
4. V-bands are nice. I don't like slip fits. I concur, slip fits never fully seal and are often sloppy. For cat backs BMW got it right and used flat gaskets and a ball/socket flange.
5. As long as it terminates at the end of the downpipe correctly, any exhaust will work with any turbo kit. There's no reason for a turbo kit to use a downpipe that terminates at a different location than stock unless you convert to a single turbo.

What this will enable us to do is several things:
Develop the most straight through and least restrictive system on the market
Allow for a more affordable exhaust
possibly integrate sound adjustability into the system
v-band the entire system to eliminate sloppy slip fit joints that NEVER seal correctly
most importantly, create an exhaust that will work with our turbo kit down the roa

[kirby135i]

Originally Posted by BerkTechnology

I agree with everything they are saying, my 2 cents to their list is:

1. Least restrictive would be dual 2.5" with straight though mufflers/resonators, not a single 3". These N54's are routinely doing 350rwhp+.
2. This is probably the #1 reason for doing a 3" single vs. 2.5" dual. There is a packaging problem when using 3" a single tube vs. 2.5" dual tubes. Clearances are already very tight under the chassis brace with dual 2.5" tubes and will be even worse with a single 3" tube. Can be done, just very tight.
3. If it is a single tip exhaust then this would be easiest to do. IMO single tips don't look right on the 1er. This is all personal preference though.
4. V-bands are nice. I don't like slip fits. I concur, slip fits never fully seal and are often sloppy. For cat backs BMW got it right and used flat gaskets and a ball/socket flange.
5. As long as it terminates at the end of the downpipe correctly, any exhaust will work with any turbo kit. There's no reason for a turbo kit to use a downpipe that terminates at a different location than stock unless you convert to a single turbo.

What this will enable us to do is several things:
Develop the most straight through and least restrictive system on the market
Allow for a more affordable exhaust
possibly integrate sound adjustability into the system
v-band the entire system to eliminate sloppy slip fit joints that NEVER seal correctly
most importantly, create an exhaust that will work with our turbo kit down the roa

your site has a turbo back system...when is that avail?

http://www.berktechnology.com/shop/p...cordPosition=1

[Black e82]

heyy guys i was actually thinking of the same thing and with the help of my local shop im getting a custom 3in dp to a 3in y pipe and a single 3in mid pipe from Riss racing. Riss racing said that there going to bring in a 135 just to make sure that it all fits on. As far as i know the process is running smoothly and should be done by this wednesday. Ill keep you all informed on how it goes

[kirby135i]

Originally Posted by Black e82

heyy guys i was actually thinking of the same thing and with the help of my local shop im getting a custom 3in dp to a 3in y pipe and a single 3in mid pipe from Riss racing. Riss racing said that there going to bring in a 135 just to make sure that it all fits on. As far as i know the process is running smoothly and should be done by this wednesday. Ill keep you all informed on how it goes

your local shop is Riss Racing or they are providing the mid pipe?

[TPLSM3]

Hey guys, looks like this thread came back from the dead. VK motorwerks & I were toying with the idea awhile back but we never took forth with it due to other projects. Looks like we might have something rolling with the exhaust though. What would you guys like to see for the 135i? Downpipe back....? Turbo back....? Like I said before, we would probably have the price be UNDER $1k. Like all other VK Motorwerks parts, it comes without the BMW tax for high quality parts.

[kirby135i]

Originally Posted by TPLSM3

Hey guys, looks like this thread came back from the dead. VK motorwerks & I were toying with the idea awhile back but we never took forth with it due to other projects. Looks like we might have something rolling with the exhaust though. What would you guys like to see for the 135i? Downpipe back....? Turbo back....? Like I said before, we would probably have the price be UNDER $1k. Like all other VK Motorwerks parts, it comes without the BMW tax for high quality parts.

I see the Dps are getting good reviews but they require some adjustment to the stock exhaust on 135is, so maybe a full turboback exhaust?

[Black e82]

No my shop is "VTR" and there dealing with riss racing and riss racing said that they finished the whole setup and that it should be shipped out by wednesday!! ill take pics and give updates on how it goes

[TPLSM3]

Originally Posted by kirby135i

I see the Dps are getting good reviews but they require some adjustment to the stock exhaust on 135is, so maybe a full turboback exhaust?

Not sure about what adjustments are needed for the DPs to fit the stock exhaust that you refer to. VK actually used my 135i as the prototype car and we never ran into any adjustments to the stock exhaust. So what do you guys want to see for an exhaust? Throw out some ideas and I know Vince can make it happen.

[bimmerboy]

+1 for a catback exhaust, since many of us have the downpipes already.. Main concerns would be cost, quality, and fitment. Something for around $700 would be great. Since most people want maximum performance without being too loud, a system with catless midpipes along with resonators would be a perfect combo.

[kirby135i]

Originally Posted by TPLSM3

Not sure about what adjustments are needed for the DPs to fit the stock exhaust that you refer to. VK actually used my 135i as the prototype car and we never ran into any adjustments to the stock exhaust. So what do you guys want to see for an exhaust? Throw out some ideas and I know Vince can make it happen.

I was referring to this post in the VK downpipe thread

Just got back from installing my 135i pipes....

1st of, thanks Vince for the shipment...it was a long time coming, but they are very good quality. Installation was a biaaatch, I didn't know it was so freaking tight in there... had to have an installer do it finally

Couple of things: The front screws are too big (the heads) to fit, so the installer had to use some of his screws (he does custom pipes, exhausts,e tc, so he has a ton of stuff). The other issue was that the fitment (extension) was about 3/8" too short. He had to losen the catback and the entire exhaust system to be able to make up that difference. When it was all put back together, it was fine, but indeed there had to be some work done in the exhaust system (losen the clamps, etc) to be able to make the fit.

Nothing that was a huge deal, but I thought you should know in case there was some other fitment issues with the 135i's. So far so good in terms of sound/performance.

[kirby135i]

i didnt sound like major prob and it might just have been an isolated issue...either way...id be in for catback system.

[TPLSM3]

After talking it over with Vince from VK Motorwerks, I think we might be working on some midpipes for the 135i. What do you guys think?

[philiopf22]

For that price on a TBE, I'd be in. I should have my 09 in a couple of weeks if they needed something for a fit check.