[Hermesf]

Anyone know if there is room on a 428i GC to install an exhaust cutout? I know I should just jack it up and look but I am an old guy and getting lazy so thought I could just ask...

http://www.summitracing.com/parts/qtp-qtec33/overview/
http://www.summitracing.com/parts/qtp-10900/overview/

[rustyminded]

someone here on forum stated he did it but on f30

[jamoka3]

Were did you see that post about the F30; I'm intrigued...

[TurboM]

There's plenty of room to install one of these on an F30, especially right near the rear axles. I'd pick as far downstream as possible to save the unit from the excessive exhaust heat and pressure. Had these on other cars and they were great, when they weren't broken or being sent back to the manufacturer. If only they could be more reliable.

[rustyminded]

Originally Posted by jamoka3

Were did you see that post about the F30; I'm intrigued...

Jamesons Viggen

He related to something like this and mentioned a 7whp difference on dyno, I don't really remember on what post though.

[Hermesf]

I was able to stop by a muffler shop today and put the car up on the lift...there is a cavity just ahead of the second catalytic converter that appears to have room to place the cutout...I will be using the low-profile unit from Quick TIme Performance so that will help the fit...if that does not work well, there is another spot just ahead of the muffler that will work for sure, but I am hoping to use the former since it will be ahaed of the second c-converter and the resonator...I am ordering parts tonight and will report back once the work is done...

[jamoka3]

Do you think by doing the exhaust cut, BMW could void your warranty? I'm curious about this install, since I have the N26 twin power Turbo engine, I feel the cut out would let the engine breathe a lot better!

[Hermesf]

Do you think by doing the exhaust cut, BMW could void your warranty? I'm curious about this install, since I have the N26 twin power Turbo engine, I feel the cut out would let the engine breathe a lot better!


Don't know but suspect it might be an issue...figure worst case, if something were to arrise, I'll just take it back to the muffler shop and remove the cutout and patch the hole and tell BMW that I hit a rock and made a repair...

It will be interesting to see if the lesser back pressure alters the thinking of the system computer and therefore it then alters the tuning of the engine...we'll see - I'll report that too if I notice any performance hit that is distinguishable...

[TurboM]

Originally Posted by Hermesf

Do you think by doing the exhaust cut, BMW could void your warranty? I'm curious about this install, since I have the N26 twin power Turbo engine, I feel the cut out would let the engine breathe a lot better!


Don't know but suspect it might be an issue...figure worst case, if something were to arrise, I'll just take it back to the muffler shop and remove the cutout and patch the hole and tell BMW that I hit a rock and made a repair...

It will be interesting to see if the lesser back pressure alters the thinking of the system computer and therefore it then alters the tuning of the engine...we'll see - I'll report that too if I notice any performance hit that is distinguishable...

Its just going to make a lot of noise. You may see a few extra HP mid-range and high in the RPM band, but not much. The most power to be gained from modifying the exhaust is eliminating the catalytic converter built into the downpipe.

Be sure they do not cut your exhaust where its oval or else it will be a real big pain repairing the stock pipe later on down the road. I'd also keep a hold of the piece they cut out when installing the cutout.

[Hermesf]

Originally Posted by TurboM

Its just going to make a lot of noise. You may see a few extra HP mid-range and high in the RPM band, but not much. The most power to be gained from modifying the exhaust is eliminating the catalytic converter built into the downpipe.

Be sure they do not cut your exhaust where its oval or else it will be a real big pain repairing the stock pipe later on down the road. I'd also keep a hold of the piece they cut out when installing the cutout.

Thanks for thoughts on future repair; my mod will be where the oval pipe is, but I am sure my guy can fix (patch) if needed.

Not at all concerned with any increae in performance - my comment was simply wondering if the computer might degrade performance somewhat as a result of the reduced back-pressure.

The whole point of this mod for me is to MAKE NOISE...I like to go out into the country and push hard on the roads and MAKE NOISE - sooths the soul!

[rustyminded]

Originally Posted by Hermesf

Thanks for thoughts on future repair; my mod will be where the oval pipe is, but I am sure my guy can fix (patch) if needed.

Not at all concerned with any increae in performance - my comment was simply wondering if the computer might degrade performance somewhat as a result of the reduced back-pressure.

The whole point of this mod for me is to MAKE NOISE...I like to go out into the country and push hard on the roads and MAKE NOISE - sooths the soul!

Then you needa catless dp with it. The setup i have now is very loud !

[Hermesf]

Originally Posted by rustyminded

Then you needa catless dp with it. The setup i have now is very loud !

How do you accomplish that - are there off-the-shelf parts or? Thanks...

[erroberts1]

I'm also very interested in this. If the cutout is controlled via radio fob, I imagine it can also be programmed to homelink which would be boss. Let us know if you proceed with this and what you think afterwards.

[rustyminded]

Originally Posted by Hermesf

How do you accomplish that - are there off-the-shelf parts or? Thanks...

you have to get an aftermarket downpipe, there are several brands, AFE, ER & Wagner ect. you can find them on each of their website or check **********s they have all brands so you can make a comparison if u want.

[Hermesf]

Oh, OK so you are not doing a temporary bypass like these cutouts, but rather a full time bypass...not sure I want to do that for this car since it is a street car and I have to get smogged every couple of years here in CA...so, only being able to make decent noise will have to do!

[rustyminded]

Originally Posted by Hermesf

Oh, OK so you are not doing a temporary bypass like these cutouts, but rather a full time bypass...not sure I want to do that for this car since it is a street car and I have to get smogged every couple of years here in CA...so, only being able to make decent noise will have to do!

yes you will smell gas from exhaust from now & then & it will sure fail CO2 emission test,
I wish i would have done this bypass with dp it would be epic to control the sound !