How To get More Power Gain with RPI Axle Back?

[M3NSTER]

I have a e92 that came with RPI Axle back exhaust and even for axle back it is really loud... I don't mind the drone I have gotten used to it. I really don't want to fork out 4-5k for an akrapovic evo system when I already have the sound I like.

I'm looking to get RPI Air Scoops, AA Power Pully, Dinan CF Intake this week. Once installed I will get a BPM Sport stage 2 Tune

What are my options before getting the tune with keeping the RPI Axle back.

To get more power am I forced to fork over another 4-5k for akrapovic evo

Thanks for all the feedback

[BrewRifle]

You could get test pipes or an x-pipe for bigger gains.

[M3NSTER]

Originally Posted by BrewRifle

You could get test pipes or an x-pipe for bigger gains.

thanks! any feedback between mastermind street or challenge?

[BrewRifle]

There are loads of threads related to the different gains with the different setups, but in general, they will all be similar depending on what you're removing. Primary cats cat removal will yield the largest gains, and this can be achieved with just test/track pipes, but can also be achieved with x-pipes. Some x-pipes removal both cats and leave resonators, while others replace the primary cats with high flow cats.

I actually went with the AA X-pipe with high flow cats and resonators to avoid the stench of running entirely catless. Resonators will help with raspyness and overly loud setups (which we both have already) to a degree(I'm still expecting it to be louder under WOT).

Good luck!

[s85e90]

Full RPI exhaust is one the best HP gains around

[M3NSTER]

Originally Posted by s85e90

Full RPI exhaust is one the best HP gains around

Sorry as this is a dumb ass question. So what exactly would I have to replace and buy to make my Axle Back Full?

[IzzyGray]

Originally Posted by M3NSTER

Sorry as this is a dumb ass question. So what exactly would I have to replace and buy to make my Axle Back Full?

X pipe plus axle back equals full system.

[M3NSTER]

Originally Posted by IzzyGray

X pipe plus axle back equals full system.

That's what I thought but wanted to make sure! haha. so I guess I should be searching for an RPI Xpipe.

[M3NSTER]

Originally Posted by s85e90

Full RPI exhaust is one the best HP gains around

thanks... pros and cons I should know about just throwing in an X pipe vs. putting x pipe with replacings cats with front pipe?

[REDBULL]

i had the full rpi GTM system on my old m3 at one point, and sold the rpi because of the drone. it did sound epic though!

as for whether you should get an x pipe or test pipes (replacing cats), x pipe gives you the option to keep ur oem pipe and swap it back if ever needed. just remember either way, catless dramatically increases sound.

an idea for the rpi axle back with the RPI or similar catless x pipe sound:

[M3NSTER]

Holy moly... Any opinion on adding the dinan mid pipe? Louder or more quieter than going x pipe?

Originally Posted by REDBULL

i had the full rpi GTM system on my old m3 at one point, and sold the rpi because of the drone. it did sound epic though!

as for whether you should get an x pipe or test pipes (replacing cats), x pipe gives you the option to keep ur oem pipe and swap it back if ever needed. just remember either way, catless dramatically increases sound.

an idea for the rpi axle back with the RPI or similar catless x pipe sound:

[REDBULL]

Originally Posted by M3NSTER

Holy moly... Any opinion on adding the dinan mid pipe? Louder or more quieter than going x pipe?

its basically an x pipe. also i have heard of some quality issues with the dinan mid pipe and they deny any claims since it is a "racing part".

if you want catless but are concerned about sound you have 2 options in my opinion:

-test pipes and leave your secondaries and resonators (still will be louder though)

-change to a valvetronic exhaust

[M3NSTER]

Originally Posted by REDBULL

its basically an x pipe. also i have heard of some quality issues with the dinan mid pipe and they deny any claims since it is a "racing part".

if you want catless but are concerned about sound you have 2 options in my opinion:

-test pipes and leave your secondaries and resonators (still will be louder though)

-change to a valvetronic exhaust

BETWEEN TEST PIPES AND DINAN MID PIPE. SAME IN POWER GAIN?

[REDBULL]

Originally Posted by M3NSTER

BETWEEN TEST PIPES AND DINAN MID PIPE. SAME IN POWER GAIN?

with test pipes you are replacing OEM cats and keeping secondaries and resonators. so no you will have a little less gain. again, i don't recommend dinan mid pipe based on what i have seen. there are many other high quality x pipes on the market.

[W///]

Originally Posted by M3NSTER

Holy moly... Any opinion on adding the dinan mid pipe? Louder or more quieter than going x pipe?

Doing anything, regardless of Xpipe or test pipe will make your setup much louder than completely OEM setup. Just be prepared for that.

FYI, I went test pipes, deleted secondaries and kept OEM resonators. Total cost = $450.

[M3NSTER]

Originally Posted by W///

Doing anything, regardless of Xpipe or test pipe will make your setup much louder than completely OEM setup. Just be prepared for that.

FYI, I went test pipes, deleted secondaries and kept OEM resonators. Total cost = $450.

I'm leaning towards RPI X pip and front pipe that deletes the secondary cats added to my Axel back to give the full rpi system

[W///]

Originally Posted by M3NSTER

I'm leaning towards RPI X pip and front pipe that deletes the secondary cats added to my Axel back to give the full rpi system

Like I said, it'll be very loud, and there's a chance it'll drone too. Personally, I think having a pair of resonators is a plus (don't know if RPI xpipe comes with one)

[REDBULL]

Originally Posted by W///

Like I said, it'll be very loud, and there's a chance it'll drone too. Personally, I think having a pair of resonators is a plus (don't know if RPI xpipe comes with one)

building on this, the rpi in specific drones like crazy. so OP just factor that in with your choice.