What's better??

[135iDCT]

Down pipe or full exhaust system are they the same in gains or

how can i change my jb from 91 octane to 93?? should i have a usb cable or any tuner can do it

tell me plz

[infinitekidM2C]

No comparison...catless downpipes

Exhausts don't do much on this ride

[135iDCT]

my 2nd Q

[miro2296]

Catless downpipes FTW!

[infinitekidM2C]

Originally Posted by 135iDCT

my 2nd Q

Sorry i'm not sure i understand ur 2nd Q and ive procede tune...however, if im not mistaken the JB3 now has autotune which will adjust the tune depending upon what type of octane you've put in there

[135iDCT]

u mean that the jb automatically it self will change to 93 oc

[infinitekidM2C]

Do you have JB+ or JB3?

[Steve1155]

So, by leaving the stock downpipe back but switching out the DP's to catless DP's will the car be MUCH louder? I want the performance and added power but I also wanna hear my radio or passengers. Last car was a 2000 z28 with pretty much straight pipes and a head and cam package. Was fun for a while but as I got little older, the sound got to be too much.

[infinitekidM2C]

Originally Posted by Steve1155

So, by leaving the stock downpipe back but switching out the DP's to catless DP's will the car be MUCH louder? I want the performance and added power but I also wanna hear my radio or passengers. Last car was a 2000 z28 with pretty much straight pipes and a head and cam package. Was fun for a while but as I got little older, the sound got to be too much.

That's what i did to maximize hp/torque but minimize noise (i've had loud exhausts so i'm over it)...and really you wont hear much difference...louder when it starts up and bit gnarlier...but after that not much difference.

[Lambobimmer]

No reason to put a catback exhaust on the 135 unless you are just doing it for the sound. Not worh the money in my opinion. Go with the downpipes if your goal is to achieve power and not sound.

[infinitekidM2C]

Originally Posted by lamboworld

No reason to put a catback exhaust on the 135 unless you are just doing it for the sound. Not worh the money in my opinion. Go with the downpipes if your goal is to achieve power and not sound.

even this newbie knows

[TreDirtyFive]

the DPs will actually create a more throaty sound as well as deliver power.

[RnmEvo9]

I can't wait to put mine in tomorrow!

[thez99]

Originally Posted by lamboworld

No reason to put a catback exhaust on the 135 unless you are just doing it for the sound. Not worh the money in my opinion. Go with the downpipes if your goal is to achieve power and not sound.

Sry but i disagree. Even the stock system on the 1er has its restrictions for sure, specially the axle back portion. The entire system is bout a half inch smaller also than my maddad whisper system, including the tips which are actually close to .75" larger than stock. It opens up then back end where its necessary, yes the DP's will gain the most power, however it also runs you into problems with legality depending on what state you are, as well as problems with running rich without a tune. So obviously if you run DP's, specially catless ones, you NEED a tune or your performance will suffer, your engine will cake up and you'll burn thru gas faster actually than with a tune.

This is a rough explanation but ive been thru several FI cars and have read alot bout exhaust vs. dp's and both together, etc. so I dont feel its right to make it sound like exhaust is a "pointless or worthless" mod, quite the contrary, and it sure as hell sets mine apart from the rest as well.

Only time id ever consider catless is if I was positive i was in a state where it didnt matter, otherwise I dont need to deal with that crap. The stock dps on the 1er are actually not THAT bad compared to most lesser or equal FI sports cars.

[135iDCT]

Originally Posted by infinitekid2002

Do you have JB+ or JB3?

jb+

[V8Beatr]

Aren't Cats required be federal law?

[135iDCT]

members what about the 93 octane is it normal to use it without retune the jb+

[Vectors2final]

Originally Posted by V8Beatr

Aren't Cats required be federal law?

I believe so, but a few states have no emission standards and therefore no one to enforce it.

[1speedbike]

Originally Posted by 135iDCT

members what about the 93 octane is it normal to use it without retune the jb+

All JB chips will automatically adjust for whatever octane gas you put in your car. Put in 91 and you will get some performance level. Put in 93 and the car and the tune adjust. Put in 100 octane race gas and the same thing happens.

[135iDCT]

Originally Posted by 1speedbike

All JB chips will automatically adjust for whatever octane gas you put in your car. Put in 91 and you will get some performance level. Put in 93 and the car and the tune adjust. Put in 100 octane race gas and the same thing happens.

Thanx u make it clear

[Vectors2final]

So with the JB, there is no going to a tuner and having a map made for you specifically for your mods? Or having BMS send you new calibrations based off your mods? It sounds super convenient, but it also sounds like you're not going to ever get the most out of your mods? Someone care to chime in?

[RnmEvo9]

Just put in downpipes on my car. The sound difference is actually very subtle, but throaty. I love the throttle response now. I really like the car much better now with the jb4 and kittyless downpipes. Map 2 feels really good!