[coolman2527]

Hello everyone, new to the forum here!

I currently have a 2020 X4 M40i and I m planning on taking it down the modification road with this thing

I want to start with something minor, starting with a cold air intake and catless downpipe, now I heard even with small mods like this, there is a possibility of getting the warranty void, but I heard most of the time it is up to the dealer if they want to continue granting the warranty or not, what are you guy's experience when dealing with this kind of modification?

I also realized there is only about another year of warranty left anyways, plus the fact that M40i got a B58 engine, which is known for being bulletproof, so is it safe to say an intake and a catless downpipe mod won't be causing any issues?

Link to Cold air intake:https://wctperformance.ca/mst-perfor...3-x4-3-0t-b58/

Link to catless downpipe: https://wctperformance.ca/mst-perfor...-us-bw-5803dp/

Any thoughts?

[Rottweiler]

Are you gonna be fine throwing cels with the catless?

When I was looking, I spoke with the main guy at AA Cats and he said they dyno’ed a car with their catless and high flow catted (GESI 400 I believe). The performance difference was minimal…maybe 3%. The difference in noise is likely not gonna be minimal…

Plus this catted pipe SHOULD not throw cels…

https://x-ph.com/active-autowerke-aa...iABEgLXhfD_BwE

[earlgsxbusa]

Iv modded my X4 with some things. I have an Evolution Works 200Cell down pipe, but I did a stage 2 93 tune and ss exhaust. Stock Intake. Mid pipe next.

Been a few days with this setup. Still feeling it out. No CELs and the car pulls hard off the line and power up the power bands.

But going to have post and sound vids when it's not raining here where I live.

[chhappy7]

Originally Posted by earlgsxbusa

Iv modded my X4 with some things. I have an Evolution Works 200Cell down pipe, but I did a stage 2 93 tune and ss exhaust. Stock Intake. Mid pipe next.

Been a few days with this setup. Still feeling it out. No CELs and the car pulls hard off the line and power up the power bands.

But going to have post and sound vids when it's not raining here where I live.

Doesn't the tune automatically disable cel for cat so that it will never come on?

[earlgsxbusa]

Originally Posted by chhappy7

Doesn't the tune automatically disable cel for cat so that it will never come on?

As far as i Can see yes.

[JAY56641]

I've done both mods to my 2020 X3 M40i. I also did a custom tune to go with it. Substantial additional power. Some things to consider if you go high flow cat or catless. Both lead the exhaust smell to be really strong. Also the warranty concerns which you listed.

I love mine but if I was to do it again I'd likely keep the cat and intake stock and just do a piggyback tune so that the warranty never becomes an issue yet get additional power.

[Rhdlife]

I am in the same boat, I have yet to pull the trigger and send my DME to Femto, because I do not want to be without a car for a week. But I do have an MST intake, VRSF downpipe, XHP Stg 3 and JB4. Tons of fun but itching for more unfortunately.

[Rottweiler]

Originally Posted by Rhdlife

I am in the same boat, I have yet to pull the trigger and send my DME to Femto, because I do not want to be without a car for a week. But I do have an MST intake, VRSF downpipe, XHP Stg 3 and JB4. Tons of fun but itching for more unfortunately.

You need a cat back exhaust and a pedal commander

For exhaust, I’m really pleased with my Stone system but FI has a strong rep as well. If on a budget…

https://x3.xbimmers.com/forums/showthread.php?t=2009519

I got the Dahler ATT pedal unit too. No additional hp but the car FEELS much more responsive. Virtually no slack re pedal input, and it has an anti-theft component as well

[Rhdlife]

Originally Posted by Rottweiler

You need a cat back exhaust and a pedal commander

For exhaust, I’m really pleased with my Stone system but FI has a strong rep as well. If on a budget…

https://x3.xbimmers.com/forums/showthread.php?t=2009519

I got the Dahler ATT pedal unit too. No additional hp but the car FEELS much more responsive. Virtually no slack re pedal input, and it has an anti-theft component as well

I did delete the resonator and kept the factory muffler

[coolman2527]

Originally Posted by Rottweiler

Are you gonna be fine throwing cels with the catless?

When I was looking, I spoke with the main guy at AA Cats and he said they dyno’ed a car with their catless and high flow catted (GESI 400 I believe). The performance difference was minimal…maybe 3%. The difference in noise is likely not gonna be minimal…

Plus this catted pipe SHOULD not throw cels…

https://x-ph.com/active-autowerke-aa...iABEgLXhfD_BwE

Ahhhh I see... now this is really making me reconsider, I have seen a lot of people mentioning that air intake don't increase much HP other than bring more volume with sound, thanks for the info tho!

[coolman2527]

Originally Posted by earlgsxbusa

Iv modded my X4 with some things. I have an Evolution Works 200Cell down pipe, but I did a stage 2 93 tune and ss exhaust. Stock Intake. Mid pipe next.

Been a few days with this setup. Still feeling it out. No CELs and the car pulls hard off the line and power up the power bands.

But going to have post and sound vids when it's not raining here where I live.

I m very interested with your video and I definitely look forward to it!

I spoke to a few buddies of mine, and they all recommend me to get it tuned,

Got a few question for ya, so there is different setup of tunes, for different octanes, what made you go with 93 octane? More HP? Is it worth it?

When you starting tuning, is other modification required? Or it would be personally preferences? Like let's say I m gonna hit stage 2 eventually, do I have to change downpipes like you did?

[Rottweiler]

Originally Posted by coolman2527

Ahhhh I see... now this is really making me reconsider, I have seen a lot of people mentioning that air intake don't increase much HP other than bring more volume with sound, thanks for the info tho!

Nothing wrong with gobs of turbo spool brother…

[coolman2527]

Originally Posted by JAY56641

I've done both mods to my 2020 X3 M40i. I also did a custom tune to go with it. Substantial additional power. Some things to consider if you go high flow cat or catless. Both lead the exhaust smell to be really strong. Also the warranty concerns which you listed.

I love mine but if I was to do it again I'd likely keep the cat and intake stock and just do a piggyback tune so that the warranty never becomes an issue yet get additional power.

Yeah I spoke to a few buddy of mine, and they are recommending me the same thing, going with tunes only, now question... after the tune is done, the dealer mechanic can find that out right? I heard BMW mechanics got some very advanced system, and they can always catch if a car has been tuned or not

[earlgsxbusa]

Originally Posted by coolman2527

I m very interested with your video and I definitely look forward to it!

I spoke to a few buddies of mine, and they all recommend me to get it tuned,

Got a few question for ya, so there is different setup of tunes, for different octanes, what made you go with 93 octane? More HP? Is it worth it?

When you starting tuning, is other modification required? Or it would be personally preferences? Like let's say I m gonna hit stage 2 eventually, do I have to change downpipes like you did?

Yes there is a way from bm3 to switch between tunes from the steering wheel. I have read on it in the bm3 forums for the B58 tune. I havent tried it yet, Im still trying to get the wifi obdc to work lol. But I went with Stage 2 93 for more hp and better burn. I have to switch tunes between the 91 and 93 to see if there is a difference. Price for 93 vs 91 here in NJ is about .20/.30 cents difference. So all in all, the Tune is very noticeable difference compared to stock. With the down pipe installed, I also do hear the turbo spooling with the windows up! Took my coworkers today for a launch..and they noticed the difference in performance.

If no mods, I would say Stage 1 91. Many posts on here either unlocked DME and tuned or used a JB4 piggy back tune. Other forum members have posted The different mods + tune. I have modded cars in the past and usually a DP and exhaust would compliment the tune better.

Ill post pics of the Exhaust next

[earlgsxbusa]

SuperSprint does stick out a little, but not bad ..quad tip 90MM each. Hopefully this week I can post Video/Sound of the Exhaust. While idle is nice, but at revs it nice to hear motor,turbo and exhaust. Interior of X4, dampens the sound. Coworker heard it from inside our office when I reved up.

[evanlol1225]

Originally Posted by JAY56641

I've done both mods to my 2020 X3 M40i. I also did a custom tune to go with it. Substantial additional power. Some things to consider if you go high flow cat or catless. Both lead the exhaust smell to be really strong. Also the warranty concerns which you listed.

I love mine but if I was to do it again I'd likely keep the cat and intake stock and just do a piggyback tune so that the warranty never becomes an issue yet get additional power.

Any dragy times? I have same year model and will be doing same thing as soon as warranty expires in OCT! I ran a 4.17 stock. Can’t wait to get mid 3s

[JAY56641]

No draggy times but my butt the custom tune with down pipe and intake produces 485 hp and torque. A good increase from stock. Butt dunk days you should def get sub 4 second.

[Crudowns]

Originally Posted by Rottweiler

Nothing wrong with gobs of turbo spool brother…

Where did you get this Strut Tower Brace? Love it.

[Rottweiler]

Originally Posted by Crudowns

Where did you get this Strut Tower Brace? Love it.

http://www.chromiumtech.co.uk/produc...&cID=1&c=29317

[M-Tyme]

Originally Posted by earlgsxbusa

Iv modded my X4 with some things. I have an Evolution Works 200Cell down pipe, but I did a stage 2 93 tune and ss exhaust. Stock Intake. Mid pipe next.

Been a few days with this setup. Still feeling it out. No CELs and the car pulls hard off the line and power up the power bands.

But going to have post and sound vids when it's not raining here where I live.

Just wondering if you got that Mid pipe? If so, what was the brand.

[earlgsxbusa]

Originally Posted by M-Tyme

Just wondering if you got that Mid pipe? If so, what was the brand.

I ended up with a Super sprint mid pipe. So I have a full super sprint exhaust with an Evolution works 200cel dp.

Since the post I have a new bm3 stage 2 93 aggr burble and the sound is awesome!

I auto x , and many people were asking why it was loud and clean at launch.
I tuned the burble for 1.5 sec pop at low rpm.

The sound with mid pipe is way throatier on the SS exhaust.
I will say it's loud on highway speed when You are behind me only when I'm higher rpm or WOT.

But if I'm in Comfort Mode, the exhaust is much quieter than being in Sport / Sport plus.

Overall, I love the SS exhaust note.

[needmorepower]

Originally Posted by earlgsxbusa

I ended up with a Super sprint mid pipe. So I have a full super sprint exhaust with an Evolution works 200cel dp.

Since the post I have a new bm3 stage 2 93 aggr burble and the sound is awesome!

I auto x , and many people were asking why it was loud and clean at launch.
I tuned the burble for 1.5 sec pop at low rpm.

The sound with mid pipe is way throatier on the SS exhaust.
I will say it's loud on highway speed when You are behind me only when I'm higher rpm or WOT.

But if I'm in Comfort Mode, the exhaust is much quieter than being in Sport / Sport plus.

Overall, I love the SS exhaust note.

Do you have a link to that mid pipe?