Best engine mods while staying CA emissions compliant

-BEASTMW- · 07-18-2020, 12:55 AM

I've had my E90 M3 6MT for 4 years, and since my EasyCare warranty is up in a year I'm faced with spending the $$ to do rod bearings and some other preventive maintenance or move on to something else (must be a sedan as I have a 1-year-old).

The only other 4-doors that interest me have problems: current gen E63S wagon (way more than I want to spend/lose), Alfa Giulia Quadrifoglio (drove one and loved it, but worried about reliability), and Tesla Model 3 Performance (drove, liked it but feel like it would get old after a while).

I do feel the itch for something a little different. I like most things about the car, especially the manual and the fact that it's paid off, haha. I think the main thing missing is a little more power which would make things fresh again.

How much power can be made while keeping the car CA emissions compliant, within a fairly reasonably cost (i.e. no Dinan stroker kit)? Ideally I'd get an S/C but don't want to hassle with smog on my daily driver.

roastbeef · 07-18-2020, 09:18 AM

pretty much nothing.

just do what you want, but allocate 1/2 day every two years to swap everything back for smog. pretty much everything is very reversible.

e36clubracer · 07-18-2020, 11:42 AM

The only thing I’ve found so far is AFE has intakes that are CARB compliant. I doubt they actually add any power but maybe they give a little more intake growl? That and cat back exhausts which only add sound.... isn’t CA awesome?!

akkando · 07-18-2020, 11:54 AM

Well, saving weight isn't against the smog rules.

-BEASTMW- · 07-18-2020, 02:31 PM

Quote:

Originally Posted by e36clubracer

The only thing I’ve found so far is AFE has intakes that are CARB compliant. I doubt they actually add any power but maybe they give a little more intake growl? That and cat back exhausts which only add sound.... isn’t CA awesome?!

Had that in mind to do for sure, but yeah, doesn't really add any appreciable power. Already have an MPE, which I like but could be a little louder.

-BEASTMW- · 07-18-2020, 02:33 PM

Quote:

Originally Posted by akkando

Well, saving weight isn't against the smog rules.

I'm a big fan of weight savings - also own a Lotus Elise and I stripped 250lbs out of my first car ('98 Integra). But I doubt there's enough that I can do that would be noticeable while staying civilized for dailying (within somewhat reasonable cost). I'm due for a battery soon so maybe I'll get a lightweight one.

s0ldats · 07-18-2020, 07:26 PM

lightweight battery can save up to 60lbs. prob best price per lb savings

akkando · 07-20-2020, 11:33 AM

Quote:

Originally Posted by s0ldats

lightweight battery can save up to 60lbs. prob best price per lb savings

What's next? wheels maybe because unsprung weight plus you can offset cost by selling current wheels?

Then maybe front seats to a sport or bucket seat?

kyippee · 07-20-2020, 03:17 PM

If it's power you want while staying SMOG compliant, the most efficient move is to just sell it and buy an F8x M3/M4, M2 comp, or other FI car

-BEASTMW- · 07-20-2020, 03:25 PM

Quote:

Originally Posted by kyippee

If it's power you want while staying SMOG compliant, the most efficient move is to just sell it and buy an F8x M3/M4, M2 comp, or other FI car

Probably true, without spending a ton on a stroker. As mentioned, I did really like the Alfa but worried about reliability. Have driven an F82 M4 ZCP and was really excited to get back into my E90 after...

akkando · 07-20-2020, 04:18 PM

Quote:

Originally Posted by -BEASTMW-

Probably true, without spending a ton on a stroker. As mentioned, I did really like the Alfa but worried about reliability. Have driven an F82 M4 ZCP and was really excited to get back into my E90 after...

I mean I think you can get a get away with an after market filter, pulley kit, a stage 1 tune, and axle back that weighs less and more free flowing (maybe helps?) Anything else the risk of failing is high.

You're biggest illegal gain if you were going to do it is something that removes primary cats (test pipes/xpipe) and a tune to support it.

GeorgeA · 07-20-2020, 04:55 PM

You can remove secondary cats, should pass inspection unless they do a visual. But OBD plug test should pass.

jd501 · 07-20-2020, 05:22 PM

Intake? I'm in LA and managed to pass the visual with a Dinan; worst case maybe half an hour to switch back to stock.

XKxRome0ox · 07-20-2020, 08:06 PM

Quote:

Originally Posted by jd501

Intake? I'm in LA and managed to pass the visual with a Dinan; worst case maybe half an hour to switch back to stock.

i just passed smog in May 2020 with a MS stage 2 intake and a valved exhaust (Bomiz prototype)

07-18-2020, 12:55 AM	#1
-BEASTMW- Lieutenant 158 Rep 455 Posts Drives: 2011 E90 M3 Join Date: Aug 2015 Location: Sunnyvale, CA iTrader: (0)	Best engine mods while staying CA emissions compliant I've had my E90 M3 6MT for 4 years, and since my EasyCare warranty is up in a year I'm faced with spending the $$ to do rod bearings and some other preventive maintenance or move on to something else (must be a sedan as I have a 1-year-old). The only other 4-doors that interest me have problems: current gen E63S wagon (way more than I want to spend/lose), Alfa Giulia Quadrifoglio (drove one and loved it, but worried about reliability), and Tesla Model 3 Performance (drove, liked it but feel like it would get old after a while). I do feel the itch for something a little different. I like most things about the car, especially the manual and the fact that it's paid off, haha. I think the main thing missing is a little more power which would make things fresh again. How much power can be made while keeping the car CA emissions compliant, within a fairly reasonably cost (i.e. no Dinan stroker kit)? Ideally I'd get an S/C but don't want to hassle with smog on my daily driver. __________________ 2011.5 E90 M3 White/Red, 6MT, ZCP, slicktop Past: '02 S2000, '01 M5, '98 Integra w/many mods
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07-18-2020, 09:18 AM	#2
roastbeef Lieutenant General 11586 Rep 12,726 Posts Drives: E92 M3 Join Date: Nov 2010 Location: Orange County, CA iTrader: (4)	pretty much nothing. just do what you want, but allocate 1/2 day every two years to swap everything back for smog. pretty much everything is very reversible. __________________ Instagram; @roastbeefmike
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07-18-2020, 11:42 AM	#3
e36clubracer First Lieutenant 294 Rep 354 Posts Drives: Ram 3500, f80M3, e36M3 Join Date: Feb 2018 Location: CA iTrader: (0)	The only thing I’ve found so far is AFE has intakes that are CARB compliant. I doubt they actually add any power but maybe they give a little more intake growl? That and cat back exhausts which only add sound.... isn’t CA awesome?!
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07-18-2020, 11:54 AM	#4
akkando Major General 5865 Rep 6,636 Posts Drives: 17 M2 DCT LBB,11 e90 M3 ZCP IB Join Date: Jan 2017 Location: Bay Area iTrader: (1)	Well, saving weight isn't against the smog rules.
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07-18-2020, 07:26 PM	#7
s0ldats First Lieutenant 54 Rep 334 Posts Drives: 2011 E90 M3 stripper Join Date: Aug 2019 Location: socal iTrader: (0)	lightweight battery can save up to 60lbs. prob best price per lb savings
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07-20-2020, 03:17 PM	#9
kyippee Lieutenant Colonel 1073 Rep 1,617 Posts Drives: E92 M3, Supra MK5, F44 235GC Join Date: Feb 2017 Location: SF Bay Area iTrader: (0)	If it's power you want while staying SMOG compliant, the most efficient move is to just sell it and buy an F8x M3/M4, M2 comp, or other FI car
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07-20-2020, 04:55 PM	#12
GeorgeA Major 758 Rep 1,408 Posts Drives: E92 M3 Join Date: Jan 2016 Location: Los Angeles iTrader: (3)	You can remove secondary cats, should pass inspection unless they do a visual. But OBD plug test should pass.
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07-20-2020, 05:22 PM	#13
jd501 First Lieutenant 371 Rep 394 Posts Drives: 2011 E92 M3 Join Date: Mar 2016 Location: Los Angeles iTrader: (0)	Intake? I'm in LA and managed to pass the visual with a Dinan; worst case maybe half an hour to switch back to stock.
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