[patrickj]

I've been all through the forums....I have a 2006 325i and would love a bit more power. What has been proven to give a hp jump besides a CAI and exhaust? My car is CPO, so I don't necessarily want to viod the warranty, but I also want to have a bit more quickness.

Thanks.

[Pyrat 2]

Sounds like what you are really looking for is more acceleration. If that is the case you really only have a few options:

• Supercharger/turbocharger. I don't know of one available for your car although they may exist.
• A new final drive gear ratio. This is fairly expensive but will definately do the job. You can either go with a replacement open differential with a higher drive ratio or get a limited slip again with a higher drive ratio. If you go the final drive route you have a few vendors available that can fill the bill.

While you can go for an exhaust or CAI the performance increase will be fairly minor compared to the other options.

[patrickj]

Thanks for the response.

Originally Posted by mdemange

Sounds like what you are really looking for is more acceleration. If that is the case you really only have a few options:

• Supercharger/turbocharger. I don't know of one available for your car although they may exist.
• A new final drive gear ratio. This is fairly expensive but will definately do the job. You can either go with a replacement open differential with a higher drive ratio or get a limited slip again with a higher drive ratio. If you go the final drive route you have a few vendors available that can fill the bill.

While you can go for an exhaust or CAI the performance increase will be fairly minor compared to the other options.

[quiksilver1029]

theres really nothing for the N/A cars that offers significant power gains. basically all you can get is intake and exhuast, and in your case you can chip yours to have the same power as a 330i, but that would prob void your warranty. if you want fast you should have gone turbo.

i really reccomend getting an intake and exhaust tho, it does make your car feel quicker and you get better throttle response. heres a video of my 328i with the AFE CAI and RE IKON exhaust

[u2b]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/Wn3Uo9psSeA&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/Wn3Uo9psSeA&hl=en&fs=1" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/u2b]

[Pyrat 2]

May want to check www.diffsonline.com or www.performancegearing.com if you are interested in a LSD prebuilt and ready to drop into your car. I have a diff on order now to give my car a bit of extra kick. Crossing my fingers that it gets delivered in the next couple weeks. The gearset is in route from Germany right now.

[abcommercial]

Originally Posted by quiksilver1029

heres a video of my 328i with the AFE CAI and RE IKON exhaust

Dude, what area of the country do you live in? That neighborhood is beautiful, at least from the camera angle. Looks like big yards, wide open streets, and no traffic.

[quiksilver1029]

Originally Posted by abcommercial

Dude, what area of the country do you live in? That neighborhood is beautiful, at least from the camera angle. Looks like big yards, wide open streets, and no traffic.

south florida, baby

[mike-y]

Since the 325, 328, 330 all have the same 3.0L motor, I'd think that with a chip/retune, it would be possible to get to at least 328i levels, maybe a bit more. The 330i has a 3 stage intake manifold - so unless you swap that, it would be harder to get to 330 level with just a retune and a few bolt ons.

I think turner motorsports offers a chip, but I haven't really looked into this yet

[ni8shadow]

Put in new cams and hope the dealers don't notice.

[TK-421]

Originally Posted by ni8shadow

Put in new cams and hope the dealers don't notice.

Good luck with that. My friend let his dealership walk all over him for small stuff I thought they wouldn't notice.

[convex]

I thought about cams for my car - E90 320i however i got the following response from Kent Cams -

"Hi,
You car has either the N43 or N46N but in either case will have BMW's patented Valvetronic system, which has variable valve lift via an electronic servo motor, so the cams and valve train are unlike conventional system, so unfortunately we are unable to offer you anything."

Kinda blew that idea out the water!

[nicknaz]

OP, NA cars are stupidly expensive to modify for more power, especially cars with limited appeal in the aftermarket world, such as US market only 328

Personally, I'd limit mods to tires and at some point in the future throw down for 335/m3 for more straight line speed

[Omni]

A great mod for the 06 325i in my opinion is to swap the single-stage intake manifold for a 3-stage from a 330i and have upsolute or evotech reflash the ECU with 330i stage 1 software.

Very few mods can give you the 40-50 HP+Torque that this mod can give.

The manifold is a straight bolt on, and the ECU flash can be done overnight.

The Manifold is around $650 from the dealer, the 2 actuator motors you need are $215 each and the software is from $400 - $700 depending on who you use. Of course you can always check ebay/salvage yards for the parts (I got the manifold off Ebay for $125).

Users Willstophe and Finvette have successfully completed this mod, and reported great results. The only Dyno data however was from Turner Motorsport(showing 262HP at the flywheel), as they used to offer a complete upgrade package for the 325i... it included hi-flow cats as well, but I believe that only accounted for a small amount of the gain.

Then you can look into performance exhaust, intake and throttle body.

Of course, this mod is not for the faint-of-heart. I have a CPO 325i also, and I'm doing this mod this winter.

[mike-y]

I there a piggy back device that can be plugged into the computer and allow re-mapped software? I know Riss is supposed to be working on, but I haven't found anything else yet.

And old friend of mine runs a dyno tuning shop, and has experience with many different types of cars and tuning software. I'd like to get something in his hands that can be used for bmws, for real-time tuning on the dyno.

[Pyrat 2]

Still thinking your best bet is a new rear end gear ratio. Doesn't give you more theoretical power but definately gives you better acceleration.

[mikeokimster]

Get an exhaust shop to fabricate a header for you.

[Omni]

Originally Posted by mdemange

Still thinking your best bet is a new rear end gear ratio. Doesn't give you more theoretical power but definately gives you better acceleration.

I definitely agree that modifying the rear end gear set-up will give you a good jump out of the hole. I've done this in previous vehicles I've owned.

I think stock is 3.08? Does anyone know what ratio is suggested for an upgrade to an 06' 325i 6MT? Also, is it even possible to modify?

[Pyrat 2]

Originally Posted by Omni

I definitely agree that modifying the rear end gear set-up will give you a good jump out of the hole. I've done this in previous vehicles I've owned.

I think stock is 3.08? Does anyone know what ratio is suggested for an upgrade to an 06' 325i 6MT? Also, is it even possible to modify?

Check with Dan at Diffsonline.com or Jim at performancegearing.com to find out what the options are for a 325. I know for the 330i 6MT Dan offers a 3.15 and 3.64. Jim offers the 3.15, 3.38, and 3.64 for the 330i. My 3.38 is on order.

[Omni]

Nice, thanks.

What about speedometer issues? After the upgrade I can assume that the speedo would be innaccurate right?

[mike-y]

I would think the speedo sensor reads the front wheels, so anything you do with the gearing wouldn't affect that (on a RWD car at least). Only wheel/tire size would affect the speedo.

[Pyrat 2]

Originally Posted by mike-y

I would think the speedo sensor reads the front wheels, so anything you do with the gearing wouldn't affect that (on a RWD car at least). Only wheel/tire size would affect the speedo.

Correct. The speedo senses the rotation of the tires so any gear changes do not affect the speedo reading.

[nomile]

Originally Posted by mdemange

Correct. The speedo senses the rotation of the tires so any gear changes do not affect the speedo reading.

I'd make sure the speed measurement is really done using the wheel sensor (makes sense to me that they'd use the ABS sensors), but - In my '95 ti the speed sensor was in the differential housing. just FYI