New z4 2.5i owner

[04cobra]

Hi guys,

I just obtained a slightly used 2004 z4 2.5i with 15k miles on it for free (family member gave it to me). I have come from some high horsepower cars 04 cobra (600hp), 09 CTS-V, modded 335i and an STI. This car for some reason is the most fun of them all...even though its slow as heck! Anyway I had some questions about it, I tried to search but it was hard to find anything related to the 2.5i...here are my questions

1. Mods - I know mods dont do too much but I was planning on doing the Dinan Stage 3, a diff swap, intake and exhaust. My main questions is on exhaust...are there a good set of headers out there? I was having trouble finding any

2. I was thinking about going with some APEX wheels...I dont really understand sizes and fitments as I have always retained my stock wheels on my cars and just changed the tires....what is the largest wheel size I can fit on an otherwise stock car, I probably will lower it a bit with some springs but that is about it. Is a staggered setup worth it at all on a 2.5i

3. I have always bought Drags for my cars, what would be some good high performance handling Tires.

4. AUX - is it possible to hook up an AUX jack to these cars? All it has is Radio/CD in the stock head unit.

I think that was all my main concerns, thanks for any help that can be given.

[pokeybritches]

First, welcome! Your questions have been answered many times over on the forums, so the search feature can expand upon the answers below:

1. Save your money and get a supercharger. Some options are: ESS Tuning (twin screw), VF Engineering (centrifugal), and G-Power (centrifugal... check out Precision Sport Industries as a dealer).

M54B25 and M54B30 headers are interchangeable. Search the E46 BMW 3 series forums for used sets, as new they are expensive. Supersprint and Technik (out of business) are known to be the best. Racing Dynamics makes headers as well.

It's better to swap the whole diff than to change gears. Is your car auto or manual? Many E46 3 series and Z4 diffs are interchangeable. I bought a unit with a 3.64 final drive from a 2.5i auto to replace the 3.07 in my 3.0i manual.

2. Do yourself a favor and read up on wheel offsets and how they work. You don't need more than 8.5" front / 9.5" rear wheels. On a non-M, I recommend 225/40/18 front and 255/35/18 rear. Apex make excellent wheels, and they can help you out. Wider isn't always better.

3. Search the wheel and tire section.

4. Yes. You can retrofit an aux in or iPod adapter. Search.

[Z4inAZ]

I wouldnt run staggered on a 2.5

They came with staggered setups from the factory but with the power these cars produce it really isnt necessary. I am eager to throw a square setup on this car... should handle even better

Not sure why anyone would need a 255 rear on a 2.5 lol these engines dont even have 200hp, I ran a 265 on my 400hp E39 M5. 225 all around is more than enough for these cars and makes them feel a little lighter on their feet

[04cobra]

Thanks for the replies....I am not sure I would want to spend 6k for an s/c plus install. For some reason I am not comfortable putting a power adder on an N/A car. Would the dinan mods and exhaust help at all?

[GP20]

I had an '03 2.5i before. Like you said, embrace that it's a slow ass car. I wouldn't waste money and bother modifying anything to make the car quicker. It's still gonna be a slow car after the mods, short of a supercharger. Just get better suspensions, an exhaust for the sound, and nicer looking wheels.

[StickMon]

There's little you can do to speed it up, but probably a lot you can do with the suspension.
My previous car was a Mk1 MR2. No low end torque, barely sufficient horsepower, but still a whole lot of fun, because you didn't have to slow down in the corners.
It had great "chuckability".

[pokeybritches]

A supercharger isn't $6k plus install. I bought mine on sale for $3375 + shipping, and did the install myself.

The other "power adders" are so mild in comparison that they aren't really worth it. You CAN make the car more fun by changing the exhaust tone.

[StickMon]

Originally Posted by pokeybritches

You CAN make the car more fun by changing the exhaust tone.

Yep. That's a must. My 13 y.o. Son was very unimpressed with the stock exhaust, so that was my very first mod. Whatever your car does or doesn't do, it has to impress your kids.
He's very pleased with the El Diablos.

[Vanne]

Originally Posted by StickMon

Whatever your car does or doesn't do, it has to impress your kids.
He's very pleased with the El Diablos.

AWESOME CALL!!!!

you are the man!!!

but yeah seriously the kids have to love it!

To the OP: welcome to the mayhem mate

[WAMz4]

Considering the car was free, why not trade up. NADA shows a 2004 2.5i with 15000 miles worth 15K retail value. Sell it and spend the few thousand you were going to spend moding for a newer 3.0 or 3.0si with 215\255 HP. Cars.com has several listed around 17-18k.

[beta]

Originally Posted by pokeybritches

A supercharger isn't $6k plus install. I bought mine on sale for $3375 + shipping, and did the install myself.

The other "power adders" are so mild in comparison that they aren't really worth it. You CAN make the car more fun by changing the exhaust tone.

Pokey speaks truth.

Originally Posted by WAMz4

Considering the car was free, why not trade up. NADA shows a 2004 2.5i with 15000 miles worth 15K retail value. Sell it and spend the few thousand you were going to spend moding for a newer 3.0 or 3.0si with 215\255 HP. Cars.com has several listed around 17-18k.

This. If you want more power, supercharge or trade up. The highest end of the spectrum is a stage 2 supercharged M (500+ hp).

Otherwise spend your mod money on non-power upgrades, there's lots of good choices.

[Huz-Z]

18 inch Apex ARC-8s would look sharp on your car. I like the silver ones myself.

A multi-function steering wheel is a nice mod if the car doesn't already have one; the M version is likely available at GetBMWParts.com.

BMW's OEM wind deflector can be had for around $500-ish. It looks very sharp and does a great job of calming the wind flow in the cabin while the top is down.

http://www.realoem.com/bmw/showparts...16&hg=54&fg=95

Here is how to install it:

http://forums.bimmerforums.com/forum...ght=windscreen

[ANUSTART]

I have a 2.5i and can address a couple of your items…

I installed a staggered APEX EC-7 setup on mine and it is great. Looks good and gives a little extra grip in the rear with the Michelin Pilot Super Sports. You'll love it. The photos were before I installed my suspension.
http://www.zpost.com/forums/showthread.php?t=819312

Here are some notes on installing springs and new dampers along with my setup. I went with the adjustable Koni Yellows and Eibach Pro Kit Springs.
http://www.zpost.com/forums/showthread.php?t=837039

[04cobra]

I dont want a super loud exhaust, but I would like a better exhaust note. What parts of the exhaust should I switch out? Catback? Or the whole thing? Is supersprint considered the best at the moment?

While the car was FREE, its still not my car, I am allowed to use it and do whatever I want. I already asked if I could trade it up for an M roadster, the answer was no, so I wish I could, but its nice not to have a car payment for once.

I definetly think the wind reflector is needed, so I will be getting that.

Maybe I am not looking hard enough but the only S/C's i see for sale are for 6k (ess for example)...any other places I should be looking? Also I assume a custom tune would be needed?

[Z@T]

Welcome and congrats to your car!

For all the slow ass car comments: You guys should rock a Z4 2.0l for an test drive.

Staggered wheels are a must for me. Even the 2.0l could be ordered with 18" staggered wheels back in the day.

Best power mod would be an M5 engine.

[04cobra]

I was thinking about Hyper Black for the wheel color, anyone have any pictures of that? I didnt see that an 18x8.5 was available in a Concave wheel, anyone know? I was going to go with 18 inch 8.5 fronts and 9.5 rears.

[yousefnjr]

I'd skip the exhaust and put in the sound generator from the 3.0i. It fits the 2.5's and will give you glorious induction noises piped into the cabin. It's great if you're looking for aggressive sound but don't want the civic-fart-can on the back.

[Z@T]

Why not 19"? They fit the wheel housing nicely!

Originally Posted by yousefnjr

I'd skip the exhaust and put in the sound generator from the 3.0i. It fits the 2.5's and will give you glorious induction noises piped into the cabin. It's great if you're looking for aggressive sound but don't want the civic-fart-can on the back.

Great advise!!! Forgot that the 2.5 does not have the sound generator!

[beta]

Originally Posted by 04cobra

I definetly think the wind reflector is needed, so I will be getting that.

I love the wind deflector, was definitely a nice upgrade and the honey really appreciated it as it doesn't mess up her 'do haha.

Check my mod thread under my sig for part numbers and instructions for the Aux-In and wind deflector.

[SimpleMan]

Originally Posted by Z4inAZ

I wouldnt run staggered on a 2.5

They came with staggered setups from the factory but with the power these cars produce it really isnt necessary. I am eager to throw a square setup on this car... should handle even better

Not sure why anyone would need a 255 rear on a 2.5 lol these engines dont even have 200hp, I ran a 265 on my 400hp E39 M5. 225 all around is more than enough for these cars and makes them feel a little lighter on their feet

Agree. I went with a squared set of Style 203's and I'm extremely happy.

[SimpleMan]

Originally Posted by yousefnjr

I'd skip the exhaust and put in the sound generator from the 3.0i. It fits the 2.5's and will give you glorious induction noises piped into the cabin. It's great if you're looking for aggressive sound but don't want the civic-fart-can on the back.

Where can I purchase the 3.0i sound generator?

[pungo]

Originally Posted by SimpleMan

Where can I purchase the 3.0i sound generator?

My 3.0si coupe had the sound generator, I removed some of the foam, sounded like something was wrong with the car. Put the foam back in. If you want sound, change the muffler.