Tunes for a 5-speed 2.5l Z4

[falkman]

Hey there, I drive a 2003 2.5l Z4 (5 speed) and I'm wondering what all I should do to this car to make it a bit more 'fun'. I was considering buying a Cayman, and getting rid of my Z4, but before I'd do that I'd like to see if I could improve my Z4 to the point (or close to) that of the Cayman for less than it would be to 'upgrade' to a Cayman.

Some of the things I had in mind: air filter, stiffer suspension, better tires, and better brakes. Not sure if anyone has other recommendations for these as far as brands/models.

Next, the more extreme ideas of doing an upgrade from the 2.5L to the 3.0L (are they on the same block? can my 2.5 be modified to be the 3.0? would it be smarter to just replace the engine completely?). Or perhaps a turbo for the engine.

I'm also wondering if there are any build differences in the 5 speed versus the 6 speed in terms of torque that the gearbox can handle, or anything else really.

Note: I don't want to 'rice' my car, I legitimately am considering upgrading this car to a proper track car once I get a new car, so I want to work towards a bit better performance over time (2-3 years).

-Brandon

[beta]

I'm sorry to be the bearer of bad news but no, there really isn't anything you can do that will make a measurable difference; and any change that would make a big difference (aka supercharging) would be better invested in upgrading the whole car. Better tires are the only thing I'd recommend for a 2.5.

For a few grand you could trade in the whole car for a 3.0 or even a 3.0si which would be noticeable. If you really like the Z try out an M, you might like it more than a cayman. It depends if you like precise riding on rails, or if you prefer something more guttural and raw.

[falkman]

I was thinking about that. I'll take a look around to see if I can find any 3.0si's or or something around. I think a M might be a bit out of my reach sadly.

-Brandon

[Beedub]

Originally Posted by falkman

I was thinking about that. I'll take a look around to see if I can find any 3.0si's or or something around. I think a M might be a bit out of my reach sadly.

-Brandon

bolt on an ESS twin screw kit and come play with the ///ms :-)

[pokeybritches]

Look for a 2003-2005 3.0i if you are interested in upgrades. The M54 engine has quite a few aftermarket options. They will be cheaper than the facelifted models, but out of the box the facelifted models are a little better (more power, and you can turn a 2006+ 3.0i to a 3.0si for less than $1000).

I would not recommend putting a lot of money into your 2.5i. It's a great car for someone else out of the box, and you would get a greater bang for the buck modifying a 3.0i.

There are a few things you can do to the 3.0i to make it much quicker. The differential is shared with the E46 (and other models), and you can swap it out for one with a different final drive fairly easily. With a Dinan intake, shark software, and a 3.64 final drive you'll see a big difference in acceleration over a stock car.

You could do the same with a 2.5i, but again you would see greater benefit with the bigger engine. DEFINITELY swap out the runflats for some max performance summer tires if temperatures in your area permit.

[jra]

E46 guys really like the shark edit. Ess sells a "stroker" software upgrade for 2.5 to 3.0 conversions. Requires 3.0 short block. You could do headers, cams, ported polished head, ltw flywheel, turbo, supercharger, etc. Search technik gen 3 headers on e46

[jra]

I've been told you can get to + 260 bhp with a built 2.5...but I would really go fi...a lot less expensive

[Beedub]

with a 2.5 id run a pro-efi ecu, get lutz to do a turbo kit, be unique and roast us all from the lights.... well.... most of us anyway ;-)

[pokeybritches]

The 3.0i shares its forged crank with the E36 M3, which has been capable of quite a bit of power. I'm not sure how strong the internals of the 2.5i are. Even with a 3.0i conversion, you will still be missing some standard features, sportier suspension (thicker sway bars I believe), wheels/tires (vs sport 3.0i), and the 6 speed transmission. The difference in price between a 2.5i and 3.0i isn't that great, and you will spend many times that amount trying to get the 2.5i up to 3.0i performance.

[strokeZ]

Originally Posted by Beedub

bolt on an ESS twin screw kit and come play with the ///ms :-)

I do! And its FUN. I even play with a GT3-RS and a Cayman R at times. Still fun. NO I am not the quickest down the straights but am right there in the corners. If I did this all over again it would the Z4M w ESS no doubt. However, I am way too deep in it now for regrets....onto Stage 2+!