Performance enhancements for Z4 2.5i

[biglet2002]

We recently attended our regional chapter of the BMWCCA's annual luncheon last weekend, and my husband got to drive the chapter's vp's new used MZ4 coupe and had a major joygasm.. sigh.. We currently own an '03 Z4 2.5i that we bought used 4 years ago, paid cash - we own it outright. We also just recently purchased (via the military discount) a new '09 e90 328i Sport sedan - that too, is paid for. In other words, we have NO car debt. My husband is rather unimpressed with our lovely roadster and wants to upgrade in a few years... .. this is rather annoying as I could think of much better ways of spending our future money, such as saving more towards retirement, etc. We have no major debt save for our mortgage. Our roadster is plenty zippy with its 184 hp, and I see no point in having 330 hp in a country that lacks an autobahnn! (Not to mention that our car gets nearly 30 mpg, insurance is relatively inexpensive for a sports car, and our property taxes are low due to its age...) Now, I know all you men out there are rolling your eyes, but think about this... unless you take the car to the track, why on earth do you "need" all this wasted power? This car is small, lightweight, and has more than enough torque and power to accelerate onto a highway on ramp and to pass traffic. Anyhow.. I mentioned to my spouse that we could look into some upgrades to add some hp to our existing car, and his response was that he didn't want "to spend thousands of $s on upgrades"... Yet, he's willing to spend over $30-40 grand on a replacement for more hp.. this makes absolutely no financial sense to me in order to satisfy a "visceral feeling" (his verbage).

So, I'm tossing a bone out there.. does anyone here on the Z4 chatboard have any advice regarding performance mods for this car (we asked about Dinan chips at the dealer, and some options were mentioned for modest improvements to hp - 15-20 hp increases.) I'd much rather spend a few thousand on a car that's already paid for and owned outright, than go into debt.. I look forward to your responses...

Lisa

[BMWI6]

There is no significant performance upgrades for this car except for a supercharger. There are plenty 2006 Z4M's in the low $20ks. I agree with you on keeping your roadster however spending thousands on upgrades is throwing money out the window.

[Chuck I]

First a short history and you will see the relationship! I've been a BMW person for a long time having had a 320i, 325, 318ti, 325i and a 330i. A few years ago I decided I wanted a Z4. I live west of DC out in the valley and Z4s were rare to see. One day I saw a used 2003 Z4 with 10,000 miles on it and fell in love even though it was a very basic 2.5 with nothing on it... Well, soon after getting the car I realized I wanted to put some "upgrades" on it. I started with little things like foglights, CD player, wind deflector, floor mats, new tail lights with the clear center, clear side lights, Aero front end and side skirts, spoiler, 3 sets of new wheels... you know, cosmetic stuff... BUT I still yearned for the power... I kept seeing the other Z4s out there...3.0s, Z4Ms... Boy were they cool and faster than my 2.5.. So, I thought I would look at some of the options out there... I decided I would sink $5,000 into the Dinan S1 package that would put new springs, shocks, air intake, exhaust, throttle body, engine struff and engine software. Well, when it was all done, it was faster, sounded better and handled much better... BUT it was now just a 2.5 with a lot of stuff on it that was still slow by comparison. Now don't take me wrong, I dearly love that car and will have it for a long time... But I finally did what I should have done in the beginning... I bought a Z4M. There is really no comparison. The DINAN Z4 2.5 is easy to drive and great for a nice day relaxing in the country. When I take the Z4M out, I know that when I get back, I'm going to be exhausted and have grin on my face that just won't go away. You have to drive the Z4M. It's very unforgiving and I must say worth every penny. I should have just bought one in the beginning and I would have saved a lot of money.. but now I have the best of both...

It's hard to put into words the feeling merging on to the highway in either of these cars, BUT you really can feel the difference between them... My gut feeling is that even if you spend the money on the upgrades to your 2.5, you still will long for more.... Chuck I

[jra]

Auto or manual? I'm in the same boat. I would rather spend 6,000 in cash over a couple of years instead of financing 20,000 and not being able to update my house. Btw, everyone is going to tell you to buy an m. that being said you have a few options:

1. supercharger
2. intake, headers, exhuast, software
3. intake, headers, exhaust, cams, software (I've driven a 330 that had this setup and I was more than impressed)
4. ess offers a "stroker" tune for a 2.5 to 3.0 conversion. you will need to do a 3.0 short block swap. info below

http://forum.e46fanatics.com/showthr...hlight=stroker

[Huz-Z]

No, not everyone will tell you to buy an M.

Texas direct Auto on eBay has a 2006 3.0si (255 hp) for $19,000 right now.

The 3.0 si is 255 hp, not as much as the Z4M's 330 hp to be sure, but its a lot more than the 2.5 or either version of the 3.0 (215 / 225 hp). Some reviews suggest that in practical terms, there's not that great a difference between the M and the 3.0si - although M fans will be sure to disagree on that!!

But M fans cannot deny that maintenance on that car can be pricey. The M requires a manual valve adjustment every so many thousand miles which is expensive. Also, some consumable items, such as the brakes, are much more costly than on any other Z4, such as the 3.0si.

Have a read of this review; I'll bet your hubby will consider an si as something that wil give him the thrill he's looking for:

http://www.auto123.com/en/bmw/z4/200...00&artid=90628

Copied directly from that article on Power and Performance:

The "si" designation represents the install of BMW's latest I-6: the 3.0-litre N52, featuring a lightweight magnesium block and BMW's latest Valvetronic, variable valve timing technology. Not only is this engine considerably more powerful than the standard Z4 3.0-litre mill, it provides much better mid-range response while improving cornering by lightening the load bore by the front wheels.

The N52 generates 255-horsepower @ 6,600-rpm and 220 pound-feet of torque @ just 2,750-rpm. That's 40 horsepower and 35 pounds of torque more than dispensed by the standard 3.0-litre engine; and what a difference it makes. Having driven the less powerful Z4 and been quite content with its gusto, I was absolutely elated burying my foot into the 3.0si. This engine pulls ferociously- especially on the highway where passing power is frankly startling.

The engine displays strength throughout its broad powerband however north of 4,500-rpm is where the after-burner effect of BMW's Valvetronic technology is most felt. Keeping the engine above this threshold produces formidable performance, not to mention an exhaust note capable of terrifying owners of domestic muscle cars. This sort of motoring, while something the Z4 3.0si is engineered to excel at, isn't appropriate on anything less than a closed track. Typical automotive operation finds the Z4 3.0si well suited to city or highway demands whilst nary breaking a sweat to keep-up or pass.

Happily, the new powerplant is packaged with a six-speed manual gearbox or an optional six-speed, paddle-shift-equipped autobox; both connected to the rear wheels. A sigh of delight was heard for miles as I climbed aboard my tester and allowed my hand to fall upon its manual stick. That may read like cheap trash but it's figuratively true. There's not much sweeter in the auto industry than BMW's six-to-six, that's six cylinders to six cogs.

[03BeastCharmer]

With M Roadsters regularly selling for $25K, the cost to change cars may be less than the cost to modify the 2.5, and you may be able to maintain your debt free feeling.

[O-cha]

Women just don't understand the need for power.

You married a man, not a woman, you should have expected this.

I'm sure he doesn't understand the need for a rack of shoes or purses (or substitute any other womanly thing), but he's probably not complaining...

184hp is nothing, Camrys have more horsepower than that nowadays.

[BMWI6]

True! My moms Jetta 2.0t has 200hp.

Originally Posted by O-cha

Women just don't understand the need for power.

You married a man, not a woman, you should have expected this.

I'm sure he doesn't understand the need for a rack of shoes or purses (or substitute any other womanly thing), but he's probably not complaining...

184hp is nothing, Camrys have more horsepower than that nowadays.

[Huz-Z]

For me anyway, the 3.0si strikes a great balance between thrilling performance and reasonable maintenance costs.

And believe me, my Z4 3.0 si is everything the article I referenced says it is. Its not a boring ride!!!!

But if maintenance costs are of no concern, get the M. If they are, the 3.0si will deliver the smile factor! Its certainly a head turner, as my wife found out one day when a guy rear-ended the car in front of him as he watched "D'Wife" drive by in the Z!

[SV Concepts III]

That engine is very well tuned from the factory so there is not a lot of power to be gained outside of a supercharger setup. However, you can make the car more responsive with simple upgrades like an Intake and Exhaust. This will help free up power and make the car a bit quicker through the range. It won't transform the car into an ///M eater (you need a supercharger for that) but would make the car more fun to drive in the meantime.

[chickdr]

Agreed on the 3.0si. Cost wise it is probably a much better option than trying to upgrade your 2.5i. With many 06's around, you can get one for a great price. I would also think your 2.5i will still fetch a decent price.

[Huz-Z]

Originally Posted by chickdr

Agreed on the 3.0si. Cost wise it is probably a much better option than trying to upgrade your 2.5i. With many 06's around, you can get one for a great price. I would also think your 2.5i will still fetch a decent price.

Meaning that if you sell the 2.5 when you upgrade to a 3.0si, your net cost will be pretty low.

[biglet2002]

Originally Posted by O-cha

Women just don't understand the need for power.

You married a man, not a woman, you should have expected this.

I'm sure he doesn't understand the need for a rack of shoes or purses (or substitute any other womanly thing), but he's probably not complaining...

184hp is nothing, Camrys have more horsepower than that nowadays.

Um... I don't collect purses or shoes.. am not a typical female.. BTW, have you ever heard of the idea of the power to weight ratio? This is a lightweight roadster. It does not need 330 hp, in fact, that sounds over-engined in my opinion. You've proven my point that it's about bragging rights, not practicality...

[biglet2002]

Originally Posted by Nick@Jlevi SW

That engine is very well tuned from the factory so there is not a lot of power to be gained outside of a supercharger setup. However, you can make the car more responsive with simple upgrades like an Intake and Exhaust. This will help free up power and make the car a bit quicker through the range. It won't transform the car into an ///M eater (you need a supercharger for that) but would make the car more fun to drive in the meantime.

That sounds like something worth researching!

[biglet2002]

Originally Posted by Huz-Z

For me anyway, the 3.0si strikes a great balance between thrilling performance and reasonable maintenance costs.

And believe me, my Z4 3.0 si is everything the article I referenced says it is. Its not a boring ride!!!!

But if maintenance costs are of no concern, get the M. If they are, the 3.0si will deliver the smile factor! Its certainly a head turner, as my wife found out one day when a guy rear-ended the car in front of him as he watched "D'Wife" drive by in the Z!

Yeah, maintenance costs are a factor, not to mention insurance and property taxes here in VA. Our current car is low cost in the taxes and insurance areas, which is really nice...

[biglet2002]

Originally Posted by Huz-Z

No, not everyone will tell you to buy an M.

Texas direct Auto on eBay has a 2006 3.0si (255 hp) for $19,000 right now.

The 3.0 si is 255 hp, not as much as the Z4M's 330 hp to be sure, but its a lot more than the 2.5 or either version of the 3.0 (215 / 225 hp). Some reviews suggest that in practical terms, there's not that great a difference between the M and the 3.0si - although M fans will be sure to disagree on that!!

But M fans cannot deny that maintenance on that car can be pricey. The M requires a manual valve adjustment every so many thousand miles which is expensive. Also, some consumable items, such as the brakes, are much more costly than on any other Z4, such as the 3.0si.

Have a read of this review; I'll bet your hubby will consider an si as something that wil give him the thrill he's looking for:

http://www.auto123.com/en/bmw/z4/200...00&artid=90628

Copied directly from that article on Power and Performance:

The "si" designation represents the install of BMW's latest I-6: the 3.0-litre N52, featuring a lightweight magnesium block and BMW's latest Valvetronic, variable valve timing technology. Not only is this engine considerably more powerful than the standard Z4 3.0-litre mill, it provides much better mid-range response while improving cornering by lightening the load bore by the front wheels.

The N52 generates 255-horsepower @ 6,600-rpm and 220 pound-feet of torque @ just 2,750-rpm. That's 40 horsepower and 35 pounds of torque more than dispensed by the standard 3.0-litre engine; and what a difference it makes. Having driven the less powerful Z4 and been quite content with its gusto, I was absolutely elated burying my foot into the 3.0si. This engine pulls ferociously- especially on the highway where passing power is frankly startling.

The engine displays strength throughout its broad powerband however north of 4,500-rpm is where the after-burner effect of BMW's Valvetronic technology is most felt. Keeping the engine above this threshold produces formidable performance, not to mention an exhaust note capable of terrifying owners of domestic muscle cars. This sort of motoring, while something the Z4 3.0si is engineered to excel at, isn't appropriate on anything less than a closed track. Typical automotive operation finds the Z4 3.0si well suited to city or highway demands whilst nary breaking a sweat to keep-up or pass.

Happily, the new powerplant is packaged with a six-speed manual gearbox or an optional six-speed, paddle-shift-equipped autobox; both connected to the rear wheels. A sigh of delight was heard for miles as I climbed aboard my tester and allowed my hand to fall upon its manual stick. That may read like cheap trash but it's figuratively true. There's not much sweeter in the auto industry than BMW's six-to-six, that's six cylinders to six cogs.

The maintenance costs spelt out here are enough to scare me away from the M.. frequent valve adjustments and brake jobs??? Yikes! The Si makes some sense...

[biglet2002]

I agree.. driving something with that much power has an intense "viscerality", if there is such a word. But this is purely a luxury here.. We don't "need" another car.. heck, we have 3 vehicles for 2 people.. (the 3rd is a pickup truck). We are both entering our mid-40s and we just purchased a brand new car last fall, a mere 4 mos ago. The only reason we were able afford both BMWs was that my husband, an Army Reservist, was deployed twice, so I was able to tighten the belt and save save save.. and buy both cars outright. (The sedan did have a small loan, which was paid off in 4 mos). I doubt we'll ever be able to be in that situation again, as my husband is getting out of the Reserves, as he's fulfilled his 8 year service obligation. So my feeling is that we are in a place that most people don't find themselves - relatively financially secure, with only a mortgage as major debt. No car loans, no major cc debt, etc. We should be greatful and enjoy what we have as there are so many out there who have so much less... I just wanted to find a way to meet him part way so to speak...

Lisa

[MFGJR]

Lisa,

Sorry I started this! Next time YOU drive it, and we'll see if you sing a different tune.

You're right that "unless you take the car to the track, why on earth do you "need" all this wasted power", and so there's only one logical thing to do--take it to the track!

See you guys soon.

F

[b0bab0i]

Get a supercharger

AA Supercharger

http://www.activeautowerke.com/viewp...x?id=Product18

ESS Supercharger

http://www.koperformance.com/BMW/tur...percharger.htm

[O-cha]

Originally Posted by biglet2002

Um... I don't collect purses or shoes.. am not a typical female.. BTW, have you ever heard of the idea of the power to weight ratio? This is a lightweight roadster. It does not need 330 hp, in fact, that sounds over-engined in my opinion. You've proven my point that it's about bragging rights, not practicality...

Lol you want to teach me about power to weight ratio? You have no idea. Most cars in BMWs current line up (actually I'm going to go ahead and make the assumption all) have a better power to weight ratio then your "zippy" roadster does. Some, not even M cars, demolish it. I can name a many "economy" cars too if you would like.

What you don't know is that the z4 is not that light of a car, 3k pounds. You can get away with that low of horsepower in a lotus elise that weighs 2k pounds.

And 1000hp is about bragging rights, 330hp is nothing to call home about.

If you think a 2.5 liter z4 is sporty then you just have a different level of perception.



I'm sure you do something your husband doesn't understand, he's probably not behind your back trying to figure out ways to make you not do it though, maybe you should be talking to him instead of posting threads.

[pokeybritches]

How many miles does the '03 have? How often does it get driven?

One thing to keep in mind is that if you trade up to either a 3.0si or M, it will be newer and probably have less miles (and therefore less maintenance costs associated with it). If you don't drive the roadster very often maintenance costs shouldn't be a big issue anyway, since most of the maintenance costs with these cars are associated with mileage.

Cold air intakes, software reflashes, headers, exhaust systems, etc. are all very expensive, and do practically nothing to enhance performance on a Z4. They do make the car sound better to some, but their performance gains are negligible. There wasn't a lot of power left on the table by BMW engineers. Most suspension "upgrades" are going to come at a price too, either in ride quality, ground clearance, tire wear, and so on. Other than a supercharger, the only performance enhancers I would consider are non-RFT tires, a limited-slip differential and higher gearing. You probably won't reach the thermal limit of the 2.5i's brakes on the street.

As far as superchargers are concerned, I'd be wary. While ESS seems like it's a reputable company (I've never dealt with them), supercharging an engine will cost $6000 + maybe $1000 or more for an install. Should anything go wrong, the dealer may/may not want to touch it. And, a BMW engine is very expensive... even the 2.5L I-6. Should the thing blow up, well, good luck. Superchargers add extra wear and tear, so maintenance vs. an M might not play in your favor.

Even with a supercharger, the 2.5 will not drive like an M. The M has more than just 330 hp. It has different brakes, suspension, seats, quad exhaust, aerodynamics, 6-speed transmission, more standard features, limited-slip, steering wheel/feel.... the list goes on. The 2.5 will never sound like the S54 (engine in the M). Even if you somehow managed to squeeze 400 hp out of the 2.5, it wouldn't sound as good or feel as good. It would only be better on paper. It would be like marrying a girl because of her resume, and not because you're in love with her. The M is a completely different car.

I'm not saying that to be snotty. I also have an '03 3.0i, and I love it. It just wasn't enough though. You might argue that it's "more practical," but isn't the practicality of a roadster in the fulfillment and enjoyment it gives you? Isn't its primary purpose "fun?" If so, then a roadster that most satisfies the "visceral feeling" within a reasonable cost is the prudent investment. A roadster that doesn't thrill is a wasted investment, and is impractical to own... it's nothing more than a cute toy. Your husband is going to want to get his thrills somewhere. If not this, then what, a boat? I say let him go for it or he will never be satisfied.

[Huz-Z]

Originally Posted by biglet2002

The maintenance costs spelt out here are enough to scare me away from the M.. frequent valve adjustments and brake jobs??? Yikes! The Si makes some sense...

Hi there!!

Just to be clear - and fair to our brethren M drivers here - I didn't say "frequent" valve and brake jobs.

What I meant is that when you have to do that work on a Z4M, it will cost more than it will on a Z4 3.0si. In fact, I don't think manual valve adjustments are needed on the 3.0si. I have seen some M drivers express displeasure with the cost of that valve and brake work on their cars.

Why not get your hubby to drive both cars. Then find out how much the brakes and valves cost on a Z4M. And buy the car that you both agree on. I'm sure you and your husband will be totally happy with a 3.0si as I am. I mean, the thing goes like a rocket and sounds amazing!! (See Footnote).

But if the purchase price and maintenance costs of a Z4M are acceptable for you - why not?

FOOTNOTE
I'm in Canada where car speedometers read in kilometers per hour, miles per hour are in tiny numbers on the dial up here. Its the other way around on US cars, and I imported my car from the US. One day I took my 3.0si on the highway and passed a guy with the Sport button engaged. No problem and I was cruising along, with the car feeling just like our '09 Accord does at 100 kph / 60 mph. I glance at the speedo - just over 100. Perfect -just at the speed limit here of 100 kph. Away I go

Then it hits me.

I'm going 100 MILES per hour. Trust me when I tell you; the 3.0si is no slouch.