Just a couple of q's

[300bhp/ton]

Hi.

Recently I've been seeing a nice looking green Z3 on the way back and forth to work. No other reason, but it has since sparked some interest in me.

I'm potentially considering a Z3 as a fun commuter vehicle as I simply couldn't stand to drive a boring hatchback or Eurobox every day, and I only need 1 seat and a small amount of space for commuting.

I've been reading the wiki about body braces:
https://zroadster.org/articles/basic-bmw-z3-suspension-modifications-by-mike-fishwick.41/

Which I found interesting. But has then since lead me to ask some other questions:

1. I'd only be considering a 2.8 manual (or 3.0 if in budget). Is there much performance difference between the early models and the 99/00 facelift ones? I think double VANOS was the main change, but does it really affect how they drive?

2. I'm fairly sure on a 328i you can swap on the older 325 inlet manifold and net a reasonable jump in HP. Is this true with the Z3? Is there a guide detailing all the bits?

3. What sort of size tyres can I fit on a Z3? I'd be looking at the body bracing, but not really into lowering massively. But I would like something that looks modified rather than standard. Can you run something like 265's on 18" all round?

4. MPG. I know BMW rate the 2.8's at approx 30mpg and that depending on driving style you'll see 28-36mpg. Ideally I'd like to keep my fuel costs lower though. So has anyone been running a 2.8 Z3 on LPG? I could sacrifice some boot space to make this happen. Any info or articles you could point me at would be most welcome.


Sorry for so many questions. But if I decide to do this I'll need to borrow some money. And I'd like to borrow the right amount to buy the car and get it how I want it all in one hit. Rather than drawing it out as a long term project, or ending up compromising with something I'm not entirely happy with. However doing this, does mean some advanced research.

Thanks.

 

[miller1098]

Hi our first Z was the 2.8 and I thought I would make a load of mods but after driving it for a while all I did was stiffen the suspension a little and put 18" 255 on the back and 18"225 on the front can't imagine LPG would ever pay for its self.buy a good one drive it and it will talk to you

 

[oldcarman]

Welcome from Canada and good luck with your search. JIM

 

[GazHyde]

Hi @300bhp/ton,

Not sure if we can get you in to a zed with 300bhp per ton that easily, but reasonable gains can be made.

The manifold conversion is fine if you can get hold of the parts, I know @z3cade carried it out so perhaps he can give you some idea on it.

My only contribution on the LPG side of things would be this picture of a car I saw some years ago. He seemed pleased enough with his system, sorry I can remeber more about it though...

LPG BMW Z3

• GazHyde
• Sep 4, 2014
• 1

LPG BMW Z3 conversion

 

[300bhp/ton]

Thanks for the info. I know LPG won't be for all, but I do enough miles that it'd probably pay for itself in a year. And 50+mpg fuel bills would be nice when you factor in the cost of LPG.

 

[300bhp/ton]

Does the 2.8/3.0 Z3 have an LSD? I recall it being optional on the 328i. I'm hoping it is standard fitment on the Z3 Roadster (UK models).

 

[smartbear]

My other halfs 2.2 model had an lsd from new (as an option I think)
Your name is familiar, did you have either a smart roadster or a lotus elise in the past?
Regards

 

[spurs fan in a coupe]

Could you be tempted by a 2.8 Z3 coupe? Massive boot for an LPG tank and more comfy in the winter as a daily drive.

I know someone with a lovely example for sale! At about 3.0 Z3 price bracket!

 

[300bhp/ton]

Could you be tempted by a 2.8 Z3 coupe? Massive boot for an LPG tank and more comfy in the winter as a daily drive.

I know someone with a lovely example for sale! At about 3.0 Z3 price bracket!

I love the look of the coupes. Didn't know you could get them in the UK apart from the M Coupe. Could you message me some details please.

 

[300bhp/ton]

My other halfs 2.2 model had an lsd from new (as an option I think)
Your name is familiar, did you have either a smart roadster or a lotus elise in the past?
Regards

Thanks. Yes smart Roadster. Still have it.

 

[smartbear]

I thought I remembered you (theroadster.net) I've got a 3.0si z4 roadster now, but had a lotus elise for a couple of years after selling my roadster coupe-my Mrs has the z3 and is smitten by it
Regards

 

[Aceman]

In answer to your questions;

1. The earlier 2.8 Z3's upto Sept' 98 were single vanos and thereafter BMW fitted the double vanos M52TU unit which although on paper had identical performance figures the M52TU unit had better low end torque and was a smoother drive as a consequence.
2. The earlier single vanos 2.8's can certainly be improved with the M50 manifold conversion and net around 30bhp along with a remap to suite. The later M52TU units can also be similarly modded but you will need the later M54 manifold off the 3.0L which will net you similar gains. As Gary says @z3cade did this conversion on his first zed but I believe he has since said he would not really recommend doing it again considering the real world performance gains but this I suppose this is a personal choice particularly if you like tinkering.
3. BMW did fit 17" 225/45 fronts, 245/40 rears as an option and there is certainly room for more if you do not intend to lower. Just be mindful that lowering the rear does create quite a bit of camber that will scrub the inner edge of the tyres. Moving to 18" will harden the ride a little but it is a popular mod although 17" is generally accepted as the best handling compromise wheel size for the zed.
4. I have no experience of LPG but you could remove the spare wheel which is located under the boot (most will be in a poor state now tbh so no loss) and use a donut tank hence saving on boot space. MPG wise upto 30 is easily achievable dropping to around 25 in town so is quite a good compromise against the potential performance that is available.

If I was you I would be looking for a late 2.8 (Oct' 98 onwards build date) as that will represent the best value available to you and is a very reliable motor.