Any Z4 23i performance increase advice out there?

[Richard227]

Hi All
Just bought a 23i 2.5 auto and a little underwhelmed with the performance. Beginning to think I should have got a 2.0l with a turbo and mapped it? Any advice out there for a nice safe power increase?
Cheers for any advice
Rich

 

[andyglym]

You'd need to dig very deep to get any significant performance gains on a normally aspirated car. A remap could give an extra 10% and a good exhaust maybe 5bhp tops I would've thought. Would sound better though.

 

[Richard227]

Hi Andy
Yeah, same as I was thinking. Fell in love with the motor before doing my homework on engines! “Doh!” Even a 2.0 ltr turbo could be mapped past 225hpl. If I can get it to 225-235 I’d be happy enough. I need to keep up with my pal’s Boxter!!

 

[Pingu]

Performance is a Power-to-Weight thing. The easiest way to increase performance is to reduce weight.

If you want to increase Power, you need to efficiently increase the amount of fuel that's burnt. This means either making the same amount of fuel burn more efficiently, or continue to inefficiently burn more fuel.

A map will improve the efficiency of the current fuel supply using the air supply and extraction that you have. It's only the oxygen molecules that you need - the rest is crud. You can maximise the oxygen by making the air denser. You can make the air denser by keeping it as cool as possible.

Improving the flow rate of the air supply is the easiest way to improve power, but it is reliant on the fuel supply keeping up using the live mapping of the ECU. Your car should be able to do this.


The route I would do is...

Lose weight
Insulate the airbox and tubing
Improve air flow
Improve exhaust flow
Uprate camshafts
Tune air flow
Tune exhaust
Map

 

[andyglym]

Hi Andy
Yeah, same as I was thinking. Fell in love with the motor before doing my homework on engines! “Doh!” Even a 2.0 ltr turbo could be mapped past 225hpl. If I can get it to 225-235 I’d be happy enough. I need to keep up with my pal’s Boxter!!

What's the standard BHP on your Zed mate?

 

[t-tony]

........ or buy the right car? Welcome Rich, I bought the "wrong" car first in a 2.0 Z3. I now have a 3.0i Z4.

Tony.

 

[andyglym]

........ or buy the right car? Welcome Rich, I bought the "wrong" car first in a 2.0 Z3. I now have a 3.0i Z4.

Tony.

Phfft

 

[Richard227]

Well, I certainly need to lose weight, so I might start with less pies!
Dont want mess with cam shafts, etc. Happy to sort air flow, exhaust and map, I think.
Would I go down the K&N route or use an upgraded filter in the original air box?

 

[t-tony]

An induction kit may or may not increase the HP but it will definitely make you smile.

Tony.

 

[andyglym]

An induction kit may or may not increase the HP but it will definitely make you smile.

Tony.

Yup whooooooosh

 

[Paul Rice]

Keep it standard and join us on our trips out.

 

[Shelly]

Hi and welcome to ZroadSter

 

[billz]

Welcome. I would not bother trying to get more BHP as it is a lost cause on an NA Engine. Exhaust will help it sound better, an induction kit can sometimes have a detrimental effect on the BHP as some have found when the have took them to rolling roads.
If you want more power then i am afraid you will need to change the model of Z you have

 

[Richard227]

Thanks for all the advice. Think ill just map it and enjoy it.
Are there any club meets or dates for the diary, up in the Northeast, Newcastle area?

 

[Paul Rice]

More happening in the summer. Bit of a drive but several of us meet up with the BMWCC on the 1st Sunday of every month at the Motorist Hub Sherburn in elmet Nr York
https://www.themotorist.com/
Also a meet up at Beamish 2nd Sunday of the Month https://www.facebook.com/blackhorsebeamish/
These are BMWCC meets but guest very welcome.

 

[Richard227]

Thanks for that, Paul.

 

[Mint]

...Are there any club meets or dates for the diary...

The club meets/runs are in the 'Forthcoming Events' section of the forum - https://zroadster.org/forums/forthcoming-events.4/

 

[Nodzed]

Dont waste your money on a remap on the 2.5. Very little gains. not surprised you dont think it's got enough go in it. Mines a manual and it's fine now. Its wasnt when I first got it it was strangled I think it had been pootled around for 50k. I ran a bottle of Redex per tank for about 6 tank fulls and revved it hard and often. Then a 3k Italian road trip and the car was transformed, still need to rev it and use the box a bit more than I am used to but now I think it's great. Bare in mind I run a Z3M too and the e89 dosent disappoint

 

[Richard227]

Thanks for that. I think i need to learn how to use the engine properly. So used to driving a blooming diesel for so long @3k rpm, I think I need to get used to using the rev range and taking it past 4.5 -5k rpm on a regular basis and learn how the engine is supposed to be used? Interested to hear more about the Redex? Ive never used it before. Using it as a weekend car, do you think using Redex benefits would be noticable after a couple of tank fulls? Its done 62k miles btw.

 

[Nodzed]

Thanks for that. I think i need to learn how to use the engine properly. So used to driving a blooming diesel for so long @3k rpm, I think I need to get used to using the rev range and taking it past 4.5 -5k rpm on a regular basis and learn how the engine is supposed to be used? Interested to hear more about the Redex? Ive never used it before. Using it as a weekend car, do you think using Redex benefits would be noticable after a couple of tank fulls? Its done 62k miles btw.

Definitely needs to be revved, its not an engine with lots of torque like the Z3 2.8s and 3.0s take mine to the limiter at least once per drive.
You what they say, a rev a day keeps the mechanic away

As for Redex you know there is a lot of division on it BUT yes in getting my engine running a bit happier I am sure it helped, the engine didn't rev freely always seemed to be struggling as I said I don't think it ever got revved and got a bit gummed up I think once everything is cleared out then no you wont notice anything further but I chuck a bottle in the M every 3 months or so too.

But revving the engine and using it a bit harder on occasions probably does more good than the Redex I suspect