More oomph out of the turbo engine

[Z4tobe]

I understand the sdrive18i, 20i and 28i engines come with the inline 4cylinder turbo engine. If I buy a Z4 with one of these engines how hard is it to make them 5 sec 0 to 60mph cars. Is it simply a remap or is more work involved such as stronger internals? Is it a lot more work with the 18i than the 28i?

Any tips or advice much appreciated!

 

[Pondy]

Well the 28i with 245BHP as standard is quoted at 5.7s 0-62 (100kph), so 60 would be around 5.6?

A standard remap (on generic software) gives around 270bhp (and more torque) on any of the N20 4 cyl blown variants (as they are the same engine).
Around 5.3-5.5 second 0-60 mph I would guess. Any more bhp/ less acceleration time will start to cost a lot more.

B21 has done all of it on an N20 (4 cyl turbo). He will give more info.

 

[Mr Tidy]

Here's a thread about E89s with remapped N20 engines in the meantime:- https://z4-forum.com/forum/viewtopic.php?t=124073&hilit=yellow+peril

B21 knows all about it - when you read that thread he used to be Pbondar.

 

[B21]

Any of the 18i, 20i, 28i can be remapped to around 265-285 BHP.with just a re-map..each car is different some make more power, some more torque, some rev some don’t.

Best done by a tuner with track record and a dyno for behalf and after..

You can get another 5 ish BHP with a sports cat..I have a spare one

A bigger turbo adds another 20 BHP but that’s a £1,500 exercise..

Later N20 with uprated fuel pump and electronic waste gate do better than earlier pneumatic waste gate versions…

With earlier N20s best get the camchain sorted .

 

[Felixlamb]

For reference. This is my remapped 20i… 5.13 seconds with a slight incline.
That was on a mildly damp road with 225 width winter tyres. I suspect one I get my 265 width summers installed I should be able to get it under 5 seconds as I’ll be able to brake-boost more.