20i engine tuning

Specific discussion about the E89 2009 Z4 (sDrive35is, sDrive35i, sDrive30i, sDrive23i)
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Liam22
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20i engine tuning

Post by Liam22 » Mon May 10, 2021 10:55 am

Hello. Wandering over from the E85/E86 forum!

I'm looking at helping a mate build a E89 track car. Looking at a 20i (184bhp) model as there are lots of them about.

Can anyone help me with what engine code this is, and what it would take to get it to 28i power levels? Is it just ECU/boost or are there physical engine/turbo changes? I'd really appreciate any pointers, thanks!

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enuff_zed
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20i engine tuning

Post by enuff_zed » Mon May 10, 2021 11:02 am

Liam22 wrote: Mon May 10, 2021 10:55 am Hello. Wandering over from the E85/E86 forum!

I'm looking at helping a mate build a E89 track car. Looking at a 20i (184bhp) model as there are lots of them about.

Can anyone help me with what engine code this is, and what it would take to get it to 28i power levels? Is it just ECU/boost or are there physical engine/turbo changes? I'd really appreciate any pointers, thanks!
Go straight to PBondar! Do not pass GO. Do not collect £200.
Peter has compiled so much info on the N20 and collated everyone else's results.
You can search on 'remap' and get hundreds of hits, but Peter has it all in one place, including lots of example dyno graphs etc.
280bhp is easy, as is a big hike in torque, right across the range.

If you happen to be near Snetterton any time soon, feel free to deviate 3 miles to me and you can see the difference it's made to my 20i.

Also bear in mind, if it's a track car, you wouldn't need all the fancy bells and whistles and the 18i is an identical engine with a different map. They seem to come with lower specs in a lot of cases, which will open up your search and maybe reduce the initial outlay.
As far as anyone has been able to prove, the 28i had slightly bigger brakes but nothing else different, but again Peter upgraded to those on his and I believe hardly noticed the difference. Tracking it would be different I'm sure.
E89 20i SDrive M Sport - Valencia Orange
E85 2.5i - Sterling Grey - Better half's fun car

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Liam22
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20i engine tuning

Post by Liam22 » Tue May 11, 2021 7:59 am

enuff_zed wrote: Mon May 10, 2021 11:02 am Go straight to PBondar!
Excellent - thank you. I found his PDF doc.

As it happens, we're looking at getting a fibreglass roof made in Attleborough, so might take you up on that!

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enuff_zed
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20i engine tuning

Post by enuff_zed » Tue May 11, 2021 11:40 am

Liam22 wrote: Tue May 11, 2021 7:59 am
enuff_zed wrote: Mon May 10, 2021 11:02 am Go straight to PBondar!
Excellent - thank you. I found his PDF doc.

As it happens, we're looking at getting a fibreglass roof made in Attleborough, so might take you up on that!
No probs. I work from home most days so give me a bit of warning though.
E89 20i SDrive M Sport - Valencia Orange
E85 2.5i - Sterling Grey - Better half's fun car

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