Upgrade 20i to 28i performance

GoSteve · Post by **GoSteve** » Wed Sep 14, 2016 12:07 am

What is required to upgrade the Z4 20i to 28i performance spec?

20i 0-60 is quoted as 6.7s, 181 bhp.
28i 0-60 is quoted as 5.5s, 246 bhp.

Is this simply a remap, or is there more to the upgrade. 36% (65 bhp) increase in power is quite significant.

Twin Turbo · Post by **Twin Turbo** » Wed Sep 14, 2016 8:25 am

You can probably get near - but depends how far you want to go:-

Stage 1: Remap/Race Chips/JB4
Stage 2: Remap/JB4 + Remove Cats

Stage 1 will probably give you around 40/45 BHP and 70 lbs torque
Stage 2 Will probably give you 50+ bhp

vester86 · Post by **vester86** » Wed Sep 14, 2016 3:29 pm

The 28i got differt pistons with another compression ratio, different turbocharger boost.

http://www.f30driver.com/forum/showthread.php?t=966132

As for your question, you can probably get away with just the remap, but BMW changes these parts for a reason...

Twin Turbo · Post by **Twin Turbo** » Wed Sep 14, 2016 8:40 pm

That is not correct for the Z4 - check real OEM

Capture.JPG

dvd112 · Post by **dvd112** » Sat Oct 01, 2016 12:08 pm

TMC tuning box, my 2.0 sits at just a tad over 246 hp and 301.9 ft lbs. TMC very good, plug in and out, been on the car for a year and no issue.
I have a graph somewhere
D

Rockford · Post by **Rockford** » Sat Oct 01, 2016 1:53 pm

The 20i and 28i share the same internals (so I am told) aand a good remap can get you very close. I was at Evolve this week and they've had similar results to the post above in terms of power gains of a 20i.

stuartinzg · Post by **stuartinzg** » Mon Oct 03, 2016 7:46 pm

If they share the same internals, why would a remap only take you to 28i levels? A 28i can be boosted to over 300.

Something doesn't add up

R.E92 · Post by **R.E92** » Mon Oct 03, 2016 11:04 pm

stuartinzg wrote:If they share the same internals, why would a remap only take you to 28i levels? A 28i can be boosted to over 300.

Something doesn't add up

I don't think there's a proper remap available for that engine, it's just a piggyback unit.

It's quite possible both engines are capable of outputting the same power but since piggyback tuning is limited to fudging a few sensor readings then for the time being I doubt the 20i will get close to 28i figures. There's only so much leeway the stock ECU allows before throwing codes when you start increasing the boost pressure and fuelling. The JB4 is quite good at avoiding them but each generation BMW seem to add a few more checks to catch out piggybacks.

Once the ECU is cracked on that engine then you might find the 20i becomes a complete bargain. Similar to how the old 3.0 E9x 325d could be tuned to the same levels as the 330d. I wouldn't hold out much hope for a full crack though, people won't be spending much R&D money on the platform since it has limited appeal to modders.

Rockford · Post by **Rockford** » Tue Oct 04, 2016 7:17 am

stuartinzg wrote:If they share the same internals, why would a remap only take you to 28i levels? A 28i can be boosted to over 300.

Something doesn't add up

That is a very valid point!

I'm only going by what Evolve Automotive told me last Wednesday whilst I was in their workshop but they were confident (and proud to tell me at length) they had recently done a 20i and with a simple ECU map had it running stock 28i power. They said the owner was over the moon - no chance he is on the forum?? If you are step up!

stuartinzg · Post by **stuartinzg** » Wed Oct 05, 2016 9:58 am

R.E92 wrote:
stuartinzg wrote:If they share the same internals, why would a remap only take you to 28i levels? A 28i can be boosted to over 300.

Something doesn't add up
I don't think there's a proper remap available for that engine, it's just a piggyback unit.

It's quite possible both engines are capable of outputting the same power but since piggyback tuning is limited to fudging a few sensor readings then for the time being I doubt the 20i will get close to 28i figures. There's only so much leeway the stock ECU allows before throwing codes when you start increasing the boost pressure and fuelling. The JB4 is quite good at avoiding them but each generation BMW seem to add a few more checks to catch out piggybacks.

Once the ECU is cracked on that engine then you might find the 20i becomes a complete bargain. Similar to how the old 3.0 E9x 325d could be tuned to the same levels as the 330d. I wouldn't hold out much hope for a full crack though, people won't be spending much R&D money on the platform since it has limited appeal to modders.

Correct me if I'm wrong, then why can't you plugin a 28i ECU and reprogram it? Or am I being simples?

R.E92 · Post by **R.E92** » Wed Oct 05, 2016 10:55 am

stuartinzg wrote:
R.E92 wrote:
stuartinzg wrote:If they share the same internals, why would a remap only take you to 28i levels? A 28i can be boosted to over 300.

Something doesn't add up
I don't think there's a proper remap available for that engine, it's just a piggyback unit.

It's quite possible both engines are capable of outputting the same power but since piggyback tuning is limited to fudging a few sensor readings then for the time being I doubt the 20i will get close to 28i figures. There's only so much leeway the stock ECU allows before throwing codes when you start increasing the boost pressure and fuelling. The JB4 is quite good at avoiding them but each generation BMW seem to add a few more checks to catch out piggybacks.

Once the ECU is cracked on that engine then you might find the 20i becomes a complete bargain. Similar to how the old 3.0 E9x 325d could be tuned to the same levels as the 330d. I wouldn't hold out much hope for a full crack though, people won't be spending much R&D money on the platform since it has limited appeal to modders.
Correct me if I'm wrong, then why can't you plugin a 28i ECU and reprogram it? Or am I being simples?

ECUs have checks. The VIN number in the ECU will likely be interrogated in some manner to determine if the ECU type matches the engine. The VIN is also stored in two other modules in addition to the DME. The CAS and another (KOMBI?). They must match before the car can be started.

There will be a few other checks between modules. If you know the location of the checkbits then you could in theory just flash the 28i file on the 20i DME.

The problem there is you need to have write access to the DME. I think companies only have partial write access.

MGB · Post by **MGB** » Wed Oct 05, 2016 11:27 am

Superchips do a 20i chip, see power curves below:

http://www.superchips.co.uk/curves/E89Z420i.pdf

Looks like the 20i runs out of power at 4500rpm and the gains are all above that.

Good value - anyone have one of these?

Twin Turbo · Post by **Twin Turbo** » Wed Oct 05, 2016 1:03 pm

Interesting graph - as it looks very similar to mine that recorded an 308Bhp

stuartinzg · Post by **stuartinzg** » Wed Oct 05, 2016 5:20 pm

R.E92 wrote:
stuartinzg wrote:
R.E92 wrote:
I don't think there's a proper remap available for that engine, it's just a piggyback unit.

It's quite possible both engines are capable of outputting the same power but since piggyback tuning is limited to fudging a few sensor readings then for the time being I doubt the 20i will get close to 28i figures. There's only so much leeway the stock ECU allows before throwing codes when you start increasing the boost pressure and fuelling. The JB4 is quite good at avoiding them but each generation BMW seem to add a few more checks to catch out piggybacks.

Once the ECU is cracked on that engine then you might find the 20i becomes a complete bargain. Similar to how the old 3.0 E9x 325d could be tuned to the same levels as the 330d. I wouldn't hold out much hope for a full crack though, people won't be spending much R&D money on the platform since it has limited appeal to modders.
Correct me if I'm wrong, then why can't you plugin a 28i ECU and reprogram it? Or am I being simples?
ECUs have checks. The VIN number in the ECU will likely be interrogated in some manner to determine if the ECU type matches the engine. The VIN is also stored in two other modules in addition to the DME. The CAS and another (KOMBI?). They must match before the car can be started.

There will be a few other checks between modules. If you know the location of the checkbits then you could in theory just flash the 28i file on the 20i DME.

The problem there is you need to have write access to the DME. I think companies only have partial write access.

I guess the best option for those who are determined is an aftermarket ECU like Syvecs/MegaSquirt? Probably a lot of work ...

Interesting: http://www.syvecs.co.uk/products/engine ... 2-m3-kits/

Check this https://www.youtube.com/watch?v=nTh0RVwB-gU

BMW 1 Series DSG supported

dvd112 · Post by **dvd112** » Wed Oct 05, 2016 7:29 pm

Really interesting, having the 2.0 with TMC is good, also an improvement in MPG, i suspect that i can get more out of it i.e. custom remap, but as said, I don't know how to go about this or where I would go. If the 2.8 is the same engine as the 2.0 then i suspect a 2.8 tuning box may work from TMC. I will call Darren at TMC tomorrow.

D

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