Z4-forum.com

Steelee wrote: ↑Sun Apr 01, 2018 12:12 pm One other thing I can't seem to work out is the stop/start it seemed to work once but now the symbol appears but with a line through it, I know in the hand book it says it only works in the correct conditions but what are these?

On my previous car the start/stop would only work when the engine was up to temp and if any sport mode was engaged, traction control was turned off or the A/C was operating but the cabin was above the set temp it would not allow the engine to switch off and would have the symbol you described.

Steelee wrote: ↑Thu Mar 29, 2018 10:11 pmCeltic

Have decided to go with Celtic as they seem to know what they are talking about, they offer stage 1 (181bhp) Stage 2 (241bhp - 277nm) or stage 3 (295bhp and 320nm) fairly sure going to stick with stage 2 as 295 seems a bit much and don't want to compromise on reliability although they have assured me the stage 3 is all within safe tolerances of the engine and drivetrain.....just know if I do go with stage 2 I will regret not knowing what could have been!! - even better they will come to home or work and do the remap at a very competitive cost

Hi
I would also be very wary about a remap under warranty, I waited until the warranty had expired on my daily driver (Focus ST) before remapping.

It's totally transformed my ST, goes like an absolute rocket now, but must admit I hadn't considered a remap on my Z4 as I was under the impression they weren't as effective on non turbo engines, I'll have to look in to it further by the sounds of it....

Hi Tinman6,

Mine is a turbo so gains are much higher, all the 2.0l turbo engines are the same, power is only limited by software so having a stage 2 tune would up the power to that of the sdrive28i and as there are no mechanical differences I don’t see there being a problem......and Celtic are very knowledgable and have done many remaps.

Ah sorry didn't realise it was a turbo, yes I've heard Celtic are very good. I did my ST remap myself with Bluefin and been extremely pleased with the improvement so if you're going to a highly recommended tuner you should be well sorted

bryand wrote: ↑Sun Apr 01, 2018 5:45 pm I'm in the same boat as you pretty much, mine is a 2.0i and I really want a remap but am holding off until the BMW warranty is up as I wouldn't trust them not to wriggle out of a claim if they knew about a remap regardless of the fault.

I had a JB4 for over 3 years - three warranty claims - gearbox, MAF sensor, and roof - no issues with BMW warranty - all these repairs were covered.

Just remove the box - before going in for a repair.

I did nearly 40K miles with JB4 stage 2 - and knocking out over 300BHP in my 28i

Twin Turbo wrote: ↑Fri May 04, 2018 3:26 pm I had a JB4 for over 3 years - three warranty claims - gearbox, MAF sensor, and roof - no issues with BMW warranty - all these repairs were covered.

Just remove the box - before going in for a repair.

I did nearly 40K miles with JB4 stage 2 - and knocking out over 300BHP in my 28i

I've heard good and bad things about the piggyback boxes so was going down the route of a permanent map, will have to do a bit more research it seems.

bryand wrote: ↑Sat May 05, 2018 12:47 pm

Twin Turbo wrote: ↑Fri May 04, 2018 3:26 pm I had a JB4 for over 3 years - three warranty claims - gearbox, MAF sensor, and roof - no issues with BMW warranty - all these repairs were covered.

Just remove the box - before going in for a repair.

I did nearly 40K miles with JB4 stage 2 - and knocking out over 300BHP in my 28i

I've heard good and bad things about the piggyback boxes so was going down the route of a permanent map, will have to do a bit more research it seems.

You should bear in mind that in most cases a piggy back box can only fool the original ECU and original software so far...

So for example if you look at Racechips that do a range of boxes for a wide range of cars and scroll down the BMW Z4 E89 N20 engines 1.8 2.0 2.8 you can see that they can only get so much gain from each engine due to the fact that they start with the limiting point of the original engine map...

So the 1.8i with one of their chip boxes cannot get anywhere near the 2.8i with the same chip box...

That in mind is a key decision point if you are doing the 1.8i or 2.0i base car power upgrade....

Some savvy people have just taken the 2.8i s/w map and re flashed a 2.0i to get the same power as the 2.8i..

So even though I originally thought the two options were closely run/...I would suggest IMHO that for the 1.8 and 2.0 fsmily the ECU REFLASH is the way to go...

Personally I wouldn’t stop at the 2.8i power level I would go to the 280bhp ish...

Celtic have now backed off from 295 to 280 just to give a bit more headroom..

If you look at all the calcs that places it well within gearbox and brake limits..

Bear in mind in the UK based on my experience you can only hold remapped full power for around 10 seconds in almost all circumstances since you run out of road...from rest your doing over 90mph...