b9 s4 v b8 s4

I have seen a few articles saying that the 3.0 V6 unit are the same albeit the later model has switched to twin turbo v the previous having the charger. Is this correct?

I had the b8 version and with a revo stage 1 remap was pretty awesome all round. Loved the car. I ended up selling it due to getting to a higher mileage but was also put off by some of the problems i had incurred, over heating etc (prior to remap and one after), but understand that was a common fault with the water pump? (metal v plastic impeller i think). Both fixed under warranty but annoying all the same.

I also had error messages appear a couple of times re the S Tronic box which put it into limp mode. But seem to fix themselves, however it did freak me out given cost to replace.
However I also notice that the new model has switched to tiptronic (i.e. like the rs models), so i guess this is proven to handle longer term higher power.

I am thinking of returning to either the s4 or s5, but only if i can match the performance of the remapped version. I guess i need to test drive the turbo to see how it drives now. I also see a few remap threads out there so will explore those too. Anyone out there have the b8 with the revo map and have driven the b9?

My decision is do i switch back to audi given the problems I had during s4 ownership or to I move to the m3.
Audi has much better tech (v.cockpit etc) and is more of a sleeper car, whereas m3 is more in your face (but still fairly tame looking) but doesnt have the tech.
 

Daggerit

Registered User
I've not driven a B8 S4 so I'm afraid that I can't compare in terms of the way the power is delivered.

I will say that I'd imagine that the engine architecture is significantly different because the exhaust ports are all integrated into the cylinder heads and exit from one outlet towards the middle of the V to spin up the turbo. The B8 will have had a traditional setup with individual port outlets on the outside of the V each going to an exhaust outlet pipe.

Internally I don't know if there's been changes to the components in terms of the connecting rods, pistons, etc. though.

I think that the biggest issue you'd have with moving to the B9 is that no one has cracked the ECU yet so there's no remaps available. You can use a tuning box like I have, which is good, but won't be as good as an ECU tune and I imagine. The output is still about 410PS and something like 625Nm I think, which is good but would probably be even higher and smoother with a proper remap.
 
I've not driven a B8 S4 so I'm afraid that I can't compare in terms of the way the power is delivered.

I will say that I'd imagine that the engine architecture is significantly different because the exhaust ports are all integrated into the cylinder heads and exit from one outlet towards the middle of the V to spin up the turbo. The B8 will have had a traditional setup with individual port outlets on the outside of the V each going to an exhaust outlet pipe.

Internally I don't know if there's been changes to the components in terms of the connecting rods, pistons, etc. though.

I think that the biggest issue you'd have with moving to the B9 is that no one has cracked the ECU yet so there's no remaps available. You can use a tuning box like I have, which is good, but won't be as good as an ECU tune and I imagine. The output is still about 410PS and something like 625Nm I think, which is good but would probably be even higher and smoother with a proper remap.

Thanks.
Ahh, they have twin scroll turbos which sit in the V don't they?

Yes i did read about the tuning box (the one you have) and have considered that, typically steered away from those things and stick to ECU maps but
might be a good temporary solution, sounds like a lot more power is definitely available! Sounds like you recommend this?

I will test drive one and see how it feels...
 

Daggerit

Registered User
Yeah, they're 'hot Vs' as they seem to call them and have the twin scroll in the middle. In standard trim it's pretty good at spinning up as far as a turbo car goes to be fair, especially compared to some of the smaller engines with big turbos strapped to them.

I like it because I know that the power is on tap if I want it but it doesn't affect fuel economy when I don't. And is removable for warranty work if needed so I'd definitely recommend one until remaps and things are available. Just as a limitation of the box, I'd say that it causes the turbo boost to come in less smoothly on occasion but not enough to worry me at all. And once it's spinning the power delivery is really good, it just runs out of puff a little at the top end because the turbo is fairly small (a bigger turbo swap would be great but no use until the ECU is cracked).

Definitely worth a test drive whilst bearing in mind that there's a pretty huge lump of midrange torque and a bit more top end available just from plugging a box in. :)
 

kanecullen89

Registered User
I've had my fair share of issues with my B8 but please don't get an M3 (or any other BMW) purely in the hope that it wont have issues like the Audi's.

BMW's are as riddled with problems as any other German manufacturer.

My advice is to drive each car and get whichever you prefer to drive. They will all cost a lot to run, maintain and repair so you might as well get the one which you enjoy the most
 
You are right, ive had 2 bmws and 2 audis.... had more "major" issues with Audi, but then i prefer their overall build quality.
I will leave the decision down to pure driving pleasure!
 

Dippy

Registered User
@trick971 - the B9 S4 has a completely new engine design compared to the B8. It has a single twin-scroll turbo (it is the RS4 which has twin monoscroll turbos on a 2.9 V6 which is a totally different engine from the S4).

AFAIK the Bosch MG1 ECU has not yet been cracked for this platform. However this series of Bosch ECUs is used across many cars and I think I read somewhere that progress is starting to be made on some of the "lower security" ones (possibly on Fords?). Whilst that would seem to be good news, I suggest limiting optimism because it does not prove that the Audi version is crackable. The other thing to bear in mind is that although of course there will be headroom, the single turbo has been sized for around 350hp and already has a relatively high boost. So the gains are modest compared to the B8 just by raising boost. Of course turbo upgrade will be possible and quite practical due to its position, however I wonder how far the tuners will be able to take this on an engine which has a higher than normal compression ratio since it involves a version of the Miller cycle.

Until the ECU is cracked, piggy-backs are the only option. These seem to be able to take the engine to around 425hp/550Nm peak. The simpler ones act by faking the boost readings to the ECU to delay wastegate opening. However they then tend to rely on the ECU to detect lean and increase fuelling, which is somewhat a "crude" control loop, and I'd suggest this is what @Daggerit has observed in "it causes the turbo boost to come in less smoothly on occasion".
 
Last edited:
Top