Tuning thoughts B9 S4 vs B8 S4?

[Chris Nelson]

Thiught I'd out this out there as this is the first thing I think when i see or hear about a new model becuase this is how my head works.
The new S4 is going to be 354bhp on a lighter body and a 3.0 turbocharged V6 engine rather than the supercharged B8 pushing 328bhp.
So....
What do we think the new engine can get tuned to?
The b8 was a belter due to the pulley upgrade being all you need for over 400bhp.
I think to get the same power gains your going to be looking at intercoolers injectors etc.
Orrrr is the B9 going to be massively downtuned so stage 2 will send it mental?

 

[ScottishA4B9]

I believe the S4 is going to be sharing the same engine as the forthcoming RS4 so I would imagine the engine in the S4 will be downtuned.

 

[Thundercliffe81]

I believe the S4 is going to be sharing the same engine as the forthcoming RS4 so I would imagine the engine in the S4 will be downtuned.

I'm pretty sure the B9 RS4 has a new 2.9 twin turbo co-built with Porsche. Read it recently.

 

[ScottishA4B9]

Ah right. I read it a few months ago so that might be new info. Be pretty good if it does.

 

[desertstorm]

I suspect the limiting factor for tunability will be the turbocharger. But as it's mounted in the V shouldn't be a massive job to whip it out and have it modded a bit. The turbo has probably been sized to give very good low down response with minimal lag It makes 500Nm of torque at 1370 RPM which is diesel territory. Maybe Audi have deliberately limited the tuning potential of the standard car to avoid a remapped S4 being quicker than an RS4.

The RS4 may follow the 4.0 TFSI route and go for 2 turbos in the V or possibly a larger item with one of the fancy electric turbocharger systems to give it some oomph at the bottom end. They are going to have to make disintive step difference in performance
http://www.autoevolution.com/news/2...-panamera-29l-twin-turbo-v6-power-109651.html

http://youwheel.com/home/2016/07/05/brief-analysis-the-2017-porsche-panameras-2-9l-turbo-v6-engine/

Probably won't have to wait too long before one of the big tuning houses gets there hands on one.

 

[Chris Nelson]

I suspect the limiting factor for tunability will be the turbocharger. But as it's mounted in the V shouldn't be a massive job to whip it out and have it modded a bit. The turbo has probably been sized to give very good low down response with minimal lag It makes 500Nm of torque at 1370 RPM which is diesel territory. Maybe Audi have deliberately limited the tuning potential of the standard car to avoid a remapped S4 being quicker than an RS4.

The RS4 may follow the 4.0 TFSI route and go for 2 turbos in the V or possibly a larger item with one of the fancy electric turbocharger systems to give it some oomph at the bottom end. They are going to have to make disintive step difference in performance
http://www.autoevolution.com/news/2...-panamera-29l-twin-turbo-v6-power-109651.html

http://youwheel.com/home/2016/07/05/brief-analysis-the-2017-porsche-panameras-2-9l-turbo-v6-engine/

Probably won't have to wait too long before one of the big tuning houses gets there hands on one.

i heard it may be betting the engine from the current S7. twin turbo v8 but a v6 sounds more likely.

sent from my portable telephone box

 

[desertstorm]

Well if they fit that in with a bit of tweaking probably looking at 500bhp standard which would be a good difference over the S4.

 

[Chris Nelson]

yeah theres no point in having an rs4 at the moment from a performance point of view maybe they want to make it a big difference

sent from my portable telephone box

 

[xpoweruk]

The S4 hasnt lost much if any weight sadly.It still weighs in at 1630kg https://www.audi.co.uk/content/dam/audi/production/PDF/PriceAndSpecGuides/a4.pdf That's the same as the B8 S4

 

[Chris Nelson]

The S4 hasnt lost much if any weight sadly.It still weighs in at 1630kg https://www.audi.co.uk/content/dam/audi/production/PDF/PriceAndSpecGuides/a4.pdf That's the same as the B8 S4

would be interesting to see a race between 2 stock ones then xp see what the 20bhp does

sent from my portable telephone box

 

[Dippy]

I'd love to see some more reports to confirm, but as has been noted the RS4 and RS5 are expected to get the 2.9L twin hot-V turbo engine that is used in the new Panamera. IIRC it is tuned to about 440PS in the Porsche and for sure would be able to achieve 500PS but it will undoubtedly by an Audi marketing decision as to what it has in the RS cars.

I have been reading a lot about the 3.0L single hot-V engine used in the B9 S4 and S5. To me it is clear that Audi has paid attention to low down performance, possibly because folks will readily compare it to the 3.0L supercharged engine. So with the twin scroll turbo in the hot-V exhaust pressure lag is minimised. Apparently Audi has also increased the CR to help with off-boost torque and so has incorporated variable cam timing to introduce the miller cycle to compensate. What I don't know is how much scope the tuners will have to tune that timing to allow for more boost.

I am only guessing but I think the turbo will have been carefully sized for minimal lag and so the max flow will be limited. I suspect that there may not be as much improvement from a stage 1 as there is with the B8. On the other had the scope for stage 2 and higher tuning should be good. Easy access to the turbo means that at some point tuners will be offering a variety of upgrades, certainly up to around 600PS or higher. But of course that always comes at the cost of increased lag.

However there is always the hurdle of cracking the ECU. There is every reason to believe that the one in the B9 will be as tough to crack or even tougher than the other ECUs Audi has been using. And finally there is the matter of the new engine design. Who is going to be first to risk their warranty on a tune for an engine which has yet to prove it's own reliability?

 

[xpoweruk]

The raised compression ratio could be detrimental for tuning too.T he B8 S4 already has quite a high CR

 

[Dippy]

There's a bit more information on APR's Facebook site. They have removed the turbo and the comment is "The turbo isn't exactly massive". More reason to suspect that stage 1 (remap only) for the B9 may not be anything special, and for a serious power hike this car is going to need a bigger turbo.

 

[desertstorm]

Oh well that confirms what I thought, just looking at the specs it seemed that the turbo must be spooling very early to generate that level of torque so must be suitably small.Twin scroll helps that though. Usually always room for a compressor wheel upgrade but if the exhaust side is small this will limit the ultimate numbers. But as you say if the ECU can't be cracked easily it's all very academic.

 

[Dippy]

I believe that the combination of no exhaust manifold, twin scroll and relatively high CR is indeed going to make it have a good low end torque with minimal lag, and I expect the first member reviews to validate that. But we all know that turbo sizing is a compromise between top end power and lag and so there is every reason to believe that Audi have not oversized the turbo. It would not surprise me if this is similar to the B5 where they used two K03s to minimise lag, but that meant a limited power hike from remap only (although the exhaust was restrictive in the B5 as well). I'm only an "armchair tuner" but I agree that the exhaust ports look pretty small to me. For sure there will be enough room for tuners to fit a bigger turbo, but if those ports are indeed restrictive then head work might be needed too.

 

[Dippy]

I came a cross this German article. No idea if the numbers are correct, but if so the CR of 11.2:1 and boost of 1.3 bar suggests that the stock engine is already highly tuned.

 

[xpoweruk]

I have read similar figures to Dippy.I think tuners are going to be getting smaller gains than in the old days of turbo you ing on lower compression engines

 

[Grubb]

http://www.abt-configurator.com/en/Audi/S4/Avant/8W00/30TFSI354

 

[xpoweruk]

http://www.abt-configurator.com/en/Audi/S4/Avant/8W00/30TFSI354

http://www.abt-configurator.com/en/Audi/S4/Limousine/8K2/30TFSI333

So less HP than they claimed on the S4 B8,but more torque

S4 B8 ABT

3,0 TFSI 245 kW (333 HP), 440 Nm to approx. 320 kW (435 HP), 520 Nm ( 383.53 FtLb )

S4 B9 ABT

3,0 TFSI 260 kW (354 HP), 500 Nm to approx. 313 kW (425 HP), 550 Nm ( 405.65 FtLb )

 

[xpoweruk]

Looking at the Graphs it's a bit swings & roundabouts between the B8/B9

 

[Daggerit]

View attachment 117634 View attachment 117635

Looking at the Graphs it's a bit swings & roundabouts between the B8/B9

I agree it's pretty close but would hazard a guess there's more potential with the B9 engine as the torque graph looks very 'clipped' at the top (although I'm assuming this is as a result of the way it's graphed for this). That said, there's a noticeably larger area under the graph for the B9 versus the B8 which in my mind makes it an overall faster car with a broader range of torque even though it loses out some power top end, potentially due to the lower rpm limiter.

 

[Dippy]

I wouldn't read too much into these graphs since they are not produced directly from a dyno. However I would expect the B9 torque curve to remain 'clipped' due to the high CR. ABT's own figures suggest that the performance of their stage 1 B9 is about the same as their stage 1 B8 which would seem right. However MRC's stage 1 for the B8 gives more power than ABT's. Furthermore ABT usually use a piggyback ECU which is expensive (I haven't checked their B9 price). So in some respects if we want to compare the "tunability" of the B9 vs the B8, it has to be compared to an MRC stage 2.

 

[Daggerit]

I wouldn't read too much into these graphs since they are not produced directly from a dyno. However I would expect the B9 torque curve to remain 'clipped' due to the high CR. ABT's own figures suggest that the performance of their stage 1 B9 is about the same as their stage 1 B8 which would seem right. However MRC's stage 1 for the B8 gives more power than ABT's. Furthermore ABT usually use a piggyback ECU which is expensive (I haven't checked their B9 price). So in some respects if we want to compare the "tunability" of the B9 vs the B8, it has to be compared to an MRC stage 2.

Yeah, that's why I'd made sure that I'd clarified I assumed the reason the graphs looked like that is because they're not from a dyno.

I imagine that the clipping could be reduced on a higher octane fuel if it's down to the CR so we'll just have to wait and see.

Instead of comparing two different companies and their tuning options I guess we'll have to wait until MRC and some others come up with more options so that we can compare the same companies for B8 and B9 models. That said, the cost of the remapping for the B8 doesn't include all the DSG gearbox repairs you have to make if you drive it hard.

 

[Dippy]

If the ABT B9 kit is the same price as the B8 kit at 3600 euros then I doubt we'll ever get a member report on what its like anyway.
Yes, the DL501 has its issues, but I'm hoping the later ones are OK - I'm off to MRC myself this week. But the B9 may have its issues too. The engine is a brand new design so we have yet to discover its reliability in stock form let alone tuned!

 

[Boosted_Six]

Bit of a thread bump but hey... I drive a mildly tuned B9 s4 and found myself in a TLGP with a B8 last weekend. I was expecting to get spanked as the B8 smelt like a de-catted exhaust and would surely have a tune and pully to go with it. This wasn't the case, in fact I just squeeked past!

Until I get a chance to dyno, I would estimate my b9 to be anywhere between 400-420bhp

I assume the weight difference and torque difference of the B9 did the trick over outright bhp as I understand even a stage one B8 makes much more than that on good petrol?

Has anyone here owned both b8 & b9 have any comments? Or lined up stock for stock b8 vs b9 to determine the core performance difference?

 

[Filipão]

Bit of a thread bump but hey... I drive a mildly tuned B9 s4 and found myself in a TLGP with a B8 last weekend. I was expecting to get spanked as the B8 smelt like a de-catted exhaust and would surely have a tune and pully to go with it. This wasn't the case, in fact I just squeeked past!

Until I get a chance to dyno, I would estimate my b9 to be anywhere between 400-420bhp

I assume the weight difference and torque difference of the B9 did the trick over outright bhp as I understand even a stage one B8 makes much more than that on good petrol?

Has anyone here owned both b8 & b9 have any comments? Or lined up stock for stock b8 vs b9 to determine the core performance difference?

What is your tune? Thanks