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Hi all, I am in the process of getting my 2010 s5 cab 3.0t stage 2. I will be going with MRC for my stage 2, been recommended by every audi owner I know lol. done the prep work went with a forge intake silicone and high flow foam filter.

just a couple of questions if anybody could help me out? still learning about superchargers.


* After looking at all the dyno results coming from a turbo background, it seems to me that you really only have the full 460-480 horses for a split second. obviously the more the engine RPM is the more the supercharger is going to wind. But I am confused as to why the power does not peak for longer ? at 3000 - 4000rpm, stage 2 the dyno is showing less power than stock. the stock map seems to be more equal/horizontal.


* surely the line from a stock map would be even more horizontal but just higher BHP rather than the climb on the stage ?


*also MRC state they modify the airbox I was wondering what do they do to it ?


Remember im learning :grin2:

Regards
 

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Hi Kilbster,
I can heartley recommend the MRC stage 2 along with the DSG gearbox remap per: https://www.a5oc.com/forums/s5-performance-mods/147185-1st-mods-complete.html
The MRC airbox mod involves drilling holes in a blanking plate, see here: https://audisrs.com/jay-s-modified-2010-b8-s4-t55467-s165.html

I'm not sure you needed to do any prep work with the intake, as as part of the Stage 2 remap they replaced the intake pipe and standard filter with a cone filter. I can't recall the specifics without opening the airbox. But the replacement pipe can be seen in a picture on this post: Not a Corrado, just had my S4 B8 tweaked at MRC!!

As for the dyno graph, I'm not sure what you mean, if you look at the results form my run on the 1st linked post, it's never lower power than stock. The power (solid lines) show continual deviation from stock by a significant margin, with the torque (dotted line) well above the stock levels throughout. Sure the at 2500 rpm there is only a around 40ps difference which grows steadily to around 90ps at 5000rpm, but with the significant extra torque the rate of acceleration is significantly different. Honestly you'll be grinning from ear to ear form the moment you drive it carefully away from MRC afraid of the beast you can unleash from beneath your right foot.
Martin
 

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The airbox used in the B8 S5 is common to other models (and it may be just the V8, I'm not sure) which have an additional air intake lower down. So there is a round air-hole which is blanked off. MRC drill out this blanking, allowing additional air to enter the box.

The reason for the short peak is that the torque curve is broad (especially compared to a turbo engine) so power continues rising to the rev limit (which is around 7200 after a TCU remap). On other cars where the power tails off it is either because the torque is also tailing off or there is restriction (intake or exhaust). On such cars the result is a broad peak. Don't confuse this as being better - how can losing power at the top end be better than a car whose power keeps increasing to the rev limit?

I'm also confused by your statement "at 3000 - 4000rpm, stage 2 the dyno is showing less power than stock". Stage 2 increases the supercharger drive ratio so this should be technically impossible. Are you confusing the torque and power curves?
 

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Discussion Starter #4
Hi Kilbster,
I can heartley recommend the MRC stage 2 along with the DSG gearbox remap per: https://www.a5oc.com/forums/s5-performance-mods/147185-1st-mods-complete.html
The MRC airbox mod involves drilling holes in a blanking plate, see here: https://audisrs.com/jay-s-modified-2010-b8-s4-t55467-s165.html

I'm not sure you needed to do any prep work with the intake, as as part of the Stage 2 remap they replaced the intake pipe and standard filter with a cone filter. I can't recall the specifics without opening the airbox. But the replacement pipe can be seen in a picture on this post: Not a Corrado, just had my S4 B8 tweaked at MRC!!

As for the dyno graph, I'm not sure what you mean, if you look at the results form my run on the 1st linked post, it's never lower power than stock. The power (solid lines) show continual deviation from stock by a significant margin, with the torque (dotted line) well above the stock levels throughout. Sure the at 2500 rpm there is only a around 40ps difference which grows steadily to around 90ps at 5000rpm, but with the significant extra torque the rate of acceleration is significantly different. Honestly you'll be grinning from ear to ear form the moment you drive it carefully away from MRC afraid of the beast you can unleash from beneath your right foot.
Martin
thank for your response,, I have decided to do some work my end with the intake went with forge intake pipe, my own high flow foam filter. to save the pennies at MRC. I noticed the Hole at the bottom of the intake I though it wasd for additional air feed. I will be doing this at the weekend.

What pipe did you use for the cold air ?

And yes I have been told I will be smiling everytime my foot touches the Accelerator
 

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Discussion Starter #5
The airbox used in the B8 S5 is common to other models (and it may be just the V8, I'm not sure) which have an additional air intake lower down. So there is a round air-hole which is blanked off. MRC drill out this blanking, allowing additional air to enter the box.
thanks I will be removing my driver fog and running an additional cold air feed to the intake top maximise this.

The reason for the short peak is that the torque curve is broad (especially compared to a turbo engine) so power continues rising to the rev limit (which is around 7200 after a TCU remap). On other cars where the power tails off it is either because the torque is also tailing off or there is restriction (intake or exhaust). On such cars the result is a broad peak. Don't confuse this as being better - how can losing power at the top end be better than a car whose power keeps increasing to the rev limit?
now you explain it constant gain is better that peaking and dropping off

I'm also confused by your statement "at 3000 - 4000rpm, stage 2 the dyno is showing less power than stock". Stage 2 increases the supercharger drive ratio so this should be technically impossible. Are you confusing the torque and power curves?
Hi, yes my mates pointed it out to me and I have now realised that I am getting confused with the torque and power curves aswell as them. they got me all confused thanks for pointing that out.
 

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The intake fitted by MRC uses a 034 Motorsport one.

I recall reading on one forum or another someone having an issue with the intake collapsing a little before they switched it for a better one recommend by MRC.
 

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@Kilbster - I recently fitted a FIS-Control MMI and have been viewing various measurements whilst driving, including intake air temperature and a related reading which shows if the ECU is reducing torque due to high IAT. Even in this hot weather I have seen nothing to concern me and I just have the standard intake and airbox mods. By all means go ahead with your extra mods, but I don't think they are needed for fast road use.
@shortbloke - where did you get that clip for the fuel line which is secured to the intake hose with 2 cable ties?
 

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@Dippy Sorry I don't know about the clip this was all done by MRC as part of the stage 2 install.
When was yours done? MRC did mine in Feb 17 and they just left the fuel pipe "loose". I have since padded it to avoid it rubbing on the air pipe, but what they did for yours looks much better.
 

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@Dippy My visit to MRC was 2 May 2017. Straight from stock to Stage 2 package (Pulley, belt, intake pipe and high flow filter) + Stronic remap. If you went for the same then I'd contact Doug and see if they can send you the same clip they've used on mine ;-)
 

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Discussion Starter #13
Just and Update for you all, the car has finally been mapped by MRC, and Wow what can I say a massive Massive MASSIVE improvement. The power delivery is amazing. Managed 470ps 598nm, but out of everything I am more impressed with the gear box remap, so much smoother on normal driving, gear changes feel a lot quicker.

The Forge INTAKE was no good, MRC actually said they can believe forge are still selling them, so this was swapped out for the 034 motorsports one provided.

Me personally think there can be more power to gain from my 3.0 v6, MRC was not prepared to install the bosch double platinum spark plugs I had on hand to change due to my plugs not being changed for a good while. Doug was happy with the result from the initial dyno runs but I would of like to have new plugs and go again. Just my personal opinion, I know they know what they are talking about, but I was a little disappointed they was no prepared to install my plugs.

However nothing bad to say about them down at MRC very nice guys, had a good old chat and a laugh with everyone there, happy to talk to you and go into depth with things as I like to learn as much as I can to gain knowledge.
 

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Had the same done to my s5 hmm wondering what else i can install to make the engine bulletrproof and maybe add a little more power? Next on the list would be to install intercooler and armytrix exhaust system
 

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Is this a single or twin pulley set up? If so, what ratio?
 

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Had the same done to my s5 hmm wondering what else i can install to make the engine bulletrproof and maybe add a little more power? Next on the list would be to install intercooler and armytrix exhaust system
Bulletproof
You can't. Tuning reduces statistical reliability because components will be more stressed and operating in an environment (typically higher temperature) which increases probabilistic failure rate. Reducing heat will help but its the stress component which dominates. What you can do is ensure that any known problem components have been uprated or replaced.

add a little more power
Power increases come from torque increases which is basically down to pulley ratio. If peak power is not at the redline (mine is for example) then this may be because airflow is restricted. Tuners of this platform have generally found that the OE exhaust is not very restrictive. There may be exhausts which are slightly less restrictive, however I am aware of one case where an aftermarket exhaust was shown to reduce power, not increase it. The inlet is restrictive which is why filter & pipe should be uprated at stage 2, and possibly/probably the extra hole in the box. Other than this the next restriction is at the throttle. There are two solutions on the market (APR and IABED) but beware that this is not a simple add-on to increase power.

install intercooler
Note that improving charge cooling will only increase torque if it is already being reduced due to excessive temperatures. I have been monitoring the temps in my MRC stage 2 (fast road use) and it is clear that my OE cooling is fine. A bigger crank pulley in combination with better rad would definitely increase power, however consider that compared to stock power to stage 2, the increase is only moderate.
 

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Thank you for the info, i definitely need to upgrade to apr double pulley asap from the mrc stage 2 pulley and install an intercooler at one point, changing stock exhaust to armytrix or capristo exhaust this week which ever one is cheaper waiting for the quote they both increase hp by 12hp and 15torque my car is currently 480hp and 580torque, I'm happy with the car at the moment but sometimes it pulls sharp and quick and sometimes it doesn't kick in if you know what i mean pulley upgrade might improve performance not sure if mdc upgrade their pulleys or i need to email vrs northampton
 
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