TMU's Glacier White B8.5 S4 - MRC Stage 2

[arad85]

I know of two cars belonging to friends that have had cats fail, probably due to the extra heat generated when tuned. The last one on 90k the cat literally broke up and blocked the downpipe hence why testpipes were fitted and the car returned to MRC for a map tweak.

Good info. Thanks.

 

[xpoweruk]

Not as often as I have on US boards

 

[xpoweruk]

Fair enough.If the cats failed I'd gut them & have universal ones put further down the system TBH.
That way the cats will be cooler & more easily accessed if they failed again

 

[V6_Man]

I remember Doug mentioned that on Saturday when I asked about x-pipes.
Also, since the upgrade I have noticed the engine generations more heat than normal. I work very close to home; 3.2 miles both ways. I believe it is normal isn't it. How do I check temperature (stupid question probably )


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[Cerbera9]

You've not heard of cats failing on UK tuned cars?

There are many dual pulley set ups in the US running more boost = more heat thus killing the cats

 

[Cerbera9]

Fair enough.If the cats failed I'd gut them & have universal ones put further down the system TBH.
That way the cats will be cooler & more easily accessed if they failed again

Exactly, why spend £1500 on and exhaust that gains nothing only then to have a cat go down that means another £1000 to fix plus a map tweak. I'd spend the money on doing the cats before the exhaust tbh

 

[xpoweruk]

Exactly, why spend £1500 on and exhaust that gains nothing only then to have a cat go down that means another £1000 to fix plus a map tweak. I'd spend the money on doing the cats before the exhaust tbh

Ahh but the exhaust sounds epic

 

[xpoweruk]

If ya have android get torque pro & an OBD dongle

I use mine every day

As you can see I keep my eye on cats,IAT's,boost

 

[V6_Man]

If ya have android get torque pro & an OBD dongle

I use mine every day

So it is an Android Phone, Torque Pro and an OBD dongle . I am unfollowing you buddy


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[arad85]

Exactly, why spend £1500 on and exhaust that gains nothing only then to have a cat go down that means another £1000 to fix plus a map tweak. I'd spend the money on doing the cats before the exhaust tbh

Point me at some replacement cats that will last longer than standard specs for a B8.5 S4/S5 and I'll pre-do the cats before they go.

Also, it's going to depend on the mechanic whether they're going to have to drop the gearbox out or not.... so cost could be high.

 

[V6_Man]

Point me at some replacement cats that will last longer than standard specs for a B8.5 S4/S5 and I'll pre-do the cats before they go.

Also, it's going to depend on the mechanic whether they're going to have to drop the gearbox out or not.... so cost could be high.

MRC do cat replacement. If I recall correctly it is £1k.


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[arad85]

Will contact them and report back here...

 

[V6_Man]

I am expecting a call from Ben@MRC tomorrow re: exhausts and RS5 brake setup. I'll check as well.


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[Cerbera9]

Tbh personally I would just go with test pipes and have the map tweaked to suit that way u know they'll never fail again, plus they are easier to fit and it doesn't require removing the gearbox

 

[arad85]

Tbh personally I would just go with test pipes and have the map tweaked to suit that way u know they'll never fail again, plus they are easier to fit and it doesn't require removing the gearbox

And how am I going to pass my MOT?

 

[xpoweruk]

And how am I going to pass my MOT?

Get to know a local garage

 

[Cerbera9]

What he said

 

[arad85]

tut.... tut.... tut....

 

[Cerbera9]

Your tuning an already quick car to further improve its performance and ability to exceed the speed limits which I'm sure like the rest of us you do from time to time so your clearly not worried about that and then your worried about a once a year emissions test!? Lol

 

[arad85]

Hey... I changed from a 2l diesel to a 3l petrol simply because of VW's emissions scandal.....

Honest.

 

[arad85]

And it's not about exceeding the speed limits, it's about who gets there quickest.....

 

[Dippy]

Since I bought the car this forum has helped a lot in learning about the car. You all are legends; treasure trove of knowledge for novices like me. Dippy's S5 and XP's B8 build posts have been very helpful in learning about the platform and what it is capable of.

Well your thread has certainly become interesting.

So go get this extra power over the MRC stage2 you need about £5000 for the following
APR Ultracharger
Decat/test pipes
Upgrade Cooler
Dual pulley set up
APR remap (MRC were reluctant to custom map a dual pulley car when spoken to about it)

Obviously I don't know the details but I can't believe that the reluctance was to provide a custom map for that ratio. After all MRC's own standard and large pulleys have a DP ratio (i.e. both are greater than that provided by the single smaller supercharger 'nose' pulley). Plus MRC was happy to fit my non-MRC pulley and provide a custom map.

Ultracharger: yes.
Decat/test pipes: no.
Upgraded cooler: yes
Dual pulley setup: thought that was included in stage 2 - Dippy has both pulleys changed AFAIK
APR remap: yes, unless you can get MRC to successfully fiddle with an ultracharger

It depends what you are after though as it isn't all about horsepower. As far as I can tell, the supercharger upgrades (i.e. the airflow mods) do more for torque lower down than peak power. That's more useful in day-to-day driving.

No, I don't have DP, I just have a crank pulley, but it is not an MRC pulley. As to whether or not MRC would entertain doing a map tweak with the UC - well if you don't ask, you certainly don't get. I may or may not take this further myself - after all 475bhp makes my car ****** fast already!

I know of two cars belonging to friends that have had cats fail, probably due to the extra heat generated when tuned. The last one on 90k the cat literally broke up and blocked the downpipe hence why testpipes were fitted and the car returned to MRC for a map tweak.

That's good to know. Do you know what mileage the car had done when it was tuned? I certainly do not disagree that the extra heat from tuning will reduce the life of the cats, but if that's around 90K then certainly I could live with it.

 

[arad85]

No, I don't have DP, I just have a crank pulley, but it is not an MRC pulley. As to whether or not MRC would entertain doing a map tweak with the UC - well if you don't ask, you certainly don't get. I may or may not take this further myself - after all 475bhp makes my car ****** fast already!

Oh wow. 475hp is a great number for crank only....

 

[Cerbera9]

Oh wow. 475hp is a great number for crank only....

I too have the MRC stage 2 package & 475hp and luv it, my friend s and I together run four MRC stage 2 S4's

 

[Cerbera9]

Well your thread has certainly become interesting.
When we Spoke to MRC they just seemed reluctant, not that they wouldn't take your money and do the work. We discussed the issues with going dual pulley being increased heat due to higher boost requiring heat management/cooler upgrade and ideally decat also the smaller charger pulley is apparently prone to belt slip due to the increase in torque and the pulley's smaller surface area, thus less frictional area to hold the belt.
The car we had was tuned around 85k and the cat gave up at 90k, now I'm not saying it was related as the cat May of been nearing the end of its life anyway but the additional heat generated from tuning most certainally didn't help. Usually cats start to break up and start to pass through the exhaust system this can be seen sometimes at nighttime under load however in this case the result was extreme, unusual and catastrophic in blocking the exhaust on one bank.
I am a fan of MRC's work and bang for buck I've found their stage 2 package to be very good. I just think that it seems to go further that this then u need all of the next level mods or nothing to make it worthwhile and then for the cost involved the gains are very minimal.


Obviously I don't know the details but I can't believe that the reluctance was to provide a custom map for that ratio. After all MRC's own standard and large pulleys have a DP ratio (i.e. both are greater than that provided by the single smaller supercharger 'nose' pulley). Plus MRC was happy to fit my non-MRC pulley and provide a custom map.


No, I don't have DP, I just have a crank pulley, but it is not an MRC pulley. As to whether or not MRC would entertain doing a map tweak with the UC - well if you don't ask, you certainly don't get. I may or may not take this further myself - after all 475bhp makes my car ****** fast already!


That's good to know. Do you know what mileage the car had done when it was tuned? I certainly do not disagree that the extra heat from tuning will reduce the life of the cats, but if that's around 90K then certainly I could live with it.

 

[skiptowncat]

Well your thread has certainly become interesting.



Obviously I don't know the details but I can't believe that the reluctance was to provide a custom map for that ratio. After all MRC's own standard and large pulleys have a DP ratio (i.e. both are greater than that provided by the single smaller supercharger 'nose' pulley). Plus MRC was happy to fit my non-MRC pulley and provide a custom map.


No, I don't have DP, I just have a crank pulley, but it is not an MRC pulley. As to whether or not MRC would entertain doing a map tweak with the UC - well if you don't ask, you certainly don't get. I may or may not take this further myself - after all 475bhp makes my car ****** fast already!


That's good to know. Do you know what mileage the car had done when it was tuned? I certainly do not disagree that the extra heat from tuning will reduce the life of the cats, but if that's around 90K then certainly I could live with it.

On 98k now, had the mrc stage 2 since 70k...no cat issues here.

 

[V6_Man]

No, I don't have DP, I just have a crank pulley, but it is not an MRC pulley. As to whether or not MRC would entertain doing a map tweak with the UC - well if you don't ask, you certainly don't get. I may or may not take this further myself - after all 475bhp makes my car ****** fast already!


475 is awesome @Dippy. Which fuel do you use?




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[arad85]

OK.

Since APR UK have a pic. of my car on their Facebook page saying they are doing ultracharger work, I will come clean and say my car is the CREC-based APR development car for the rest of the World. They have been working on my car since last week with a tuner from APR head office who flew over specifically to do this. I have dyno run graphs but can't share the data from that at the moment. What I can say is the gains on this engine going from single -> dual pulley are all in the low-down torque rather than peak hp.

Today, they have fitted the ultracharger. Let's see if they can tune with it on the CREC based engine - I've been told it's a totally different tune on the newer EU engines. Based on my analysis of the data from the APR page, I'm expecting the ultracharger to kick the torque up across the whole range, but "double kick" it at the areas where improvement starts to fade on the dual pulley.

 

[Cerbera9]

Cool can you confirm the full spec/mods on this car?

 

[V6_Man]

OK.

Since APR UK have a pic. of my car on their Facebook page saying they are doing ultracharger work, I will come clean and say my car is the CREC-based APR development car for the rest of the World. They have been working on my car since last week with a tuner from APR head office who flew over specifically to do this. I have dyno run graphs but can't share the data from that at the moment. What I can say is the gains on this engine going from single -> dual pulley are all in the low-down torque rather than peak hp.

Today, they have fitted the ultracharger. Let's see if they can tune with it on the CREC based engine - I've been told it's a totally different tune on the newer EU engines. Based on my analysis of the data from the APR page, I'm expecting the ultracharger to kick the torque up across the whole range, but "double kick" it at the areas where improvement starts to fade on the dual pulley.

Awesome buddy. Believe it is the black one on their page, right?


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[arad85]

Sure, base spec in my sig. Mods (as of right now), APR stage 2+ tune, APR TCU tune, APR supercharger pulley, Carbonio intake system, APR crank pulley, APR CPR v2, ultracharger. Currently being tuned for the ultracharger.

Mods to go before I get it back: 034 transmission insert, 034 rear sway bar, AWE resonated touring exhaust.

 

[arad85]

Awesome buddy. Believe it is the black one on their page, right?

Could be... could be...

Don't want to subvert your thread and will start my own when the time is right, but thought a bit of disclosure was right given the number of posts I have made and the fact that APR have disclosed they are working on the UC in the UK (I didn't know they'd disclosed until earlier today!!).

 

[Dippy]

When we Spoke to MRC they just seemed reluctant, not that they wouldn't take your money and do the work. We discussed the issues with going dual pulley being increased heat due to higher boost requiring heat management/cooler upgrade and ideally decat also the smaller charger pulley is apparently prone to belt slip due to the increase in torque and the pulley's smaller surface area, thus less frictional area to hold the belt.

Yes, that's what I was alluding to. As you agree, MRC is a great company and they only want to do work that they can "approve" of. Good on them for that.

The car we had was tuned around 85k and the cat gave up at 90k, now I'm not saying it was related as the cat May of been nearing the end of its life anyway but the additional heat generated from tuning most certainally didn't help. Usually cats start to break up and start to pass through the exhaust system this can be seen sometimes at nighttime under load however in this case the result was extreme, unusual and catastrophic in blocking the exhaust on one bank.

Not the answer I was hoping for Whilst it is "likely" that the cat has aged, it is also "possible" that it was fine and got killed by the tune. Well @arad85 is kindly using his cats as test subjects now

I am a fan of MRC's work and bang for buck I've found their stage 2 package to be very good. I just think that it seems to go further that this then u need all of the next level mods or nothing to make it worthwhile and then for the cost involved the gains are very minimal.

I totally agree. As my wife would say "more money than sense". I call it getting the best I can if I can afford it (And I did get a big discount when I bought my car)

475 is awesome @Dippy. Which fuel do you use?

I think apart from one or two tanks of 95 at the start of ownership I have always used mostly Shell Nitro with the occasional tank of Momentum. I always assumed that the stock S5 ECU does not advance timing to take advantage of anything higher than 95 RON, but I didn't care and always paid for the best fuel. However I discussed this with Doug and he wasn't sure that it was true. I never compared performance between fuels so I can't say.

Anyway, I filled up with Momentum before getting to MRC (because there is that Tesco nearby) and told Doug that I mostly use Shell Nitro because I have to go out of my way to get to Tesco stations where I live. He said that aside from bad batches, Nitro and Momentum are much the same octane. So my car has been optimised for 99 RON and I will continue to use Nitro, but when I get the choice, Momentum instead.

Today, they have fitted the ultracharger. Let's see if they can tune with it on the CREC based engine - I've been told it's a totally different tune on the newer EU engines.

I couldn't find any info about the OEM TB, but APR has already stated that the engine probably won't run if the UC is fitted without a remap. That suggests that the motor and position sensor signals in their UC TB are sufficiently different from the OEM that ECU settings need to be changed. So undoubtedly their challenge is only to find where the setting are in the SIMOS 16 since it is different from the SIMOS 8.4/5. I would be shocked if this is anything more than a minor challenge.

 

[arad85]

Not the answer I was hoping for Whilst it is "likely" that the cat has aged, it is also "possible" that it was fine and got killed by the tune. Well @arad85 is kindly using his cats as test subjects now

Yes I am. How very kind of me!

I messaged MRC earlier and they do do replacement cats based on metal 200 cell cats that are MOT friendly. If you need them, they're gonna cost upwards of £1500 fully fitted (including 6 hours labour). The price I was quoted was higher than that, but that's the order of price - depending what sort of discount you can haggle - if any.

 

[GarethS4]

Why are the cats so dear to get replaced on the s4

 

[arad85]

I have no idea, but those are not Audi parts, so don't know how widely available they are and whether there is some custom pipework needed. Will do some research locally to see what's available.

 

[xpoweruk]

labour wise it's because they are so awkward to get at

 

[xpoweruk]

The US guys have started testing these https://www.aliexpress.com/item/Mer...567255.html?shortkey=uimieAfY&addresstype=600

 

[arad85]

Bumf says bolts direct to LHD engine. I reckon they haven't tried a RHD one... Guess that's one way to get rid of the cats....

 

[arad85]

Over £1000 of that >£1500 was for the cats... They quoted 6 hours labour, which given the placement I thought fair enough.