RS6 motor limits?

[jibberjive]

I know the limiting factor is usually the tip tranny, or the available turbo upgrades mostly being hybrids, but has anyone found the limits of the stock engine power/torque-wise? Have you guys heard of any engine failures, and if so, under what circumstances? What's the highest powered RS6's you've heard of? I'm new to this forum, but not new to Audi's, and I'm looking to do some learnin on about the 4.2tt (we've got one in our family).

[ttboost]

I hope to find out...

[amanda]

mine has 950 nm torque ;)

[alrightroad]

Amanda, how in the world is your trans and TC holding up? You guys must be flushing your triptronics with gently warmed tea and we American gentlemen flush our transmissions with burning hot drip coffee?

[amanda]

Amanda, how in the world is your trans and TC holding up? You guys must be flushing your triptronics with gently warmed tea and we American gentlemen flush our transmissions with burning hot drip coffee?


Dont ask me, my tc is an ACE one and thats fine but the box is hersheys

[ttboost]

Ahhh you already HAVE an Ace TC..didn't even get that...Sheesh...

[Spidercat]

I know the limiting factor is usually the tip tranny, or the available turbo upgrades mostly being hybrids, but has anyone found the limits of the stock engine power/torque-wise? Have you guys heard of any engine failures, and if so, under what circumstances? What's the highest powered RS6's you've heard of? I'm new to this forum, but not new to Audi's, and I'm looking to do some learnin on about the 4.2tt (we've got one in our family).


If you mean motor only, the Gumpert Apollo uses a modified version of the RS6's 4.2 TT. They have 3 power levels, and make up to 789 bhp.
This would obviously kill a stock RS6 transmission, however. Cooling would present some issues as well in an RS6, I would imagine.

[JSRS6]

If you mean motor only, the Gumpert Apollo uses a modified version of the RS6's 4.2 TT. They have 3 power levels, and make up to 789 bhp.

Ive been wondering if Gumpert sells anything for this. Likely prohibitively expensive, but would be nice to know.

[amanda]

Ahhh you already HAVE an Ace TC..didn't even get that...Sheesh...

yes and its all good tc wise

[bmwade]

mine has 950 nm torque ;)

What is the HP? And what mods?

[marklar182]

Trans, cooling, stock exhaust manifolds are the limiting factors IMO.

[amanda]

What is the HP? And what mods?

This is from when I first joined but the car isn't the same as its been a works in progress since ;)

http://www.rs6.com/showthread.php/22456-Newbie-(with-a-BIG-engine)?highlight=1st+loba+c5+rs6+amanda

[jibberjive]

Oh yeah, I forgot about the Gumpert Apollo. Anyone have any good links bookmarked that detail the differences (if any) on the engine internals for it?

Do you guys think there is a market for a nice complete big turbo kit (550+whp) without the huge European prices, or do you think most people who would be interested have already bought their turbo setups? I'm talking like a complete kit, from fueling to tuning to turbos/exhaust manifolds.

[bmwade]

Oh yeah, I forgot about the Gumpert Apollo. Anyone have any good links bookmarked that detail the differences (if any) on the engine internals for it?

Do you guys think there is a market for a nice complete big turbo kit (550+whp) without the huge European prices, or do you think most people who would be interested have already bought their turbo setups? I'm talking like a complete kit, from fueling to tuning to turbos/exhaust manifolds.

There are always new buyers. Like me, bought in July. and when my TC finally gives way I will probably rebuild the box and upgrade the turbos. I suspect that in 10 years you will be able to count the number of C5's that are bone stock on one hand, at least in the US.

[milka]

I will be able to let you know very soon, as I'm about to turn the boost up on my car now that I have 1000cc injectors fitted!!!

I also have 0A3 manual conversion, twin GTX3071 turbos, twin Tial external gates, upgraded intercoolers, surge tank with twin pumps, etc, etc, etc

On low boost (12.5psi) she did 380awkw on an Australian Mainline dyno where APR chipped cars with exhaust normally get 270-280 awkw.

Oh, I have a build engine ready to go incase I do anything really bad to this one too...

[marklar182]

Oh yeah, I forgot about the Gumpert Apollo. Anyone have any good links bookmarked that detail the differences (if any) on the engine internals for it?

From what I have found;

Gumpert- Dry Sump oil system, Different exhaust manis/Turbos, Bigger Injectors, 4163cc displacement, 9.2:1 Compression
RS6- 4172cc displacement, 9.8:1 Compression

Bore and stroke are the same.

Either Gumpert uses a different piston, or more likely a thicker head gasket/spacer.

[jibberjive]

I will be able to let you know very soon, as I'm about to turn the boost up on my car now that I have 1000cc injectors fitted!!!

I also have 0A3 manual conversion, twin GTX3071 turbos, twin Tial external gates, upgraded intercoolers, surge tank with twin pumps, etc, etc, etc

On low boost (12.5psi) she did 380awkw on an Australian Mainline dyno where APR chipped cars with exhaust normally get 270-280 awkw.

Oh, I have a build engine ready to go incase I do anything really bad to this one too...

Yeah, I've been following your build on Nefmoto, nice job! I may be joining you shortly with figuring out the last few things in the ECU for the manual swap.


From what I have found;

Gumpert- Dry Sump oil system, Different exhaust manis/Turbos, Bigger Injectors, 4163cc displacement, 9.2:1 Compression
RS6- 4172cc displacement, 9.8:1 Compression

Bore and stroke are the same.

Either Gumpert uses a different piston, or more likely a thicker head gasket/spacer.
Thanks. I'm curious if the pistons/connecting rods are the same, as it's usually one of those two that are the weakest link in the engine chain. If the stock internals can handle the power of the max power Gumpert, then that is very promising! Something that makes me think the pistons might be different though is the fact that the displacement is slightly different.

[SteveKen]

HT Motorsports is slowly creeping up to over 800 HP on this project. It is an RS6 block and heads, but I'm not sure what more is left of it.

http://www.youtube.com/watch?v=zOgeLYF5HdE&feature=player_embedded

[ttboost]

I don't feel so bad now...monster IC...monster headers...who knows what else...Been looking at my engine sitting on my table in my garage...was hoping to do something turbo-wise...pretty deflating how much room we have...

[milka]

SteveKen, have you had any luck with the ABS/ESP side of things? I have a new ABS controller that I am hoping to have coded to manual very soon (as soon as I have it in my hands actually). The ECU is already set to manual and is showing it's a manual via CAN bus. But I can't recode the ABS module as I don't think it's possible with the RS6 unit.

Oops sorry don't mean to thread jack.

To get back on topic, my built motor has Mahle forged pistons (8.8:1 comp), Pauter rods, head work, etc.

[jibberjive]

HT Motorsports is slowly creeping up to over 800 HP on this project. It is an RS6 block and heads, but I'm not sure what more is left of it.

http://www.youtube.com/watch?v=zOgeLYF5HdE&feature=player_embedded

Judging from their other videos, I'm inclined to say that that is an RS4 motor (unless you've got some more details other than just the video). Any idea which EFR turbos they have on there? 800fwhp (~625awhp) is impressive no doubt, but I've got to say that, without the restraints of cooling, header limitations, intake on turbo etc, I'm surprised there isn't a little more power on a race gas blend and 31psi (depending on what turbos they are of course). Crazy motor nonetheless.


SteveKen, have you had any luck with the ABS/ESP side of things? I have a new ABS controller that I am hoping to have coded to manual very soon (as soon as I have it in my hands actually). The ECU is already set to manual and is showing it's a manual via CAN bus. But I can't recode the ABS module as I don't think it's possible with the RS6 unit.

Oops sorry don't mean to thread jack.

To get back on topic, my built motor has Mahle forged pistons (8.8:1 comp), Pauter rods, head work, etc.

No need to worry about the thread jack, keep us apprised on any developments on the ABS/ESP front.

As for your motor build, any details on how you went about building the Alusil motor (piston alloy, piston-wall clearances ran, what rings/shape, special processes to treat the cylinder,etc)? If that's something you want to keep proprietary or simply not talk about, that's perfectly fine, just thought I'd ask because I'm curious. Were the pistons special order?

[scottmandu]

HT Motorsports is slowly creeping up to over 800 HP on this project. It is an RS6 block and heads, but I'm not sure what more is left of it.

http://www.youtube.com/watch?v=zOgeLYF5HdE&feature=player_embedded

That engine is fully built rods/valves/pistons.

[milka]

Interesting, numbers seem quite low for 30psi, race gas blend, unless of course the turbos are not that big. With GT30 turbos and that much boost I would be expecting >1000HP at the crank. Is this being developed to be put into a car? Not many cars I can think of that will take that IC.

[ttboost]

Yeah..looks more like an expensive fact finding mission to me...

[milka]

As for your motor build, any details on how you went about building the Alusil motor (piston alloy, piston-wall clearances ran, what rings/shape, special processes to treat the cylinder,etc)? If that's something you want to keep proprietary or simply not talk about, that's perfectly fine, just thought I'd ask because I'm curious. Were the pistons special order?

I got really lucky with the spare engine I picked up it only had 2500km on it. When we stripped it and took it to my engine builder he said it was not even run in yet so we did not do anything with the bores. The pistons are custom order from Mahle with Alusil specific rings as the ring material is different to normal rings. The pistons themselves are same spec as stock execpt forged and 8.8:1 comp. I was prepared to get the cylinders honed as per Alusil requirements (my engine builder has done quite a few porsche Alusil engines before). I do have another spare block which I may actually look at putting in Darton Sleeves depending on how this engine goes. In all honesty I don't think it will be needed as with these turbos I will be surprised if I will be able to use anything above 25psi. Plans are 18-20psi for the stock engine and then 25-28 psi for the built engine starting with 98 (which is US 93oct) and then going to E85 if I feel like it. I'm happy to share anything about my build, I just wish others had the same thinking....

[ttboost]

What are you using for turbos?

[milka]

What are you using for turbos?


2 * GTX3071 Turbos, .82 Twin Scroll Housings
2 * Tial MVs gates
1000cc EV14 injectors (850cc 3 bar running at 4 bar)
twin Pierburg Pumps with surge tank
Twin B5 S4 MAFs (probably going twin R32 MAFs soon)

My full build thread is http://www.ozaudi.com/forums/showthread.php?t=20790&page=6 ther are too many pics to put it up on rs6.com as well. Sorry you may need to register to see the pics. If you want to see any in particular let me know and I will post.

I will post my initial dyno graph which was ~380awkw on 12.5psi on the auto tune with just some lemmiwinks settings, that was before the injectors and pumps were installed and I was maxing everything out, injectors, pumps, MAFs. That was also running way too rich but at the time I did not have enough control with just lemmiwinks, now thanks to Nefmoto I am tuning it properly. Initial Dyno graph below:

13223

[ttboost]

Thank you for the info. I guess I'll have to join later to see pics. Can we assume that you fabricated new headers for the 3071's, with waste gate ports?

[milka]

Thank you for the info. I guess I'll have to join later to see pics. Can we assume that you fabricated new headers for the 3071's, with waste gate ports?

Yep a lot of fabrication work, I think I pulled and installed the engine/gearbox over a dozen times to check fitment and clearances. If you do join up there are a lot of pics of all the fabrication work. Here is a little view of the fabircation work.

13226
13227

[ttboost]

I DID join and DID look at all the pics. Took me a while to realize that everything is backwards and upside down!!!
Fantastic build and exactly what I always wanted to do...

[jibberjive]

Milka, is it safe to say that those big turbos wouldn't have fit in any way with the big RS6 tiptronic tranny in there?

[ttboost]

I don't see how and definitely not with stock manifolds...

Stock turbo

13240

[jibberjive]

I don't see how and definitely not with stock manifolds...

Stock turbo

13240

Yeah, definitely not talking about with stock manifolds.

[milka]

Milka, is it safe to say that those big turbos wouldn't have fit in any way with the big RS6 tiptronic tranny in there?

No chance of fitting them with the Auto in there. The manual is so much smaller and even then there is no real additional space in there most clearances are max 10mm a few are smaller. It really is a very tight fit, especially if you put external gates in there, these ones are also the Tial MVS watercooled, which means more plumbing in a place where there is not enough room to begin with....

If anyone were to try this or if I was to try it again, I would highly recommend to forget about twin scroll just because of the extra space required for the dual runners.

[milka]

Here is a quick pic of one of the manifolds without the ceramic coating and titanium heat wrap
13242

[RS8]

Does anyone know how much power the original pistons and connecting rods can handle?

Because I have an Broken RS6 engine (one piston and conrod is totally damaged) with only MTM ecu and bigger turbos= 861Nm/3946rpm

[ttboost]

IMO, that engine didn't blow up because of too much power. 861nm is only 635ft/lbs. Myself and many others are making way over that now on stock turbos and transmission with just a flash...I plan on going further after my 6 speed conversion. I would think a purpose built Cosworth V8 turbo engine can make up to, if not more than 1000hp, with proper fueling and tuning of course...

[blmlozz]

I would find that scenario(1000hp on stock internals) unlikely to say the least.

there are so few of these cars it's a complete guess, but this is not a purpose built cossworth engine , it's a plain 4.2L worked by their magic hands. It not some racebred F1 ready thing.

The only facutal evidence I've seen to this topic would be related engines from this era having a decent amount of breathing room built-in. The APB TTV6 and 1.8T generally start to shoot rods through the block at ~ double the stock Hp. I would assume the same would hold true for the 4.2TT, but we're talking about 720 HP at the wheels at that point, and I would pause at the thought of running that much power through a 10 year old fatigued engine that also happens to cost north of $20K.

Rods and pistons, even for this engine, are obtainable and not crazy expensive.

[RS8]

The RS6 Rods are identical to the rods in an old A8 32valve 300hp engine !?

13243
Or do you see any difference between them in this picture?

[blmlozz]

There's clearly a difference in the pistons, and it would *appear* that there's a very minor difference in the rods, but that could be the angle.

The other 'difference' that's both invisible and is incredibly important is what metal they're made from.

[RS8]

Here is the broken RS6 rod:

[RS8]

Is it only Pauter that makes new rods for RS6 or where can i buy cheap forged rods and Pistons for RS6 ?

[blmlozz]

Is it only Pauter that makes new rods for RS6 or where can i buy cheap forged rods and Pistons for RS6 ?
I'm unsure of your definition of 'cheap' but,
Give 034motorsports a call. They're based in Cali if international transactions matter to you.

[milka]

Why bother with cheap components in an engine like this? Get a set of Pauter rods and if you want to Mahle forged pistons, you get what you pay for!

Also I don't think that with 861nm you have reached the max of what the engine can handle. I'm pushing way above that and touch wood no issues so far. Who is tuning your car? What injectors/MAF/fuel pumps are you running?

[RS8]

My rod was fine for about 7000km with 861nm before it was damaged.
044 fuelpump, rs6 injectors, rs6 MAF, 98okt Europe fuel, upgraded K04 turbos and MTM ecu made for it from Dahlback Racing .
Castrol EDGE 0w-30 FST oil
------------

In a 5cyl engine you can have over 1000hp with cheap forged rods. 1000hp/5cyl=200hp 200x8=1600hp

This is what 034 have:

http://www.034motorsport.com/engine-components-audi-v8-audi-v8-3642-forged-rod-set-p-546.html

http://www.034motorsport.com/engine-components-audi-v8-piston-set-je-forged-42l-32v-v8-p-22416.html

But maybe I just had bad luck? and don't need other rods and pistons,
Or can it be the stock RS6 downpipe and exhaust system because I had a back pressure measured in the downpipes= after turbo that was half ! of the turbo boost? So before turbo it have been even higher, Or will I only lose hp with that and not damage the engine?
(but I will build 3" downpipes now)

[RS8]

Is it true that you can't get more than 550 engine hp with the RS6 exhaust manifolds?

or is it 550hp on the wheels they talk about?

I saw that Amanda got 550hp and 950nm with this:
Loba cams/gaskets
Loba turbo's 650's
Head skim
Wagners
Uprated fuel pump and reg
Silicone hose kit
Rebuilt gearbox
A Viper custom remap

[4everRS]

The RS6 Rods are identical to the rods in an old A8 32valve 300hp engine !?

13243
Or do you see any difference between them in this picture?
RS8, could you please post a pic of the side of the rods, rather than the face of them? No way to tell a difference from that pic. I want to see the casting lines on the side.

[RS8]

Here you have some pictures.

Audi A8 from 1995 !! and RS6 2003

[na1mt]

They look different to me.

[RS8]

And what is different except the colour?

There will also be a little difference at each cast, so the small difference you see may not be because of it is stronger or better.

[milka]

My rod was fine for about 7000km with 861nm before it was damaged.044 fuelpump, rs6 injectors, rs6 MAF, 98okt Europe fuel, upgraded K04 turbos and MTM ecu made for it from Dahlback Racing .Castrol EDGE 0w-30 FST oil------------If you have upgraded turbos and fuel pump but you are still running stock injectors I would be very worried. Did you do logs of the injector duty cycle especially high in the rev range? When I was just running 12.5 psi on the wastegate springs I was over 100% duty cycle above 6000rpm and the AFR would lean off. That was only on 12.5 psi, ok my turbos are bigger but if your tune is asking for more than 15 psi from your upgraded turbos I would say you would be leaning out higher in the revs. If you have some logs I would love to see them

[RS8]

It is RS6 numbers on them but I don't know if it has been modified anything. Perhaps they have modified the pressure regulator for higher fuel pressure.

Because there were no marks of detonation so it has not been reached problems with too little fuel.
Turbo pressure was about 18-19psi !
I didn't log injector duty cycle.

How big injectors can I have with the RS6 MAF ?

[milka]

You can have as big injectors as you want, i'm currently running 1000cc@4bar and linearizing them before I change back to R32 MAFs and then tune them in. One step at a time.

If you are talking 18-19 psi to redline there is no way stock injectors will handle it even at 5 bar boost pressure. By my calculations at 5bar the injectors are 456cc and pushing them at 100% (which you shouldn't do) theoretical max BHP about 600 with a 5 bar fuel pressure. Get yourself a couple of wideband sensors and learn to use ME7logger, logging is your best friend!

Can I ask who wrote your custom tune for your setup (mainly upgraded turbos nothing else, what spec?) Or are you running a std MTM RS6 tune?

[RS8]

Here is a pull on 12psi at 4000rpm

<tbody>









RPM
LM
Throttle
ignition
exhaust
exhaust
Turbo


/min
g/s
%
°BTDC
°C
°C
mbar


1200
16.14
12-05-05
24-08-01
415.0
410.0
1020.0


1200
36.72
12-12-02
24-08-01
415.0
410.0
1020.0


1240
47.28
22-07-01
19-05-01
415.0
410.0
1020.0


1280
45.69
72-09-01
15.0
415.0
410.0
1020.0


1360
46.75
95-07-01
15.0
415.0
410.0
1030.0


1440
53.39
99-06-01
15-08-01
415.0
410.0
1040.0


1480
56.47
100.0
16-05-01
415.0
410.0
1060.0


1560
59-06-01
100.0
18.0
420.0
415.0
1080.0


1640
64.72
100.0
18.0
420.0
415.0
1100.0


1720
68.67
100.0
18.0
420.0
415.0
1120.0


1800
73.58
100.0
18-08-01
425.0
420.0
1130.0


1880
81.92
100.0
18.0
430.0
420.0
1160.0


2000
85-03-01
100.0
18-08-01
430.0
425.0
1180.0


2080
90.72
100.0
18-08-01
435.0
430.0
1200.0


2160
97.25
100.0
18.0
440.0
435.0
1230.0


2240
102.36
100.0
18-08-01
445.0
440.0
1260.0


2360
113.47
100.0
18.0
450.0
440.0
1280.0


2440
124.94
100.0
18-08-01
455.0
445.0
1330.0


2560
128.78
100.0
19-05-01
460.0
450.0
1360.0


2680
144.56
100.0
20-03-01
470.0
460.0
1410.0


2800
165.25
100.0
21.0
475.0
465.0
1470.0


2920
173.75
100.0
18-08-01
480.0
470.0
1550.0


3040
192.22
100.0
20-03-01
490.0
475.0
1610.0


3200
214.25
100.0
16-05-01
500.0
485.0
1700.0


3360
226.56
100.0
19-05-01
500.0
490.0
1800.0


3520
243.36
100.0
16-05-01
510.0
495.0
1840.0


3680
255.78
100.0
19-05-01
520.0
505.0
1850.0


3880
30-10-30
100.0
17-03-01
530.0
515.0
1850.0


4000
274.92
100.0
16-05-01
540.0
525.0
1840.0


4160
292.36
100.0
12.0
555.0
535.0
1860.0


4320
305.47
100.0
15-08-01
565.0
550.0
1860.0


4440
311.31
100.0
12-12-08
570.0
555.0
1860.0


4600
318.42
100.0
14-03-01
585.0
570.0
1830.0


4720
330.69
99-06-01
15-08-01
595.0
585.0
1820.0


4880
337.28
99-06-01
13-05-01
610.0
600.0
1790.0


5040
343.31
100.0
12-11-03
630.0
610.0
1780.0


5160
347.39
100.0
17-03-01
635.0
620.0
1750.0


5280
359.86
100.0
15.0
650.0
635.0
1740.0


5400
363.17
100.0
16-05-01
660.0
650.0
1710.0


5520
355.86
100.0
15.0
675.0
655.0
1690.0


5640
39-10-29
100.0
12-12-08
685.0
670.0
1680.0


5760
35-05-29
100.0
17-03-01
690.0
680.0
1660.0


5880
35-05-29
100.0
14-03-01
705.0
690.0
1650.0


5960
35-05-29
100.0
18-08-01
710.0
695.0
1660.0


6080
35-05-29
100.0
21.0
720.0
710.0
1640.0


6160
35-05-29
100.0
21.0
730.0
715.0
1630.0


6280
35-05-29
99-06-01
21-08-01
735.0
725.0
1610.0


6400
35-05-29
100.0
18.0
740.0
730.0
1640.0


6440
35-05-29
100.0
21-08-01
750.0
740.0
1630.0


6560
35-05-29
100.0
23-03-01
755.0
745.0
1610.0


6640
35-05-29
100.0
22-05-01
765.0
755.0
1630.0


6720
35-05-29
100.0
20-03-01
770.0
760.0
1620.0


6800
35-05-29
100.0
24-08-01
775.0
765.0
1620.0


6880
35-05-29
100.0
21-08-01
785.0
775.0
1630.0


6960
35-05-29
100.0
27.0
785.0
775.0
1640.0










</tbody>


Paper showing engine power: 454hp and 770nm

[RS8]

You can have as big injectors as you want, i'm currently running 1000cc@4bar and linearizing them before I change back to R32 MAFs and then tune them in. One step at a time.

If you are talking 18-19 psi to redline there is no way stock injectors will handle it even at 5 bar boost pressure. By my calculations at 5bar the injectors are 456cc and pushing them at 100% (which you shouldn't do) theoretical max BHP about 600 with a 5 bar fuel pressure. Get yourself a couple of wideband sensors and learn to use ME7logger, logging is your best friend!

Can I ask who wrote your custom tune for your setup (mainly upgraded turbos nothing else, what spec?) Or are you running a std MTM RS6 tune?

Dahlback racing has mounted 6speed manual gearbox and bigger turbos and 044 fuel pump, but MTM has done the ECU for the manual gearbox and for the bigger turbos.
But it have stock RS6 downpipes and exhaust system.

[RS8]

But are you using the RS6 MAF with 1000cc injectors? and if it works why do you change to S4 or R32 MAF ?

[RS8]

This 2 measurements is with another engine (not the one with broken conrod) and this is with stock RS6 injectors and stock RS6 fuel pressure regulator because I thought it was stock parts in the old engine that dahlback racing had built,
unfortunately I melted a piston during the measurement after 4300rpm, But it is strange that only one piston is bad, you can't se any detonation on the other ones? So I think there was something like dirt? with that cylinders injector that caused the melted piston.
Or maybe the knock sensors saved the other pistons? because something happend at 3880rpm = look at the ignition table.

This is with 21 psi !! but I only got 862nm at 3946rpm, but that is with only 9° BTDC and a piston thats begin to melt down..

So now I buliding engine number 3 and that one will have Big injectors and bigger exhaust system with modified exhaust manifolds.

13293



<tbody>
RPM
LM
Throttle
ignition
exhaust
exhaust
Turbo


/min
g/s
%
°BTDC
°C
°C
mbar


840
10.75
12-03-05
23-03-01
415.0
415.0
1020.0


840
24.50
12-09-04
12.0
415.0
410.0
1020.0


1000
30.42
97-06-01
9.0
415.0
410.0
1030.0


1120
39.69
99-06-01
15.0
415.0
410.0
1060.0


1280
45.78
100.0
15-08-01
415.0
415.0
1080.0


1480
51.92
100.0
17-03-01
420.0
420.0
1100.0


1640
63.61
100.0
17-03-01
425.0
425.0
1130.0


1800
70.67
100.0
20-03-01
435.0
430.0
1170.0


2000
88.72
100.0
19-05-01
445.0
440.0
1220.0


2200
99.97
100.0
17-03-01
455.0
445.0
1290.0


2440
117.92
100.0
18.0
465.0
460.0
1390.0


2720
146.75
100.0
18-08-01
480.0
470.0
1570.0


3000
181.94
100.0
20-03-01
500.0
490.0
1790.0


3400
248.64
100.0
14-03-01
520.0
510.0
2070.0


3880
326.72
100.0
9.0
540.0
525.0
2390.0


4560
35-05-29
100.0
9.0
570.0
560.0
2500.0


4680
35-05-29
100.0
12-03-08
605.0
590.0
2500.0


5040
35-05-29
100.0
6.0
640.0
625.0
2420.0


5360
35-05-29
100.0
12-04-05
680.0
670.0
2400.0


5640
35-05-29
100.0
6.0
730.0
715.0
2370.0


5880
35-05-29
100.0
12-08-03
770.0
755.0
2400.0


6040
35-05-29
100.0
9.0
810.0
795.0
2400.0


6200
35-05-29
100.0
9.0
840.0
815.0
2440.0


6320
35-05-29
100.0
9.0
875.0
840.0
2420.0


6400
35-05-29
100.0
12-08-03
905.0
855.0
2470.0


6480
35-05-29
100.0
12-08-03
930.0
870.0
2490.0


6560
35-05-29
99-06-01
12-08-03
950.0
880.0
2490.0


6600
35-05-29
100.0
12-08-03
965.0
895.0
2490.0


6600
35-05-29
100.0
12-09-08
975.0
915.0
2480.0


6600
35-05-29
100.0
9.0
990.0
925.0
2290.0


5320
20.58
12-07-08
0.0
1000.0
935.0
1340.0


3360
20-06-01
12-07-08
-2.3
1000.0
935.0
1140.0


1720
17.42
12-05-05
-8.3
995.0
930.0
1080.0


0
3.72
12-02-07
24.0
1005.0
945.0
1050.0


0
3.72
12-02-07
24.0
1055.0
995.0
1040.0


0
3.72
12-02-07
24.0
1110.0
1055.0
1030.0


0
3.72
12-02-07
24.0
1110.0
1105.0
1020.0


0
3.72
12-03-01
24.0
1110.0
1110.0
1020.0


0
3.72
12-07-05
24.0
1110.0
1110.0
1020.0

</tbody>

[RS8]

I bought this car with damaged engine= broken conrod from another guy that had paid Dahlback racing for all modifications.
But that guy had been driving the car for a long time on 20psi !!
So I only bought an Rs6 engine from a scrapyard and put on the bigger turbos from the old engine but I didn't put on the injectors and pressure regulator because it had the same numbers on them so I thought it was the same.. but I think now that it wasn't after this 2 dyno runs that results in a melted piston.

[milka]

Well all this is very interesting but based on what you showed I can come to the following conclusions:

That first pull at 12psi @ 4000 then tapers to ~7.5 psi at redline, that is very weak probably only a touch over stock power.

That second log, who ever did that tune for you should be shot! Sorry but if you are running stock injectors and boosting to 2.5bar absolute then ofcourse something is going to go pop! Also it says 2.5bar but actually you have hit the max resolution for the boost pressure sensor so it could be way above that and you would never know. Do yourself a favour and do 2 things before you blow your next engine up. put a manual boost controller or EBC in there to cap the boost at 1 bar (~2000 absolute) then get ME7logger working. It will let you monitor over 60 metrics 12 times a second, then you can monitor IDC, knock correction, boost req, boost actual, MAF voltages, etc etc. If you need a hand with that let me know this is crazy what you are doing, I bet your actual boost is way too high. Are you still runing the n75? Seriously pull the boost down and log everything then slowly start to ramp boost up. If you are running a chip made for normal turbos with larger turbos with stronger wastegates these are the issues you will see.

Sorry I don't want to be negative but I don't want you to blow your next engine up either. If you do the same thing with a built engine it will still go pop, maybe a run or 2 later but it will.

[milka]

The reason I'm going to bigger MAFs is that I'm starting to max these out at about 17psi flat to redline (don't forget I have bigger turbos so more air). highest MAF readings I have seen are over 520 g/s on RS6 MAFs but at this point they are too high and if the MAFs give the wrong reading then the injectors give the wrong amount of fuel. Oh and get a set of widebands on there otherwise you are just running blind.

[milka]

To give you an idea what ME7logger will give you here are 3 screen shots of excel, scrolling across the screen at the end of a 3rd gear run with ~1.2bar boost (i.e. ~2200 absolute), there is so much data on each line you can see exactly what the engine is doing, even the internal RAM variables are being logged.
132961329513294

[milka]

I bought this car with damaged engine= broken conrod from another guy that had paid Dahlback racing for all modifications.
But that guy had been driving the car for a long time on 20psi !!


So you bought a car with a busted engine, bought another engine but did not change the tune and expected a different result? Get someone that knows what they are doing to do a proper tune for you, please. RS6 engines are quite strong but event the strongest engine will blow up with bad tuning that has too much boost for the MAFs and injectors.

[RS8]

The first pull is with the n75 disconnected, so only the wastegates are holding the pressure and they are on 16psi !! but I think the backpressure is to high for the wastegate spring.

No not to get a different result.
This 2 dyno and loggs was only to measure the power on the car beacuse the previous owner didn't now it !!
The old MTM tune had been done on the streets and not on a dyno..

so it was no one that was tuning the engine now because I was using the old MTM tuning that had worked for a long time for the owner before me and I had not changed anything so I only wanted to se the power before I start to change exhaust system and do other modifications.

And if you look at the dyno runs you can se the boost pressure and that is measured from a vacuum tube on the engine and not from the OBD and it shows only 20psi=1.4bar = 2.4 absolute

So I was never over 2.5bar absolute


And I have had mounted 1 wide band lambda but unfortunately I couldn't look on it now during this 2 dyno runs.

[milka]

20 psi, is too much boost. I will only say it once more then you can blow your next engine up and I won't try to stop you.

Turn the boost down, log everything AFR, IDC, MAF, Indv Cyl Retard, Misfires, boost, EGT at the same time before turning up the boost. Then turn it up slowly, and keep monitoring.

Don't trust what someone else tells you about a car, check everything yourself and log everything to make sure there is nothing wrong with it. There are other people here that are running over 900nm and don't have any problems because their tune is safe.

I don't want you to blow another engine, I'm trying to help you, if you want my help with any of this just let me know, I'm not here to argue a mute point.

[RS8]

I'm logging with Ross-tech Vag-Com but I can't see so much values at the same time? what is you using to log with?

I was going to only use 12psi because the broken conrod.. but I wanted to know now on 1 pull how much power the engine was giving on 1.5bar because the previous owner thought he had over 700hp but I thought maybe 600hp..

[milka]

That's what I have been telling you use ME7logger, you can get it here:

http://nefariousmotorsports.com/forum/index.php?PHPSESSID=f9p0umlsri7mognk8kfq8e7b36&topic=837.0title=

Well now you know that 1.5 is too much, start with 12 psi, then do 15psi, then 18 psi etc. And log everything to make sure nothing is reaching it's limit. i.e. MAFs, injectors, fuel pumps, turbos, etc etc

If you have problems getting me7logger to work let me know, it is an awsome tool, my car would not be at it's current point without it.

Oh, and just use your Ross-tech cable

[Kgnast]

There are always new buyers. Like me, bought in July. and when my TC finally gives way I will probably rebuild the box and upgrade the turbos. I suspect that in 10 years you will be able to count the number of C5's that are bone stock on one hand, at least in the US.


LOL, Bone stock, but then again, it just arrived. It wont stay this way for long...... god willing and the auto-customization market and real estate markets come along nicely, we'll get some nice goodies for the new pup....

[jibberjive]

Since I'm used to seeing dyno plots in ft-lb, it threw me off for a second when the hp and tq didn't cross each other on that plot.

That sucks to hear about your motor, and it's a shame that you weren't able to catch it in time by looking at your EGT's or wideband.

As for ME7Logger, I've done a small writeup that should get you started pretty quickly. I copied it in this forum, because I doubt you RS6 guys randomly peruse the B5 S4 section on Audizine ha:

http://www.rs6.com/showthread.php/25190-****-Guide-on-How-to-Take-and-Graph-Logs-****

[jibberjive]

And I agree with Milka, run an MBC in parallel with the N75 to cap it fairly low, until you're able to get some bigger injectors and a custom tune for them.

And call me crazy, I thought the Dahlback crazy upgrade for RS6's was GT30's, not KKK turbos?

[RS8]

About this boost controllers, What is MBC or EBC ? price?

The bigger KKK turbos did the owner bought himself and gave them to DBR so they could mount them.

Does anyone know if OBD2 splitter cable will work fine with ME7logger ?
http://www.ebay.com/sch/i.html?_trksid=p4634.m570.l1313&_nkw=obd2+splitter&_sacat=0&_from=R40
Because then i can ME7 log with my computer with one cable and also let the the dyno machine have some info like rpm from the other cable..

[jibberjive]

MBC stands for manual boost controller, and EBC stands for electronic boost controller. Hallman makes a good MBC that works with our cars. EBC's are more expensive (and more featured), but since you're just using the boost controller to cap the boost by running it in parallel with the N75 (just as a stop-gap until you can get your hardware/tune sorted), you wouldn't make use of the features of the EBC. So I'd say just go with the cheapest Hallman MBC you can find. I'll find you a diagram of how to wire it in with your N75 a little later.