Turbos - options.

[welwynnick]

RS Engineers use billet input shafts from Australia to reinforce the transmissions. Proven at 1400 Nm+

Thanks.

Is that what you use?

How do you achieve 1320Nm? That's almost 1000 lb-ft!

Nick

[FUBAR]

Is that what you use?

How do you achieve 1320Nm? That's almost 1000 lb-ft!

Nick

Somebody else did my gearbox, so no.

You need bigger turbos, de-cat, bigger DPs, intercoolers, w/m injection and bigger injectors/fuelpump upgrade.

[FUBAR]

There must be some kind of problem with TTE1000+ since there are no results yet and they were saying (on another forum) that there are few cars that will be tuned shortly - this was in March.
On the other hand I got the impression that TTH/ RS ENgineers are not very good in advertising their stuff (also communication doesn't look like their stronger side). Everything is in German and their web site was very poor (when I was checking it few month ago). Also there is not much information for modifications on tuned cars.

THT & RS Engineers is only a two man show, they are very busy. THT performance = tuning. RS Engineers = mechanical work. Antonio who runs RS Engineers works at Porsche during the day, and at RS Engineers in evenings/weekends. He gets alot of e-mails, try calling after 1530 CET. They have done many 1000+ hp C6 RS6 builds.

[RS6-T28RPH]

Just had notification from TTE that my TTE1000 conversion is complete and the turbos are on their way back to the UK, will chuck some piccies up when they arrive

[welwynnick]

I should have results this week, unfortunately we had a hold up on the exhaust side of things. I’ve went full 3.5” from the turbos back, I wanted to retain some level of quiet. Opted for 5” silencers and the wrong size came, so we lost a couple of days waiting on new ones. Exhaust is now finished and the car will be back at Mrc tomorrow for a week of testing and mapping. As said TTEs rep suggests we should do 1000hp minimum especially with my spec. My car ran 880ps and 1200nms on the 850’s on a mild map and 1008ps on race fuel. I’m hoping the new turbos do 1050+ps on 99 and upwards of 1150 on race. I think the curve will move slightly to the right as it’s a bigger turbine wheel, I’m hoping we don’t lose too much spool as the 850’s were incredible in that sense. Will post all findings good and bad throughout next week

I've been pondering this for a while. What does it take to get 1kbhp from an RS6, and do you need a 3.5" exhaust?

One approach is to look at tuned Golf Rs. They only have 2 litres and four cylinders, but they're good engines, and with a turbo, intake, exhaust and tuning they reach 500 bhp and 500 lb-ft. The current RS3 with 5 cyl / 2.5 litres does that with just tune. Although those engines are newer, I think the V10 has all the raw ingredients, it just needs enough cooling, and to get the fuel and air in and out. Therefore, whatever a tuned Golf has, double that.

The cooling looks simple to summarise but difficult to implement. You need 25-30 litres total charge cooling matrix volume, which is about double what's available today. That, or WMI.

I've been reading around a lot, so I don't have any specific links, but there does seem to be a general consensus among tuners that you need to keep intake and exhaust gas speed below about Mach 0.3, or 100 m/s.

As long as you avoid confusing discussion about cylinder head flow rates, there's also a consensus that intake flow = 1.5 cfm x bhp, and exhaust flow = 2.2 cfm x bhp.

Therefore 1kbhp of any denomination will make about 700l/s intake and 1000l/s exhaust flow. If you divide those by 100m/s you get 70 cm2 and 100 cm2 respectively, which equate to internal diameters of 66mm and 80mm - quite big pipes, then. Can anyone tell me how big the throttle bodies are?

What I found interesting was that all those people who I thought were wrong to simply assume that exhaust flow = intake flow weren't actually very wide of the mark. I presumed they didn't take into account the volume of the combustion products of the fuel, which must surely increase the volume of exhaust substantially. However, when you do the chemistry it turns out it doesn't.

80% passes through unaffected of course, and the water and CO2 generated only have slightly higher volume than the oxygen that's consumed. The end result is the exhaust flow is only about 8% higher, and most of the increase comes from the higher temperature. There's probably a big clue in the intake and exhaust valve sizes - they're fairly similar, with the intakes only a little larger.

Finally, I came across one other useful rule of thumb for turbo engines. Going back to the rule cfm = 1.5 x bhp, the cross-sectional area of the turbo compressor inducer (inlet) sets a limit to the power of an engine. The intake air cannot exceed the speed of sound. There are lots of other limitations that contrive to limit power, but there's nothing you can do to exceed Mach 1 at the inlet.

That got me wondering if the turbo fin tips exceeded the speed of sound, and I found lots of data in the Garrett & Borg Warner Catalogs, but it'll wait for another day.

EDIT: And the answer to that question is yes. After looking at a lot of turbo specs in the catalogs above, the max compressor exducer tip speed typically sits in the range of 560 to 580 m/s, so about Mach 1.7, regardless of whether it's a tiny turbo or a huge one.

There are lots of smart guys round here and maybe you knew all that, but I thought it was interesting.

I'm very much looking forwards to hearing from S4Player and T28RPH again, of course.

Nick

[IanH755]

I'd say 3.5in at the turbo dropping to 3in after the CAT and cross-flowed, either X or H, seems to be the norm for most the 1000 hp cars I've seen so far.

[RS6-T28RPH]

My TTE1000 have just arrived back from Germany which is ace, just that MRC dont have the downpipes on the shelf, back order time

plan is to do turbos and down pipes, tune the car, get baseline figures, then do ICs, map and dyno, aquamist and dyno, then gearbox with the final blow-your-cock-off map to see how much it will make overall. Will be interesting to see what each upgrade does to power curves and numbers.

[welwynnick]

I think we'll all be rooted to this thread. I'm especially intrigued by the individual contributions made by bigger intercoolers and by water injection - not just on ultimate power, but also on the shape of power and torque curves.

Aren't you going to get your gearbox uprated while the engine is out for the turbo change? That sounds like part of your ultimate plan, and removing the engine twice can't be that much fun. Is it possible to remove the gearbox alone?

It can't be long before S4 Player has some news as well.

Nick

[welwynnick]

I'd say 3.5in at the turbo dropping to 3in after the CAT and cross-flowed, either X or H, seems to be the norm for most the 1000 hp cars I've seen so far.

viewtopic.php?f=47&t=132483&p=918947#p918947

I'd been thinking that the RS6 C6 was at a disadvantage compared with extreme tuned cars like turbo Lambos, GTRs and Supras, but I'm having second thoughts. 1khp is big number for ANY road legal car, no-matter what it is. There are lots of fundamental things standing in the way, but the RS6 does seem to have the potential - turbos, manifolds, cylinder heads, bottom end, transmission, brakes etc.

I was reading the Extreme Turbo Systems site, whose twin turbo Hurracan uses 2 x 3.5" exhausts, and the biggest and baddest GTRs and Supras only have single 4" pipes - smaller than 2 x 3". So maybe the RS6 isn't at much of a disadvantage at all.

The RS6 has one final advantage that's usually taken for granted. There are tuners like MRC who can actually tune them properly. I think that's really important and often overlooked. It also has the cunning benefit of a rather good disguise!

Nick

EDIT: You know, those big power twin turbo Lambos aren't quite as powerful as you might expect. There's not a lot of information, but the starting point ought be really good - a large capacity high revving engine with great volumetric efficiency. Later versions of the Gallardo made 560 bhp, and the Huracan started with 610 bhp. In other words, similar power to the RS6, and well over 100 bhp/litre from naturally aspirated engines.

However, twin turbo Gallardo's actually make 800-900 bhp on a stock engine, and Huracan's make about 900-1000 hp. All those tuners are keen to promote how much power their engines make with race fuel. Yes, it's a lot of power, but it's less than 200 bhp/litre, and Golfs etc with bolt-on tuning routinely make more than that, without revving beyond 7000.

There's a clue in the ETS website: their stock engine tune only runs 10psi, and it needs 8000 rpm to make the power. Perhaps they have to avoid detonation, or bottom end or transmission damage, but either way there's not much torque. Those engines, like highly tuned Audi 4.2 and 5.2 litre engines, have a high 12.5:1 compression ratio. Production turbo engines are always lower than that, allowing boost and more ignition.

Turbo Lambos can certainly achieve a lot more, but only on modified engines. With few cost constraints, those engines have different pistons and rods, maybe valves, camshafts, cylinder liners or even blocks. That allows them to run any compression ratio they want, and I bet they make it lower.

I don't actually know how much boost tuners use on the RS6, but I'm sure it's more than 10psi. I think this might be yet one more surprise advantage of the RS6 V10.

Edit: I just read the CFI Designs website and they also use 3.5" exhausts for all their Audi and Lambo twin turbo conversions.

https://cfi-designs.com/vehicles/lamborghini-huracan/

[welwynnick]

Anybody interested in big power might be interested in the Milletech intake that replaces the standard airbox and filter.

It looks very nice, with big pipes, smooth turns and big cylindrical filters.

However, there's no cold air intake, which might hurt real world performance.

https://www.audiboost.com/content.php?1 ... mm-intakes

https://www.boostaddict.com/images/impo ... 5332-1.jpg

If there was a way of integrating those filters into the stock airboxes they might be on to a winner.

Nick

[RS6-T28RPH]

I think we'll all be rooted to this thread. I'm especially intrigued by the individual contributions made by bigger intercoolers and by water injection - not just on ultimate power, but also on the shape of power and torque curves.

Aren't you going to get your gearbox uprated while the engine is out for the turbo change? That sounds like part of your ultimate plan, and removing the engine twice can't be that much fun. Is it possible to remove the gearbox alone?

It can't be long before S4 Player has some news as well.

Nick

I will ultimately get the gearbox done, have no objection removing the engine twice, mainly because its not me doing it but I want to benchmark each part of the upgrade for my own curiosity. I may however remove the gearbox from scope and just get it done at the same time as turbos and downpipes and ignore it from the benchmarking. All in the name of science etc.

Bit of a delay at the moment as MRC dont have the downpipes on the shelf, apparently they are on back order at present but have my name on a set when available.

In other news, just rolled over the 150k mark, the last 30k of which has been at MRC stage2 730ps and she's holding up strong

[S4Player]

I think we'll all be rooted to this thread. I'm especially intrigued by the individual contributions made by bigger intercoolers and by water injection - not just on ultimate power, but also on the shape of power and torque curves.

Aren't you going to get your gearbox uprated while the engine is out for the turbo change? That sounds like part of your ultimate plan, and removing the engine twice can't be that much fun. Is it possible to remove the gearbox alone?

It can't be long before S4 Player has some news as well.

Nick

I will ultimately get the gearbox done, have no objection removing the engine twice, mainly because its not me doing it but I want to benchmark each part of the upgrade for my own curiosity. I may however remove the gearbox from scope and just get it done at the same time as turbos and downpipes and ignore it from the benchmarking. All in the name of science etc.

Bit of a delay at the moment as MRC dont have the downpipes on the shelf, apparently they are on back order at present but have my name on a set when available.

In other news, just rolled over the 150k mark, the last 30k of which has been at MRC stage2 730ps and she's holding up strong

You won’t be able to release the full potential without doing the gearbox . Mrc are having a new dyno installed, dougs cleared a full two weeks to work on mines. The turbos aren’t doing what we expected hence there being delays with my figures, I’m also changing my exhaust spec to exactly what iainH has suggested. 3.5” into 3” with X pipe

[S4Player]

Also seen someone mention torque, my car made 1440nms on the 850’s

[S4Player]

I'd say 3.5in at the turbo dropping to 3in after the CAT and cross-flowed, either X or H, seems to be the norm for most the 1000 hp cars I've seen so far.

viewtopic.php?f=47&t=132483&p=918947#p918947

I'd been thinking that the RS6 C6 was at a disadvantage compared with extreme tuned cars like turbo Lambos, GTRs and Supras, but I'm having second thoughts. 1khp is big number for ANY road legal car, no-matter what it is. There are lots of fundamental things standing in the way, but the RS6 does seem to have the potential - turbos, manifolds, cylinder heads, bottom end, transmission, brakes etc.

I was reading the Extreme Turbo Systems site, whose twin turbo Hurracan uses 2 x 3.5" exhausts, and the biggest and baddest GTRs and Supras only have single 4" pipes - smaller than 2 x 3". So maybe the RS6 isn't at much of a disadvantage at all.

The RS6 has one final advantage that's usually taken for granted. There are tuners like MRC who can actually tune them properly. I think that's really important and often overlooked. It also has the cunning benefit of a rather good disguise!

Nick

EDIT: You know, those big power twin turbo Lambos aren't quite as powerful as you might expect. There's not a lot of information, but the starting point ought be really good - a large capacity high compression high revving engine with great volumetric efficiency. Later versions of the Gallardo made 560 bhp, and the Huracan started with 610 bhp. In other words, similar power to the RS6, and well over 100 bhp/litre from naturally aspirated engines.

However, twin turbo Gallardo's actually make 800-900 bhp on a stock engine, and Huracan's make about 900-1000 hp. All those tuners are keen to promote how much power their engines make with race fuel. Yes, it's a lot of power, but it's less than 200 bhp/litre, and Golfs etc with bolt-on tuning routinely make more than that, without revving beyond 7000.

There's a clue in the ETS website: their stock engine tune only runs 10psi, and it needs 8000 rpm to make the power. Perhaps they have to avoid detonation, or bottom end or transmission damage, but either way there's not much torque. Those engines, like highly tuned Audi 4.2 and 5.2 litre engines, have a high 12.5:1 compression ratio. Production turbo engines are always lower than that, allowing boost and more ignition.

Turbo Lambos can certainly achieve a lot more, but only on modified engines. With few cost constraints, those engines have different pistons and rods, maybe valves, camshafts, cylinder liners or even blocks. That allows them to run any compression ratio they want, and I bet they make it lower.

I don't actually know how much boost tuners use on the RS6, but I'm sure it's more than 10psi. I think this might be yet one more surprise advantage of the RS6 V10.

1.45 bar mines peaked at and tapered to 1.3 on the tte 850’s

[welwynnick]

Also seen someone mention torque, my car made 1440nms on the 850’s

= 1062 lb-ft

That's an extraordinary amount of torque for any engine to generate and survive. And your gearbox builder must be really good.

My rule of thumb for the best tuned engines is:

100 Nm per litre per bar

So 1440 Nm is what I'd expect from a superb engine running two bar boost, with really good cooling and sensible ignition. I think you said you used bigger ICs and WMI?

The water must be evaporating and adding to the water vapour generated by the fuel burning, so you have more combustion products than you would otherwise. Effectively you're ingesting more fuel and air without ingesting more volume.

Normally, increasing boost gives decreasing returns, because the higher temperature requires the ignition to be retarded.

Nick