Ultimate VTG engines
09-08-2011, 04:12 PM
#31
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Wurlie,Basal,MGR, thanks for reading 
TT Turbine, what petrolhead doesn't like revving out
911Slow, It is a feat getting these stubborn engineers to change their views - well done !
Sharkster, the 200mph club is growing
Guy, Exactly where do you want me to attach this camera, to my 3 year olds car seat in the back
Rickard, yes I am looking forward to sharing data with you, particularly further up the speed range, but you are using conventional turbos I think so you will not be pegged at 700hp ?
GT, When you stop terrorizing mainland Europe in your beast we need to do that back to back, there's a lot to learn from that comparison. same day, same conditions....
bbywu,
Bob, following on from my comment to GT above, he runs expansion manifolds and his acceleration indicates he can run 740hp, this is contradictory to what RS told me, he tested the expansion manifold on the engine dyno and says 680hp is the limit. He says it cannot flow enough air, not big enough......
So the turbo manifolds are to flow the air needed to go above 680hp and theoretically at lower boost although my maximum power only available sub 50c IAT is at 1.55bar so not exactly lower boost ?
Using turbo intake manifolds was the biggest challenge because the GT2 ECU could no longer be used, the 997 turbo program had to be completely re-written to work with the two wheel driven GT2 with all the interaction between the 4WD system being redundant and a new traction control had to be written in..... this is what took them 3 weeks with the Porsche/Bosch engineer !
What I find baffling is that other tuners say they "use" the 997 turbo intake on GT2s without problem, notably Todd K...... I suspect a little band aid/hot wiring is going on ?
TT Turbine, what petrolhead doesn't like revving out
911Slow, It is a feat getting these stubborn engineers to change their views - well done !
Sharkster, the 200mph club is growing
Guy, Exactly where do you want me to attach this camera, to my 3 year olds car seat in the back
Rickard, yes I am looking forward to sharing data with you, particularly further up the speed range, but you are using conventional turbos I think so you will not be pegged at 700hp ?
GT, When you stop terrorizing mainland Europe in your beast we need to do that back to back, there's a lot to learn from that comparison. same day, same conditions....
bbywu,
Bob, following on from my comment to GT above, he runs expansion manifolds and his acceleration indicates he can run 740hp, this is contradictory to what RS told me, he tested the expansion manifold on the engine dyno and says 680hp is the limit. He says it cannot flow enough air, not big enough......
So the turbo manifolds are to flow the air needed to go above 680hp and theoretically at lower boost although my maximum power only available sub 50c IAT is at 1.55bar so not exactly lower boost ?
Using turbo intake manifolds was the biggest challenge because the GT2 ECU could no longer be used, the 997 turbo program had to be completely re-written to work with the two wheel driven GT2 with all the interaction between the 4WD system being redundant and a new traction control had to be written in..... this is what took them 3 weeks with the Porsche/Bosch engineer !
What I find baffling is that other tuners say they "use" the 997 turbo intake on GT2s without problem, notably Todd K...... I suspect a little band aid/hot wiring is going on ?
I have a 997 turbo engien with gt2 turbos and some extra godies...like gt2 rs ic, free exhoust and etc..I also run a gt2 ecu on 997 turbo engien and no problemos.. maybe RS tuning not are the god out there and other also can do nice works
09-08-2011, 05:22 PM
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09-08-2011, 09:25 PM
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Wow looking at the data above toby our engines are producing similar power in very different ways.. My 740hp gt2 intake vtg engine makes same power with 1.42bar at over 7000 rpm but with 25+ ignition angle (vs 17 degrees in your tt intake engine) and also with lambda around 0.85 area vs 0.78 in yours. Ie a lot leaner and with more ignition timing and less boost. It amazes me how it is possible to achieve power in this engine with such different tuning parameters. My tuner insists that leaner is the way to go, most tuners disagree (some race teams are actually running lean too though) but in all honesty lean seems to be working in mine with no problems for 20k kms so far.
I hope we get to compare but not sure I ll bring this car to London as it would be pretty useless there..
I hope we get to compare but not sure I ll bring this car to London as it would be pretty useless there..
09-09-2011, 07:02 AM
#34
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Sharky
Clucth was a massive issue for me, I like to daily drive, have had sintered before
and have discussed triple plate stuff at length and while those who have them say they are great etc I always felt they were saying that because they didn't really have any alternative (bit like people who say the Carrera GT clutch is fine when you get used to - not for me it isn't ).
So I asked RS to limit the torque so we could use the 890NM Sachs set up.
When they first tested it they used a FWFW but it slipped and also apparently it was pretty noisey. They fitted the dual mass back on and it holds OK at least for now in relatively warm 15c+ weather. The important thing is it is a doddle to drive, perfect for all traffic driving and lovely to modulate.
Sin911
Giving up wasn't really an option but trust me all the waiting and then the ECU problem was not a pleasant experience.
Guy
I will try a sucker mount
Oh dear, I don't want to get into a 6bling stylee tuner-off on this thread......
I am sure there are "others who also do nice works" also
These threads are so we can all make our minds up who we use and we can bench mark our results/service etc..... when I dropped my car off at RS Tuning they had 4 Carrera GT engines on engine stands having 6 litre conversions, they do not advertise, they build equisite, bespoke, unique Porsche engines - yes to me they probably are "gods" of Porsche tuning but they are also horrible to deal with and very expensive and I have no doubt that your guy is better to work with
On the ECU issue all I know is to get it running to THEIR standards required hiring the Bosch guy who wrote the code for Porsche and exclusive use of the engine dyno for three weeks, it wasn't the full load/power stuff which was the problem it was the part load/throttle maps needing mapping every 250rpm which were difficult.
As far as full load which is all 6blingers seem bothered about, I look forward to seeing your data logs and we can discuss in a calm way
GT
As you mentioned before using the expansion manifold means a completely different strategy of tuning. I have posted below an exert from my engine running 660PS and expansion manifold.
You can see 24 deg advance and around 0.83 lambda (boost was about 1.5/6bar). Note the MAF at peak power is 1738kh/hr...
You report that your motor, revving to 7800rpm has an appetite for spark plugs ? Well I'm hoping mine is tuned to be no worse than a stock GT2, I will report back as it happens !
A couple more pics.
The 900+NM at 3000rpm bent three drive shafts, these shafts attach to the engine dyno. This doesn't happen on the road as we have wheelspin to save us.
Here is my souvenir
Clucth was a massive issue for me, I like to daily drive, have had sintered before
and have discussed triple plate stuff at length and while those who have them say they are great etc I always felt they were saying that because they didn't really have any alternative (bit like people who say the Carrera GT clutch is fine when you get used to - not for me it isn't
).So I asked RS to limit the torque so we could use the 890NM Sachs set up.
When they first tested it they used a FWFW but it slipped and also apparently it was pretty noisey. They fitted the dual mass back on and it holds OK at least for now in relatively warm 15c+ weather. The important thing is it is a doddle to drive, perfect for all traffic driving and lovely to modulate.
Sin911
Giving up wasn't really an option but trust me all the waiting and then the ECU problem was not a pleasant experience.
Guy
I will try a sucker mount
I am sure there are "others who also do nice works" also
These threads are so we can all make our minds up who we use and we can bench mark our results/service etc..... when I dropped my car off at RS Tuning they had 4 Carrera GT engines on engine stands having 6 litre conversions, they do not advertise, they build equisite, bespoke, unique Porsche engines - yes to me they probably are "gods" of Porsche tuning but they are also horrible to deal with and very expensive and I have no doubt that your guy is better to work with
On the ECU issue all I know is to get it running to THEIR standards required hiring the Bosch guy who wrote the code for Porsche and exclusive use of the engine dyno for three weeks, it wasn't the full load/power stuff which was the problem it was the part load/throttle maps needing mapping every 250rpm which were difficult.
As far as full load which is all 6blingers seem bothered about, I look forward to seeing your data logs and we can discuss in a calm way
GT
As you mentioned before using the expansion manifold means a completely different strategy of tuning. I have posted below an exert from my engine running 660PS and expansion manifold.
You can see 24 deg advance and around 0.83 lambda (boost was about 1.5/6bar). Note the MAF at peak power is 1738kh/hr...
You report that your motor, revving to 7800rpm has an appetite for spark plugs ? Well I'm hoping mine is tuned to be no worse than a stock GT2, I will report back as it happens !
A couple more pics.
The 900+NM at 3000rpm bent three drive shafts, these shafts attach to the engine dyno. This doesn't happen on the road as we have wheelspin to save us.
Here is my souvenir
09-09-2011, 12:13 PM
#35
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Sharky
Clucth was a massive issue for me, I like to daily drive, have had sintered before
and have discussed triple plate stuff at length and while those who have them say they are great etc I always felt they were saying that because they didn't really have any alternative (bit like people who say the Carrera GT clutch is fine when you get used to - not for me it isn't ).
So I asked RS to limit the torque so we could use the 890NM Sachs set up.
When they first tested it they used a FWFW but it slipped and also apparently it was pretty noisey. They fitted the dual mass back on and it holds OK at least for now in relatively warm 15c+ weather. The important thing is it is a doddle to drive, perfect for all traffic driving and lovely to modulate.
Sin911
Giving up wasn't really an option but trust me all the waiting and then the ECU problem was not a pleasant experience.
Clucth was a massive issue for me, I like to daily drive, have had sintered before
and have discussed triple plate stuff at length and while those who have them say they are great etc I always felt they were saying that because they didn't really have any alternative (bit like people who say the Carrera GT clutch is fine when you get used to - not for me it isn't
).So I asked RS to limit the torque so we could use the 890NM Sachs set up.
When they first tested it they used a FWFW but it slipped and also apparently it was pretty noisey. They fitted the dual mass back on and it holds OK at least for now in relatively warm 15c+ weather. The important thing is it is a doddle to drive, perfect for all traffic driving and lovely to modulate.
Sin911
Giving up wasn't really an option but trust me all the waiting and then the ECU problem was not a pleasant experience.
PS There's a non-sprung Sachs sport disc for your car that's actually 2.5 pounds lighter than the stock one. And it's not that 4 puck cintered hell thing lol! I've used that once in my own car and it was living hell
09-09-2011, 12:30 PM
#36
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Once my car is done (a month or so) I'll share some info with you guys to compare (Champion Motorsport 3.8l GT2).
Although trainwreck.com (what I call 6Bling) is based in the US not everyone here in the US subscribes to those juvenile debates.
For what it's worth I lean more towards GT's tune than TB993tt's. More ignition timing, less boost, less fuel, and probably better heat management and better efficiency, but I'm not a tuner nor am I an engine builder. There are lots of ways to skin a cat so to speak. For me, my goal is to keep the motor from flying apart at higher than OEM power levels for prolonged periods of time (30 minutes, or a typical track DE session).
09-09-2011, 12:32 PM
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BTW I know how to do the CGT idle clutch set off and I still hated it - maybe my skinny chicken legs have something to do with it
09-09-2011, 12:38 PM
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That statement right there tells me a lot about both your tunes.
Once my car is done (a month or so) I'll share some info with you guys to compare (Champion Motorsport 3.8l GT2).
Although trainwreck.com (what I call 6Bling) is based in the US not everyone here in the US subscribes to those juvenile debates.
For what it's worth I lean more towards GT's tune than TB993tt's. More ignition timing, less boost, less fuel, and probably better heat management and better efficiency, but I'm not a tuner nor am I an engine builder. There are lots of ways to skin a cat so to speak. For me, my goal is to keep the motor from flying apart at higher than OEM power levels for prolonged periods of time (30 minutes, or a typical track DE session).
Once my car is done (a month or so) I'll share some info with you guys to compare (Champion Motorsport 3.8l GT2).
Although trainwreck.com (what I call 6Bling) is based in the US not everyone here in the US subscribes to those juvenile debates.
For what it's worth I lean more towards GT's tune than TB993tt's. More ignition timing, less boost, less fuel, and probably better heat management and better efficiency, but I'm not a tuner nor am I an engine builder. There are lots of ways to skin a cat so to speak. For me, my goal is to keep the motor from flying apart at higher than OEM power levels for prolonged periods of time (30 minutes, or a typical track DE session).
I think I saw you talking about your new build on 6bling ? glad you've come here to join in....
It is the heat management bit that is the power killer..... how do you think you will have "better heat management" ? a 30 min session will be quite demanding for a VTG motor won't it ?
09-09-2011, 12:53 PM
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Actually the one you've been reading about on trainwreck.com belongs to the yellow GT2. I've gone that route because of the R&D from the tear downs of several motors at Champion which, as far as I'm concerned, show excessive case warping and flexing problems at what I considered to be "safe" power output.
I use the Champion 68mm turbos. They are probably good for about 450hp flow each. The wheels and the bigger exhaust housings flow quite a bit more air so I don't think (note, not "know") EGTs will be a problem. I too have the 997TT intake manifolds and I understand your problem with the tune at mid rpm/mid-full throttle application. Although the GT2 manifolds are a nice conversation piece I don't think they are all that special.
For what it's worth I already have done multiple 30 minute sessions at Road America with my car with the 68mm turbos, and no heat issues to speak of (RA has three straights where I use 6th gear well into the 5K rpm range, and is the VMax of what I intend to use for the car since no other tracks in the US are as high speed). Looking at the exhaust manifolds I can see that there isn't that much heat- at least, not much more than OEM levels. Once I get my car back I can get some logging done with my Durametric, but to be honest I don't think it's comparable since we are talking different builds, different fuel, etc.
FYI here is my car on Champion's Flickr page- http://www.flickr.com/photos/champio...7626189983096/
I use the Champion 68mm turbos. They are probably good for about 450hp flow each. The wheels and the bigger exhaust housings flow quite a bit more air so I don't think (note, not "know") EGTs will be a problem. I too have the 997TT intake manifolds and I understand your problem with the tune at mid rpm/mid-full throttle application. Although the GT2 manifolds are a nice conversation piece I don't think they are all that special.
For what it's worth I already have done multiple 30 minute sessions at Road America with my car with the 68mm turbos, and no heat issues to speak of (RA has three straights where I use 6th gear well into the 5K rpm range, and is the VMax of what I intend to use for the car since no other tracks in the US are as high speed). Looking at the exhaust manifolds I can see that there isn't that much heat- at least, not much more than OEM levels. Once I get my car back I can get some logging done with my Durametric, but to be honest I don't think it's comparable since we are talking different builds, different fuel, etc.
FYI here is my car on Champion's Flickr page- http://www.flickr.com/photos/champio...7626189983096/
Last edited by Nick Wong; 09-09-2011 at 01:02 PM. Reason: added link for pics.
09-09-2011, 01:04 PM
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09-09-2011, 01:44 PM
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Nick,
Would love to see some Durametric data well into 6th gear..... boost, IAT, MAF, timing, rpm,speed,ambient.....
I hear what you say about the the Champion 68mm turbos but have yet to see full load data on them, is a bigger exhaust housing enough to produce lower IATs ? I am told it is the VTG mechanism itself when used to create the mega torque curves which causes the heat ?
BTW I have changed the title of the thread, it would be great if all those with bigger VTG tuned engines could join in with their experiences and share builds and data
Would love to see some Durametric data well into 6th gear..... boost, IAT, MAF, timing, rpm,speed,ambient.....
I hear what you say about the the Champion 68mm turbos but have yet to see full load data on them, is a bigger exhaust housing enough to produce lower IATs ? I am told it is the VTG mechanism itself when used to create the mega torque curves which causes the heat ?
BTW I have changed the title of the thread, it would be great if all those with bigger VTG tuned engines could join in with their experiences and share builds and data
09-09-2011, 02:53 PM
#42
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I don't know if I totally agree with your point that VTG tech is the source of heat issues.
Conventional fixed A/R turbos are efficient in one area of their flow. The rest of the the flow is marginalized.
A properly tuned VTG turbo should be efficient across a broader range of flow.
Heat into a turbo is usually generated by exhaust outflow, right? So the less heat out of the heads, the lower the heat accumulation at the exhaust housing.
Heat from the heads can be managed in several ways (see- several ways to skin a cat). One way is to advance the ignition timing. Another is to add more fuel. The third is to lower boost. And a fourth is to change cam timing, duration, and/or lift, and along that thought, changing valve sizes.
If you're creating "mega-torque" which from what I understand most US tuners do NOT do, you will create more heat. That is a byproduct of creating more power. How you manage that heat is the question- how efficient is the engine design and tune?
Just some thoughts for discussion...
Conventional fixed A/R turbos are efficient in one area of their flow. The rest of the the flow is marginalized.
A properly tuned VTG turbo should be efficient across a broader range of flow.
Heat into a turbo is usually generated by exhaust outflow, right? So the less heat out of the heads, the lower the heat accumulation at the exhaust housing.
Heat from the heads can be managed in several ways (see- several ways to skin a cat). One way is to advance the ignition timing. Another is to add more fuel. The third is to lower boost. And a fourth is to change cam timing, duration, and/or lift, and along that thought, changing valve sizes.
If you're creating "mega-torque" which from what I understand most US tuners do NOT do, you will create more heat. That is a byproduct of creating more power. How you manage that heat is the question- how efficient is the engine design and tune?
Just some thoughts for discussion...
09-10-2011, 01:36 AM
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09-10-2011, 08:42 AM
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Let me chip in here as well if I may. Nick you are right about what you say above but you can't achieve ignition timing over toby's engine without the expansion intake that cools the air significantly at high rpm. This is the inherent weakness of vtg technology thhat p tried to address and now has this intake on all turbo models including then the .2 turbo and 2 rs.
So the compromise at the end is simple. Do you get better results with turbo intake, more boost, less ignition timing, more fuel or with expansion intake were you sacrifice boost but get 10-15 degrees colder air and thus can use 25+ degrees ignition and run much leaner lambda? Before my tune I also thought by listening to everyone (except sported and apparently Pierre Ofsky and few other race teams) that the 1st option was the way to go. But after seeing how much power we got in the top end in my engine when the expansion intake does it's thing and power goes crazy with less boost but more ignition I think that maybe they were right. The feeling is that you get a turbo engine with huge torque build up from around 3k to 5.5k then power flattens until 6.5 and then it feels like an n/a engine making more and more power until the sad reality of the rev limiter hits at 7.8k lol! If we could rev to 8k + this setup would make more and more power for sure. (not advised without changing the variable valve mechanism).
I need to try some runs with 18 ambient to see what happens compared to Toby s ultimate vtg build that went with option 1 to evaluate really what happens. At 10 ambient the data were quite good in mine but need to try in more difficult conditions now.
The thing is that champion will not attempt to tune your car with the gt2 intake in my understanding as they don't believe in what I mentioned above for 700 real hp possible with the expansion intake.
But it's difficult to tune and required experience.
So the compromise at the end is simple. Do you get better results with turbo intake, more boost, less ignition timing, more fuel or with expansion intake were you sacrifice boost but get 10-15 degrees colder air and thus can use 25+ degrees ignition and run much leaner lambda? Before my tune I also thought by listening to everyone (except sported and apparently Pierre Ofsky and few other race teams) that the 1st option was the way to go. But after seeing how much power we got in the top end in my engine when the expansion intake does it's thing and power goes crazy with less boost but more ignition I think that maybe they were right. The feeling is that you get a turbo engine with huge torque build up from around 3k to 5.5k then power flattens until 6.5 and then it feels like an n/a engine making more and more power until the sad reality of the rev limiter hits at 7.8k lol! If we could rev to 8k + this setup would make more and more power for sure. (not advised without changing the variable valve mechanism).
I need to try some runs with 18 ambient to see what happens compared to Toby s ultimate vtg build that went with option 1 to evaluate really what happens. At 10 ambient the data were quite good in mine but need to try in more difficult conditions now.
The thing is that champion will not attempt to tune your car with the gt2 intake in my understanding as they don't believe in what I mentioned above for 700 real hp possible with the expansion intake.
But it's difficult to tune and required experience.
09-10-2011, 11:43 AM
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What a chronicle of tuning nirvana 
Fair play to you TB
Words cannot describe how the car feels under full throttle and, much like Michael Corleone's visit to Cardinal Lamberto, it changed things for me. The engine has freakish response at all revs and the big VTG's posses negligible lag. The motor is very smooth in delivery though shocking none the less.
Having had the pleasure of piloting the car last weekend here in Albion, I have been thinking this past week how to best describe the nature and 'feel' of the venerable 3.9 engine in the silver bullet's rump. From driving a few RS tuned turbo engines (inc. my own) over the last 5 years, the usual experience when revving out a gear is smooth though rabid torque escalation with the accompanying mule like kick in the back. Then post peak torque as the NM curve eases off the motor displays manic rev hungry action as the PS curve then soars like a Teutonic albatross* towards the rev limiter.
....... the GT2 has massive peak torque though the difference is that the kick in the back is sustained and actually increases all the way to the limiter such is the ferocity of the ensuing power curve. You feel an ever escalating wall of massive power pushing you towards the horizon and 200+ mph feels easily obtainable, the advent of the VTG turbo for blown Pork should be celebrated and marked with a national holiday.
This is the shocking thing, there is no let up nor respite from the motor, at any revs in any gear it just winds up and goes with no hesitation. It is unnerving, intimidating, terrifying, thrilling, and glorious in a strange 'am I going to die very shortly' kind of way. A wild ride like no other I have experienced, to put it in perspective I drove my SL65 afterwards and the V12 felt somewhat pedestrian !
The whole package of the engine, chassis, and general set-up blend together to give an intoxicating hit - the factory experience on steroids, as a proper tuning package should be.
Enjoy
MOD.
* = think I got a little carried away there !
Fair play to you TB
Words cannot describe how the car feels under full throttle and, much like Michael Corleone's visit to Cardinal Lamberto, it changed things for me. The engine has freakish response at all revs and the big VTG's posses negligible lag. The motor is very smooth in delivery though shocking none the less.
Having had the pleasure of piloting the car last weekend here in Albion, I have been thinking this past week how to best describe the nature and 'feel' of the venerable 3.9 engine in the silver bullet's rump. From driving a few RS tuned turbo engines (inc. my own) over the last 5 years, the usual experience when revving out a gear is smooth though rabid torque escalation with the accompanying mule like kick in the back. Then post peak torque as the NM curve eases off the motor displays manic rev hungry action as the PS curve then soars like a Teutonic albatross* towards the rev limiter.
....... the GT2 has massive peak torque though the difference is that the kick in the back is sustained and actually increases all the way to the limiter such is the ferocity of the ensuing power curve. You feel an ever escalating wall of massive power pushing you towards the horizon and 200+ mph feels easily obtainable, the advent of the VTG turbo for blown Pork should be celebrated and marked with a national holiday.
This is the shocking thing, there is no let up nor respite from the motor, at any revs in any gear it just winds up and goes with no hesitation. It is unnerving, intimidating, terrifying, thrilling, and glorious in a strange 'am I going to die very shortly' kind of way. A wild ride like no other I have experienced, to put it in perspective I drove my SL65 afterwards and the V12 felt somewhat pedestrian !
The whole package of the engine, chassis, and general set-up blend together to give an intoxicating hit - the factory experience on steroids, as a proper tuning package should be.
Enjoy
MOD.
* = think I got a little carried away there !