The quest for 520hp: Cargraphic / RS-Tuning / RUF
#136
is the requirement of their Motorsport intercooler to go to 550PS, an intercooler which didn't cool better than stock when I tested it,
#137
Please share with us in detail which "additional work" was done to your engine and the ballpark cost for these extra steps that you took.
Were the modifications done to your engine similar to what Martyn did to his RS 520PS kit?
I PMed you my email address.
#138
Information on its way to you.
Regarding the torque curve of 804NM. It has value in illustrating what can be done without exotic parts and with proper parts mix and mapping.
As far as the cause I wish I could tell you, the fact is I don't know what part of what was done made the difference. I bought the car with the work done already and I don't know enough about Martyn's car to comment.
I am sure that Gerhard at RS Tuning could tell you both the scope of the work and the cost. They are difficult to reach but good once you get them.
Regarding the torque curve of 804NM. It has value in illustrating what can be done without exotic parts and with proper parts mix and mapping.
As far as the cause I wish I could tell you, the fact is I don't know what part of what was done made the difference. I bought the car with the work done already and I don't know enough about Martyn's car to comment.
I am sure that Gerhard at RS Tuning could tell you both the scope of the work and the cost. They are difficult to reach but good once you get them.
Last edited by LAT; 11-22-2009 at 02:32 AM.
#139
Your engine was built using the then advanced techniques and parts. It has twin plug IIRC which RS Tuning made work with the Motronic MAF system with full overboost capability and boost control. It has the latest head sealing which was then proprietry to RS, these two features allowed the boost to be deployed to enable that amazing torque number - there were no other tuners able to produce this level of torque then and even now this is a big number for a 993tt !
You also got the then latest version of KKK race turbos with integral wastegates all blowing through the ultra rare race Porsche Motorsports intercooler... Your engine is special
#140
Okay maybe they were exotic parts 10 years ago but now less so as technology moves forward. Aren't these parts more of a durability benefit then for pure output. The head sealing I agree contributes to the overboost capability, this however is not an expensive option and worth the insurance it provides.
It is however only a single plug with Motronic MAF system.
It is however only a single plug with Motronic MAF system.
#142
Hi, can someone explain to me 'overboost' in our engines? It's how much boost the motronic ecu allows if conditions are right that is a function of how the motronic senses boost? Is it something that's programed in to the ecu to allow or something that happens by accident because ecu cannot control things fast enough. Not quite sure. If it's something that's programed into the ecu, why is it 'over' - isn't it something that's supposed to happen?
#143
Hi, can someone explain to me 'overboost' in our engines? It's how much boost the motronic ecu allows if conditions are right that is a function of how the motronic senses boost? Is it something that's programed in to the ecu to allow or something that happens by accident because ecu cannot control things fast enough. Not quite sure. If it's something that's programed into the ecu, why is it 'over' - isn't it something that's supposed to happen?
This is my take on it.
6th gear full throttle at 2000rpm and let the engine rev right through the rev range (need a long track !) as it passes peak torque area this is where maximum boost will occur (and for purposes of this answer it is my 993tt) the boost in DIN conditions will be 1.3bar peak nicely controlled then falls back as peak torque passes.
In 2nd gear the loading on the engine will not allow such a high boost figure at peak torque, this is a function of lack of loading (like on a chassis dyno)
Now "overboost" is when one is cruising then boots the throttle WOT at just before peak torque in a gear higher than 3rd (for the aformentioned loading). If I do this in 6th the boost will ramp up very quickly and boost higher than that 1.3 bar, this is the "overboost" it is programmed in by RS (I think the factory has it also but probably at a less aggresive level) now the other part of what you put above comes into play which is because the whole wastegate actuation mechanism is pretty slow the actual amount of overboost is not very well controlled, mine could go up to 1.6bar and occasionally could go so high that the Motronic would trigger the ignition cut out to protect the engine this is obviously a little too high !
The overboost will work at all revs once past peak torque and it works better after peak torque, so if you slow for a corner in 3rd then come back WOT at say 5000rpm the Motronic will allow the boost to climb to a higher level than that preprogrammed (as in the 6th gear original test) and you will have more power than you will see on a dyno sheet at that point.
I do not know how much of an RS Tuning technique this is ? I know they were talking about it on the 7GT2 also so it is something they seem to know a lot about. I guess the fixed boost cars will certainly not have it...
In the context of 993tt tuning, overboost requires that head sealing and ideally twin plug to be able to cope with the cylinder pressures at peak torque which the overboost can generate.
#144
All of the above
The overboost will work at all revs once past peak torque and it works better after peak torque, so if you slow for a corner in 3rd then come back WOT at say 5000rpm the Motronic will allow the boost to climb to a higher level than that preprogrammed (as in the 6th gear original test) and you will have more power than you will see on a dyno sheet at that point.
The overboost will work at all revs once past peak torque and it works better after peak torque, so if you slow for a corner in 3rd then come back WOT at say 5000rpm the Motronic will allow the boost to climb to a higher level than that preprogrammed (as in the 6th gear original test) and you will have more power than you will see on a dyno sheet at that point.
#145
I have scanned in the RS engine dyno sheets for the single plug 520 kit. This is the sheet they would send to prospective customers - your results may vary.
The torque is limited by having the standard head sealing, to go more than 710NM (OK 735NM ) you need the EVO style flame ringing to allow the 1.2bar+ mid range overboost.
As has been pointed out to get the thing working right all other "bits" must be in fine fettle. MOD500 has this very build and ended up needing all new valve springs as this is a weak point in standard engines with a few miles on them which becomes apparent with the added power - this didn't show up on the engine dyno and we only got to know about this following extensive 60-130mph testing revealed that the power was not always there !!
The other problem is the turbos - RSK24/26s are now a bit "old hat", I'm sure Kevin can ellaborate although there are no new programs to deal with the later version 24/26s (OK there are but you will need twin plug and other stuff to work with that program)
I don't know what I'd do if starting afresh...... I know Phelix's felt like it had 100hp when he kindly let me drive it and it had a supposed ~480hp and smaller blowers IIRC. The beauty of the big 24/26s is they do give you that nice wallop of torque but with single plug, cams and 3.6 they do take a bit of winding up whereas something like the Ruf 490 comes on much earlier. I'd be tempted to see what Kevin has been doing with a smaller hybrid - do you have any proper dyno sheets Kevin (not the Sportec stuff ) or ideally a PB/DB data sheet 60-130 or similar ?
Edit:
Re Ruf........ I like Ruf car packages, I have owned a CTR and have bought other stuff over the years when I have visited him.....but. He is liked in the US and UK and some middle eastern countries. The main reason was the original yellowbird CTR which got him on the map big time, the numbers were fabulous in the day, 213mph in 1988 !!!! - it was RS who invented and built the engine for the yellowbird and then went on to beat the yellowbird in a 1/4mile acceleration test.
Ruf went on to build good 964 and 993 road engines, RS went on to build race winning aircooled twin turbo motors and become THE place for turbo race engines in Europe.
What is interesting is since the CG tie up the marketing machine of CG will put RS engines where they belong, witness the latest 0-300 shootout where the CG 997tt with 630PS/900NM beat the Ruf RT12 685NM/860NM by 2.5s !!!
I asked in Germany about Ruf and he has stated 685PS as the limit for the Mezger engine and appears to be very focused on electric technology and apparently has interests in some electric plants ! I still think his 993 turboR 490 is a good bit of kit
The torque is limited by having the standard head sealing, to go more than 710NM (OK 735NM ) you need the EVO style flame ringing to allow the 1.2bar+ mid range overboost.
As has been pointed out to get the thing working right all other "bits" must be in fine fettle. MOD500 has this very build and ended up needing all new valve springs as this is a weak point in standard engines with a few miles on them which becomes apparent with the added power - this didn't show up on the engine dyno and we only got to know about this following extensive 60-130mph testing revealed that the power was not always there !!
The other problem is the turbos - RSK24/26s are now a bit "old hat", I'm sure Kevin can ellaborate although there are no new programs to deal with the later version 24/26s (OK there are but you will need twin plug and other stuff to work with that program)
I don't know what I'd do if starting afresh...... I know Phelix's felt like it had 100hp when he kindly let me drive it and it had a supposed ~480hp and smaller blowers IIRC. The beauty of the big 24/26s is they do give you that nice wallop of torque but with single plug, cams and 3.6 they do take a bit of winding up whereas something like the Ruf 490 comes on much earlier. I'd be tempted to see what Kevin has been doing with a smaller hybrid - do you have any proper dyno sheets Kevin (not the Sportec stuff ) or ideally a PB/DB data sheet 60-130 or similar ?
Edit:
Re Ruf........ I like Ruf car packages, I have owned a CTR and have bought other stuff over the years when I have visited him.....but. He is liked in the US and UK and some middle eastern countries. The main reason was the original yellowbird CTR which got him on the map big time, the numbers were fabulous in the day, 213mph in 1988 !!!! - it was RS who invented and built the engine for the yellowbird and then went on to beat the yellowbird in a 1/4mile acceleration test.
Ruf went on to build good 964 and 993 road engines, RS went on to build race winning aircooled twin turbo motors and become THE place for turbo race engines in Europe.
What is interesting is since the CG tie up the marketing machine of CG will put RS engines where they belong, witness the latest 0-300 shootout where the CG 997tt with 630PS/900NM beat the Ruf RT12 685NM/860NM by 2.5s !!!
I asked in Germany about Ruf and he has stated 685PS as the limit for the Mezger engine and appears to be very focused on electric technology and apparently has interests in some electric plants ! I still think his 993 turboR 490 is a good bit of kit