| UltimateLurker | 06-02-2005 06:04 PM |
HP/Torque of the WRC cars
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Does anyone have any confirmed HP and Torque numbers for the WRC cars?
| wgknestrick | 06-02-2005 06:08 PM |
I don't think GT3-GT4 is too far off.
| MikeWRX-NJ | 06-02-2005 06:09 PM |
[url]http://www.swrt.com/35023.html[/url]
300bhp @ 5500rpm
[email�protected] -OR- [email�protected]
^^ if i did the conversion correctly.
300bhp @ 5500rpm
[email�protected] -OR- [email�protected]
^^ if i did the conversion correctly.
| SilverSurfer04STi | 06-02-2005 06:18 PM |
I think it would be kinda cool if there were no HP restrictions in the WRC.
| driggity | 06-02-2005 06:21 PM |
[QUOTE=SilverSurfer04STi]I think it would be kinda cool if there were no HP restrictions in the WRC.[/QUOTE]
Until people started dying.
[IMG]http://www.dukevideo.com/image/product/2990.jpg[/IMG]
Until people started dying.
[IMG]http://www.dukevideo.com/image/product/2990.jpg[/IMG]
| SilverSurfer04STi | 06-02-2005 06:24 PM |
That's what roll cages are for. ;)
Joking...
Not even sure if it would make much of a difference in some of the low traction environments they race in. Would be fun to watch on the tarmac though.
Joking...
Not even sure if it would make much of a difference in some of the low traction environments they race in. Would be fun to watch on the tarmac though.
| mr. m | 06-02-2005 06:34 PM |
[QUOTE=driggity]Until people started dying.
[/QUOTE]
ive read that todays wrc(or whatever the top class is) cars are faster than the group b cars were.
[/QUOTE]
ive read that todays wrc(or whatever the top class is) cars are faster than the group b cars were.
| Caplin 2.5 | 06-02-2005 06:37 PM |
How the hell do they get 433 torque!? thats soooo much.
| STi_Guy04 | 06-02-2005 07:07 PM |
yea back in the day, they use to have no restrictions on WHP, until too may WRC Fans started dying, or end up very very hurt, Also There was somthing about Audi using v8s and they just wanted to even out the playing field... I may be wrong, but thats what I heard awhile back,
| Weasel 555 | 06-02-2005 07:17 PM |
from www.rally-live.com
�
�
Citreon WRC Car :
Type
Transversed, 30� tilted
Capacity
1998 cc (4 cyl.)
Power
315 bhp @ 5 500 tr/mn
Maximum torque
580 Nm @ 2 750 tr/mn
Valves
4 per cylinder
Engine management
Magneti Marelli
Turbo
Garrett
- - - - - -
Subaru WRC Car:
Type
Flat 4, 16 valves
Capacity
1994 cc
Power
300 bhp @ 5 500 tr/mn
Maximum torque
600 Nm @ 4 000 tr/mn
Engine management
Subaru
Turbo
IHI
- - - - - - - - - - -
Mitsubishi WRC Car:
Type
4G63 - DOHC, 4 cylinders, 16 valves
Capacity
1996 cc
Power
300 bhp @ 5 500 tr/mn
Maximum torque
550 Nm @ 3 500 tr/mn
Engine management
Magneti Marelli, Multi injection
Turbo
Mitsubishi
- - - - - - - - - -
Ford WRC Car:
Type
Ford 2.0-litre Cosworth Duratec R, 4 cylinders, 16 valves
Power
300 bhp @ 6 500 tr/mn
Maximum torque
550 Nm @ 4 000 tr/mn
Turbo
Garrett
- - - - - - - - - - - -
Peugeot WRC Car:
Type
XU7JP4, 4 cylinders, 16 valves
Capacity
1997 cc
Power
300 bhp @ 5 250 tr/mn
Maximum torque
580 Nm @ 3 500 tr/mn
Engine management
Magneti Marelli Step 9
Turbo
Garrett
info taken from [url]www.rally-live.com[/url]
Type
Transversed, 30� tilted
Capacity
1998 cc (4 cyl.)
Power
315 bhp @ 5 500 tr/mn
Maximum torque
580 Nm @ 2 750 tr/mn
Valves
4 per cylinder
Engine management
Magneti Marelli
Turbo
Garrett
- - - - - -
Subaru WRC Car:
Type
Flat 4, 16 valves
Capacity
1994 cc
Power
300 bhp @ 5 500 tr/mn
Maximum torque
600 Nm @ 4 000 tr/mn
Engine management
Subaru
Turbo
IHI
- - - - - - - - - - -
Mitsubishi WRC Car:
Type
4G63 - DOHC, 4 cylinders, 16 valves
Capacity
1996 cc
Power
300 bhp @ 5 500 tr/mn
Maximum torque
550 Nm @ 3 500 tr/mn
Engine management
Magneti Marelli, Multi injection
Turbo
Mitsubishi
- - - - - - - - - -
Ford WRC Car:
Type
Ford 2.0-litre Cosworth Duratec R, 4 cylinders, 16 valves
Power
300 bhp @ 6 500 tr/mn
Maximum torque
550 Nm @ 4 000 tr/mn
Turbo
Garrett
- - - - - - - - - - - -
Peugeot WRC Car:
Type
XU7JP4, 4 cylinders, 16 valves
Capacity
1997 cc
Power
300 bhp @ 5 250 tr/mn
Maximum torque
580 Nm @ 3 500 tr/mn
Engine management
Magneti Marelli Step 9
Turbo
Garrett
info taken from [url]www.rally-live.com[/url]
| Anibalz | 06-03-2005 09:03 AM |
[QUOTE=Caplin 2.5]How the hell do they get 433 torque!? thats soooo much.[/QUOTE]
They can produce 3.0 Bar (Absolute) of Boost Pressure at 2500 rpm, which gives around +200 hp at 2000 rpm, and Boost levels can get as high as 4.0 Bar (Absolute) at around 3000-4500 rpm with hp rating being within 10 hp of the peak 330 hp from 4500 to 6000 rpm. In other words, lots of power from 2000 to 7500 rpm. All of that with a 34 mm (1.34-in.) intake restrictor and 98-octane Super Unleaded Fuel.
If you need to make conversions:
1 bar = 14.7 psi = 0.1 MPa
They're absolute readings, so it will be something 29.4 psig @ 2500 rpm and 44.1 psig @ peak boost.
They can produce 3.0 Bar (Absolute) of Boost Pressure at 2500 rpm, which gives around +200 hp at 2000 rpm, and Boost levels can get as high as 4.0 Bar (Absolute) at around 3000-4500 rpm with hp rating being within 10 hp of the peak 330 hp from 4500 to 6000 rpm. In other words, lots of power from 2000 to 7500 rpm. All of that with a 34 mm (1.34-in.) intake restrictor and 98-octane Super Unleaded Fuel.
If you need to make conversions:
1 bar = 14.7 psi = 0.1 MPa
They're absolute readings, so it will be something 29.4 psig @ 2500 rpm and 44.1 psig @ peak boost.
| jblaine | 06-03-2005 11:36 AM |
[QUOTE=Anibalz]All of that with a 34 mm (1.34-in.) intake restrictor and 98-octane Super Unleaded Fuel.[/QUOTE]
And lots of water injection.
And lots of water injection.
| STi-Spec C | 06-03-2005 12:59 PM |
i thought that WRC was restricted to 300hp? if that's true then why do citeron have a 315hp engine?
| kwilson36 | 06-03-2005 01:19 PM |
Sequential shift tranny also helps....
| mbiker97 | 06-03-2005 01:47 PM |
[QUOTE=Caplin 2.5]How the hell do they get 433 torque!? thats soooo much.[/QUOTE]
Antilag and water injection. ;)
also:
[quote=a racing engine magazine]Boost in inversely proportional to rpm, so you have twice as much boost at 3000 rpm as you do at 6000 rpm[/quote]
Manifold pressure is as high as 4 bar absolute (so ~43 psi on a boost gauge).
more info here:
[url]http://www.freebmw.net/mbiker97/Smart/Subaru%20WRC%20Paper/[/url]
Antilag and water injection. ;)
also:
[quote=a racing engine magazine]Boost in inversely proportional to rpm, so you have twice as much boost at 3000 rpm as you do at 6000 rpm[/quote]
Manifold pressure is as high as 4 bar absolute (so ~43 psi on a boost gauge).
more info here:
[url]http://www.freebmw.net/mbiker97/Smart/Subaru%20WRC%20Paper/[/url]
| Pavlo | 06-03-2005 04:24 PM |
and for the observant you will notice that the subaru makes 329hp, at least, if the above figures are to be believed.
Paul
Paul
| pio!pio! | 06-03-2005 05:05 PM |
yup
since they are limited to around 300hp..get to 300hp as quickly as possible and then stay there....:)
since they are limited to around 300hp..get to 300hp as quickly as possible and then stay there....:)
| eastcoastbumps | 06-05-2005 11:56 PM |
[QUOTE=STi-Spec C]i thought that WRC was restricted to 300hp? if that's true then why do citeron have a 315hp engine?[/QUOTE]
Well they're not really limited to 300hp. They have a restrictor on the intake that limits them to about 300hp worth of air flow. Its common in a lot of professional racing and really levels the playing feild. Some debate that limiting fuel would make for more real world advancements in engine design, but it would be too difficult to do.
Well they're not really limited to 300hp. They have a restrictor on the intake that limits them to about 300hp worth of air flow. Its common in a lot of professional racing and really levels the playing feild. Some debate that limiting fuel would make for more real world advancements in engine design, but it would be too difficult to do.
| Homemade WRX | 06-06-2005 12:13 AM |
[QUOTE=MikeWRX-NJ][url]300bhp @ 5500rpm
[email�protected] -OR- [email�protected]
^^ if i did the conversion correctly.[/QUOTE]
you did :disco:
[QUOTE=pio!pio!]yup
since they are limited to around 300hp..get to 300hp as quickly as possible and then stay there....:)[/QUOTE]
not so much limited but they can't get around that choke flow with the restrictor...so thermo/aero/physically limited
[email�protected] -OR- [email�protected]
^^ if i did the conversion correctly.[/QUOTE]
you did :disco:
[QUOTE=pio!pio!]yup
since they are limited to around 300hp..get to 300hp as quickly as possible and then stay there....:)[/QUOTE]
not so much limited but they can't get around that choke flow with the restrictor...so thermo/aero/physically limited
| akira02rex | 06-06-2005 12:12 PM |
I remember seeing Mcrae's focus that was AWD with like 600hp on some site..musta been when they had no restrictions. Something doesn't add up here about the "as high as 40psi" thing..You say there is a restrictor in the intake..so technically the turbo's intake is what determines how air is going to be allowed to be "compressed" and for some reason it doesn't add up that having a restrictor would allow enough air into the intake to be compressed at 40psi and not have some serious problems lol. Seems like there would be an EXTREME amount of heat buildup there with so little air and trying to cram it in, basically starving the hell out of the turbo. I'm doing more research on this!
| akira02rex | 06-06-2005 12:32 PM |
Ok I did a little more reasearch..
The restrictor used on the intake of the turbo started out as being 38mm, and now is down to 34mm. The reason these cars have so much torque is not because they have 40psi+ lol, it's because they use a bit larger turbo than stock and the restrictor is actuallying speeding the air movement up resulting in higher torque numbers. They don't have loads of hp down low either..there peak hp is around 5-6k rpm just like every other car out there. They could care less about hp..they want the torque because as we all know horsepower is just a byproduct of torque anyways.
If you guys can come up with better reasoning than me then go ahead..but 40psi from a turbo is rediculous..especially considering not many turbos can even do that! Is the T88H even capable of that?! That thing has an 88mm compressor lol. And I know for a fact the WRC cars are NOT using anything close to that!
More info:
[QUOTE]Engine modifications include a new, Mitsubishi sourced, turbocharger which is bigger than the one fitted to previous versions and now blows a 0.93 bar maximum boost.[/QUOTE]
What's that like 14psi lol.
And information on the restrictors:
[url]http://www.rallycars.com/Cars/turbo_restrictors.htmlhttp://www.rallycars.com/Cars/turbo_restrictors.html[/url]
:banana:
The restrictor used on the intake of the turbo started out as being 38mm, and now is down to 34mm. The reason these cars have so much torque is not because they have 40psi+ lol, it's because they use a bit larger turbo than stock and the restrictor is actuallying speeding the air movement up resulting in higher torque numbers. They don't have loads of hp down low either..there peak hp is around 5-6k rpm just like every other car out there. They could care less about hp..they want the torque because as we all know horsepower is just a byproduct of torque anyways.
If you guys can come up with better reasoning than me then go ahead..but 40psi from a turbo is rediculous..especially considering not many turbos can even do that! Is the T88H even capable of that?! That thing has an 88mm compressor lol. And I know for a fact the WRC cars are NOT using anything close to that!
More info:
[QUOTE]Engine modifications include a new, Mitsubishi sourced, turbocharger which is bigger than the one fitted to previous versions and now blows a 0.93 bar maximum boost.[/QUOTE]
What's that like 14psi lol.
And information on the restrictors:
[url]http://www.rallycars.com/Cars/turbo_restrictors.htmlhttp://www.rallycars.com/Cars/turbo_restrictors.html[/url]
:banana:
| driggity | 06-06-2005 12:51 PM |
[QUOTE=akira02rex]If you guys can come up with better reasoning than me then go ahead..but 40psi from a turbo is rediculous..especially considering not many turbos can even do that![/QUOTE]
Uh, just read the article that mbiker97 linked to. I think that David Lapworth probably has a good idea of how the engine setup works.
Uh, just read the article that mbiker97 linked to. I think that David Lapworth probably has a good idea of how the engine setup works.
| akira02rex | 06-06-2005 12:55 PM |
and read mine
And that article he posted talks about ABSOLUTE PRESSURE. If you knew anything about turbos you'd know absolute pressure is the turbo's pressure at the turbine outlet added to atmospheric pressure...which is 30-40psi..
And that article he posted talks about ABSOLUTE PRESSURE. If you knew anything about turbos you'd know absolute pressure is the turbo's pressure at the turbine outlet added to atmospheric pressure...which is 30-40psi..
| Pavlo | 06-06-2005 01:12 PM |
The latest Subaru WRC cars run over 3bar GAUGE PRESSURE at peak boost.
Absolute pressure has nothing to do with turbochargers at all, especially nothing to do with the turbine. Absolute pressure is simple a measurement referenced from zero, or complete vaccum. The atmosphere is at 1 "atmosphere" which is as good as 1 bar as makes no difference.
But of course they do cannot run over 3bar up to the redline, but they can run that much boost at 2500rpm. At the redline they are just over 0.5 bar gauge.
There is a lot more going in an WRC than you may think. The fuel is NOT 98 octane, it is an FIA controlled unleaded, oxygenated race fuel that works very well on turbo engines, much better than the octane number alone would suggest. They do indeed run water injection, and a variety of compression ratios that can exceed 10:1. The restrictor is a 34mm orifice, which has to be maintained for a short length, and be within a certain distance of the turbo. The compressor wheel has a 70mm maximum diameter too. The turbos used on the WRC cars are very different to the average VF34 or whatever you may find on a Group N car. And now they are tuned to get the best out of the restrictor.
With the FIA trying to limit the power to 300hp, it may not be a good idea to exceed that on paper or they may change the rules again ;)
Paul
Absolute pressure has nothing to do with turbochargers at all, especially nothing to do with the turbine. Absolute pressure is simple a measurement referenced from zero, or complete vaccum. The atmosphere is at 1 "atmosphere" which is as good as 1 bar as makes no difference.
But of course they do cannot run over 3bar up to the redline, but they can run that much boost at 2500rpm. At the redline they are just over 0.5 bar gauge.
There is a lot more going in an WRC than you may think. The fuel is NOT 98 octane, it is an FIA controlled unleaded, oxygenated race fuel that works very well on turbo engines, much better than the octane number alone would suggest. They do indeed run water injection, and a variety of compression ratios that can exceed 10:1. The restrictor is a 34mm orifice, which has to be maintained for a short length, and be within a certain distance of the turbo. The compressor wheel has a 70mm maximum diameter too. The turbos used on the WRC cars are very different to the average VF34 or whatever you may find on a Group N car. And now they are tuned to get the best out of the restrictor.
With the FIA trying to limit the power to 300hp, it may not be a good idea to exceed that on paper or they may change the rules again ;)
Paul
| mbiker97 | 06-06-2005 01:12 PM |
[quote=rallycars.com article]
FIA Turbo restrictors
Following the extinction of the GroupB rally cars, FIA introduced devices known as turbo restrictors in order to limit the maximum output of turbocharged engines. These are to be applied to all GroupA, WRC and GroupN vehicles taking part in FIA competitions. FIA explains the introduction of turbo restrictors with safety reasons. Like many other FIA decisions this an unfortunate one. Most rally drivers are complaining that the cars are less easy to drive with these devices fitted since the chassis handling capacity is under-exploited.
A turbo restrictor is essentially a tube fitted directly on the turbocharger's air intake. I will not go into very technical (bureaucratic) details on their geometry but their main purpose is to reduce the turbine's air intake flow and, consequently, its output. The internal diameter of the restrictor is being continually reduced by FIA regulations from 38mm (1992) to 36mm (1994) to 34mm (1995) and now 32mm on GroupN cars (the 34mm restrictor still applies to GroupA cars). Turbo restrictors also increase the turbo's lag time but most teams overcome this effect by fitting anti-lag systems.
The turbo restrictor's effect is mostly noticed in high engine RPM (above 5000). In this region of operation, the engine's output is very dependent on air flow. This is why engine heads are ported and air intake channels are polished to optimize air flow. The restrictor's effect on engine torque is beneficial. Peak torque values are obtained in medium engine rotational speeds. The presence of the restrictor, which actually accelerates the gases flowing through it and directs the to the center of the turbocharger's compressor wheel, essentially increases the engine torque. We can roughly estimate the drop in engine power to be as high as 40% whereas the engine torque can be increased, through appropriate engine management, by around 20%.
The use of the restrictor not only has negative effects on the engine's output but also introduces other side effects. For instance the technology research applied to the mechanical parts racing engines is now almost pointless. Engineers try to find ways to optimize the engine's output by optimizing its electronic management rather than the engine internals. Rally car racing engines are less sophisticated, mechanically, than they might be if the FIA didn't impose the use of restrictors. Since most rally cars are based on commercial vehicles the latter are available with engines that are also less interesting mechanically.[/quote]
So where exactly does it say anything about boost levels?
Turbo diesels can run as much as 100psi (gauge) from their turbos. Also relating the stock WRX Mistu turbo to the $15,000+ IHI WRC turbo is worthless. The article I linked to say the newest (a couple years old though) Subaru WRC runs 4 bar absolute, which as Pavlo mentions is ~3 bar gauge.
FIA Turbo restrictors
Following the extinction of the GroupB rally cars, FIA introduced devices known as turbo restrictors in order to limit the maximum output of turbocharged engines. These are to be applied to all GroupA, WRC and GroupN vehicles taking part in FIA competitions. FIA explains the introduction of turbo restrictors with safety reasons. Like many other FIA decisions this an unfortunate one. Most rally drivers are complaining that the cars are less easy to drive with these devices fitted since the chassis handling capacity is under-exploited.
A turbo restrictor is essentially a tube fitted directly on the turbocharger's air intake. I will not go into very technical (bureaucratic) details on their geometry but their main purpose is to reduce the turbine's air intake flow and, consequently, its output. The internal diameter of the restrictor is being continually reduced by FIA regulations from 38mm (1992) to 36mm (1994) to 34mm (1995) and now 32mm on GroupN cars (the 34mm restrictor still applies to GroupA cars). Turbo restrictors also increase the turbo's lag time but most teams overcome this effect by fitting anti-lag systems.
The turbo restrictor's effect is mostly noticed in high engine RPM (above 5000). In this region of operation, the engine's output is very dependent on air flow. This is why engine heads are ported and air intake channels are polished to optimize air flow. The restrictor's effect on engine torque is beneficial. Peak torque values are obtained in medium engine rotational speeds. The presence of the restrictor, which actually accelerates the gases flowing through it and directs the to the center of the turbocharger's compressor wheel, essentially increases the engine torque. We can roughly estimate the drop in engine power to be as high as 40% whereas the engine torque can be increased, through appropriate engine management, by around 20%.
The use of the restrictor not only has negative effects on the engine's output but also introduces other side effects. For instance the technology research applied to the mechanical parts racing engines is now almost pointless. Engineers try to find ways to optimize the engine's output by optimizing its electronic management rather than the engine internals. Rally car racing engines are less sophisticated, mechanically, than they might be if the FIA didn't impose the use of restrictors. Since most rally cars are based on commercial vehicles the latter are available with engines that are also less interesting mechanically.[/quote]
So where exactly does it say anything about boost levels?
Turbo diesels can run as much as 100psi (gauge) from their turbos. Also relating the stock WRX Mistu turbo to the $15,000+ IHI WRC turbo is worthless. The article I linked to say the newest (a couple years old though) Subaru WRC runs 4 bar absolute, which as Pavlo mentions is ~3 bar gauge.
| akira02rex | 06-06-2005 01:15 PM |
Still doesn't make sense running 3bar at that low of an rpm..how would that even be possible with a 2liter engine? The supras running T88's don't reach anywhere close to that until 5-6k rpm and they have a whole liter ontop of those engines.
| mbiker97 | 06-06-2005 01:19 PM |
You are thinking about this incorrectly. A Supra running a T88 is simply a dyno queen. 1000 rpm power band max. WRC cars are tuned for the most area under the curve as that is what gets you out of the corners faster. You are also forgetting about antilag. With antilag they are somewhat continuously dumping fuel into the exhaust manifold to keep the turbo fully spooled. They don't need to run that big of the turbo to hit huge boost numbers in the low end. I bet it's not much bigger than ~600-700 cfm. They know that a bigger turbo won't help them in the upper rpm range as the restrictor naturally limits the flow.
| REXLR8 | 06-06-2005 01:40 PM |
[QUOTE=driggity]Until people started dying.
[IMG]http://www.dukevideo.com/image/product/2990.jpg[/IMG][/QUOTE]
omghi2 early to mid 80's group b rally cars. those things were death traps,lol, but sooo......****ing......sick
[IMG]http://www.dukevideo.com/image/product/2990.jpg[/IMG][/QUOTE]
omghi2 early to mid 80's group b rally cars. those things were death traps,lol, but sooo......****ing......sick
| Pavlo | 06-06-2005 02:28 PM |
[QUOTE=akira02rex]Still doesn't make sense running 3bar at that low of an rpm..how would that even be possible with a 2liter engine? The supras running T88's don't reach anywhere close to that until 5-6k rpm and they have a whole liter ontop of those engines.[/QUOTE]
You need to realise that the WRC cars are using special turbos, but they are not magical. It can't hold the high pressure at high RPM, because that would translate to very high flow, and the flow is quite well contained by the resitrctor.
The restrictor also helps in allowing lots of boost at low RPM without causing surge, because of the high speed into the turbo. But if you look at the actual power at 2500 it's obviously very good for 2500rpm, but quite low in general terms at under or close to 300hp. Since the flow is overall low, the turbo is not put under the stress you imagine.
At the other end of the scale, we can look at the T88. This is a turbo that needs lots of exhaust flow to get it going, it will not wake up before 5000rpm on a 2.4 engine, probably a little higher. But once it does get going, the size of the compressor allows very good flow into the engine which means/needs high boost, and the large exhaust side means minimum resitriction on the engine. A WRC turbo exhaust side needs to flow no more than the overal power ceiling of the engine, say 330hp for arguments sake, which is TD05 territory. A TD05 turbo can spool very nicely on a road car, but add a high compression engine, high velocity heads, enhanced ALS system etc, and the turbine can really get going.
Paul
You need to realise that the WRC cars are using special turbos, but they are not magical. It can't hold the high pressure at high RPM, because that would translate to very high flow, and the flow is quite well contained by the resitrctor.
The restrictor also helps in allowing lots of boost at low RPM without causing surge, because of the high speed into the turbo. But if you look at the actual power at 2500 it's obviously very good for 2500rpm, but quite low in general terms at under or close to 300hp. Since the flow is overall low, the turbo is not put under the stress you imagine.
At the other end of the scale, we can look at the T88. This is a turbo that needs lots of exhaust flow to get it going, it will not wake up before 5000rpm on a 2.4 engine, probably a little higher. But once it does get going, the size of the compressor allows very good flow into the engine which means/needs high boost, and the large exhaust side means minimum resitriction on the engine. A WRC turbo exhaust side needs to flow no more than the overal power ceiling of the engine, say 330hp for arguments sake, which is TD05 territory. A TD05 turbo can spool very nicely on a road car, but add a high compression engine, high velocity heads, enhanced ALS system etc, and the turbine can really get going.
Paul
| ride5000 | 06-06-2005 03:37 PM |
akira02rex, i hope you are learning something here.
| MinesFaster | 06-06-2005 10:55 PM |
The specifics of the turbocharger
�
�
"Mitsu made a TD06HR 15GK2 wheel just for the high PR low mass flow life of anti lag and restrictor, it was fitted to likely restrictor candidate EVO5-7 versions. But dont bother tring to track one down for your EVO8, it loses a bunch of choke flow rating to get the high PR capability."
This is a direct quote of Robert Young of Forced Performance when I asked him about WRC turbochargers. The rest of the conversation isnt going to be relayed here, but suffice it to say there is ALOT of technology in the internal aerodynamics of these turbochargers.
To answer Akira02rex so clearly as to be ABSOLUTE- the only way these turbos are capable of producing that much boost that low is Antilag. Ever seen a WRC with malfunctioning antilag? They call it colorful things like "lacks throttle response" or "isnt repsonsive to the throttle anymore". Firing a cylinder on an open exhaust valve is equivalent to an M80 in a pop can. There is alot of kinetic (as well as thermal) energy being released before the turbo. Turbochargers that see regular antilag use have a very short service cycle. Being 2.0L isnt even part of the equation.
Additionally I have noticed that the Racetech article is being aluded to or quoted. To clear up a few details:
1. 10:1 motors are used at high altitude events only
2. 4 BAR absolute is also high altitude only
3. 36psi is the normal boost ceiling for Subaru WRC cars
4. With the new 2 event per engine rule, reliability is now much more a factor and has decreased the overall thermal load placed on internals. This is achieved with less compression and less boost.
5. 36psi of boost can be realised by 2500rpm with the antilag system on. As has been pointed out this will taper to negligable amounts nearing redline as the vacuum generated on the intake side of the 34mm restrictor has taken considerably more affect.
This is a direct quote of Robert Young of Forced Performance when I asked him about WRC turbochargers. The rest of the conversation isnt going to be relayed here, but suffice it to say there is ALOT of technology in the internal aerodynamics of these turbochargers.
To answer Akira02rex so clearly as to be ABSOLUTE- the only way these turbos are capable of producing that much boost that low is Antilag. Ever seen a WRC with malfunctioning antilag? They call it colorful things like "lacks throttle response" or "isnt repsonsive to the throttle anymore". Firing a cylinder on an open exhaust valve is equivalent to an M80 in a pop can. There is alot of kinetic (as well as thermal) energy being released before the turbo. Turbochargers that see regular antilag use have a very short service cycle. Being 2.0L isnt even part of the equation.
Additionally I have noticed that the Racetech article is being aluded to or quoted. To clear up a few details:
1. 10:1 motors are used at high altitude events only
2. 4 BAR absolute is also high altitude only
3. 36psi is the normal boost ceiling for Subaru WRC cars
4. With the new 2 event per engine rule, reliability is now much more a factor and has decreased the overall thermal load placed on internals. This is achieved with less compression and less boost.
5. 36psi of boost can be realised by 2500rpm with the antilag system on. As has been pointed out this will taper to negligable amounts nearing redline as the vacuum generated on the intake side of the 34mm restrictor has taken considerably more affect.
| akira02rex | 06-07-2005 10:22 AM |
Thanks for the replies :)
It makes sense now with some explaining!
I guess I have heard of anti-lag systems but totally forgot about it lol.
And as for the 1000hp supras being dyno queens, think again hehe! There are PLENTY of them who regularly run at the track trying to break records, ever heard of saad saad, ryan woon, peter blach, etc? anyways, off that topic, thanks for the info guys.
It makes sense now with some explaining!
I guess I have heard of anti-lag systems but totally forgot about it lol.
And as for the 1000hp supras being dyno queens, think again hehe! There are PLENTY of them who regularly run at the track trying to break records, ever heard of saad saad, ryan woon, peter blach, etc? anyways, off that topic, thanks for the info guys.
| MustGoFast | 06-07-2005 04:17 PM |
buy track you mean 1/4 mile right... not much of a place in a WRC discussion or even in a racing w/ corners discussion.
| 4SFED4 | 06-07-2005 07:02 PM |
If you believe any of the WRC engines are only producing 300-315BHP I have bridge for sale I would like to tell you about! :lol:
Doesn't seem strange they ALL make 300-315BHP?
Doesn't TQ = BHP at 5250RPM?
Whilst they ARE limited by the restrictor size... they are all making more (much more) than 300BHP. It is the politics of the FIA that (IMO) determines what the teams print.
What they do with anti-lag is just amazing... F1 and WRC engine technology is fantastique!
Cheers,
-Brian
Doesn't seem strange they ALL make 300-315BHP?
Doesn't TQ = BHP at 5250RPM?
Whilst they ARE limited by the restrictor size... they are all making more (much more) than 300BHP. It is the politics of the FIA that (IMO) determines what the teams print.
What they do with anti-lag is just amazing... F1 and WRC engine technology is fantastique!
Cheers,
-Brian
| Phatron | 06-07-2005 07:13 PM |
Wow, I am simply amazed. I figured the wrc cars were maybe mid 12 sec. 1/4 mile type cars. As the 300 bhp is ~220 whp. I just figured they were about the same as a usdm STi, but quicker because of the gearing.
I never did the conversion on the torque just because the hp was about the same, I figured the torque would be around 300 ft*lbs.
After seeing that torque number I am way more impressed. Those things have to be able to crank out a low 11 sec, maybe 10 sec 1/4 mile. With the launch control, anti lag, and the gearing.
Anyone ever come across any 1/4 mile numbers for these bad boys?
I never did the conversion on the torque just because the hp was about the same, I figured the torque would be around 300 ft*lbs.
After seeing that torque number I am way more impressed. Those things have to be able to crank out a low 11 sec, maybe 10 sec 1/4 mile. With the launch control, anti lag, and the gearing.
Anyone ever come across any 1/4 mile numbers for these bad boys?
| Homemade WRX | 06-08-2005 01:55 AM |
[QUOTE=4SFED4] Doesn't TQ = BHP at 5250RPM?
[/QUOTE]
ROFL...if that is true, explain how a GSX-R 600cc motor running a 20 mm restrictor makes only 48 lb-ft and 86 hp @ the wheels...the torque never even meets the hp level...so many variables go into the outcome performance and powerbands of motors...there is no simple formula that is 100% right all the time
[/QUOTE]
ROFL...if that is true, explain how a GSX-R 600cc motor running a 20 mm restrictor makes only 48 lb-ft and 86 hp @ the wheels...the torque never even meets the hp level...so many variables go into the outcome performance and powerbands of motors...there is no simple formula that is 100% right all the time
| K1WRC | 06-08-2005 02:33 AM |
Ummm, just to clear things up here.... Torque is always more than horsepower (at the same rpm) up until 5252rpm then at that point horsepower is always more than torque (at the same rpm). Horsepower = (Torque * RPM) / 5252. 5252rpm is where torque and horsepower always cross, on any engine. So if a wrc car was making 433 ft.lbs. at 4000 rpm then it is making almost 330 hp at 4000 rpm. Oh, by the way this formula doesn't give horsepower if you enter something other than ft.lbs. for torque.
Anyway, that's my rant...
Anyway, that's my rant...
| Impreza01 | 06-08-2005 06:32 AM |
[QUOTE=Phatron]Wow, I am simply amazed. I figured the wrc cars were maybe mid 12 sec. 1/4 mile type cars. As the 300 bhp is ~220 whp. I just figured they were about the same as a usdm STi, but quicker because of the gearing.
I never did the conversion on the torque just because the hp was about the same, I figured the torque would be around 300 ft*lbs.
After seeing that torque number I am way more impressed. Those things have to be able to crank out a low 11 sec, maybe 10 sec 1/4 mile. With the launch control, anti lag, and the gearing.
Anyone ever come across any 1/4 mile numbers for these bad boys?[/QUOTE]
Road and Track did a test back in 2001 or 2002 of the last GC bodied WRC car. It ran low 11s on the quarter mile with RALLYING GEAR RATIOS. By the time they were at the end of hte track, I think they already had shifted to fifth.
You have to realize that even though they have 300 bhp, they have a buttload amount of torque and are very light compared to road going cars.
I never did the conversion on the torque just because the hp was about the same, I figured the torque would be around 300 ft*lbs.
After seeing that torque number I am way more impressed. Those things have to be able to crank out a low 11 sec, maybe 10 sec 1/4 mile. With the launch control, anti lag, and the gearing.
Anyone ever come across any 1/4 mile numbers for these bad boys?[/QUOTE]
Road and Track did a test back in 2001 or 2002 of the last GC bodied WRC car. It ran low 11s on the quarter mile with RALLYING GEAR RATIOS. By the time they were at the end of hte track, I think they already had shifted to fifth.
You have to realize that even though they have 300 bhp, they have a buttload amount of torque and are very light compared to road going cars.
| John Vanos | 06-08-2005 08:37 AM |
All this does not even begin to take into account the differentials and the tires. Both of those together coupled with the torque and low gearing are what make WRC cars so devastatingly quick. I read somewhere that a Prodrive N10 group N car is faster than a 1998 WRC subaru. That may give you an indication of how much faster the WRC cars have got over the same period of time.
| LyveWRX | 06-08-2005 08:55 AM |
Also consider that with the trick diffs and gearboxes the WRC cars will be able to give exceptional 1/4mi times on most any surface, not just tarmac.
| AndyRoo | 06-08-2005 09:59 AM |
[QUOTE=mr. m]ive read that todays wrc(or whatever the top class is) cars are faster than the group b cars were.[/QUOTE]
they certainly set faster times, but i'm not sure about faster.
- andrew
they certainly set faster times, but i'm not sure about faster.
- andrew
| White 2.5rs | 06-08-2005 10:00 AM |
group b were around 500 hp if i remember correctly...doubtful they were faster
| Kha0S | 06-08-2005 10:20 AM |
Look at it this way... the air going through a restrictor must move at just under the speed of sound in order to maintain proper flow. So, the theoretical maximum airflow through the restrictor can be calculated by:
Flow = restrictor orifice area * speed of sound
= pi*r^2 * speed of sound
= 3.14159 * (0.034m / 2)^2 * 340 m/s = 0.309 cubic meters per second
= 18.5 m^3/min = 653 CFM.
The work capacity of the engine (horsepower or torque) is directly proportional to the airflow entering the engine and the volumetric efficiency of the engine.
/Andrew
Flow = restrictor orifice area * speed of sound
= pi*r^2 * speed of sound
= 3.14159 * (0.034m / 2)^2 * 340 m/s = 0.309 cubic meters per second
= 18.5 m^3/min = 653 CFM.
The work capacity of the engine (horsepower or torque) is directly proportional to the airflow entering the engine and the volumetric efficiency of the engine.
/Andrew
| mbiker97 | 06-08-2005 10:42 AM |
^^ Nice math there Kha0S.
| LyveWRX | 06-08-2005 12:55 PM |
Group B didn't have electro-hydraulic diffs and tranny. Even though they might have had a higher top speed, they wouldnot have accelerated quite as fast as todays cars. That's what makes the 300HP WRC cars of today so quick, Rally is not about top speed, most HP, or fastest 1/4mi. Its about best time over a variety of surfaces and conditions. With the additon of the one motor/two events rule it also adds a bunch about durability and tactics.
| Chuck H | 06-09-2005 12:38 PM |
[QUOTE=Homemade WRX]ROFL...if that is true, explain how a GSX-R 600cc motor running a 20 mm restrictor makes only 48 lb-ft and 86 hp @ the wheels...the torque never even meets the hp level...so many variables go into the outcome performance and powerbands of motors...there is no simple formula that is 100% right all the time[/QUOTE]
Time to hit the textbooks again. As another post noted, hp is simply torque * RPM / 5252. It's impossible for the torque to never meet the hp level if they're plotted to the same scale. They have to cross at 5252 RPM. It's easy for the peak hp number to be higher than the peak torque number on a high-revving engine like a bike motor, though, because they still make decent torque WAY past 5252 RPM, so the RPM multiplier really starts to help out the hp number.
It's actually a very simple formula, and it's correct 100% of the time by definition. It's just not always simple to equate real world performance against peak torque and hp numbers because they only tell a tiny part of the story.
Time to hit the textbooks again. As another post noted, hp is simply torque * RPM / 5252. It's impossible for the torque to never meet the hp level if they're plotted to the same scale. They have to cross at 5252 RPM. It's easy for the peak hp number to be higher than the peak torque number on a high-revving engine like a bike motor, though, because they still make decent torque WAY past 5252 RPM, so the RPM multiplier really starts to help out the hp number.
It's actually a very simple formula, and it's correct 100% of the time by definition. It's just not always simple to equate real world performance against peak torque and hp numbers because they only tell a tiny part of the story.
| vizor | 06-09-2005 02:49 PM |
Chuck H is spot on. Here is a fictitious HP curve created off the cuff that meets a 300 max hp limit. The torque curve was calculated from the HP curve to show just how drastically the two can differ.
And, they cross at 5252 RPM.
[IMG]http://relro.net/hp.png[/IMG]
And, they cross at 5252 RPM.
[IMG]http://relro.net/hp.png[/IMG]
| steveson | 06-09-2005 04:56 PM |
Can't find the old post, but about a year ago someone posted a link to an automotive engineering publication (British, I believe) where they did an amazing analyses of the 2004 Subaru WRC motor/tranny/management system. I remember something over 400 ft/lbs of torque and 200hp @3k revs and then a solid "over 300" from shortly thereafter to readline. It was beautiful engineering for sure. But my memory sucks and it could all be in my head.
| Impreza01 | 06-10-2005 01:46 AM |
[QUOTE=White 2.5rs]group b were around 500 hp if i remember correctly...doubtful they were faster[/QUOTE]
You're wrong. Nicky Grist commented once that the WRC cars are faster. The reason is because whate WRC lacked in power compared to the Group B cars, they made up in handling. It's like taking a Lotus Elise with its 190 hp against a SVT Cobra Mustang (350+hp). The Cobra is by no means sloppy, and it has way more power than the Lotus, but the Lotus has razor knife handling and would beat the Cobra on a track assuming it isn't a Nascar-like oval ring.
You're wrong. Nicky Grist commented once that the WRC cars are faster. The reason is because whate WRC lacked in power compared to the Group B cars, they made up in handling. It's like taking a Lotus Elise with its 190 hp against a SVT Cobra Mustang (350+hp). The Cobra is by no means sloppy, and it has way more power than the Lotus, but the Lotus has razor knife handling and would beat the Cobra on a track assuming it isn't a Nascar-like oval ring.
| Mopho | 06-10-2005 02:21 AM |
Link->[URL=http://www.stormloader.com/groupb/comparison.html]Group B car vs WRC car comparison[/URL]
| mbiker97 | 06-10-2005 10:03 AM |
[QUOTE=steveson]Can't find the old post, but about a year ago someone posted a link to an automotive engineering publication (British, I believe) where they did an amazing analyses of the 2004 Subaru WRC motor/tranny/management system. I remember something over 400 ft/lbs of torque and 200hp @3k revs and then a solid "over 300" from shortly thereafter to readline. It was beautiful engineering for sure. But my memory sucks and it could all be in my head.[/QUOTE]
See post #15. ;)
See post #15. ;)
| AlbaScoob | 06-10-2005 10:44 AM |
[QUOTE=driggity]Until people started dying.
[IMG]http://www.dukevideo.com/image/product/2990.jpg[/IMG][/QUOTE]
yeah, gone are the GpB days...
I recall the first time I felt and smelt(!) the Quattros, 6R4s and 205 T16s fly past me whilst spectating the Lombard Rally (GB) in '84...amazing cars
[IMG]http://www.dukevideo.com/image/product/2990.jpg[/IMG][/QUOTE]
yeah, gone are the GpB days...
I recall the first time I felt and smelt(!) the Quattros, 6R4s and 205 T16s fly past me whilst spectating the Lombard Rally (GB) in '84...amazing cars
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