Carrera GT Dyno Test 620HP - A little frightening!
Discussion
Guys,
Just wanted to let you know, that you can still rely on Porsche to quote conservative horsepower figures. I had my CGT on the Dyno yesterday at Silverstone and it showed on three consecutive occasions 620 HP at the flywheel and 512 HP at the wheels, equating approximately to an 18% loss through transmission etc - I believe the official manufacturer figure is 612HP. My car is over two years old and is absolutely standard - I thought it was a great demonstration of engine performance and quality - and the graph showed 'race-car' like characteristics. Torque was a little down recording just over 420 Ft Lb, but they said that this was due to not being able to achieve full throttle at the optimum revs.
The Company, WRC, (using Dyno Dynamics) who performed the test had real problems tying the back end of the car down on to the rollers, and on several frightening occasions the car appeared to jump out of the rollers - they said that the combination of power and an 'extraordinary level of mechanical grip' causes this to happen- but that they have only experienced this with race cars!
The guys down at WRC (who I believe EVO use) are a good bunch and understand our Porsche cars, and so I strongly recommend that you try them out if you have the need.
Regards.
P.s. I don't mean this thread to sound like a brag!
Just wanted to let you know, that you can still rely on Porsche to quote conservative horsepower figures. I had my CGT on the Dyno yesterday at Silverstone and it showed on three consecutive occasions 620 HP at the flywheel and 512 HP at the wheels, equating approximately to an 18% loss through transmission etc - I believe the official manufacturer figure is 612HP. My car is over two years old and is absolutely standard - I thought it was a great demonstration of engine performance and quality - and the graph showed 'race-car' like characteristics. Torque was a little down recording just over 420 Ft Lb, but they said that this was due to not being able to achieve full throttle at the optimum revs.
The Company, WRC, (using Dyno Dynamics) who performed the test had real problems tying the back end of the car down on to the rollers, and on several frightening occasions the car appeared to jump out of the rollers - they said that the combination of power and an 'extraordinary level of mechanical grip' causes this to happen- but that they have only experienced this with race cars!
The guys down at WRC (who I believe EVO use) are a good bunch and understand our Porsche cars, and so I strongly recommend that you try them out if you have the need.
Regards.
P.s. I don't mean this thread to sound like a brag!
carl carrera said:
on several frightening occasions the car appeared to jump out of the rollers
That sounds 'interesting'!!. Are they insured if it takes off through the nearest wall?! Next time you do something like this: be sure to PM me first so I can watch
BTW. What fuel were you running fot that test?
Globulator said:
carl carrera said:
on several frightening occasions the car appeared to jump out of the rollers
That sounds 'interesting'!!. Are they insured if it takes off through the nearest wall?! Next time you do something like this: be sure to PM me first so I can watch
BTW. What fuel were you running fot that test?
Hey Globulator, can we come round when you next dyno this? !!
www.pistonheads.com/members/showcar.asp?carId=42715
You can avoid the risk of the car jumping of the rollers by speaking to the guys at Parr. Their dyno attaches directly to the hub (ie they take the wheel off and bolt directly onto the hub). Not sure if they can handle a CGT with its centre lock hubs, but at least it will eliminate tyre slip on the rotors.
Why could they not get full throttle open? Doesn't sound right to me.
Why could they not get full throttle open? Doesn't sound right to me.
Kurgen_ said:
Globulator said:
carl carrera said:
on several frightening occasions the car appeared to jump out of the rollers
That sounds 'interesting'!!. Are they insured if it takes off through the nearest wall?! Next time you do something like this: be sure to PM me first so I can watch
BTW. What fuel were you running fot that test?
Hey Globulator, can we come round when you next dyno this? !!
www.pistonheads.com/members/showcar.asp?carId=42715
27th-28th April at Duxford there is pilot and crew training, so come along, you should be able to see lots of it, I should be down there on the Saturday ;D
Listen to the start of the Catch 22 film to get an idea of the sound..
johnfm said:
You can avoid the risk of the car jumping of the rollers by speaking to the guys at Parr. Their dyno attaches directly to the hub (ie they take the wheel off and bolt directly onto the hub). Not sure if they can handle a CGT with its centre lock hubs, but at least it will eliminate tyre slip on the rotors.
Why could they not get full throttle open? Doesn't sound right to me.
Why could they not get full throttle open? Doesn't sound right to me.
They were really having trouble with wheel spin. They also raised the rear rollers up each time to ensure the car was sitting properly in the rollers and couldn't jump out evne having been tied down! I didn't quite understand the whole physics thing and flywheel mathematical extrapolation polava. May be someone can shed some light on this for me.
I am interested in the hub option - I may speak to Parr separately on this matter. Thanks.
Globulator said:
carl carrera said:
on several frightening occasions the car appeared to jump out of the rollers
That sounds 'interesting'!!. Are they insured if it takes off through the nearest wall?! Next time you do something like this: be sure to PM me first so I can watch
BTW. What fuel were you running fot that test?
Hiya mate,
It really was nerve racking watching my car jumping around! It didn't even occur to me to check whether they had sufficent insurance cover in place in the event of a catastrophe!
regards.
p.s. sorry i didn't get to speak to you last Saturday, hope you had a good time.
Oh here goes another dyno slanging match. Get the popcorn in.
The hub dyno design is really neither fish nor fowl. It records torque/bhp at the hubs. Well we dont drive on the hubs, we use tyres and these form an important part of the losses.
An engine or bench dyno provides accepted flywheel horsepoer, a chassis dyno or rolling road [the good ones anyway] provide accepted power at the wheels and some even have quite accurate flywheel calculated horsepower. A hub dyno is neither of these ?
Hub dynos also place undue stresses and strains on wheel bearings and suspension components as the centre line of the driven component is now much further from its support than if it were on tyres.
As for not giving the CGT full throttle until 5000, it simply produces so much torque so violently we could not get it tied in to a point we were happy with within a reasonable timeframe. We had work to do [run was f.o.c. & these people had places to be] So it was easier to moderate the throttle slightly. Not the most accurate but none the less safe. If you want deadly accurate, then remove the engine and run it ion a bench dyno.
The owner was happy that we returned his P&J unharmed. Reference insurance all power test as conducted entirely at owners risk.
Allan
The hub dyno design is really neither fish nor fowl. It records torque/bhp at the hubs. Well we dont drive on the hubs, we use tyres and these form an important part of the losses.
An engine or bench dyno provides accepted flywheel horsepoer, a chassis dyno or rolling road [the good ones anyway] provide accepted power at the wheels and some even have quite accurate flywheel calculated horsepower. A hub dyno is neither of these ?
Hub dynos also place undue stresses and strains on wheel bearings and suspension components as the centre line of the driven component is now much further from its support than if it were on tyres.
As for not giving the CGT full throttle until 5000, it simply produces so much torque so violently we could not get it tied in to a point we were happy with within a reasonable timeframe. We had work to do [run was f.o.c. & these people had places to be] So it was easier to moderate the throttle slightly. Not the most accurate but none the less safe. If you want deadly accurate, then remove the engine and run it ion a bench dyno.
The owner was happy that we returned his P&J unharmed. Reference insurance all power test as conducted entirely at owners risk.
Allan
carl carrera said:
Hiya mate,
It really was nerve racking watching my car jumping around! It didn't even occur to me to check whether they had sufficent insurance cover in place in the event of a catastrophe!
regards.
p.s. sorry i didn't get to speak to you last Saturday, hope you had a good time.
It really was nerve racking watching my car jumping around! It didn't even occur to me to check whether they had sufficent insurance cover in place in the event of a catastrophe!
regards.
p.s. sorry i didn't get to speak to you last Saturday, hope you had a good time.
The whole car was jumping around? Jeeezzzz
Sorry I missed you saturday, I saw you chatting at the opposite end of the car park to where your car was when I arrived and didn't manage to catch you up. I did notice you had the roof closed though, I'll have to speak to you about that next month
weltmeister said:
Oh here goes another dyno slanging match. Get the popcorn in.
The hub dyno design is really neither fish nor fowl. It records torque/bhp at the hubs. Well we dont drive on the hubs, we use tyres and these form an important part of the losses.
An engine or bench dyno provides accepted flywheel horsepoer, a chassis dyno or rolling road [the good ones anyway] provide accepted power at the wheels and some even have quite accurate flywheel calculated horsepower. A hub dyno is neither of these ?
Hub dynos also place undue stresses and strains on wheel bearings and suspension components as the centre line of the driven component is now much further from its support than if it were on tyres.
As for not giving the CGT full throttle until 5000, it simply produces so much torque so violently we could not get it tied in to a point we were happy with within a reasonable timeframe. We had work to do [run was f.o.c. & these people had places to be] So it was easier to moderate the throttle slightly. Not the most accurate but none the less safe. If you want deadly accurate, then remove the engine and run it ion a bench dyno.
The owner was happy that we returned his P&J unharmed. Reference insurance all power test as conducted entirely at owners risk.
Allan
The hub dyno design is really neither fish nor fowl. It records torque/bhp at the hubs. Well we dont drive on the hubs, we use tyres and these form an important part of the losses.
An engine or bench dyno provides accepted flywheel horsepoer, a chassis dyno or rolling road [the good ones anyway] provide accepted power at the wheels and some even have quite accurate flywheel calculated horsepower. A hub dyno is neither of these ?
Hub dynos also place undue stresses and strains on wheel bearings and suspension components as the centre line of the driven component is now much further from its support than if it were on tyres.
As for not giving the CGT full throttle until 5000, it simply produces so much torque so violently we could not get it tied in to a point we were happy with within a reasonable timeframe. We had work to do [run was f.o.c. & these people had places to be] So it was easier to moderate the throttle slightly. Not the most accurate but none the less safe. If you want deadly accurate, then remove the engine and run it ion a bench dyno.
The owner was happy that we returned his P&J unharmed. Reference insurance all power test as conducted entirely at owners risk.
Allan
Not a slanging match. Just advice to an owner to consider other options if he's not comfortable with his car jumping around.
As for tests 'at owners risk', I find this approach disconcerting. Are you suggesting if the car leaves the rollers and slams into a wall, or your rollers jam/seize and cause damage or your operator damages the car, the owner is left to pick up the tab?
Do owners know this before the test?
Globulator said:
Kurgen_ said:
Globulator said:
carl carrera said:
on several frightening occasions the car appeared to jump out of the rollers
That sounds 'interesting'!!. Are they insured if it takes off through the nearest wall?! Next time you do something like this: be sure to PM me first so I can watch
BTW. What fuel were you running fot that test?
Hey Globulator, can we come round when you next dyno this? !!
www.pistonheads.com/members/showcar.asp?carId=42715
27th-28th April at Duxford there is pilot and crew training, so come along, you should be able to see lots of it, I should be down there on the Saturday ;D
Listen to the start of the Catch 22 film to get an idea of the sound..
Must be a bugger walking the the props through on a PBY before start-up
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