Dyno test what power?
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My understanding is that the way to keep all these dyno numbers at par is through the use of a measuring standard such as DIN 70020, where all the parameters are converted to one set..temperature plays a major role, atmospheric pressure, humidity, what periferals are used in the car etc..Any dyno run not "corrected" is worthless,to say "corrected" is not enough, it has to be corrected to a certain standard, SAE or DIN or whatever, ideally DIN for worldwide comparisons.
BTW, on the quartermile I would measure the trap speed and weight as a bench for hp rather than time elapsed as you will "reduce" the variance driven by driver's ability to start.
BTW, on the quartermile I would measure the trap speed and weight as a bench for hp rather than time elapsed as you will "reduce" the variance driven by driver's ability to start.
Racer
Joined: Dec 2004
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From: England
I recently had my car (Varioram) dynoed, and it was suggested that my cam timing may be off. The dyno shows power falling off at around 5krpm. The specialist suggested that the cam timing needs to be sorted - something about older models using vernier pulleys that were "pinned", but later models using a pulley that was just "screwed on tight" (and prone to slipping).
Is cam timing a common problem on later Varioram cars, or is the specialist talking you-know-what? Max power on dyno showed about 255hp, and the curve thereafter was decidedly dodgy and not smooth.
Lots of you guys here have more technical experience than me on the nuts and bolts of the 993 engine, and I would really appreciate your advice before putting down my hard earned...
Thanks --
Is cam timing a common problem on later Varioram cars, or is the specialist talking you-know-what? Max power on dyno showed about 255hp, and the curve thereafter was decidedly dodgy and not smooth.
Lots of you guys here have more technical experience than me on the nuts and bolts of the 993 engine, and I would really appreciate your advice before putting down my hard earned...
Thanks --
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zoomzoom
I am not an expert, but these seem to be affecting cars in Continental Europe only. You being in the UK and all I don't think you should worry about it. If you do a search you will find some people who had a lot of hp added because timing was off in one of the banks from the factory. But that was in Continental Europe only I think.
I am not an expert, but these seem to be affecting cars in Continental Europe only. You being in the UK and all I don't think you should worry about it. If you do a search you will find some people who had a lot of hp added because timing was off in one of the banks from the factory. But that was in Continental Europe only I think.
Racer
Joined: Dec 2004
Posts: 385
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From: England
Hi Jean,
After doing a bit of a search and reading other peoples' comments, it sounds like the garage may be right
He talked about locking the cams with the older style cams, and the power outputs were definitely down. Multiple dyno runs gave 255hp (flywheel) or around 230 at the wheels. I'm heading down to Le Mans next week, and I've got the car booked in the day after my return. Service is to set cam timing, and for a complete dyno check and possible remap. I'll post back after the service is done... I'm expecting good things!
Thanks --
After doing a bit of a search and reading other peoples' comments, it sounds like the garage may be right
He talked about locking the cams with the older style cams, and the power outputs were definitely down. Multiple dyno runs gave 255hp (flywheel) or around 230 at the wheels. I'm heading down to Le Mans next week, and I've got the car booked in the day after my return. Service is to set cam timing, and for a complete dyno check and possible remap. I'll post back after the service is done... I'm expecting good things!
Thanks --
Intermediate
Joined: Oct 2004
Posts: 28
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From: Melbourne, Australia
993CAB-95 Standard Motor dyno chart
This is my chart for a standard motor, 3.6.https://rennlist.com/forums/newreply.php
Racer
Joined: Sep 2004
Posts: 296
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From: Aliso Viejo, CA
As a refernece here is my chart with an Andial chip it in (detonation was audible at the drop off section around 5500 rpm). I was using a ~93.5 octane mix. I now have a Rennsport chip, but haven't retested yet (no affiliation, just happy).
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From: Chicago
Originally Posted by zoomzoom
Hi Jean,
After doing a bit of a search and reading other peoples' comments, it sounds like the garage may be right
He talked about locking the cams with the older style cams, and the power outputs were definitely down. Multiple dyno runs gave 255hp (flywheel) or around 230 at the wheels. I'm heading down to Le Mans next week, and I've got the car booked in the day after my return. Service is to set cam timing, and for a complete dyno check and possible remap. I'll post back after the service is done... I'm expecting good things!
Thanks --
After doing a bit of a search and reading other peoples' comments, it sounds like the garage may be right
He talked about locking the cams with the older style cams, and the power outputs were definitely down. Multiple dyno runs gave 255hp (flywheel) or around 230 at the wheels. I'm heading down to Le Mans next week, and I've got the car booked in the day after my return. Service is to set cam timing, and for a complete dyno check and possible remap. I'll post back after the service is done... I'm expecting good things!
Thanks --
Thanks!
Racer
Joined: Dec 2004
Posts: 385
Likes: 1
From: England
Here are the printed stats before the work gets done...
Power at flywheel (corrected) = 255.9 Bhp (DIN 70020) @ 5667rpm
Power at flywheel (measured) = 252.1 Bhp
Power at wheels = 227.3 Bhp
Power loss = 24.8 Bhp
Max engine torque (corrected) 255.7 lb ft @ 4601Rpm
Baro pressure 1013mb
Min ambient temp = 22deg C
Max ambient temp = 30deg C
The specialist showed me the plots of what a normal 3.6 had, and the plot was a smooth curve all the way up to 285-290 Bhp (flywheel) without any sudden jerkiness at the 5-5.5k rpm mark. Fingers crossed for the work to be done... I'm hopeful of hitting the factory numbers - if not even better! I'll post the numbers after surgery... watch this space...
Power at flywheel (corrected) = 255.9 Bhp (DIN 70020) @ 5667rpm
Power at flywheel (measured) = 252.1 Bhp
Power at wheels = 227.3 Bhp
Power loss = 24.8 Bhp
Max engine torque (corrected) 255.7 lb ft @ 4601Rpm
Baro pressure 1013mb
Min ambient temp = 22deg C
Max ambient temp = 30deg C
The specialist showed me the plots of what a normal 3.6 had, and the plot was a smooth curve all the way up to 285-290 Bhp (flywheel) without any sudden jerkiness at the 5-5.5k rpm mark. Fingers crossed for the work to be done... I'm hopeful of hitting the factory numbers - if not even better! I'll post the numbers after surgery... watch this space...
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Originally Posted by zoomzoom
I recently had my car (Varioram) dynoed, and it was suggested that my cam timing may be off. The dyno shows power falling off at around 5krpm. The specialist suggested that the cam timing needs to be sorted - something about older models using vernier pulleys that were "pinned", but later models using a pulley that was just "screwed on tight" (and prone to slipping).
Is cam timing a common problem on later Varioram cars, or is the specialist talking you-know-what? Max power on dyno showed about 255hp, and the curve thereafter was decidedly dodgy and not smooth.
Lots of you guys here have more technical experience than me on the nuts and bolts of the 993 engine, and I would really appreciate your advice before putting down my hard earned...
Thanks --
Is cam timing a common problem on later Varioram cars, or is the specialist talking you-know-what? Max power on dyno showed about 255hp, and the curve thereafter was decidedly dodgy and not smooth.
Lots of you guys here have more technical experience than me on the nuts and bolts of the 993 engine, and I would really appreciate your advice before putting down my hard earned...
Thanks --
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Zoomzoom your peak hp is at 5700 RPMs so the engine is still pulling beyond 5000 RPM. I don't remember very well where the stock N/A hp peaks but it should not be very far off.
FWIW temperature measurements and barometric pressure do not matter much as the DIN correction takes care of it and computes it back at 20 Degrees C. Do you have the "uncorrected" numbers handy?
FWIW temperature measurements and barometric pressure do not matter much as the DIN correction takes care of it and computes it back at 20 Degrees C. Do you have the "uncorrected" numbers handy?
Racer
Joined: Dec 2004
Posts: 385
Likes: 1
From: England
I assume the "measured" 252.1Bhp is the uncorrected number? The curve is smooth up until 5k rpm. Then the curve suddenly goes very bumpy with a slightly rise to it's max near 5700rpm. It falls off after that. to me, a 30+Bhp loss is significant - especially if it's supposed to be an "over-engineered Porsche". This suggests to me that something is wrong... or am I being to picky?
