Dyno a C4 on a two wheel dyno, possible?
04-07-2005, 11:22 PM
#4
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Couldn't you just put the front on jack stands to keep it in the air?
AH!!! I'M JUST KIDDING! I'm not certain, but I'm pretty sure all-wheel drive + 2 wheel dyno = big trouble.
Brian
AH!!! I'M JUST KIDDING! I'm not certain, but I'm pretty sure all-wheel drive + 2 wheel dyno = big trouble.
Brian
04-08-2005, 02:15 PM
#6
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If you put a 964 into a rear wheel dyno it WILL launch itself out of the dyno when the rear wheels spin up and reach approximately 10 to 13 kph. At speeds below this you are just damaging the front diff and centre diff along with the centre diff lock.
The 993 C4 also requires an AWD dyno or free front rollers unless the front diff is disconnected. The vicous coupling does not act as a traditional differential so it can be operated without the front diff connected (drive shaft removed). A 964 cannot the AWD is purely mechanical and permanently connected.
This actually happened in a Californian testing station a few years. I remember the damage done was horrendous to the station and to the C4. The owner at the time was a Rennlister but this was long before the days of this forum.
Ciao,
Adrian.
The 993 C4 also requires an AWD dyno or free front rollers unless the front diff is disconnected. The vicous coupling does not act as a traditional differential so it can be operated without the front diff connected (drive shaft removed). A 964 cannot the AWD is purely mechanical and permanently connected.
This actually happened in a Californian testing station a few years. I remember the damage done was horrendous to the station and to the C4. The owner at the time was a Rennlister but this was long before the days of this forum.
Ciao,
Adrian.
04-08-2005, 02:48 PM
#7
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Originally Posted by Adrian
If you put a 964 into a rear wheel dyno it WILL launch itself out of the dyno when the rear wheels spin up and reach approximately 10 to 13 kph.
Marc
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04-08-2005, 06:36 PM
#9
Racer
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Thanks for the reply, I just took over a Mustang tuner shop in Santa Clara, CA and a 993 C4 wanted his car dynoed. I was told by another shop is was possibly if we disabled the front drivetrain. A few 993 owners told me it was possible. I'll have to get the car on a lift and see the linkage. I think if it was possible all the disassembling would not be worth it. No C4 dyno's.
04-08-2005, 06:58 PM
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Even if it was possible, what's the point, what will you learn. Surely you would want to test the car as is, with all the inherent loss through the transmission etc ?
04-08-2005, 07:34 PM
#11
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We test 993 AWD cars all the time on a 2wd dyno as Adrian said by disconnecting the front driveshaft. Works fine. I've done 964C4 on awd dynos just fine.
04-10-2005, 05:12 PM
#12
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Take a look at this picture. This is my C4 on an AWD dyno. The rear wheels are mechanically connected to the front wheels.
You should be able to imagine what would happen if the rear wheels were turning and the fronts were not permitted to turn.
Never put a 964 C4 into a 2WD dyno.
Ciao,
Adrian.
You should be able to imagine what would happen if the rear wheels were turning and the fronts were not permitted to turn.
Never put a 964 C4 into a 2WD dyno.
Ciao,
Adrian.
04-10-2005, 05:59 PM
#13
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Adrian,
I've probably asked this before but do you (or anyone else for that matter) have any pictures showing how/where to properly tie-down a 964 onto a dyno? Triangulate off the toe-hooks? Straps around the control arms? For the past five years I've been able to avoid the state government mandated dynometer emissions testing but I'm not sure I will be able to do so again this year.
I've probably asked this before but do you (or anyone else for that matter) have any pictures showing how/where to properly tie-down a 964 onto a dyno? Triangulate off the toe-hooks? Straps around the control arms? For the past five years I've been able to avoid the state government mandated dynometer emissions testing but I'm not sure I will be able to do so again this year.
04-10-2005, 08:58 PM
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Jason,
The two times I've had mine checked (MASS State Inspection), the inspection guy gave up after looking under the car, and ended up doing some static engine test, idle and 2500 rpm........ he had a fun time trying to keep the speed at 2500 for something like 2 minutes...... but they didn't even try to tie it down....... I wouldn't worry about it.......
The two times I've had mine checked (MASS State Inspection), the inspection guy gave up after looking under the car, and ended up doing some static engine test, idle and 2500 rpm........ he had a fun time trying to keep the speed at 2500 for something like 2 minutes...... but they didn't even try to tie it down....... I wouldn't worry about it.......