RS fan hub instl photos
#31
Yeah. It works fine, just not ideal for normal street driving. Sluggish at low rpm. And I assume lots of potential carbon buildup since very weak spark down there. Once you are over 3k, it's full amperage from the alternator and nothing to worry about. So until I switch, I am 3k+ all the time.
#34
No argues...but guys- lots of guys have used the RS pulley with no issues for years- so did I. Except that the issue is there if you look closer.
You won't kill anything using the RS pulley - but if you are curious - stick a tester on the battery and measure volts and amps at various rpm. Over 3k matches 1:1 with and without the single belt conversion. Down below, not so much. But it'll run fine to the normal "butt dyno"...no worries. For me the difference was enough to change back...
You won't kill anything using the RS pulley - but if you are curious - stick a tester on the battery and measure volts and amps at various rpm. Over 3k matches 1:1 with and without the single belt conversion. Down below, not so much. But it'll run fine to the normal "butt dyno"...no worries. For me the difference was enough to change back...
#36
Is the "low voltage at idle" issue with the single pulley belt also there on a standard 964 RS from the factory or are there other differences on the RS that makes the low rpm voltage not an issue?
What is the OEM RS idle speed from factory?
I have a 964 carrera that was built as a 964 RS 3.8 replica and is fitted with a basically new 3.8 built engine that use a 993 engine block and electronics as a base and Individual throttle bodies.
At Idle speed there is some ( ! ) dash error light many times and the idle is rough ( probably to be expected with ITB and single pulley etc ) and as soon as I accelerate a little more to about 2000 rpm the dash error light turns off by itself.
I think that probably as others reported the alternator makes a too low voltage at low idle with single pulley and apart from fitting back a standard pulley setup I d like to know if there are any other things or mods to improve the low idle voltage without reverting back to standard.
Thanks
What is the OEM RS idle speed from factory?
I have a 964 carrera that was built as a 964 RS 3.8 replica and is fitted with a basically new 3.8 built engine that use a 993 engine block and electronics as a base and Individual throttle bodies.
At Idle speed there is some ( ! ) dash error light many times and the idle is rough ( probably to be expected with ITB and single pulley etc ) and as soon as I accelerate a little more to about 2000 rpm the dash error light turns off by itself.
I think that probably as others reported the alternator makes a too low voltage at low idle with single pulley and apart from fitting back a standard pulley setup I d like to know if there are any other things or mods to improve the low idle voltage without reverting back to standard.
Thanks
#37
Is the "low voltage at idle" issue with the single pulley belt also there on a standard 964 RS from the factory or are there other differences on the RS that makes the low rpm voltage not an issue?
What is the OEM RS idle speed from factory?
I have a 964 carrera that was built as a 964 RS 3.8 replica and is fitted with a basically new 3.8 built engine that use a 993 engine block and electronics as a base and Individual throttle bodies.
At Idle speed there is some ( ! ) dash error light many times and the idle is rough ( probably to be expected with ITB and single pulley etc ) and as soon as I accelerate a little more to about 2000 rpm the dash error light turns off by itself.
I think that probably as others reported the alternator makes a too low voltage at low idle with single pulley and apart from fitting back a standard pulley setup I d like to know if there are any other things or mods to improve the low idle voltage without reverting back to standard.
Thanks
What is the OEM RS idle speed from factory?
I have a 964 carrera that was built as a 964 RS 3.8 replica and is fitted with a basically new 3.8 built engine that use a 993 engine block and electronics as a base and Individual throttle bodies.
At Idle speed there is some ( ! ) dash error light many times and the idle is rough ( probably to be expected with ITB and single pulley etc ) and as soon as I accelerate a little more to about 2000 rpm the dash error light turns off by itself.
I think that probably as others reported the alternator makes a too low voltage at low idle with single pulley and apart from fitting back a standard pulley setup I d like to know if there are any other things or mods to improve the low idle voltage without reverting back to standard.
Thanks
Does your battery stay charged, or do you know the draw at idle with whatever electronics you are normally running? Amp issue?
#38
My Idle was about 850 to 890 rpm and I noticed that I had to give a slight throttle input for the engine to start well and that when idling especially when cold it was a little rough and low and the ( ! ) warning light was turning on and then off as soon as I accelerate above 1500 rpm...
I adjusted the idle mechanically to around 1100 rpm and it seems to be much better starts without throttle and no error on dash etc...
I think that especially with my eninge buit 3.8 engine setup with ITB, cams, single pulley, etc... the alternator does not give enough voltage at just 850 rpm...
But still I d like to know the OEM RS ( and eventually RSR ) recommended idle, and if there are any other mods ( or eventually an aftermarket alternator ) that would improve the spark between idle and 3000 rpm with the single pulley setup
I don't know the actual draw at idle but I do not have particular problems with the battery charge ( but I disconnect it when not in use and charge it so not sure about that )
I adjusted the idle mechanically to around 1100 rpm and it seems to be much better starts without throttle and no error on dash etc...
I think that especially with my eninge buit 3.8 engine setup with ITB, cams, single pulley, etc... the alternator does not give enough voltage at just 850 rpm...
But still I d like to know the OEM RS ( and eventually RSR ) recommended idle, and if there are any other mods ( or eventually an aftermarket alternator ) that would improve the spark between idle and 3000 rpm with the single pulley setup
I don't know the actual draw at idle but I do not have particular problems with the battery charge ( but I disconnect it when not in use and charge it so not sure about that )
Last edited by Maxi_z; 11-08-2021 at 06:57 AM.
#39
My Idle was about 850 to 890 rpm and I noticed that I had to give a slight throttle input for the engine to start well and that when idling especially when cold it was a little rough and low and the ( ! ) warning light was turning on and then off as soon as I accelerate above 1500 rpm...
I adjusted the idle mechanically to around 1100 rpm and it seems to be much better starts without throttle and no error on dash etc...
I think that especially with my eninge buit 3.8 engine setup with ITB, cams, single pulley, etc... the alternator does not give enough voltage at just 850 rpm...
But still I d like to know the OEM RS ( and eventually RSR ) recommended idle, and if there are any other mods ( or eventually an aftermarket alternator ) that would improve the spark between idle and 3000 rpm with the single pulley setup
I don't know the actual draw at idle but I do not have particular problems with the battery charge ( but I disconnect it when not in use and charge it so not sure about that )
I adjusted the idle mechanically to around 1100 rpm and it seems to be much better starts without throttle and no error on dash etc...
I think that especially with my eninge buit 3.8 engine setup with ITB, cams, single pulley, etc... the alternator does not give enough voltage at just 850 rpm...
But still I d like to know the OEM RS ( and eventually RSR ) recommended idle, and if there are any other mods ( or eventually an aftermarket alternator ) that would improve the spark between idle and 3000 rpm with the single pulley setup
I don't know the actual draw at idle but I do not have particular problems with the battery charge ( but I disconnect it when not in use and charge it so not sure about that )
Is it the RS/RSR idle rpm or the power requirements at idle for those cars? Weren’t those really stripped down? The alt doesn’t provide full amp@idle.
There is a 6 phase alternator out there by Classic Retrofit that provides more amp at idle.
Last edited by Ubipa; 11-08-2021 at 07:19 AM.