Modifying a Porsche G50 Transaxle
- Thread starter Bill D
- Start date
Bill,
No need to reverse anything in the G50/52 if run behind the engine and inverted.
When mounted in a Posrsche, the transaxle is in front of the engine. Mentally rotate the engine/transaxle combination around the drive shafts so that the engine is in front. The transaxle is now upside down (inverted) as is the engine. If the engine would run in such a situation, the drive forces and gearing would work just fine. In a GT40, we replace the Porsche engine with a Ford engine (right side up) by using an adapter plate.
Now ... depending on the clearance you have at the rear of the tranaxle, you may have to replace or modify the tail housing to get enough room. G50/50 tail housings are shorter and so come up every once in a while at the salvagers.
Hope this helps.
No need to reverse anything in the G50/52 if run behind the engine and inverted.
When mounted in a Posrsche, the transaxle is in front of the engine. Mentally rotate the engine/transaxle combination around the drive shafts so that the engine is in front. The transaxle is now upside down (inverted) as is the engine. If the engine would run in such a situation, the drive forces and gearing would work just fine. In a GT40, we replace the Porsche engine with a Ford engine (right side up) by using an adapter plate.
Now ... depending on the clearance you have at the rear of the tranaxle, you may have to replace or modify the tail housing to get enough room. G50/50 tail housings are shorter and so come up every once in a while at the salvagers.
Hope this helps.
Bill,
Spray bars are needed in high horse power applications ... as is transaxle oil cooling. I lucked into a zero hour box with all of the fittings for spray bars so I'm going to use them and run the oil through a cooler while I'm at it.
Depends on just how heavy a foot you intend to imploy.
I really don't think these things are going to hold up to a 4000 rpm clutch dump launch. Might want to try to restrain yourself from that sort of thing.
Ah ... the compromises we make ;>)
Spray bars are needed in high horse power applications ... as is transaxle oil cooling. I lucked into a zero hour box with all of the fittings for spray bars so I'm going to use them and run the oil through a cooler while I'm at it.
Depends on just how heavy a foot you intend to imploy.
I really don't think these things are going to hold up to a 4000 rpm clutch dump launch. Might want to try to restrain yourself from that sort of thing.
Ah ... the compromises we make ;>)
Ron McCall
Supporter
Mike,
Is there a supplier in the US that offers a "turn key" G-50 with the spray bars and such?
I am planning 660hp and 500tq.
What about a clutch?
What is available and how much $$$?
Thanks,
Is there a supplier in the US that offers a "turn key" G-50 with the spray bars and such?
I am planning 660hp and 500tq.
What about a clutch?
What is available and how much $$$?
Thanks,
Talk to Chris Fisher at Powerhaus II ([email protected]). If anyone can make a G50/52 survive, they can.
I would worry about that much HP though ... sounds like you might be in RBT land or in need of a Porsche 930 transaxle which I believe were used with engines approaching a 1000 horse. They are 4 speeds and do take some restructuring for our kind of use.
By the way, I thought I was a bid daft for the big powerplant going into mine. I suspect a real cam in it would deliver 550 hp. At what point is enough ... enough?
I would worry about that much HP though ... sounds like you might be in RBT land or in need of a Porsche 930 transaxle which I believe were used with engines approaching a 1000 horse. They are 4 speeds and do take some restructuring for our kind of use.
By the way, I thought I was a bid daft for the big powerplant going into mine. I suspect a real cam in it would deliver 550 hp. At what point is enough ... enough?
Tim Kay
Lifetime Supporter
Patera1889 & BillD
My .02, the complete oiler setup is recommended most definitely for prolonged racing, ie endurance. For track days and around town, street racing the benefit of oiling the gears would be minimal. Although, simply oiling the ring gear alone is a good idea regardless, due to the fact that when the trans is inverted the ring gear is not 'bathing' in oil as it is when not inverted. Also, as Mike said, the cooler is a good idea as well.
Along with Patrick Motorsports there is guy in Lake Havasu City that has a Porsche trans shop named California MotorSports. His name is Bobby Hart @ 928-855-5755. He also does the rebuilds and oiler setups along with shorten nose pieces and cable shift units.
My .02, the complete oiler setup is recommended most definitely for prolonged racing, ie endurance. For track days and around town, street racing the benefit of oiling the gears would be minimal. Although, simply oiling the ring gear alone is a good idea regardless, due to the fact that when the trans is inverted the ring gear is not 'bathing' in oil as it is when not inverted. Also, as Mike said, the cooler is a good idea as well.
Along with Patrick Motorsports there is guy in Lake Havasu City that has a Porsche trans shop named California MotorSports. His name is Bobby Hart @ 928-855-5755. He also does the rebuilds and oiler setups along with shorten nose pieces and cable shift units.
[ QUOTE ]
They are 4 speeds and do take some restructuring for our kind of use.
[/ QUOTE ]
What sort of restructuring are you talking about Mike? I will be using one of these units and any info would be most appreciated.
They are 4 speeds and do take some restructuring for our kind of use.
[/ QUOTE ]
What sort of restructuring are you talking about Mike? I will be using one of these units and any info would be most appreciated.
The ring gear of the 930 has to be flipped.
See www.renegadehybrids.com for details.
Renegade does good work..but bring big checkbook.
MikeD
See www.renegadehybrids.com for details.
Renegade does good work..but bring big checkbook.
MikeD
[ QUOTE ]
The ring gear of the 930 has to be flipped.
[/ QUOTE ]
Mike Dozier. Not if you invert it.
Mike Starling. Was that what you were referring too? Or is there other work that is worth doing?
Regards,
The ring gear of the 930 has to be flipped.
[/ QUOTE ]
Mike Dozier. Not if you invert it.
Mike Starling. Was that what you were referring too? Or is there other work that is worth doing?
Regards,
Russ,
Spent all day finishing the adapters from the half shafts to the G50/52 ... 17-4PH SS is a B**ch to tap. I am so glad to have that job done! Just checked in to the forum.
To be clear, I have no personal experience with the 930 box. I was refering to the flip of the ring gear as mentioned by a number of folks who have used them. Apparently these guys were not able to invert the box due to some steric limitation in their chassis design.
Please let us know if whst you find out as you work though your installation!
Thanks,
Spent all day finishing the adapters from the half shafts to the G50/52 ... 17-4PH SS is a B**ch to tap. I am so glad to have that job done! Just checked in to the forum.
To be clear, I have no personal experience with the 930 box. I was refering to the flip of the ring gear as mentioned by a number of folks who have used them. Apparently these guys were not able to invert the box due to some steric limitation in their chassis design.
Please let us know if whst you find out as you work though your installation!
Thanks,
Chris Duncan
Supporter
""Is there a supplier in the US that offers a "turn key" G-50 with the spray bars and such? ""
Patrick Motorsports and PowerHaus II are the ones I know of.
Don't forget the difference between the G50-0X series and the G50-5X series.
The -0X is good to about 450HP and the 5X to about 600HP.
The difference is the 5X has a larger ring gear.
""I am planning 660hp and 500tq.""
no sidestepping the clutch with either of these
""What about a clutch?""
KEP makes a nice single disc, light press plate, good to about 600HP
""What is available and how much $$$?""
With limited slip the -0X is about $3500 and the -5X is about $7000 in "turn key" condition from a builder. Maybe less from an individual owner.
Patrick Motorsports and PowerHaus II are the ones I know of.
Don't forget the difference between the G50-0X series and the G50-5X series.
The -0X is good to about 450HP and the 5X to about 600HP.
The difference is the 5X has a larger ring gear.
""I am planning 660hp and 500tq.""
no sidestepping the clutch with either of these
""What about a clutch?""
KEP makes a nice single disc, light press plate, good to about 600HP
""What is available and how much $$$?""
With limited slip the -0X is about $3500 and the -5X is about $7000 in "turn key" condition from a builder. Maybe less from an individual owner.
Chris Duncan
Supporter
""due to the fact that when the trans is inverted the ring gear is not 'bathing' in oil as it is when not inverted""
There's not much difference in oiling when the G50 is inverted other than having to run the oil level a little higher. This may result in a small loss of HP which is essentially negated by running Redline synthetic. The ring gear is bathed regardless it's the diff bearings that need the higher oil level to reach them.
Spray oiling and a cooler is mandated by higher HP and endurance requirements in either the normal or inverted position, but like you say it's not really necessary for street and occasional track use.
There's not much difference in oiling when the G50 is inverted other than having to run the oil level a little higher. This may result in a small loss of HP which is essentially negated by running Redline synthetic. The ring gear is bathed regardless it's the diff bearings that need the higher oil level to reach them.
Spray oiling and a cooler is mandated by higher HP and endurance requirements in either the normal or inverted position, but like you say it's not really necessary for street and occasional track use.
Ron McCall
Supporter
Thanks guys.
Bill,
I think you're right on the edge of the strength of a standard G50. My concern would be that going Yah-ha on it once too many times would destroy it.
The adapters are not the same. Depending on the approach to the starter, the flywheels, clutch, and pressure plates are different too.
Kennedy indicates that the following clutch and pressure plate for the G50/52 (the short one with the ring gear in front that uses the long Porsche starter as opposed to the longer G50 or G50/50 clutch with the ring gear in the rear) are good to 525 lb-ft of torque:
Clutch Disk
Porsche part number for "Club" clutch disk with the springs
I2010-60518
Pressure Plate
Porsche part number for 3100-3400 lb clamp force pressure plate for 1992-911 Turbo:
I2000-33738
I think you're right on the edge of the strength of a standard G50. My concern would be that going Yah-ha on it once too many times would destroy it.
The adapters are not the same. Depending on the approach to the starter, the flywheels, clutch, and pressure plates are different too.
Kennedy indicates that the following clutch and pressure plate for the G50/52 (the short one with the ring gear in front that uses the long Porsche starter as opposed to the longer G50 or G50/50 clutch with the ring gear in the rear) are good to 525 lb-ft of torque:
Clutch Disk
Porsche part number for "Club" clutch disk with the springs
I2010-60518
Pressure Plate
Porsche part number for 3100-3400 lb clamp force pressure plate for 1992-911 Turbo:
I2000-33738
Peter Delaney
GT40s Supporter
[ QUOTE ]
There's not much difference in oiling when the G50 is inverted other than having to run the oil level a little higher. This may result in a small loss of HP which is essentially negated by running Redline synthetic. The ring gear is bathed regardless it's the diff bearings that need the higher oil level to reach them.
[/ QUOTE ]
Hi Kalun, I have heard so many variations as to how much oil to run in an inverted stock G50 - anywhere from 3 to 4 Litres. When you say "a little higher", does that mean nearer the 4L mark, or as some owners recommend, just filling the box up to the level of the side filler plug ?
Any clues would be greatly appreciated.
Kind Regards,
Peter D.
There's not much difference in oiling when the G50 is inverted other than having to run the oil level a little higher. This may result in a small loss of HP which is essentially negated by running Redline synthetic. The ring gear is bathed regardless it's the diff bearings that need the higher oil level to reach them.
[/ QUOTE ]
Hi Kalun, I have heard so many variations as to how much oil to run in an inverted stock G50 - anywhere from 3 to 4 Litres. When you say "a little higher", does that mean nearer the 4L mark, or as some owners recommend, just filling the box up to the level of the side filler plug ?
Any clues would be greatly appreciated.
Kind Regards,
Peter D.
Tim Kay
Lifetime Supporter
Peter,
I have a vent on the top of my G50\52 so I put in 4 quarts plus or minus (I have a cooler and pump) then I attach a catch can to the vent and run the car. Any excess blows out the vent into the catch can. If none comes out, add some 'till it does. (This is only in theory /ubbthreads/images/graemlins/blush.gif , my trans builder decribed this procedure. I have yet to apply it to my new installation /ubbthreads/images/graemlins/smile.gif)
I have a vent on the top of my G50\52 so I put in 4 quarts plus or minus (I have a cooler and pump) then I attach a catch can to the vent and run the car. Any excess blows out the vent into the catch can. If none comes out, add some 'till it does. (This is only in theory /ubbthreads/images/graemlins/blush.gif , my trans builder decribed this procedure. I have yet to apply it to my new installation /ubbthreads/images/graemlins/smile.gif)
For those who are going to cool the oil of a transaxle, the differential oil pump sold by Pegasus for the purpose IS the Tilton pump ... at a cost of $199.95 which is the cheapest I've seen! Mine arrived yesterday and I was very pleasantly surprised to find a Tilton box inside the big box.
http://www.pegasusautoracing.com/ProductDetails.asp?RecId=156
http://www.pegasusautoracing.com/ProductDetails.asp?RecId=156
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