new thoughts: on pro's and con's of 3.8litre conversion?
#16
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Another question on this subject please
The ROW gear option sounds VERY appealing, and I know it doesn't add DIRECTLY to the HP rating, but what kind of HP would you figure it adds from the improved performance?.......the 10-15 HP you get from a chip.....the 18 HP you get from a 3.8 conversion....the 100 hp you would get from supercharging?
Thanks
The ROW gear option sounds VERY appealing, and I know it doesn't add DIRECTLY to the HP rating, but what kind of HP would you figure it adds from the improved performance?.......the 10-15 HP you get from a chip.....the 18 HP you get from a 3.8 conversion....the 100 hp you would get from supercharging?
Thanks
#18
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Just as food for thought the full kit which includes
- 6 cylinderheads, bare
- 6 intake valves 51.5 mm
- 6 exhaust valves 43.5 mm
- 6 piston and Cylinders 102.0 mm
- 2 camshafts Euro RS ( for hydr. lifters )
- 6 intake bloc's
- 2 intake manifolds
#19
Three Wheelin'
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[quote]Originally posted by Shark01:
<strong>Another question on this subject please
The ROW gear option sounds VERY appealing, and I know it doesn't add DIRECTLY to the HP rating, but what kind of HP would you figure it adds from the improved performance?.......the 10-15 HP you get from a chip.....the 18 HP you get from a 3.8 conversion....the 100 hp you would get from supercharging?
Thanks</strong><hr></blockquote>
Shark,
I have the G50/21-2. It is not really like adding 50hp... it is a great upgrade and the car is quicker (with the help of the LWF upgrade) The key with this upgrade is you stay in the power band shifting from 2nd to 3rd 4th to 5th ect. The rev drop on the upshift does not take you out of the sweet spot (I think the rev drop is around 200rpms) thus you have more power at your disposal. If my car was a street only car, I'm not sure it would be worth the 6K it is going to cost you to regear your trans. 6K will only get you 3/4 of the way. Once the box is opened, you will be tempted to change your shift forks, steel syncros for 2nd gear (assuming you used steel for 3rd-6th) for these 2 improvements your looking at another 2500.00 at least. Also, while its out, the aforementioned LWF/clutch, 2K... you see what I mean? For a car that lives on the track, it is a great upgrade as any track junkie will tell you, you can never be fast enough and the ROW gear box will help with that quest!
<strong>Another question on this subject please
The ROW gear option sounds VERY appealing, and I know it doesn't add DIRECTLY to the HP rating, but what kind of HP would you figure it adds from the improved performance?.......the 10-15 HP you get from a chip.....the 18 HP you get from a 3.8 conversion....the 100 hp you would get from supercharging?
Thanks</strong><hr></blockquote>
Shark,
I have the G50/21-2. It is not really like adding 50hp... it is a great upgrade and the car is quicker (with the help of the LWF upgrade) The key with this upgrade is you stay in the power band shifting from 2nd to 3rd 4th to 5th ect. The rev drop on the upshift does not take you out of the sweet spot (I think the rev drop is around 200rpms) thus you have more power at your disposal. If my car was a street only car, I'm not sure it would be worth the 6K it is going to cost you to regear your trans. 6K will only get you 3/4 of the way. Once the box is opened, you will be tempted to change your shift forks, steel syncros for 2nd gear (assuming you used steel for 3rd-6th) for these 2 improvements your looking at another 2500.00 at least. Also, while its out, the aforementioned LWF/clutch, 2K... you see what I mean? For a car that lives on the track, it is a great upgrade as any track junkie will tell you, you can never be fast enough and the ROW gear box will help with that quest!
#20
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Blackdawg:
You got a lot of good answers especially from the guys who have done it, like Vinny and 993RS. Steve Weiner as always cuts directly to the best (bang for buck) engine/drivetrain modifications regarding his comments on gears, LWF and a chip. Others have mentioned this, but it depends on what you are planning on doing with your car. I feel that the biggest feature of the 3.8l kit is bragging rights. If you are racing your car and the only mod you haven’t done is the motor, then it makes good sense to consider that modification, however; there are several modifications that I would prioritize before the motor. My list would look something like the following: (most of these items are aimed at DE and Club Racing)
Light weight wheels and R Compound tires
Suspension (shocks, springs, monoball tops and strut brace)
Race seats and proper racing harnesses
Brake upgrade
LWF
Roll bar or roll cage
Reducing the car’s weight
DME/Chip upgrade
Solid engine and transmission mounts
Additional suspension components like the RS uprights and monoball cartridges
Transmission re gear
3.8l upgrade
The OEM Porsche Power kit is not recommended for SERIOUS racing because the cylinders are of a slip fit design. It is fine for the street and moderate short distance club race type activities. As Steve W. points out, there are other ways to get to 3.8l than the OEM power kit. I have done all of these mods and more on a previous 993 and was very disappointed in the engine upgrade. You do get a little more HP and more torque, but not $16,000 worth. Weight reduction, suspension and gears were some of the best modifications once the basic stuff was done. This is just my opinion and other drivers/racers would most likely prioritize mods differently, but it is another data point from someone who has done it.
You got a lot of good answers especially from the guys who have done it, like Vinny and 993RS. Steve Weiner as always cuts directly to the best (bang for buck) engine/drivetrain modifications regarding his comments on gears, LWF and a chip. Others have mentioned this, but it depends on what you are planning on doing with your car. I feel that the biggest feature of the 3.8l kit is bragging rights. If you are racing your car and the only mod you haven’t done is the motor, then it makes good sense to consider that modification, however; there are several modifications that I would prioritize before the motor. My list would look something like the following: (most of these items are aimed at DE and Club Racing)
Light weight wheels and R Compound tires
Suspension (shocks, springs, monoball tops and strut brace)
Race seats and proper racing harnesses
Brake upgrade
LWF
Roll bar or roll cage
Reducing the car’s weight
DME/Chip upgrade
Solid engine and transmission mounts
Additional suspension components like the RS uprights and monoball cartridges
Transmission re gear
3.8l upgrade
The OEM Porsche Power kit is not recommended for SERIOUS racing because the cylinders are of a slip fit design. It is fine for the street and moderate short distance club race type activities. As Steve W. points out, there are other ways to get to 3.8l than the OEM power kit. I have done all of these mods and more on a previous 993 and was very disappointed in the engine upgrade. You do get a little more HP and more torque, but not $16,000 worth. Weight reduction, suspension and gears were some of the best modifications once the basic stuff was done. This is just my opinion and other drivers/racers would most likely prioritize mods differently, but it is another data point from someone who has done it.
#21
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I've recently considered the g50/21/31 upgrade. I called a local mechanic and Paul Guard about pricing. Both recommended that if you're going to do this, and stay with spec ratios, its better to buy an entire transmission then actually regearing the existing unit. It can get pricey if you have a fixed 2nd gear (mess with the mainshaft) and want the steel synchros, so i was told. I was quoted a new /31 box for $7500. Of course, this may not be economically feasiable for some.
#22
RL Technical Advisor
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Hi:
Just a short note on the regearing option,....
There are a few ways to do this and each one has varying tradeoffs. I'd tell someone that the "50 HP" equivalent really applies to a close-ratio gearset, rather than ROW or RS setup.
One thing we do here is install the current 5th gear into the 6th gear position, and change 2nd, 3rd, 4th, and 5th to suit. Most folks do not need a car that goes 160+ MPH; what they really want is a car that is bloody quick to 120 MPH and still cruise down the highway.
This is really a neat setup and FAR better than the RS or RSCS gear stack, IMHO of course.....
Just a short note on the regearing option,....
There are a few ways to do this and each one has varying tradeoffs. I'd tell someone that the "50 HP" equivalent really applies to a close-ratio gearset, rather than ROW or RS setup.
One thing we do here is install the current 5th gear into the 6th gear position, and change 2nd, 3rd, 4th, and 5th to suit. Most folks do not need a car that goes 160+ MPH; what they really want is a car that is bloody quick to 120 MPH and still cruise down the highway.
This is really a neat setup and FAR better than the RS or RSCS gear stack, IMHO of course.....
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#23
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[quote]Originally posted by Hank Cohn:
<strong>....because the cylinders are of a slip fit design. ...</strong><hr></blockquote>
What is "slip fit design" and in what way is it different from the basic stock design? Would appreciate any comments. Thanks.
<strong>....because the cylinders are of a slip fit design. ...</strong><hr></blockquote>
What is "slip fit design" and in what way is it different from the basic stock design? Would appreciate any comments. Thanks.
#24
RL Technical Advisor
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[quote]Originally posted by Ran:
<strong>
What is "slip fit design" and in what way is it different from the basic stock design? Would appreciate any comments. Thanks.</strong><hr></blockquote>
Hi Ran:
There are 2 different 102mm P/C sets used for 3.8 conversions that differ in cylinder wall thickness.
The ones used on the 3.8 RS have the same wall thickness that the original 100mm (3.6) ones do so these can be "slipped in" the case without any machine work.
The second ones are used are the 3.8 RSR race engine and are thicker so the case spigots must be enlarged to fit. Everyone calls this set the "bore-in" ones, and these are far superior for racing and very high compression use. As these are much thicker, they stay round when hot and the ring seal is much much better!
Hope this helps,
<strong>
What is "slip fit design" and in what way is it different from the basic stock design? Would appreciate any comments. Thanks.</strong><hr></blockquote>
Hi Ran:
There are 2 different 102mm P/C sets used for 3.8 conversions that differ in cylinder wall thickness.
The ones used on the 3.8 RS have the same wall thickness that the original 100mm (3.6) ones do so these can be "slipped in" the case without any machine work.
The second ones are used are the 3.8 RSR race engine and are thicker so the case spigots must be enlarged to fit. Everyone calls this set the "bore-in" ones, and these are far superior for racing and very high compression use. As these are much thicker, they stay round when hot and the ring seal is much much better!
Hope this helps,
#25
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I came real,real close to the 3.8 enhancement while my C2S was at Werk 1. At the time, April-02, the factory was having difficulty sourcing the cams for the 3.8 kit, however it was the cost vs. performance which jettisoned the idea.
Here's what I opted for: A ROW G50/21-2 gearbox,RS short shift kit and ROW M030.
Having driven the car briefly in Germany I can report that the ROW gearbox & shift kit is the bomb! The engines sweet spot is always close by.
Lufthansa Air Cargo just delivered the car to LAX this week and I can't wait to retrieve it.
Road Trip to Colorado...take-n-the back roads listening to the engine all the way.
Here's what I opted for: A ROW G50/21-2 gearbox,RS short shift kit and ROW M030.
Having driven the car briefly in Germany I can report that the ROW gearbox & shift kit is the bomb! The engines sweet spot is always close by.
Lufthansa Air Cargo just delivered the car to LAX this week and I can't wait to retrieve it.
Road Trip to Colorado...take-n-the back roads listening to the engine all the way.