Performance improvement for '95 993 - What's worthwhile?
11-10-2001, 01:55 PM
#1
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Performance improvement for '95 993 - What's worthwhile?
I've been giving some thought to doing some relatively minor things to my '95 993 w/ Tiptronic tranmission to enhance the performance.
One of the things that I've thought about is a simple ship upgrade. I came across the following info on the Autothority upgrade - I'm curious if the info is accurate and if this yields any noticable improvement.
Stage 1 Chip upgrade only +13 hp
Stage 2 Chip upgrade + filter +18 hp
Are these results realistic & noticable? Are there other chips available that yield better results?
I was also thinking about an Airbox mod (such as that from Fabspeed) - any opinions?
My intention is to maintain the car as a daily driver; but if I can do some relatively easy/inexpensive things to enhance the performance, that's what I'm after. What things should I be considering? I don't think I'm interested in thingss like rebuilding the engine, supercharging, turbocharging, etc...
Thanks for your input.
One of the things that I've thought about is a simple ship upgrade. I came across the following info on the Autothority upgrade - I'm curious if the info is accurate and if this yields any noticable improvement.
Stage 1 Chip upgrade only +13 hp
Stage 2 Chip upgrade + filter +18 hp
Are these results realistic & noticable? Are there other chips available that yield better results?
I was also thinking about an Airbox mod (such as that from Fabspeed) - any opinions?
My intention is to maintain the car as a daily driver; but if I can do some relatively easy/inexpensive things to enhance the performance, that's what I'm after. What things should I be considering? I don't think I'm interested in thingss like rebuilding the engine, supercharging, turbocharging, etc...
Thanks for your input.
11-10-2001, 07:09 PM
#2
Burning Brakes
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Rick:
If I were you, I would give Steve Weiner and Rennsport Systems a call at 503.244.0990.
He is a frequent contributor to the board and can steer you in the right direction. A chip is not just a chip. It should be programmed to the octane level of gas that you use (or what is available to you). If you are going to spend the $ on a chip, talk to him. They program the chips according to your usage.
As for the airbox change, I believe it does little other than alter the sound of the engine (exhaust). Some might say that it improves hp, but I think it is more of a psychological effect. If a better sound is what you are looking for, talk to Robin for the RSR mufflers (www.p-car.com).
Good luck.
If I were you, I would give Steve Weiner and Rennsport Systems a call at 503.244.0990.
He is a frequent contributor to the board and can steer you in the right direction. A chip is not just a chip. It should be programmed to the octane level of gas that you use (or what is available to you). If you are going to spend the $ on a chip, talk to him. They program the chips according to your usage.
As for the airbox change, I believe it does little other than alter the sound of the engine (exhaust). Some might say that it improves hp, but I think it is more of a psychological effect. If a better sound is what you are looking for, talk to Robin for the RSR mufflers (www.p-car.com).
Good luck.
11-11-2001, 06:11 PM
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A good mod for you to consider is a sports exhaust system that uses a crossover design for the catalytic converters and seperate the two banks of exhaust gasses.
The standard system has the two banks meeting in a central collector which causes a restriction.
You can also replace the standard headers/heat exchangers for a set of equal length units.
In the UK we have performed this conversion and with the headers/cats/sports final silencers, sports intake air filter and chip we see 20bhp and 22N/m torque increase.
The standard system has the two banks meeting in a central collector which causes a restriction.
You can also replace the standard headers/heat exchangers for a set of equal length units.
In the UK we have performed this conversion and with the headers/cats/sports final silencers, sports intake air filter and chip we see 20bhp and 22N/m torque increase.
11-12-2001, 12:35 AM
#4
RL Technical Advisor
FWIW,........ 
The exhaust looks to me like they do merge in the middle but its very hard to tell with all that heat shrouding around them. If I had an extra set here, I would blow some air through to be positive however, Porsche usually connects their exhausts on street cars so its a very good bet.
Connecting both sides makes more power and torque, not less. Its rather critical "where" they join, as well.
I've observed this on every Porsche 911 engine that I've built since 1973; street or race motor. The Dyno doesn't lie,....
IMHO, the 20 HP is coming from perhaps better mufflers and a chip. We get 16-18 HP from the chip, alone. Equal-length headers are great on engines using cams with some duration and overlap to utilize the scavenging pulses generated by such
things. Carrera and even the RS cams used in street-type Motronic engines have wide lobe centers and do not have hardly any overlap (for emissions) and thus, don't respond very much to headers.
Now,....the 3.8 RSR engine (350HP) darned well does respond quite nicely to some good equal-length headers and is well worth it.
Hope this helps,......
The exhaust looks to me like they do merge in the middle but its very hard to tell with all that heat shrouding around them. If I had an extra set here, I would blow some air through to be positive however, Porsche usually connects their exhausts on street cars so its a very good bet.
Connecting both sides makes more power and torque, not less. Its rather critical "where" they join, as well.
I've observed this on every Porsche 911 engine that I've built since 1973; street or race motor. The Dyno doesn't lie,....
IMHO, the 20 HP is coming from perhaps better mufflers and a chip. We get 16-18 HP from the chip, alone. Equal-length headers are great on engines using cams with some duration and overlap to utilize the scavenging pulses generated by such
things. Carrera and even the RS cams used in street-type Motronic engines have wide lobe centers and do not have hardly any overlap (for emissions) and thus, don't respond very much to headers.
Now,....the 3.8 RSR engine (350HP) darned well does respond quite nicely to some good equal-length headers and is well worth it.
Hope this helps,......
11-12-2001, 06:14 AM
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Steve,
I am new to the site, having only recently been introduced by one of my customers (what have I been missing !)
I see that you are one of the regular contributors, and obviously devote much time to the site, great !
With regards to the mods to a '95 model 993, I can only speak from experience here in the UK. I think that due to a number of variables between the UK/European market and America, that different results will be found with similair conversions.
As you say, the dyno does not lie, all our conversions are proven before and after with dyno records, and I congratulate you on your quest to make the fellow members aware that if they are considering any upgrades to follow this practice.
For your information the 993 standard catalytic converter housing meets in the middle and the two banks are not seperated internally.
I agree that the engine requires decent back pressure for the engine to purge the cylinder efficiently, this is why removing the cats will lose torque.
The system that we fit is made by the German company Cargraphic, who I know are represented in the States.
The system that I described is TUV rated for the figures that I quoted. I have found that the TUV tested products tend to ensure that quality proven products hit the market, whereas in the States, I think that you do not have such controls, and a lot of products hit the market that do not work. Believe me, we have fallen foul to this in the past, as have a great many of my customers and colleagues.
An interesting observation, is that Porsche now follow the route of seperating the two banks of gasses, the layout of the 996 clearly proves this.
I am interested if you have actually tried the crossover system in the States, and found it not to work ?
I am new to the site, having only recently been introduced by one of my customers (what have I been missing !)
I see that you are one of the regular contributors, and obviously devote much time to the site, great !
With regards to the mods to a '95 model 993, I can only speak from experience here in the UK. I think that due to a number of variables between the UK/European market and America, that different results will be found with similair conversions.
As you say, the dyno does not lie, all our conversions are proven before and after with dyno records, and I congratulate you on your quest to make the fellow members aware that if they are considering any upgrades to follow this practice.
For your information the 993 standard catalytic converter housing meets in the middle and the two banks are not seperated internally.
I agree that the engine requires decent back pressure for the engine to purge the cylinder efficiently, this is why removing the cats will lose torque.
The system that we fit is made by the German company Cargraphic, who I know are represented in the States.
The system that I described is TUV rated for the figures that I quoted. I have found that the TUV tested products tend to ensure that quality proven products hit the market, whereas in the States, I think that you do not have such controls, and a lot of products hit the market that do not work. Believe me, we have fallen foul to this in the past, as have a great many of my customers and colleagues.
An interesting observation, is that Porsche now follow the route of seperating the two banks of gasses, the layout of the 996 clearly proves this.
I am interested if you have actually tried the crossover system in the States, and found it not to work ?
11-13-2001, 01:08 PM
#6
Rennlist Member
When most people say performance, they generally mean acceleration. I assume this is what you are looking for. IMHO, the most dramatic performance fix is to change out the ring and pinion. There is a unit out from ANDIAL that will lower your final gear ratio in the transaxle some 16%. This equates to better acceleration across the board, of course at the expense of top speed. R&P @ about $1,500 and 20 hours of labor to install and set up the R&P....ergo, about $3,600. Keep in mind your top speed at 170 mph will be lower...you can live with that!
While you are in the tranny, and you have another couple of thousand $'s, consider some close ratio gears, perhaps a 993 RS gear set!In the final analysis, you will have that Mustang/Camero acceleration, and for all intents and purposes, you will have a bone stock 993, and not have messed with the electronics.
If you are up for electronic chip HP, stick with Steve Weiner. He knows what he is doing and has established a fine reputation in the Northwest and across Rennlist.
The air box and filter (Sound Package) is good for some extra noise..I question how much HP evolves from this change...no reliable dyno tests available...the same story with muffler changes, although Joe Fab does have some dyno data for his Fabspeed 993 mufflers. Porsche did a great job with the 993 exhaust...I can't believe many HP can be forthcoming here. If you go to headers, no more cabin heat!
Take the car out on the track, you'll be surprised on how much HP and performance is available from a bone stock 993. I had better get back to work and off this bloody list...it is addictive (The List), not work.
While you are in the tranny, and you have another couple of thousand $'s, consider some close ratio gears, perhaps a 993 RS gear set!In the final analysis, you will have that Mustang/Camero acceleration, and for all intents and purposes, you will have a bone stock 993, and not have messed with the electronics.
If you are up for electronic chip HP, stick with Steve Weiner. He knows what he is doing and has established a fine reputation in the Northwest and across Rennlist.
The air box and filter (Sound Package) is good for some extra noise..I question how much HP evolves from this change...no reliable dyno tests available...the same story with muffler changes, although Joe Fab does have some dyno data for his Fabspeed 993 mufflers. Porsche did a great job with the 993 exhaust...I can't believe many HP can be forthcoming here. If you go to headers, no more cabin heat!
Take the car out on the track, you'll be surprised on how much HP and performance is available from a bone stock 993. I had better get back to work and off this bloody list...it is addictive (The List), not work.
11-13-2001, 01:23 PM
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rick-fwx:
I am not sure what you want to accomplish, but the biggest change you can make to the car is suspension and weight. Suspension is easy, weight is difficult and expensive. A decent suspension can take 2-5 seconds of your lap times at the track while lower weight decreases braking distances, improves turn-in and acceleration. Some areas of weight savings are the hood, front fenders, wheels, carpeting, door panels, radio gear and rear decklid. If you are driving on the street, I wouldn't compromise the crash integrity of the car by removing the front or rear aluminun crash beams or the doors with their integrated intrusion protection bars. Air conditioning and all of its related components are not really a target for street cars either. There is a lot of weight to be saved in the exhaust system, but again, it is expensive and could compromise the streetability of the car.
Just my thoughts,
Hank Cohn
I am not sure what you want to accomplish, but the biggest change you can make to the car is suspension and weight. Suspension is easy, weight is difficult and expensive. A decent suspension can take 2-5 seconds of your lap times at the track while lower weight decreases braking distances, improves turn-in and acceleration. Some areas of weight savings are the hood, front fenders, wheels, carpeting, door panels, radio gear and rear decklid. If you are driving on the street, I wouldn't compromise the crash integrity of the car by removing the front or rear aluminun crash beams or the doors with their integrated intrusion protection bars. Air conditioning and all of its related components are not really a target for street cars either. There is a lot of weight to be saved in the exhaust system, but again, it is expensive and could compromise the streetability of the car.
Just my thoughts,
Hank Cohn
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11-13-2001, 04:56 PM
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schacht993,
the headers that I recommended, are available with or without heat exchangers, so no heater worries!
Hank has a good point, fit the new Bilstein PSS9 dampers, and shave seconds off your lap-times
the headers that I recommended, are available with or without heat exchangers, so no heater worries!
Hank has a good point, fit the new Bilstein PSS9 dampers, and shave seconds off your lap-times
08-19-2009, 12:51 AM
#9
Burning Brakes
I have been searching the forums for more information on this topic and there doesn't seem to be much "current" information. With all of the technological improvements made since the last post here (2001) is it still impossible to make real HP improvements (not just audible) without spending gobs of cash?
08-19-2009, 07:27 AM
#12
Three Wheelin'
Steve, you are correct that the cat (at least on a 95) merges.
The other performance upgrade is stickers. 1hp per sticker. Rennlist sticker is worth maybe 3.
dave
The other performance upgrade is stickers. 1hp per sticker. Rennlist sticker is worth maybe 3.
dave
08-19-2009, 09:12 AM
#13
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When most people say performance, they generally mean acceleration. I assume this is what you are looking for. IMHO, the most dramatic performance fix is to change out the ring and pinion. There is a unit out from ANDIAL that will lower your final gear ratio in the transaxle some 16%. This equates to better acceleration across the board, of course at the expense of top speed. R&P @ about $1,500 and 20 hours of labor to install and set up the R&P....ergo, about $3,600. Keep in mind your top speed at 170 mph will be lower...you can live with that!
While you are in the tranny, and you have another couple of thousand $'s, consider some close ratio gears, perhaps a 993 RS gear set!In the final analysis, you will have that Mustang/Camero acceleration, and for all intents and purposes, you will have a bone stock 993, and not have messed with the electronics.
If you are up for electronic chip HP, stick with Steve Weiner. He knows what he is doing and has established a fine reputation in the Northwest and across Rennlist.
The air box and filter (Sound Package) is good for some extra noise..I question how much HP evolves from this change...no reliable dyno tests available...the same story with muffler changes, although Joe Fab does have some dyno data for his Fabspeed 993 mufflers. Porsche did a great job with the 993 exhaust...I can't believe many HP can be forthcoming here. If you go to headers, no more cabin heat!
Take the car out on the track, you'll be surprised on how much HP and performance is available from a bone stock 993. I had better get back to work and off this bloody list...it is addictive (The List), not work.
While you are in the tranny, and you have another couple of thousand $'s, consider some close ratio gears, perhaps a 993 RS gear set!In the final analysis, you will have that Mustang/Camero acceleration, and for all intents and purposes, you will have a bone stock 993, and not have messed with the electronics.
If you are up for electronic chip HP, stick with Steve Weiner. He knows what he is doing and has established a fine reputation in the Northwest and across Rennlist.
The air box and filter (Sound Package) is good for some extra noise..I question how much HP evolves from this change...no reliable dyno tests available...the same story with muffler changes, although Joe Fab does have some dyno data for his Fabspeed 993 mufflers. Porsche did a great job with the 993 exhaust...I can't believe many HP can be forthcoming here. If you go to headers, no more cabin heat!
Take the car out on the track, you'll be surprised on how much HP and performance is available from a bone stock 993. I had better get back to work and off this bloody list...it is addictive (The List), not work.
08-19-2009, 09:24 AM
#15
Rennlist Member
I don't know if they give any extra power but my Cargraphic 100 cell sports cats certainly freed up the system a lot. It feels a lot easier to rev. Makes a nice noise as well!
Cheers,
David
Cheers,
David