996 Performance

[Abraxas]

Greetings All,

New to Renntech; love the site and am very impressed by all the expertise and helpful posts available. I'm sure this has been discussed elsewhere (but I don't seem to be able to locate the relevant post). I have a 1999 C2 (6sp) with a Fabspeed performance exhaust (from cat back) fitted. Sounds great and the quality is excellent. Any suggestions for additional (mild) performance upgrades? I'm thinking of helping the engine breath better and consider putting in a cold air intake and/or revised plenum. I've read about potential problems resulting from air flow sensors effects and check engine lights. Also, would you recommend starting to think about an ECU upgrade? Thank you.

[Cesarfl]

Greetings All,

New to Renntech; love the site and am very impressed by all the expertise and helpful posts available. I'm sure this has been discussed elsewhere (but I don't seem to be able to locate the relevant post). I have a 1999 C2 (6sp) with a Fabspeed performance exhaust (from cat back) fitted. Sounds great and the quality is excellent. Any suggestions for additional (mild) performance upgrades? I'm thinking of helping the engine breath better and consider putting in a cold air intake and/or revised plenum. I've read about potential problems resulting from air flow sensors effects and check engine lights. Also, would you recommend starting to think about an ECU upgrade? Thank you.

Don't waste your money, not much you can do to the engine, other that supercharger upgrade about 10K, or buy a turbo 996 instead, other than that you are going to spend a ton of money for no more than 10 HP.

[Abraxas]

Greetings All,

New to Renntech; love the site and am very impressed by all the expertise and helpful posts available. I'm sure this has been discussed elsewhere (but I don't seem to be able to locate the relevant post). I have a 1999 C2 (6sp) with a Fabspeed performance exhaust (from cat back) fitted. Sounds great and the quality is excellent. Any suggestions for additional (mild) performance upgrades? I'm thinking of helping the engine breath better and consider putting in a cold air intake and/or revised plenum. I've read about potential problems resulting from air flow sensors effects and check engine lights. Also, would you recommend starting to think about an ECU upgrade? Thank you.

Don't waste your money, not much you can do to the engine, other that supercharger upgrade about 10K, or buy a turbo 996 instead, other than that you are going to spend a ton of money for no more than 10 HP.

Thanks for your reply and sharing your insights, Cesarfl. I'm not looking for maximum raw power here as I actually like the characteristics of the naturally aspirated engine for everyday driving. The upgrades I'm looking for make a noticeable difference at lower revs. If I end up with about 30 to 35 additional hp (incl. exhaust, air intake, plenum) and related torque gains, that's a 10 plus percent increase in total hp.

[Loren]

Greetings All,

New to Renntech; love the site and am very impressed by all the expertise and helpful posts available. I'm sure this has been discussed elsewhere (but I don't seem to be able to locate the relevant post). I have a 1999 C2 (6sp) with a Fabspeed performance exhaust (from cat back) fitted. Sounds great and the quality is excellent. Any suggestions for additional (mild) performance upgrades? I'm thinking of helping the engine breath better and consider putting in a cold air intake and/or revised plenum. I've read about potential problems resulting from air flow sensors effects and check engine lights. Also, would you recommend starting to think about an ECU upgrade? Thank you.

Don't waste your money, not much you can do to the engine, other that supercharger upgrade about 10K, or buy a turbo 996 instead, other than that you are going to spend a ton of money for no more than 10 HP.

Thanks for your reply and sharing your insights, Cesarfl. I'm not looking for maximum raw power here as I actually like the characteristics of the naturally aspirated engine for everyday driving. The upgrades I'm looking for make a noticeable difference at lower revs. If I end up with about 30 to 35 additional hp (incl. exhaust, air intake, plenum) and related torque gains, that's a 10 plus percent increase in total hp.

I agree I seriously doubt you will get what these folks are advertising on a normally aspirated car. In some case folks lose midrange power and torque.

[c70Pete]

Greetings All,

New to Renntech; love the site and am very impressed by all the expertise and helpful posts available. I'm sure this has been discussed elsewhere (but I don't seem to be able to locate the relevant post). I have a 1999 C2 (6sp) with a Fabspeed performance exhaust (from cat back) fitted. Sounds great and the quality is excellent. Any suggestions for additional (mild) performance upgrades? I'm thinking of helping the engine breath better and consider putting in a cold air intake and/or revised plenum. I've read about potential problems resulting from air flow sensors effects and check engine lights. Also, would you recommend starting to think about an ECU upgrade? Thank you.

Don't waste your money, not much you can do to the engine, other that supercharger upgrade about 10K, or buy a turbo 996 instead, other than that you are going to spend a ton of money for no more than 10 HP.

Thanks for your reply and sharing your insights, Cesarfl. I'm not looking for maximum raw power here as I actually like the characteristics of the naturally aspirated engine for everyday driving. The upgrades I'm looking for make a noticeable difference at lower revs. If I end up with about 30 to 35 additional hp (incl. exhaust, air intake, plenum) and related torque gains, that's a 10 plus percent increase in total hp.

I agree I seriously doubt you will get what these folks are advertising on a normally aspirated car. In some case folks lose midrange power and torque.

I agree with Loren... I don't know about 35 hp.... change in powerband is more likely.... however..

I also have a 99 C2 with with PSE and found the GIAC ECU flash to be worthwhile upgrade... feels good after 4500 rpm and removes the lethartic spot in the 3.4 engine @ 3200 rpm....

I would recommend the GIAC flash and if that's not enough then some 200 cell hi-flow cats from Cargraphic (excellent quality) for more top end punch... the GIAC flash will adapt nicely to those cats... but that's it.. don't bother with headers.... I also don't know about the plenum... questionable.

[Abraxas]

Greetings All,

New to Renntech; love the site and am very impressed by all the expertise and helpful posts available. I'm sure this has been discussed elsewhere (but I don't seem to be able to locate the relevant post). I have a 1999 C2 (6sp) with a Fabspeed performance exhaust (from cat back) fitted. Sounds great and the quality is excellent. Any suggestions for additional (mild) performance upgrades? I'm thinking of helping the engine breath better and consider putting in a cold air intake and/or revised plenum. I've read about potential problems resulting from air flow sensors effects and check engine lights. Also, would you recommend starting to think about an ECU upgrade? Thank you.

Don't waste your money, not much you can do to the engine, other that supercharger upgrade about 10K, or buy a turbo 996 instead, other than that you are going to spend a ton of money for no more than 10 HP.

Thanks for your reply and sharing your insights, Cesarfl. I'm not looking for maximum raw power here as I actually like the characteristics of the naturally aspirated engine for everyday driving. The upgrades I'm looking for make a noticeable difference at lower revs. If I end up with about 30 to 35 additional hp (incl. exhaust, air intake, plenum) and related torque gains, that's a 10 plus percent increase in total hp.

I agree I seriously doubt you will get what these folks are advertising on a normally aspirated car. In some case folks lose midrange power and torque.

I agree with Loren... I don't know about 35 hp.... change in powerband is more likely.... however..

I also have a 99 C2 with with PSE and found the GIAC ECU flash to be worthwhile upgrade... feels good after 4500 rpm and removes the lethartic spot in the 3.4 engine @ 3200 rpm....

I would recommend the GIAC flash and if that's not enough then some 200 cell hi-flow cats from Cargraphic (excellent quality) for more top end punch... the GIAC flash will adapt nicely to those cats... but that's it.. don't bother with headers.... I also don't know about the plenum... questionable.

Thank you all for your feedback. Now, basically the consensus here is that the gains in hp and torque of any of the abovementioned modifications (exhaust, cold air intake, ecu upgrade) are, in fact, not additive? The manufacturers will state dynoed 10-20 hp at the rear wheels for any of the mods. To me it's then a question of making sure that the components work well together and lead to improvements in the desired segment of the powerband. For example, GIAC ECU flashs are available specifically for vehicles with performance exhausts and/or cold air intake fitted. Any downsided to the ECU flash as far as drivability is concerned. I would really like to keep the car as close to stock as possible with just a little extra low end power and proper Porsche sound (which I've already achieved).

[dr914jr]

I have cold air intake and plenum on my 99 996. I can say that the upgrades have given me the ability to hang with my friends 06 GTO.(He's not a happy camper.) The extra power is minimal but the sound is worth twice the money. :D

[KevinMac]

I hope the mods are not the reason you can stay with a GTO, hopefully the GTO you are talking about is the 400HP version, since the published specs are pretty close with the 996 edging the goat out in 0-60. ( based on published #'s after test drives)

Anyway be careful with the cold air intakes, some suck in hot air and may cause a lower output. I agree the published numbers adverised by OEM mods is over exagerated.

Edited August 12, 2008 by KevinMac

[dr914jr]

Ya he has a stock 6.0 with the SAP package. While numbers don't lie on the street it was apparent he had a slight edge due to his wider than factory rear tires. Traction is all that stops him from crushing me entirely. But after opening up the intake and installing headers the field is level once again.

I couldn't agree more that it's important to have a shield to protect the cool air.

[Yoops Racing]

when I bought my 99 996 I asked all the same questions and yes many will tell you if you are looking for 30-150 extra hp dont waste your time on anything but Superchargers and a 15k price tag. I thankfully did not listen. I have added some toys to my stock 996 that I have enjoyed the results from. The RSS plenum and EVOMS cold air intake woke up my sleeper 996. I just added aftermkt exhaust and even though the sounds is quite a bit louder than stock - it is a nice addition. I will consider a ECU flash to tie it all together, but so far I do not feel any loss of any power anywhere in the rpm range. My advice is this - if you want to spend some $$$ on upgrades, Go to the forums that offer group discounts/group buys to save some money. Anything for these P cars is ridiculously expensive compared to aftermkt mustang or vette parts. We as owners have a bullseye on our backs to pay more for everything because it says porsche...buyer beware.

Most importantly....have fun doing it. Remember the Twin Turbo prices are falling quick, and will continue to drop and for mid 40s low 50s you can get all the horsepower you need.....

[c70Pete]

when I bought my 99 996 I asked all the same questions and yes many will tell you if you are looking for 30-150 extra hp dont waste your time on anything but Superchargers and a 15k price tag. I thankfully did not listen. I have added some toys to my stock 996 that I have enjoyed the results from. The RSS plenum and EVOMS cold air intake woke up my sleeper 996. I just added aftermkt exhaust and even though the sounds is quite a bit louder than stock - it is a nice addition. I will consider a ECU flash to tie it all together, but so far I do not feel any loss of any power anywhere in the rpm range. My advice is this - if you want to spend some $$$ on upgrades, Go to the forums that offer group discounts/group buys to save some money. Anything for these P cars is ridiculously expensive compared to aftermkt mustang or vette parts. We as owners have a bullseye on our backs to pay more for everything because it says porsche...buyer beware.

Most importantly....have fun doing it. Remember the Twin Turbo prices are falling quick, and will continue to drop and for mid 40s low 50s you can get all the horsepower you need.....

interesting... I LOST power with the EVOMS intake on my 99 C2 and went back to the stock airbox & K&N filter with great results... I haven't tried the plenum yet...

when you flash your car with the GIAC flash I'd be interested to hear some feedback given the mods you have...

[dr914jr]

I use the K&N 63 series that has a heat shield. I can't say that it's instillation helped or hurt performance but the sound is intoxicating. The IPD plenum was the exact opposite. There was only a slight difference in sound but the extra power was very apparent. I was very impressed with how much thought went into the design of the plenum. You never know what you're going to get in terms of quality in the after market. It was nice not to be disappointed.

[Yoops Racing]

interesting... I LOST power with the EVOMS intake on my 99 C2 and went back to the stock airbox & K&N filter with great results... I haven't tried the plenum yet...

when you flash your car with the GIAC flash I'd be interested to hear some feedback given the mods you have...

hmmm I did not notice any power loss with just the EVOMS...but the sound definitey was changed for the better. I believe when you add any of this aftermarket crap to a 996 you have to give the ECU time to "get used to" or compensate for the changes The plenum woke it up and seems to complement the EVOMS - I guess better air flow = more power and better throttle response. My new mufflers have definitely added power and one sweet sound.

I am researching Flash options now - hopefully more to come.

Edited August 14, 2008 by Yoops Racing

[sixtosune]

I have a (Very) early 996 C2 with low miles (km's actually, 52.000). I read lots of posts on the EVOMS/ K&N 63 CAI's; I ended up going for the K&N 63 CAI. I'm not sure if I really gained power (although throttle response is better, and I could swear from 4,5k to 7k it really does feel quite a bit livelier) but the SOUND is absolutely Intoxicating and utterly addictive :jump: . The only thing I'm still planning to do is to swap the K&N filter with a Dryflow unit from AEM (seems like a sensible way to insure against the oily K&N eventually blowing my dear MAF).

Next for me will be mufflers, sport cats and headers. I'm really inclined for the Fabspeed.

Again, all in all I don't belive there's that much to gain in terms of HP even with all these mods (certainly not what the manufactures of these parts usually claim) but the gains in terms of response and SOUND (yes this is quite important, specially in water-cooled 911's, who all sound like vacuum cleaners in stock form, from all the emissions-legislation-restrictive-crap that Porsche has had to add to comply with this that and the other regulation..) make it all worthwhile. A feast to our sensory organs. I don't think I'd trade up to a Turbo either; there's something to be said about a simple but beautiful sounding, normally aspirated, 2wd 911.

btw this is my first post here even though I've been lurking around for a while; great forum Loren ! I'll make my way to the donations page.

Edited August 20, 2008 by sixtosune

[medtech]

Abraxas,

I would like you to have performance & save money. Since you already have an exhaust that flows well and sounds good you don't need to do anything else there.

As far as the intake, I would highly suggest the BMC F1 free flow filter for $110. It seems too simple but it works great. You will get much better sound and better throttle response (especially on a tiptronic). I think it has just as much if not more surface area than the EVOMS CAI (I haven't measured them). If you take out your stock airbox and look at it up close you will see that it is very well designed and has all the elements of a CAI already built into it. It sucks cold air in via the snorkel, and it that's not enough air then it has holes drilled in the bottom. It's huge! And I suppose if you wanted even more airflow you could probably cut away a corner and cover it with mesh. Personally, I ordered the EVOMS CAI, and after taking apart the stock airbox, I sent it back.

Take the other $400 you would have spent on the CAI and spend it on a suspension upgrade.

Good Luck!

A

:renntech:

[KevinMac]

Just out of curiosity anyone try the 996 RSS Intake Plenum.

http://www.rpmracinginc.com/2products-rss.htm

Edited August 21, 2008 by KevinMac

[dr914jr]

I have've had the RSS plenum installed for about two months now. After installing headers, intake, and plenum I can say definitively the plenum offered by far the most noticeable gains. The car is clearly more responsive and powerfull throughout the entire rpm range. I was very nervous about shelling out the $1000 but I have been very happy with the purchase.

[silver arrow]

Butt dynos are very tricky to calibrate properly. Find a local dyno day before you do any upgrades and dyno the car after upgrades. Try to match conditions as close as possible and you will probably find that those telling you to expect 10hp are correct. If you want a better sound, by all means get an exhaust, but I wouldn't expect a lot of extra hp.

[Abraxas]

Abraxas,

I would like you to have performance & save money. Since you already have an exhaust that flows well and sounds good you don't need to do anything else there.

As far as the intake, I would highly suggest the BMC F1 free flow filter for $110. It seems too simple but it works great. You will get much better sound and better throttle response (especially on a tiptronic). I think it has just as much if not more surface area than the EVOMS CAI (I haven't measured them). If you take out your stock airbox and look at it up close you will see that it is very well designed and has all the elements of a CAI already built into it. It sucks cold air in via the snorkel, and it that's not enough air then it has holes drilled in the bottom. It's huge! And I suppose if you wanted even more airflow you could probably cut away a corner and cover it with mesh. Personally, I ordered the EVOMS CAI, and after taking apart the stock airbox, I sent it back.

Take the other $400 you would have spent on the CAI and spend it on a suspension upgrade.

Good Luck!

A

:renntech: