craigmakes321

I am dtermined to up grade the intake and exhaust of my '03 996. To that end I have purchased fabspeed headers from a fellow Rennlister, and now am debating x-pipe with cat vs. over-under with cats aftermarket pipes. I will be keeping my PSE muffler system. Any experience/problems/recommendations are appreciated. A heads up on any of these parts for sale would be great too.

As for the plenum,I am leaning toward the IPD x-51 upgrade. The competition model with the larger throttle body seems to add potential problems with the ECU, but let me know what you think!

Thanks

extanker

get a base dyno first

RngTrtl

like extanker recd, get the baseline dyno and then when you are all done, get a finished dyno sheet and compare the two. This will show you and others the gains or the lack there of.

5CHN3LL

Between my 986 and 996, I've tried almost every intake on the market. Other than causing my MTBMSR* to drop dramatically, I saw no benefit. The most commonly cited "benefits" from intake upgrades are "sounds really mean" and "according to the butt dyno, the extensive drop in torque is justified by the impossibly small peak HP boost."

There is some good news, though: 996 intake upgrades are dyno-proven to add at least as much power as all known combinations of JDM/K&N/Nitrous Express stickers.

* Mean time between MAF sensor replacement

extanker

not to mention....well i will......the exhaust DRONE at where you do most of your driving [rpm] from the low torque losing system

craigmakes321

I had a 81 sc that was noticeably improved by changing out the exhaust system.

Going on faith and physics on this one, not interested in parsing the merits of dyo'ing, butt dyno, placebo effect, etc. If I do a dyno now, and don't get anything more than I already have once I have spent the money, I will have a few expensive anchors on my car; kind of a silly way to find out if it works.

I believe the dyno sheets that IPD and Fabspeed put out, and so am really looking for people who have experienced/recommend these or other products.

Mike Murphy

cds72911

I have an IPD Comp and GT3 TB. I don't get any codes, but 1 is a pretty small sample size. Does it do anything but lighten your wallet? Who knows.

I was happy to get rid of the stock exhaust, for weight reduction alone. The stock mufflers weigh a ton. I know you said you wanted to stay stock, but my guess is that is better bang for the buck.

Also, the under drive pulleys seem to be liked - you don't get any more power out of the engine, but you suffer less parasitic drag, so it is like getting a teeny bit of free horsepower to the wheels.

And yes, a TT would be swell, but to me that is not a realistic option - I have normally aspirated 996 because it is the Porsche I can afford that allows me to have a 911 driving experience. Every TT I've looked at (unless it is a tiptronic) is at least 2x or more the price of an equivalent normally aspirated 996. Buying a TT is not a realistic option for me at this time in my life.

5CHN3LL

The $7,500 Fabspeed performance package - which is some beautiful kit, don't get me wrong - works out to $288 per additional HP with a total yield of less than 10% more HP over stock. Trying to accomplish these numbers without the tune (part of this package) would be dang near impossible.

The underdrive crank pulley is far and away the best method to free up some additional power to the wheels. It comes with its own set of potential downsides, but at least the underdrive pulley is a mathematically sound upgrade. The numbers I've seen indicate 10HP increase at the wheels, for a per-HP cost of roughly $21 (based on the cost of the Tarrett pulley, which I used on both my 986 and 996). Anything else you buy - unless it's a matched set like the Fabspeed - is a very expensive crapshoot.

John@Fabspeed

5CHN3LL

Question:
if the $7500 996 Performance package "Increases horsepower and torque by 26 hp and 51 ft-lbs of torque"
(http://www.fabspeed.com/porsche-996-...mance-package/)

and the x-pipe on its own delivers "+25whp/32ft-lbs" for $2,295
http://www.fabspeed.com/porsche-996-...verter-x-pipe/)

The rest of the kit is responsible for an additional 1HP and 19lb-ft...for $5k more?

I'm not trying to be argumentative - but the math here is obviously eluding me.

John@Fabspeed

Totally understandable. You can't 'stack' horsepower per se - there is a point of diminishing returns.

Also, take into consideration the added benefits of the Performance Package include a dramatic increase in low-end along with a much more linear torque curve.

Notice the deltas across the entire powerband compared to just the 996 Sport Cat X-Pipe:

craigmakes321

Yikes! I was trying to avoid this type of thread. My view is any bolt-on mod to any car is probably going to only improve the performance incrementally. It's a matter of willingness to spend for those increments, and what is the total improvement of all increments. IPD guarantees the performance improvements for their product or send it back. Can't go wrong with that.

I am interested in this under-drive pulley, it's the first I have heard about it. Where can I read more? Not to antagonize 5chn3ll, but you say "the numbers I have seen" give 10 more horses for the pulley. Why do you believe "those numbers" anymore than the published dyno sheets from IPD or Fabspeed?

5CHN3LL

I'm not suggesting that Fabspeed or any other reputable vendor would mislead folks about their products' effectiveness. However, the vast majority of lesser 996 "upgrades" are not backed up by dyno results. When folks start stacking crappy parts - Chinese knockoff headers and Chinese knockoff sport cats and a Chinese knockoff intake - the results are almost always crappy; instead of seeing HP and torque gains, you're lucky to not LOSE one, the other, or both.

When I was shopping for an underdrive pulley, I'm pretty sure I found the dyno sheets to back up the numbers. Regardless, the UD pulley is a time-tested and proven way to put more power down. When the engine makes the same amount of power but less of it is used for purposes other than accelerating, you go faster. It's no panacea - your water pump will turn slower than it was designed to across RPM ranges, as will the power steering and alternator. However, it's one of the most economical ways to eke performance out of the M96 without messing with I/H/E.

Again, I'm not knocking Fabspeed - I'd be running some of their stuff if I was interested in putting some serious bling on my 996.

5CHN3LL

The gains from an underdrive pulley are modest, but they are consistent and it's a dirt cheap mod.