The usual mods yielding no fruit

FYI...From the PCA letters section today (what are we to assume about chipset upgrades after this?): Classification: Engine Subject: 2001 996 No Power Increase Model: 996 C2 Year: 2001 Total Mileage: 57,000 Car Use: Street use only Question: I upgraded my totally stock 996 with B&B Headers and Muffler, Evo Air Intake, and an Upsolute ECU Upgrade. The car was put on the dyno before and after the modifications. I actually "lost" 2 horsepower! The shop that installed the mods other than the computer upgrade had no explanation. I had that done while living in Atlanta. I now live in the Orlando area and am using a local shop for maintenance. They told me the Porsche engines are built at such a high level of high performance from the factory that these upgrades don't offer much of a gain. I find that hard to believe. Is it possible Upsolute accidently "detuned" my computer? The car drives great and performs well but I certainly expected to get better performance for all the money spent. Any ideas??? THX Answer: If you read some of my previous answers to this sort of question, you will know that I am not surprised at your report. Basically as I've said repeatedly, over the years Porsche has left less and less "on the table" in terms of easy power increases. I also say that the only way to know what you're getting is to dyno the car before & after. The next step could be to systematically work through the combinations. For example try the stock exhaust, or another brand of exhaust, and see if that makes any difference, with the other changes still on the car. Joel Reiser - PCA WebSite - 4/20/2007

hhmmm. Seems weird as you'd think that the exhaust would/should let the engine breathe at least a "little" bit better? I'm not totally surprised at the rest though.

I basically agree to the context of this post although I've a K&N CAI and a GHL exhaust on my car. Both sound great and fast but might not have increased HP. However, I still believe that there are legal restrictions like emission- and noise control laws, so Porsche has to choose sub-optimal components, especially for the intake and exhaust. In Germany for instance, cars need to be pretty quiet when passing at certain speeds. I think that's the main reason why Porsche had to add an on/off switch to their PSE system. It's further right that complex electronics interact with mechanical components but doesn't the ECU adapt to a changed set-up, even with the stock software and doesn't it take some break-in time for the ECU and every single of the mentioned mods? Beside power, car manufactures do also try to optimize the fuel efficiency of their cars (more and more regulations request a certain fleet fuel efficiency; the EU is going in this direction, so that's maybe one of the reasons why Porsche tries to buy VW) and set HP and acceleration points of their models in context to their- and other manufacturers car fleets as well as customer demands and market requirements. In a lot of countries tax and insurance premiums vary with the HP of the car, so a 310HP car would cause a higher purchase price and running cost than a 300HP car. Keep in mind, not all customers/P car owners are so car crazy as we are. To optimize (actually reduce) production cost, car manufacturers do also choose sub-optimal materials and designs for their parts (ever heard about lean manufacturing). Porsche as a mass car producer is there no exception. Dynos do not measure the effect of weight gains. Almost every aftermarket exhaust is lighter than the stock system. Summarized, I'm not a strong believer that Porsche squeezed every potential out of their cars but it might be right that quick wins are hard to find.

Considering that 2001 was the last year of the 3.4 it makes sense. If a simple exhaust, intake and chip was all the car needed for additionally power, why would Porsche have increased the capacity to 3.6 in 2002 for a 25hp increase? I have not seen good evidence that the typical bolt on mods (other than an SC) on the 3.4 or 3.6 of the 911 have resulted in much if any increase in power. In fact there is some indication that most aftermarket exhaust systems that claim peak power increases have some torque and/or power loss in the lower RPM's. Porsche really seems be optimizing the flat 6 in the modern 911 and not leaving much on the table. However, I don't think that is necessarily true on the Boxster S and Cayman S, as there seems to be some evidence that at least on the exhaust side gains can be made. To me this appears to be a result of intentional "detuning" by Porsche to not upset the intended performance position of the Cayman S relative to the rest of Porsche line up. However, as mentioned above weight savings can definitely equal to better performance numbers out of the same power. I think the market pressure to GTize the 911 have definitely taken there toll in this area. So if installing a heavier & quieter vs. louder & lighter exhaust (with the same power) is intentional detuning, then yes Porsche "detunes" the car.

Corrected or uncorrected HP? Can be a big difference.

Unless you have a TT..then the chip does give70-100hp and 60-100lbft....really. JB

Yes on turbo cars a chip does alot because it allows more turbo boost, and then gives you more hp....

No arguement from me...the Turbo is a completely different animal than the NA cars. Modifications definitely provide gains in the Turbo.

This "issue" is not inclusive to Porsche's naturally aspirated engines. Power gains from I/H/E/ECU on my two previous cars (S2000's F20C and the M3's S54) are neglible, though many people try to prove earnestly that they do in order to justify their $s expended. I want the aftermarket exhaust because of the looks/weight savings/ and most importantly, sound. The intake is more for sound than anything else. Headers, imo, are a complete waste of $. Enjoy your swaps for what it is -- don't expect any power gains from them on n/a engined rides 911 or BMW or Honda or Toyota or Ferrari.

great info...its so hard to NOT spend money on those things. It almost like you want to spend money even if you dont need or it wont do a thing. I am convinced..no more "performance" mods...just looks, sounds, maybe suspension (I already have the RoWm030 set up).

Look at what the X51 has. To get 25 hp PAG changed the heads, intake, cams, computer, headers and more! There is NO way that a k&n air filter will get you 25hp.

Sure would like to see a dyno graph or two.

Probably needed new spark plugs. :-)

Only mod that would give you more power (lots and lots more power) is the Supercharger. All others are for show or sound improvements

i say forget the engine mod and save up for the next one......