hwk72

Can it be that the hp loss would have changed when (a) driving some time with the new headers as the ECU would have adapted to the new exhaust flow or (b) with a ECU flash that would consider the design of the new headers.

What I'm still trying to find out is what effect the exhaust backpressure issue has on the performance as the ECU is programmed to support a specific (stock) set-up.

Mfletch

JW, sorry about your disappointing results. I'm sure I will get flamed over this; however, I think you just proved that you get what you pay for. I may be ignorant, but the only thing that I really care about when considering the benefit of a performance modification is does it make my car go faster both on the street and the track The improved sound is an added bonus. You did a great job (by doing a before & after dyno run) of showing that the cheap headers are a waste of money. I would not give up on the idea altogether. I bought a quality set of headers, Billy Boat, and put them side by side next to the stock header. The difference in quality is obvious. Look at this months issue of Excellence. There are several companies that build or sell what appear to be (I have not seen all of them in person) quality headers including Tubi, Fabspeed, Supersprint, Billy Boat, Remus, Evolution Motorsports, Cross, etc.
We all know that Evolution Motorsport's Vortech supercharger system adds horsepower consistent with what they claim. I don't understand why we don't believe their claims regarding their other products (cold air induction, exhaust system, GIAC chip). I have dealt with several companies while rebuilding my 996 that went way above and beyond in helping me. Evolution Motorsports and The Racers Group were just two of those companies. I wouldn't hesitate to call The Racer's Group and ask them what headers they recommend & what kind of improvement you should expect.
I don't think too many people will argue that RUF and 9ff have been able to seriously improve the Porsches that they have worked their magic on. In the February 2005 issue of Excellence there is an article titled "Jet Blue: an early 996 reveals it's truecolors" It is their interpretation of a 996 Club Sport. They take a 3.4 996 put it on a diet and added some more power. They increased power to 337bhp and 269.4 ft/lb of torque. They claim a 0-60 time of 4.7 seconds and a top speed of 185 mph. This article provides an excellent blueprint for improving the performance of our cars. The engine modifications included a larger volume aluminum intake manifold, high lift camshafts & stronger valve springs, gas flowed & shaved cylinder heads, headers using larger diameter equal-length pipes, modified mufflers with larger pipes, recalibrated ECU, and a GT3 Cup intake & BMC air cleaner....We can get more power out of our cars, it just comes at a price.

10 GT3

Mfletch, you are right to a point. Do you think that it costs anymore to make a good set of headers for a 911 over a Mustang? The only factor here is volume. The design time and materials are the same. There is no questionable doubt that make of our parts are artifiically inflated. Other parts like B&M shifters for our cars are in the same price range as other lower makes.

If you talk to Ruf about intakes, headers and exhausts; they will tell you they are all worthless. They haven't seen major gains from header s or intakes and no gains from Porsche's PSE. Keep in mind that these comments are based on the parts they tested, mostly sourced from Germany. They haven't tested an EVO or a K&N intake. They haven't tested a Fabspeed or a Tubi exhaust. That doesn't mean you can't make gains. I made 22 rwhp with a pair of used Fabspeed mufflers and a K&N intake. There may be headers out there that make decent gains, but you have to put them on your car and dyno test them to find out for sure.

This is why this was a really good thread. It is a real world result, not the typical opinions without a basis of fact.

ScottArizona

I would love to see a before and after dyno with just a set of quality headers. I know my mechanic, who I trust a great deal swears by the fabspeed units, and is so confident about the benefits he offers rides in his customers' cars before purchase so that the potential buyer can determine whether it is worthwhile.

ElTorrente

I read that same article, and I like the 9ff. It is interesting though, that several mags have tested the c2 - totally stock - at 4.6secs to 60. They did a lot of expensive modifications to that car in order to squeeze out the performance, and I think it's obvious that you just can't bolt on some headers and really expect much to happen.

Headers will allow slightly more power in the higher rpm ranges, and they will shift the torque band higher. O.k., that's fine if you are at the drag strip- but 99.9999% of the time that I'm not actually in the act of racing someone, especially on a 3.4ltr car, I want that torque in the lower rpm range for driveability.

Mfletch

02 Carrera, I couldn't agree more about the cost of Mustang vs Porsche headers. I actually had a set of inexpensive headers on my Saleen (MAC unequal length shortys...less then $200) that made a ton of power.
El Torrente, I think those of us with the tip (especially those of us with a lead right foot) are able to get more frequent use of the higher rpm range because in the auto mode it will kick down to the lowest gear possible.

jw996

If anyone is interested in my headers to see how they perform on their car, I'll take $100 + shp. PM me. I know you guys are going to be fighting over them. They looook real preddy. JW

Porsche_Smile

preddy is all that matters jw...... i'll take 20......gl with the ebay sale...... word of advice, don't post the dyno....

Shark

Here is the definative statement. Headers work better than manifolds because the seperate exhaust streams are kept seperated longer........letting the energy disapate before the streams are jammed together creating turbulence and back pressure.

This is why long headers work better than shorties......which is the problem in a rear engine, rear exhaust car.....there just isn't enough room.

RayGT3

Big gains are made on headers that enter the collector in the firing order. They are big and ugly, not used commonly as there is a bunch of plumbing piping crossing from one side of the engine to the other, but they really work well. Probablly a best case performance wise but not real practicle.

turbo138

Hi Jw, I'll take your header.
Thanks.

jw996

Hold the pressess, I was at the shop switching out the headers and when the first one was un bolted and dropped down the gasket was put on wrong blocking 35-40% of the out flow, from the head. Put gasket on correctly and drove short distance. Seems that it initially runs better, seat of pants dyno. With the brain fart corrected, I will get a better read and might dyno again out of curiosity. Makes since why I would of lost so much power considering that one engine bank was restricted 35-40% at least,that would of really sent mixed signals to ecu. I know you guys are choppen at the bit to buy my pipes but you will have to wait on ecu and dyno run for real #'s. Keep you posted. JW

Gator911

That is one hell of a loss for a header...

What were the conditions of both dynos

jw996

Temperatures were probably 10 degree difference. If you saw how much of the chamber was blocked by metal gasket you would assume that was what caused such a great loss. The ecu was also probably effected also. I will let you know next week after new dyno run. JW

Dale Gribble

good on you jw...you've done the rennlist community a great service and we appreciate your input.

patiently waiting the new results.

cheers!