which power kit do I get
 

Im unsure which package to get for my 98. There is the fabspeed maxflow exaust system from fabspeed.com or the 2.5l stage 3 power kit from ********************************************.com What do you guys think?

Michael

I think all the aftermarket power kits for a 2.5L are a waste of time and $$$. Get to the track, fine tune your driving chops and add a nice set of sticky tires.

The one from auto atlanta claims a 30hp increase. How can that be a waist?

Don't believe everything you read on the internet.

You get betta grains by going wit this.

http://www.electricsupercharger.com/

You ask to see their dyno charts and compare them
 

and ask if you get your money back if you don't achieve their claimed gains...because you won't. I know a fellow who tried over a dozen mufflers on his car looking for one his shop could recommend. He has his own dyno so it was a very controlled experiment. He was really surprised at how many of the mufflers actually lost HP, torque and mileage. He also took the car with each muffler out on the road to see if there were real world problems or improvements. Most of the mufflers had an unbearable drone.

Be very careful of the claims made.

I've seen a 2,700.00 muffler reduce output over a stock arrangement by over 25HP on a stock 3.2 engine.

My experience with most aftermarket equipment for these engines has been very unfavorable.. It seems that too many things are developed for sound or visual appeal.

To get 30HP I have to increase displacement or add my cams and head work... Then i still use a stock muffler!

performance gains on the porsche
 

Michael,
I used to work for a company called PPR (pacific power racing) on silverstone race course. We used to manufacture all manner of complete exhaust systems for cars such as fomula 300, williams renault touring cars and the porsche but to name a few.
As has been stated in this thread it is very very hard to get ANY performance gains out of changing the system for some shiny model on the porsche. We had to develope a system for the carrera 4 and managed to get hold of a Porsche GB system to compare. Even with improved welding techniques (TIG as apposed to the mig used) pulse tuning the very short system and using different lengths of perforated bends inside (radius formed) we saw only losses !!
In the end we had a guy who uesd a venturi system (several cones and changes of size) different types of damping material we only ever made a 7hp gain on superchips rolling road.
A full pulse tuned gas flowed system with reduced core catalist would be both expensive and although it would reduce restriction it would only be enough to see very small gains.

Hope this helps

Regards
Steve

So all the headers, all the cold air intakes, and all these muffelers don't do anything?!?!? Why in the world do they sell and claim all this crap then.

$$$$$$$$$$$ :)

"ALL" would be a term that would be too general, as some things do give some gain.. I have yet to see anything that performed as well as it should for the cost, thats the difference.. Most just cost a lot of money and add an annoying drone to the engine.

Guess why you see these systems advertised so much?? Because thats what sells them, its not word of mouth and the systems exceeding expectations. I have learned that lots of people buy the systems for a sound or because they cost LESS in some instances than replacement OE systems.

I have also seen some people buy them just so they'd have the ability to add them to their signature line along with all their other snazzy gadgets that they've added to their cars. That sure is an expensive signature line!

The claims are generally made because the developers generally don't expect anyone to test their products more extensively than they do... I have sent many emails and reports to some of these companies over time, but none have even had the common decency to respond...

The one company that made the system that LOST 27HP on a bone stock 3.2 engine said the engine was "breaking" when the test was done.. But they had no explanation for the next group of data that I provided when we swapped the stock system back onto the engine and picked up 25 of that 27 HP loss back to back!

The problem is few of these people know what makes an engine function, fewer have ever made a single repair on an M96 engine or done more than add some "modifications" to it...

Fact is a 250.00 under drive pulley adds more power than most any other single modification...

I'm curious then how Fabspeed posts these dynos? Do they just run until they find anomolies?

The previous owner had this work done to mine, so I thought it was a nice bonus when I picked the car up. Also this car moved better than the other I testdrove, but that one could have had something else going on, or it could have just been the 200lb salesman in the passenger seat :D

But still I just don't know how in good conscience this company can make these claims if by everyone else's accounts, they flatly adversely affect HP.

Yet again we are talking generally here.. Some systems DO give some sort of gain, but the question is how much each one of those additional HP costs.

I sourced a set of expensive headers for my Wife's 996 Land Speed Car (that holds 4 records) and installed them.. I did back to back dyno work and no matter what I could not get back the 6Hp that they cost me, until I removed them and went back to stock. Using the data logger (DL-2) the 0-60 and 40-80 ETs substantiated what the dyno illustrated.

How much is 5Hp worth??? I can get 5-7 (RWHP) with a 225.00 pulley!

Now I am no dyno expert, but I had a pro shop here in Houston do back-to-back dyno pulls on my boxster before and after I put on my cheap eBay headers and I had a nice HP and torque bump. The weather was stable that day too (in other words, it didn't start pouring down rain mid day which would have changed both temp and humidity factors)...I'm just sayin'

The loud, twin-chamber aftermarket muffler I added did not diminish gains from the new headers and stock cats. Makes the car sound more powerful than it is though and the cabin drone is deafening if you're stuck in traffic with the top up (ie, for rainy days) and moving through 2-3k RPM's a lot of the time.

I've dumped plenty of money into my car (arguably more than most every other forum member) and doing a high speed DE was hands-down the best way to discover my 2.5 doesn't need any more power. Holy crap it's got LOADS of power when driven right on a track.

A vast majority of us driving our cars in town light-to-light make us feel the car is underpowered and we want more torque. It's just not designed for this kind of driving... buying a 997 Turbo if you're rich or a Corvette (if you're not as rich) is the car for straight line performance.

The cheap ebay headers aren't a bad deal.. Because you pay an adequate amount for the power they give.

Above that, I have been less than impressed.. If I have a chance tomorrow evening between appointments I'll drag up some of the dyno comparisons I did back in 2008 and post them.

Randall,
Would you mind sharing the numbers?
I have some Chinese headers sitting on my shelf in fear of breaking header bolts for a minimal gain.
Your numbers may convince me to have someone do the install for me.

Dyno graphs attached

Randall's gains are less than I have seen with the Chinese headers.. But his power numbers are in line with all the cars I have had on my dynojet that were in good health.

Randall, which are the before and after direct runs?

Thanks Randall
It looks like you saw ~ 10HP / 7TQ gain right away & it seemed to climb another 5HP as the computer learned the new breathing capabilities.
That's around 9% HP & 12% TQ gain. More than I expected. Looks like I need to do this.

Any other variables in play between runs 4/5 and 6/7/8?

Summary:
Baseline
Run 1 169.80 HP 149.56 TQ
Run 3 169.27 HP 147.91 TQ

Chinese Headers
Run 4 179.27 HP 165.85 TQ
Run 5 179.65 HP 164.38 TQ

Twin-Chamber Muffler + Chinese Headers
Run 6 181.29 HP 165.63 TQ
Run 7 182.51 HP 166.24 TQ
Run 8 184.24 HP 166.92 TQ

Actually, it's not the breathing as much as it was adding the muffler.

The first run was a baseline. The second was after the Chinese headers were added. The third was after the muffler was added to the Chinese headers.

My butt dyno felt the bump in torque and the parts were free, so I couldn't lose on this deal... except for the twin chamber muffler being so freakin' loud with cabin resonance.