casualsurfer

I've looked high and low and all I see are people buying piecemeals and their comments. I'm curious to see Cobb Stage 2 Power Pack's actual dyno results vs. Prodrive Stage 3 Power Pack's actual dyno results, and also personal feelings.

Could anyone help?

casualsurfer

I'm going to do some analysis of both vendors' claims. Let's take a look at the basic components:

Prodrive Power Pack Stage 3:
- Rear muffler
- Mid pipe
- Catless downpipe
- Catless uppipe
- Intercooler Y pipe
- ECU reflash

Dyno Chart


Cobb Stage 2:
- Turbo back exhaust
- AccessECU

Dyno Chart


Now since I'm a newbie, I will guess that Cobb's turbo back exhaust system includes all of the stuff Prodrive includes except for the intercooler Y pipe.

Comparing the claimed numbers:
Prodrive (using the 4th gear numbers)
HP: 228.2 @ 7317RPMs
Torque: 222.2 Kpa @ 4251RPMs

Cobb:
HP: 224.4 @ 5500RPMs
Torque: 223.2 @ 5100RPMs

- I don't know the conversion between Kilo Pascal to lb/ft (assuming that's what the Mustang Dyno was spitting out), but let's set that one aside for now.

All my experience in tuning are from doing B-series and F20C (S2000), but a dynochart is a dynochart, so let's discuss.

1. The parts lists don't seem that much different - you have most of the basic bolt-ons, the ECU tuning. Difference is in the Y-pipe. And from all the reading I've done, the Y pipe supposedly does give some gains (Samco pipes), so 1 extra brownie point for Prodrive.

2. 3rd gear dyno seems to be odd for the WRX. I only did a quick search and read about STi's need to dyno in 5th gear, but I'm assuming WRX would dyno more accurately at 4th? When I used to dyno S2000s, 3rd gear was the way to go because it was closest to the 1:1 ratio.

- Problem: I don't know what gear was used for Cobb's dyno runs. Different gears can show different results.

3. Peak numbers: This is what most ricers care about, and (unfortunately) what most magazines talk about. When I used to tune my S2000, the goal wasn't all about peak power, it's the entire powerband - I'm sure for most of us that holds true. It's pretty obvious that Cobb's chart shows it peaking before Prodrive's curve, but Prodrive's curve doesn't seem to peak and fall like Cobb's (although the fall seemed pretty smooth.

- Problem: I don't know the gap between the sample numbers taken for each chart, so although Cobb's curve seemed smoother than Prodrive, it's very difficult to tell if that's due to number of samples or it's an inherent feature of the mustang dyno.

4. Performance numbers:

Cobb's claim based on customer feedback:
0-60 mph : 4.6 seconds
1/4 mile : 13.4 @ 101.5 mph

Prodrive's claim
0-60 mph : 5.08 seconds
1/4 mile : 13.76 @ 96.85 mph

- Problem: The difference of 0.52 seconds here from 0-60 is significant enough to question the driver's abilities, and also each car's environmental factors of the day of testing (temperature, humidity, altitude, etc.), plus each car's other equipment - for example, was Cobb's car stripped? Was Prodrive's car stripped? What was the weight of each car? What tires were used? Tire pressure?

5. Conclusion: with a price difference of $809 plus tax, it would seem at first glance that Cobb is the way to go. From the dyno chart given, it allows the turbo to spool faster, reaches peak power quicker, and pretty much maintains that peak power through redline with some degradation. However, looking at Prodrive's power curve, it seems to make sense for someone who might want to have a nice and steadily rising power curve (instead of a drop) as you reach higher into the RPM range.

My biggest problem when I started tuning S2000 back in 2000~2002 was the VTEC spike and the huge drop in power past 8300RPMs to redline. There were ways to move the curve to the right, but eventually the S2000 community figured out more and more ways to do it (check www.s2ki.com for more info).

Tuning is based on personal philosophy. I would like to see everyone's opinion but I firmly believe in taking a look at the numbers and charts - that is, if they are equal in terms of the equipment used and testing methods. The easiest conclusion I reached from looking at the 2 charts is that I can't make up my mind! Both seemed genuine, but each used a different testing method and God knows what each car's condition was.

So, where can I find dyno charts on 2 similarly equipped cars running purely on Cobb and purely on Prodrive?

Irvine Subaru recommends Prodrive, I'm leaning towards Prodrive because they're down the street from me. However, I don't know if I could NOT tinker with my car as time goes on. I had, for example, no less than 7 different exhaust systems on my S2000 - well, I was dyno tuning and selling the stuff so I had no choice at the time, but each one had its advantages and disadvantages.

I'm not wealthy, but I do feel comfortable enough to pluck down some money for the WRX. I didn't get the STi because I needed to be low key about my car, and also the 1.9% APR financing didn't apply to STi

casualsurfer

Question: what's the difference between Cobb's ECU and Cobb's AccessPort handheld device? Should I get both?