In an effort to put out the best possible PEMs we've researched and hit a wall. The problem lies in the front header piece. Opening the inlet as people are isn't doing anything because the inlets are already 1.53" (as big as the port in the head). The problem is the lower section of the manifold. It's 2" OD and 1.63" ID. At that section you're sharing with the other ports.Trying to exhaust all 3 front cylinders out of a single 1 5/8" pipe is crazy. It's no wonder so many people pop front pistons and have questionable gains from other PEMs on the market. The rear manifold and crossover aren't as bad. Notice the crossover is also 2" OD, like the front mani, but because it's thin wall you get 1.91 ID. So, the front mani is the narrowest section of the exhaust, giving you 2.09 sq/in of exhaust area. The crossover and rear manifold are up to 2.89 sq/in. So the front manifold section is over 30% smaller than the entire rest of the manifold network and it's the only section that guys selling PEMs aren't doing!

Fortunately ZZPerformance now offers a cost effective solution. The powerlog uses 1 5/8 primaries which feed a 2 1/4" pipe into the crossover. Uses factory mounting, so all the factory bolts and gaskets can be re-used.

Now with no core charge on front Power logs, angled primaries, stainless tig welds, and machined flange with larger opening.

• Excellent for use with our downpipes
• No loss in torque as seen with headers on the L36 engines
• Perfect upgrade for turbo kits (stainless version only)
• Low cost 
• Lowers KR and keeps the front bank of pistons safer.
• Quicker engine cool downs from eliminating the cast iron
• Power log is 5 pounds lighter than OEM cast front!
• Doing the front only gives great gains and takes less than 30 minutes!

*Do not wrap these exhaust pieces as cracking can result.

Customer updates from May of 2007

Over 10WHP gained from the addition of the powerlog and no other changes!

I also wanted to post that I just went through my 1st full tank of gas after the plog (yes I drive a lot) and I have picked up a few MPG as well. About 35-40 miles extra to the tank on the exact same commute as before the plog. Below is from another member who scanned before and after his powerlog install. Notice how much more timing is achieved and KR eliminated! Stock front exhaust manifold scan below, as you can see some light KR up top. Powerlog Added scan this is with the front 3 cylinders skewed with 2% extra fuel. I also added 1-2 degrees extra timing and raised my Base PE by .1 (leaner).