Hello All,Curious if anyone has proven stillens catback exhaust claim of 20hp/20ft of torque,by dyno before and after?Thanks Tom

I highly doubt it. They make good stuff, but always over-rated IMO.

It will not give you an AVERAGE increase of 20/20. But if you take the worst baseline run, then take the best stillen run, you will probably get close to 20/20. I have an 03.5 5AT sedan and dynoed 211HP stock and 229HP after. The Stillen is a good, well built system. Good fitment and the newer, quieter version is supposed to sound great. You will not be disappointed with the gains. It pulls real strong. Actually feels like more than 20 IMO. Ive got the resonated testpipes on there now and those really boosted power even more. When it kicks down a gear at WOT, it really hits hard.

A suggestion. As part of your personal research you might want to check out the mods on the top seven cars that dynoed in the 17 car G35 Dyno Marathon (SolCal Dyno Day) a while back. Then get a copy of our Exhaust Shootout Article (Fall 2003) as well as Turbo Magazine's December 2004 issue.

DaveO

I recall seeing someone do a pre and post Stillen CAI + Catback
at Dynopack a while ago.. (it was in the old g35driver forum tho)
and pulled a peak increase of 25/20 hp, tq..

i will try to see if i can find the dyno plot

hope this helps,
Godmans

Expect 8-10whp/wtq on a Dynojet for the Borla or Stillen dual exhausts whether it's a G or a Z. Other advantages of these exhausts are their lighter weight and improved sound. Don't expect a legit 20whp. It's BS.

Dave I always enjoy reading the other side from your perspective. Some of the time I think you're right and say what others don't want to hear.

The one thing I would like to suggest is a slight name change for you though to- "Doubting Dave"

Forget the dual exhaust. Just get the Stillen axle-back... But who do we know thats selling the stillen axle-back for a cheap price? Hmmm?

I believe the Stillen is about 20-lbs HEAVIER than stock. -T

Even with the dual piping, it is much lighter than stock.

Trust me, I had to transport both my stock exhaust and the Stillen.

This is the first time I am hearing the Stillen is 'lighter' than stock. Of course I am speaking in terms of the COUPE not sedan, but the old version STILLEN coupe was HEAVIER than stock. It was the exhaust which provided the most GAINS but the only downside was that it was NOISY and HEAVY (I heard the revision is quieter...but not sure if its lighter). Again this all may be irrelevant if ur talking about the sedan version as I cannot comment on that.

yes irrelevant. casue your under the sedan section.

I'm no authority, but I've read here many times that Stillen was heavier than stock. So I assumed it was "common knowledge". Not that I don't trust you , but I'd love to have a definitive answer on this. Any published specs to compare?

When I installed the orginal stillen exhaust on my G35 sedan it felt a tad heavier then the stock system I was removing. I could be wrong but based on how it felt in my own hands it definatly felt heavier.

I have the Gen1 Stillen and it "seemed" heavier than stock. I carted both around and the Stillen felt heavier. The axle back section alone is a quite beefy. Not scientific though, sorry.