Ok, just my opinion, but I'm up for someone showing me a better exhaust manifold solution than this.
(Scroll down if you want to look at the manifold instead of or before reading all this!)
A couple months ago I got together with one of the best header fabricators and manufacturers in the country, Stainless Headers Mfg. Inc. Chris is the guy to talk to there, he's calling the shots and was awesome to work with. What I asked them to do was to build an exhaust manifold that would bolt up to an Ecotec and be able to mount an EFR turbo on. I wanted it to last forever, (was kidding on that one obviously, but what they came up with looks pretty damn bullet proof) flow with lots of velocity and efficiency without any restrictions, and fit a Kappa without ANY clearance issues. I also wanted to make sure it was made with high quality stainless, no cast or cheap import stuff. (That one was easy, Chris said they ONLY use high quality stainless steel to build all their manifolds and headers.) Chris was up for the challenge and he and the fabricator that worked on it absolutely hit a home run. The manifold is a work of art, and clearly fits and works perfectly. It wasn't an easy job, making a 4 into 1 collector in the limited space we have to work with is no easy task. When they sent me the first picture of the collector I was blown away! Just seeing that first shot I knew I'd picked the right guys for the job.
When I got the completed manifold, I was more than a little impressed. I almost didn't want to put it on my car it looked so good! Flawless welding, impressive designing and an obvious effort towards durability. We'd talked about adding slip joints to eliminate any chance of cracking, but seeing all 4 runners with them made me more than happy on that respect. One of the problems with building a small, short runner turbo manifold is there's no place for any movement to occur. There's quite a bit of expansion and contraction that happens when you're going from dead cold to red hot, and if there's no room to flex and move it could end up cracking. The slip joints totally eliminate that by giving it a place to move. These joints aren't just a pipe inside a pipe either, there's actually 3 layers of pipe, two on one side and the one on the other side is sandwiched between those two. So to answer the leakage possibility questions, I can say they don't leak. The fit in the slip joints is extremely tight, it's not like you can move them.
The fit on my Sky was perfect, actually more clearance all the way around than the stock manifold. The EFR turbo is in an excellent spot as far as downpipe and intake placement. Everything bolted up easily and with a couple thousand miles on it so far, NO leakage or any other issues. The manifold actually looks very much like it did before running it and getting it hot, they obviously use only the best materials to make their manifolds.
As far as performance, guess what? I haven't dyno'd it since putting this manifold on! (Hella lolz if you've read some of my other posts about my car!) I log my car pretty much everytime I drive it, and do plenty of 60-100mph runs to know what the difference is though. I can guarantee it's making more power with this manifold. My best 60-100 before was around 3.6 or 3.7, since putting this manifold on I've done a bunch of runs and ALL have been right around 3.4 seconds! I've actually backed off boost to keep fueling issues at bay. If I splurge and fab up a secondary fuel rail and pump I'm guessing I could be close to 500whp with the boost turned all the way back up. I really like driving my car instead of seeing pieces of it's engine laying underneath though so I'm not sure I'll be going for more power!
One other thing I noticed since going to this manifold, seems a little weird but I guess possible... the fuel mileage difference between 60 and 80mph isn't as great. Like most cars, my Sky always used to take quite a hit on mpg's when you get over 70mph. Since I put this manifold on, cruising at 75-80mph gets not a whole lot less than cruising at 65. Now I've done a fair amount of tuning also, so I'm not gonna say the manifold did it, but it's certainly possible. The way they made the runners so even and the fact they go smoothly into the turbo, it could (or should) have an effect on cruise efficiency. Another thought is the fact that the runners are slightly smaller in diameter than what I had before, so the velocity most likely is helping things. I did notice that the high rpm boost levels most definitely went up, I know because I had to tune them back down a bit.
So what I ended up with was exactly what I wanted, a well designed, well made, efficient and durable exhaust manifold to bolt my EFR turbo on. Thanks Stainless Headers!!!!
Here's the other part I was really happy about... I've worked with Dave at Werks Performance quite a bit, I believe he is one of the smartest, most honest and easiest to deal with guys out there. I wanted Dave and Werks to be a part of this, and since both Dave and Chris are such awesome guys, it worked! They've worked out a deal where Stainless Headers AND Werks Performance will both be the exclusive dealers for these manifolds! That means Werks will have TWO manifold choices for their EFR kits, their in-house built manifold, which works awesome, and this manifold as an upgrade for guys that want the ultimate EFR exhaust manifold solution! (In case anyone is wondering, no, I'm not getting anything out of this! I already got what I wanted, the best manifold made for my car. I just figured if Stainless Headers was willing to custom build this for me, why should I have the only one?) Another question I'm sure will come up, will this fit a Cobalt or HHR? I'm not real sure but I don't think so in the case of this particular design. Dave is working on also putting them on the Cobalt's so I think he's gonna figure out what needs to be modified in the design to work with them. Stainless Headers can make pretty much anything you want, so I'm guessing if you call and talk to Chris about this manifold being built a little differently so it will fit a Cobalt, he'll take good care of you and figure out how to do it.
Thanks for reading this big long blabbering post guys! Here's some pics for you, and a link to more on my Photobucket site. Any questions ask away!
Ecotec Turbo Manifold pictures by j16450yz - Photobucket
Stainless Headers Mfg., Inc. fabricates custom headers in stainless and mild steel
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