Stillen Headers + F.I. HFCs?
 

Hey guys

Im looking to buy the Stillen Headers to finish off my F.I. HFCs and exhaust. I checked out the F.I. Headers but they cancel out the HFCs. The stillen headers dont eliminate the HFCs. My question is if I would have any fitment issues mixing the stillen headers with my HFCs? Just wanna make sure! Thanks!

You shouldn't have any problems with them as they are supposed to be a direct stock header replacement.

What's your primary reason for holding off on the LTH's?

nope. you should not have fitment issues.

MD cops around the DC/MD/VA area are anal about everything. Its illegal not to have cats so i dont wanna deal with the b.s.

ok... and the fact they cost $1200 lol

Ok fair enough, then I'd say the Stillen headers + HFC is a good happy medium for you. I'd recommend having them wrapped or Ceramic Coated before you install them though just to keep some heat out of your engine bay.

And as for the $1200, you'd get some of that back selling your HFC's :tup:

I'm looking into doing this as well since I just found out that Stillen headers don't require removal of the cats. Once you get them, I would love to hear them in person since I live in MD too. You should come out to the meets some time :tup:

Also, any idea of how long the install time is? Would help me figure out how much it might cost to install it.

Edit: After doing some more research it seems that the gains are not worth the time/cost for the Stillen headers. Seems to be only 2-3 whp gain up top and actually lose some TQ.

Is that in peak numbers? Or throughout the powerband? Was it tuned for the headers or just bolten on/dyno'd?

You would have to get the car tuned if you install the headers as it throws off the A/F ratio enough to cause anything from a very lean condition to very poor driveability.

Not really sure, but that's what Dreamer was saying in every thread I read about them :bowrofl:

It was just at work, so I didn't get to spend too much time doing research on them.

Let's just assume a tune is a given after I get all of my bolt-on breather mods. What I want to know is after getting an exhaust (I have the Berk), Berk HFC, and G3 intakes, would it be worth it to get these headers? Don't want to go with the FI LTH because of the issue with eliminating cats. Or would something like the Motordyne intake manifold be better?

Basically I'm trying to figure out which of these combinations would be best:

Exhaust/HFC/Intakes/Tune
Exhaust/HFC/Intakes/Headers/Tune
Exhaust/HFC/Intakes/Intake Manifold/Tune

From what I've seen, gains are varied with the Stillen headers. Most of the gains are around 5rwhp or so with a few around 10rwhp gained with full intake and exhaust setups. Torque doesn't move much though. Most of the posts I have read from people who had experience with the Stillen headers said it is not worth it unless you find them for a very good price online. They are also much easier to install than LTHs which is a bonus, plus they sound good!

If you are going for max peak HP/TQ, go for the 2nd option. If you want to gain more of a balance in HP/TQ, the last option will be best. I personally have the first option and have 320rwhp/263wtq which is plenty for me, I might get a more aggressive tune later and see if I can get a bit more.

For track performance, balanced HP/TQ would be better right? If so, I will do that. I might also add some pulleys as well if that would make any difference on the best choice.

I almost have the second set up. I have a Berk exhaust, Berk HFC and stillen headers. Now I can't speak for different headers but with the Stillen headers it makes the HFC, and Berk exhaust not fit right. I first installed the headers and then the rest. After I installed the Berk exhaust and the HFCs the exhaust didn’t sit right under my car. I was planning on making a thread about this later when I was able to get some pictures up but haven’t gotten around to taking the pictures or fixing the problem. Under the car the exhaust toward the end passes over a metal plate and under the car itself. I don’t know if it’s the exhaust or the headers but it makes the exhaust sit on top of that plate. So at around 4500 rpms my exhaust rattles a bit against the metal plate and causes a very terrible noise. I called Berk about this and I told them what was going on. I didn’t know what was causing this at the time that I called and I wanted to ask them if they knew what was causing the noise. The very first thing that they asked me was if I had Stillen headers and I said how did you know that? They said that the Stillen headers are a bit different then stock. They push the Berk Exhaust back and down. They told me that I should loosen up my exhaust and push it up as high as I can and then retighten it. I haven’t done this yet as I work to much but I hope to this weekend. Honestly if I had to do it over again I wouldn’t have bought the headers. I would sell them if I could find someone to take them out for me. I haven’t taken them out for if it did it would cost me about 400 and I would sell the headers for about that much. So in the end the headers would pay for the removal. So my two cents would be not to spend the money on headers.

Exhaust/HFC/Intake/Tune
Thats all you really need.
As said before thousands of times on the forums, our cars are already well made and i am mostly talking about our headers. Thats just a waste of money if you ask me and if you ask the majority of the members here. Ive read many positive comments regarding an uprev tune after your basic installs. I too will tune my Z next Wed and will have this combo. In the end its your car and Its just my opinion. Good luck with the choice you make.

I totally agree with you. I wish that I hadnt bought my headers.

I think it's the Stillen headers that are causing the fitment issues, which is what I've read from some other threads. I think I've decided not to get the headers, but now I just need to decide about the Motordyne intake manifold. Just trying to squeeze out as much power as I can without spending tons of money on it.