Headers for SC'd Z
 

Hi,

I was running 6psi with hks SC kit previously. Now that i'm building the engine, I'm thinking of bringing the boost up to 10psi. Currently I have impul headers. The runners are 41mm each and the end collector looks small. They did glow while my tuner was pushing it on a dyno. Not sure if the tune is aggresive or its simple too restrictive. I'm afraid if they would build back presure and causes high exhaust temp.

Yes, I've tried using the "SEARCH BUTTON". I couldn't find relevant threads about it. Anyone else who is SC'd please give me some advise on what headers should I be looking at or if the ones I have is sufficient.

My power goals is 370whp (I'm located in a 36 degree C with high humidity area). I'm using test pipes with Y-back nismo exhaust. Do you guys think this setup is suitable?

Your advise is highly appreciated. Thanks in advance.

For the best gains I'd say to find a fabricator to build long tubes for you. But available market Tomei make power over stock or stillen headers as they provide decent gains. Also the headers glowing is normal, there are some Z dyno videos all over that show as well.

I've measured Tomei headers. They are 42mm runners with uneven length and a slightly bigger collector. Would it be the best fit for SC application? My guess it could only be slightly better than the impul I had.

If i'm not wrong, more air being squeez into the engine would also means more air being pushed out of it.

Anyone can help me on this?

Wish I had more experience to help you.

No worries. Appreciated your help man

Header manufactures are going to make headers that bolt up to available test pipes. Collector is about 60 mm.

If you want to go bigger you will have to go custom. Then you have another problem. If you go with a 80 mm collector what do you bolt it to?

Yea. Totally agree with you on the size matching. I'm just wondering what headers does the high boosted SC members use. I've read alot of post where members use undersized pulleys producing 400 over whp. Do they change their headers or just maintain the stocks. If changed, what is the prefered model?

Don't worry about building your engine for 10psi with a supercharger. Get rid of the y-pipe and do a true dual exhaust. The headers are not where your flow is being restricted. I'm not familiar with the HKS system and what pulleys are available for it, but I can share my experience. I had the 3.12 pulley and test pipes along with my stock y-pipe and stock exhaust for my Vortech and made about 350whp. I switched out to the 2.87 pulley and went with the dual exhaust and my boost pressure remained about the same 11psi vs 10 psi for the 3.12 but went to 414whp. Even the stock headers/manifolds are able to flow plenty well and up to 700hp from what I have heard. Sounds like you are already building your engine though, what compression ratio are you going for?

Thanks for the reply. I did a comparism of HKS vs Procharger dyno sheet. Both pushing 6 psi boost. HKS is better in terms of response while Procharger tops up more on the high revs. I believe the bigger compressor chargers like Vortech and Procharger would give alot more power at 10psi. I dropped compression to 8.5:1(Just incase if I do TT kit later).

I'm going for HKS true dual exhaust system. The stock headers are definitely bigger than the aftermarket. But I'm hoping to use impul due to the tuned length. Would the tuned headers actually flow more than stocks? Anyone with aftermarket headers please advise.

350Z400rwhp,

I notice on your sig u r using snow's meth stage 2. I have the same unit but I don't quite understand the tuning part. I'm trying to make sense where I should start and end. Maybe you could help.

IMO, SC works same as N/A. Headers is not worthy without cams. If you plan to go TT in future, save money from headers.

I already have JWT S1 cams and impul headers. I just wanna find out if its efficient to use them on 10psi setup :)

I run jet hot coated Nismo headers

Gotcha, humm I'm also not familiar witg how HKS sc boost runs. The guy who posted 'johnylaw', he has HKS SC(I think) he will know better.

And snow kit, when I had them, I set spary at 4psi. You can see huge a/f drops once it spary.

Sorry, couldn't help you better.

Are you using HKS SC kit as well? Would like to learn more about it from you.

Appreciated it man:thumbup:


Any other SC boys who are using different setups please come in.

I used Strup header and test pipes into a Turbo XS 3" exhaust on my car when it was SC. I was able to make 414whp at 10psi last year on that setup.

I have a 3.12 Vortech setup on my revup.
I'm using an Apexi midpipe and backbox, Vortech supplied intake, stock headers, cams and cats.
When I was doing my research before installing this, I read that compressors don't quite work like turbos - you need SOME backpressure for best results.
For this, most people were not suggesting true duals, so I followed this advice.

I also found out that the more free flowing your breathing is, the lowest your boost will be, all other things equal.

So, to sum up:
1) Bigger intake/exhaust will result in lower boost (good thing for your engine).
2) Superchargers need a little backpressure to maintain good low end torque.
3) You can upgrade to smaller diameter pulleys to keep same boost levels, which will in turn result in higher power numbers, but maybe lower tq.
4) Most people avoid true duals on SC installs.

My setup made 400whp using a Haltech Platinum ECU.

Mine starts spraying at 3-4psi and increases until it hits 100% at 10psi. The Snow Perf. Stage 2 is a progressive unit. My tuner also pulled a degree or two of timing. My air/fuel is 11.4 with meth off and 11.9-12 with meth on.