Hey guys, new to this forum and thank you! I'm just starting a NB build for AutoX. Going with a Rotrex C30-84 and trying to decide between flat top intake and Skunk 2 amongst a million other things that go through my head at 2:08 AM. I saw some past stuff about this with turbo but not SC

 

They're equal in power gains, if you have a 94-97 head, you have no choice and I'd recommend the S2. If you have a NB head, I'd recommend the square top for ease of install, fitment, throttle body location is OE, and all the PCV/booster ports are where they're supposed to be. And power potential is equal between the S2/square top in my experience. About the biggest mod I do to square tops is drill/tap the back of the upper half for 1/8NPT for a dedicated ECU MAP port.

 

Hope y'all don't mind jumping into this thread but I'm gearing up to similar to install a C30-94 Rotrex in a '99 NB1 along with swapping in a Square Top for the VICS.
I'm new RE this mod (old school Chevy V8 guy) - Any pic / thread link of where you tapped the Square Top for teh ECU MAP port?

Thanks, SA

 

Not sure a pic is needed, there’s a large vertical surface on the back of the removable upper half. I drilled and tapped it for 1/8npt, use a 1/8npt to 3/16 (or whatever size you need) brass hose barb fitting.

 

News to me that you would do this. I'm still Teeing my MAP of the FPR source from the IM (and running a flattop). Not optimal?

 

My flat top only has one vacuum port by the throttle body, beyond the little ones I keep tied together (this seems to drain any blow by out of a cavity that otherwise collects oil). I use that single port for the BOV. After that it just seemed easy enough to drill/tap for another. I still T the FPR reference off it.

 

I'm a big fan of drilling and tapping a couple 1/8" npt threads and installing hose barb fittings for boost gauges/wastegate/etc. It's such a cleaner install than a bunch of tees or a vacuum dist block and should be more responsive.

 

When I bought my square top I was trying to figure this out as well, and found this thread.
Bought a 1/8"npt drill and tap set on Amazon, mocked up a good location, marked it, drilled a pilot, drilled it using the provided bit, and tapped, piece of cake.
Thanks guys!

 

You guys got me wondering how bad using this port for MAF/FPR ref is:



the port on the right, just post throttle body. It looked like a good post tb port to source maf/fpr from, so I used that. The rear port off runner #1 seemed ok to use for the BOV, but I wouldn't use it for anything important.

 

I ran a skunk 2 on my Rotrex setup. I liked it a lot because it cleaned things up and made more room to get to things.

The built motor in my car just spun a bearing. So, I'm going to k-swap. I have a skunk2 manifold and throttle body I am going to post in the for sale forum as soon as it will let me get in there and post it. It will be in a post with a bunch of other stuff and way cheaper than buying a new one.