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Skunk2 Street Manifold

63K views 96 replies 15 participants last post by  UdwanaGaMama  
#1 ·
Hey Forum
Is anyone out here running a SKunk2 Manifold and 80mm K-Tuned throttle body? I need some feed back good or bad.. Car is under construction and would like to work out any kinks before I turn the key..
 
#2 ·
#6 ·
I just got 20 of them in stock and we are doing testing and we are doing the CNC port design now on the runners. It will be an improvement over OEM manifolds, but I think you are going to need the plenum spacers. It shares the B-Series 1.85L plenum and it will have to be opened up to accept an 80mm TB. I'll post some pictures when I get a chance.
 
#17 ·



80mm TB is an overkill in my opinion. Here is my ported S2 Street waiting for its time. It has been ported by hand and opened to 74mm.

Will be matched with ZDX TB and 0.5l spacer on K20/K24 frank and I will then dyno it to check if it's a better option than my ported RRC.

I checked it on flowbench @28 and there is an improvement over non ported.
 
#25 ·
I still dont see the stock intake manifold as "overkill".....i simply see it as it's not OPTIMIZED when all other parts are stock as well. Overkill, would mean the intake manifold is unfit to function properly. I see overkill as a part that would require internal modification to perform better than the oem counterpart.

I also think our depiction of "stock" engine was different. I was referring to the engine itself being internally stock and assuming the basic bolt on modifications are being used. I don't recall the last time I've seen a K series vehicle using 100% stock parts without the car being driven off the manufacturers lot.
 
#26 ·
Hey i needed some advice too so I have a 2006 rsx base with the k20a3 motor I just recently put new exhaust with Invidia Cat-backs with Dc sports race headers and I also swapped the throttle and intake manifold with the skunk2 intake manifold with 70mm everything went on perfectly except for 2 senors that were originally on old intake manifold the big ugly plastic intake and i dont know where to put the 2 senors or how to make the computer to stop reading those senors i believe they are IMRC senors or the IACV? Could really use some professional advice because every time i start my car now it always revs at 2000rpm and wont go down unless i slowly release the clutch which is bad because im basically riding the clutch just so it will not rev high
 
#48 · (Edited)
I think concerning Skunk2 Street manifold there are some issues:
- there is no Intake Air Bypass Valve that only OEM manifolds have and that is only needed to operate on OEM injectors,
- there is no place for map sensor - you either have place for map sensor in your TB or need special TB adapter that will have one,
- there are no dedicated places for EVAP or Brake Booster - you use holes in the S2 manifold's plenum for that
- there is IACV for K20A type TBs,
- there is no water channel in it so for K20Z type engines you need special adapter that allows managing the water coming from the head.

For people that would like to use this manifold with RBC/RRC/RSP type TB (OEM K20Z TB) or with i.e. ZDX TB (with adapter) you must remember, that this manifold has different bolt pattern than manifolds mentioned above (it has K20A bolt pattern). This means that as far as I know for K20Z type head with or without DBW you need to change TB bolt pattern by welding the plenum intake side or using special adapter that I am not sure even exists.
 
#56 · (Edited)
Guys,

I was doing Skunk2 Street manifold dyno test today. The patient is fully built K24/K20 frank 87,5x99 (CR 12,6).

THIS IS SAME DYNO, SAME CAR, SAME DAY, SAME TUNER, SAME TYRES, SAME TEMPERATURES etc.

Pics of a ported S2 manifold:

Image


Image


Here are dyno graphs of RRC and Skunk2 Street manifold. RRC manifold was opened to 72mm, ported inside and welded. S2 manifold was ported inside, opened to 74mm and had 0,5l spacer.

I couldn't use bigger spacer with S2 manifold as I was limited by FN2 chasis. Also what might be important, RRC was used with Hondata Heatshield Gasket - I couldn't use this gasket with S2, as I would not be able to fit the manifold into the engine bay, so S2 was tested using standard OEM manifold gasket.

RRC dynos were more/less tuned with AFR and VTC. VTEC was 4400rpm on both runs and I didn't change it as I wanted to check overall performance difference of those two manifolds in 5000+ rpm range

When tuning S2 manifold, I tuned AFR precisely and I checked 30-40* VTC settings within the 0-7000 rpm range and 15-40* VTC settings within 7000-8500 rpm range.

Here are the graphs. They are shifted about 400 rpm left as I had my rpm redline set 8200-8400rpm.


Skunk2 (both lines) - best 312HP at 8400 rpm and 303Nm at 6300 rpm:

Image


Skunk2 (bold line) vs. RRC (thin line):


Image


There are so minor dimples on S2 graph that I think could be eliminated with some more AFR tuning. But they do not blure the image of the both manifolds.

My conslusions are that these manifolds are a bit different. RRC manifold seems to be a bit better manifold for a DD than Skunk2 Street. It shows tiny few Nm more in the mid range, but the differences are very small and was not felt in the car. Important part is however that when we tried to spin the engine higher, the power curve of S2 manifold was still climbing after 8000 rpm. In that range (after 7500rpm) RRC manifold was starting to give up.

I would say that ported S2 manifold would be a definately better option than ported RBC, which gave worse numbers than ported RRC on that car.

I think that if you have like 8500-9000 rpm red line motor (K24 or K20), then S2 manifold may give you significant amount of additional ponies than RRC will not. It will additionally provide a lot of mid range, that i.e. S2 Ultra Race will not.

Maybe with bigger spacer this manifold would give even better results, but it was not possible for me to check it.
 
#57 ·
I was doing Skunk2 Street manifold dyno test today. The patient is fully built K24/K20 frank 87,5x99 (CR 12,6).
Yesss sir, you did it :D! Thanks deibral for sharing your results, which cause huge effort! I really appreciate it!
  • I would like to ask some question if you don't mind to answer:
  • So both IM, the RRC and the S2 UStreet where polished and measured at the flow bench?
  • Did you measure the runner length of both IM?
  • Does the RRC flange and the S2 UStreet flange have the same runner size, shape and localication?
I am surprised, the VE production of the S2 UStreet manifold tells a different story than the spec'd data it does. According the torque comparison it would tell us the S2 IM has shorter and wider runners and would need more displacement or or and more engine speed like you already did mention. Are those runners even shorter than the RRC runners?

Anyway, awesome work man! I really appreciate it!

Markus
 
#64 · (Edited)
Onexyros: thank you for your kind words, I really apreciate it.

Yes, I tested this setup on TODA cams with ported RRC, ported RBC and stock (nonported) RSP. On K24/K20 the RSP manifold was the worst of them all. It provided decent midrange (similiar to stock RBC, and worse than stock RRC), but was not even a close match to the other two from 6500-7000 rpm up top as I remember. Difference was like 20-25HP at the redline.

The above setup, where I compare RRC with S2, runs DC Elite Endurance cams that I think are modified DC 3.2 but with higher duration.