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Skunk2 BP intake manifold

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Old 11-08-2017 | 09:05 PM
  #121  
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You guys just need to build Exocets. Pretty much a straight shot to all the fasteners. ;-)
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Old 11-08-2017 | 09:11 PM
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Originally Posted by boileralum
You guys just need to build Exocets. Pretty much a straight shot to all the fasteners. ;-)
Everything but the damn injectors. Having to take that top manifold half off every time you want to mess with the injectors gets old quick.
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Old 11-08-2017 | 09:44 PM
  #123  
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First, how often are you all screwing with the injectors, and second, how hard is it to remove the upper IM? I think I can have it off in about 2 minutes with an impact gun.
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Old 11-08-2017 | 10:18 PM
  #124  
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seems like every other day lol
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Old 11-08-2017 | 10:58 PM
  #125  
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Originally Posted by Steve Dallas
I will have you all know that buying a square top off eBay from a guy named Steve is perfectly safe, and is a desirable thing to do. Furthermore, Steve is both an Analyist and a Therapist, also known as an Analrapist, so you would be in very good hands.
Man if you just get into making artisanal cheese you'll have it all..




​​​​​​​Oh and random s2 intake speculation here....pick whatever
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Old 11-17-2017 | 06:21 PM
  #126  
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For $400 it doesn't seem like a bad buy considering squaretops tend to be more expensive except for the one unicorn on Ebay.
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Old 11-17-2017 | 10:42 PM
  #127  
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I've got currently 18 Squaretop Manifolds Stateside if anyone needs one...have really been holding off making any posts about them for the longest time however I think it is probably time to flood the market with them at this point...so much for the "hard to find"...
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Old 11-17-2017 | 10:45 PM
  #128  
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Originally Posted by ScratchNSniff
I've got currently 18 Squaretop Manifolds Stateside if anyone needs one...have really been holding off making any posts about them for the longest time however I think it is probably time to flood the market with them at this point...so much for the "hard to find"...
So what's your asking price? Can you not post this in the sale forum?
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Old 11-17-2017 | 11:13 PM
  #129  
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Originally Posted by ScratchNSniff
I've got currently 18 Squaretop Manifolds Stateside if anyone needs one...have really been holding off making any posts about them for the longest time however I think it is probably time to flood the market with them at this point...so much for the "hard to find"...
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Old 11-18-2017 | 08:12 AM
  #130  
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Great results! (By this I mean real world results) I would consider this or a flattop on my 01 swapped 94 for simplicity's sake especially if it makes more FI.
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Old 11-19-2017 | 11:42 AM
  #131  
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Originally Posted by emilio700
A few more hp between 7000-8000 just like the stock engine. The difference was the S2 lost a bunch of midrange in the process. That surprised us.
The plot line you see above the rest in the midrange is the square top. We repeated it a few times heat soaked and it stayed within 2whp. Of note was the way the S2 died at 7700. We had the fuel cut set at 8100 for the S2. The square top kept pulling past where the S2 nosed over so we bumped the limiter to 8300. This again, surprised us. While the S2 clearly flows more at peak, it does so only in a narrow rpm band then chokes. Perhaps that is the result of careful 2nd order resonance optimization but lower average velocity? That's the same type of thing with intake ports with big CFM numbers but low velocity. One big dyno peak but nothing before or after.

We saw the S2 gain about 6whp for an 800rpm window up high but lost the same 6whp over 1400rpm in the midrange. For a 6 spd car, it could be personal preference either way. For a 5 spd car with the wider ratios, the square top would be faster.
No gains form the spacers. We're putting the square top back on for Super Lap this week. So N/A at least, we're not seeing much to get excited about. How about those used square top price fluctuations?

It will be a few weeks before we get it on Bullet with the TSE EFR6258 kit. Based on these results though, I'm not expecting any gains there either.

Can you link me to the cam specs? I made a IM runner length spreadsheet but its hard to know what the correct wave speed would be (have to guess based on intake air temp/pressure). I can look at your dyno sheet and guess at the 3rd wave peak being about 7750 rpm and then use that to help back my way into a more accurate wave speed.
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Old 11-20-2017 | 01:32 AM
  #132  
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I don't think it's the intake manifold choking the flow at high rpm, it's the cams. The small variance between the flat top and the S2 is just different locations of harmonics rather than any sort of flow restriction through the manifold. To me it doesn't look like the cams are very big considering the minimal harmonic movement and also the power is nosing down so early. Maybe 264 degree or something around that. The cams would need to be up nearer to the 300 degree range to get the power to continue pushing up past 8000 where it needs be for this manifold to flow.... then again maybe the curved runners just aren't working.

I think the conclusions are still good though. This manifold won't really do much on a typical N/A build but it's basically on par with a flat top. On a purpose built race engine targeting max power maybe it starts to work, but then it will still need everything pushed to the limits to be better than a flat top and then at that point a modified Honda S2 with it's straight runners or large ITBs would be better again.
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Old 11-20-2017 | 09:10 AM
  #133  
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Agreed. The radically curved runners are not doing the S2 manifold any favors. At the point where it is starting to flow one would probably be better off building a straight runner manifold from scratch.

On a side note we have decided not to do the turbo evaluation. As I doubt anyone else will ever perform controlled testing the world will just have to remain guessing. Based on what I've learned about manifolds I would expect it to have essentially the same effect that it did on our normally-aspirated builds. That is to say, my guess is no useful gains with F/I.
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Old 11-20-2017 | 09:17 AM
  #134  
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I agree. No disappointment from this mt.netter! Once again thanks for taking the time to evaluate this product and give the community some data driven results. I hope going forward everyone puts this amount of detail into their product lines(the detail you put into dynoing that is). Disappointed in Skunk2 or whatever they are called.
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Old 11-20-2017 | 10:12 AM
  #135  
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Yep, awesome data collection.
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Old 11-20-2017 | 03:50 PM
  #136  
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Because taking a quick picture or saying anything specific about the cuts required for installation is hard, here's the info on mounting this to the NB2 head.

The problem is the frontmost upper stud hole. The extra height there for compatibility between heads is too high for the FPR on the NB2 fuel rail. I imagine the story's the same on the NB1. The (laughably useless) thicker gasket would reduce the severity of cut required, but generally speaking on the NB2 you can just cut off the whole top stud hole there.
Attached Thumbnails Skunk2 BP intake manifold-uncut_manifold_fpr_clearance.jpg   Skunk2 BP intake manifold-minimum_cut_nb2_head_stock_fpr.jpg   Skunk2 BP intake manifold-cut_manifold_with_fpr_mounted.jpg   Skunk2 BP intake manifold-cut_manifold_with_fpr_mounted_2.jpg  
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Old 11-20-2017 | 03:55 PM
  #137  
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thank you for sharing the pics/info.
hopefully that crappy graphite gasket you put in is temporary and you used a proper MLS
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Old 11-20-2017 | 04:08 PM
  #138  
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Eh, just used what I was given. Not my engine or car. :>

If it needs to be swapped out later so be it. It's a pretty easy job.
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Old 11-25-2017 | 03:16 AM
  #139  
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Originally Posted by emilio700
Agreed. The radically curved runners are not doing the S2 manifold any favors. At the point where it is starting to flow one would probably be better off building a straight runner manifold from scratch.

On a side note we have decided not to do the turbo evaluation. As I doubt anyone else will ever perform controlled testing the world will just have to remain guessing. Based on what I've learned about manifolds I would expect it to have essentially the same effect that it did on our normally-aspirated builds. That is to say, my guess is no useful gains with F/I.
Gotta say. That is pretty weak. This is miataTURBO.net and you post na results and bail on it. The only thing that can tell is the dyno. We wanted to see turbo results in the first place. We were hoping you would provide. Obviously, the turbo intake manifold shoot outs need to be left to fm. Or is there something you arent telling us?

I am tracking with the curved runner, but come on.
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Old 11-25-2017 | 03:22 AM
  #140  
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Or you could pony up for a manifold and dyno time, instead of bitching on the internet, which is free. From what I see (being an owner of a squaretop boosted built motor) what Emilio has projected for the outcome of that dyno test is spot on, and were it my money, I wouldn't spend it.
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