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On dyno today with Taxi. Preliminary results are that the spacers made no difference on this high hp N/A build. Made 182whp regardless of no, one or two spacers. Minor fluctuations in midrange power were just noise. Nothing repeatable. We did notice that the first pull after swapping parts with everything cold would give us a nice Dyno Queen number 3-5whp higher.
Stopping for lunch then we'll put the squaretop on. Plots will be posted tomorrow probably.
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.
They will. But now when some n00b starts spamming every other thread with "you should get the s2, you'll pick up power" I'll have more basis of slapping them.
I've nothing against the s2 at all, I'm glad it was made, but unless it's drastically different on a boosted car vs n/a, we now know why s2 didn't post any plots.
Emilio and crew have proven the S2 matches the Flattop, right. So this is just an alternative (not an improvement), one that's available to purchase NIB from vendors. Still delivers the same gains over USDM manifolds, and probably a decent pick up for people with the cash to burn. If it's worth getting a flattop, it's worth considering the S2.
I'll be sticking to stock for sometime yet myself.
Wow! Betcha sales won't continue on those skunk2s...thanks for all that Emilio!
Betcha they will.
Emilio proved (thank you so much btw), that the S2 holds up well to the Square top manifold as far as power numbers go. Bit lost in midrange for a bit gained in top-end. Given that the S2 weighs less, can be purchased brand new (not used off a 10 year old car with 100,000 miles from some guy on ebay named Steve), I say there's definitely still a place for them here. Also from personal experience, those doing VVT swaps will benefit greatly from the S2 manifold as they do not have to do any bending of fuel lines or shaving of the intake manifold to run the fuel lines. In addition, they grant much more room in to access fuel injectors and wiring.
... you also get a decent place to source your boost pressure from at the rear of the manifold - the square/flat-top requires tapping the rear of the manifold or sharing the brake booster barb).
I'd definitely consider it if it makes changing injectors easier. Man that was probably one of the hardest parts of my turbo install and I'm not looking forward to changing them every time I have to get emissions tested. Speaking of emissions, does eliminating the VTCS butterflies trigger a CEL on the stock ECU?
It would be cool not to have to split the square top to access the injectors. But I'm still not turned on by how difficult it seems to be to install an s2. Either way, less what-if's and conjecture. I'll wait for boosted results.
Given that the S2 weighs less, can be purchased brand new (not used off a 10 year old car with 100,000 miles from some guy on ebay named Steve), I say there's definitely still a place for them here.
Yes, you can buy it new as opposed to a used Squaretop from a guy named Steve. The thing is ... there's literally nothing to fail on a squaretop intake manifold. There are no moving parts. At most you might need to have it washed in a parts cleaner, unless the thing has been physically damaged in some way. So, as far as used parts go, a squaretop purchase is about as low-risk as they get. And, the squaretop actually fits correctly without modification, which is somewhat inexcusable for Skunk2 to have done.
Originally Posted by SamS
I'd definitely consider it if it makes changing injectors easier. Man that was probably one of the hardest parts of my turbo install and I'm not looking forward to changing them every time I have to get emissions tested. Speaking of emissions, does eliminating the VTCS butterflies trigger a CEL on the stock ECU?
Yes, that is my understanding, that it throws a code. Perhaps @curly can chime in, I discussed this briefly with him at one point. @SamS if you need to meet obd2 emissions, you could consider using an Xede piggyback with the stock ecu. I happen to have one I could sell you. Easier (still a PITA, but easier) and less messy than swapping injectors.
Thanks Emilio for sharing this data with the community.
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.
I'd definitely consider it if it makes changing injectors easier. Man that was probably one of the hardest parts of my turbo install and I'm not looking forward to changing them every time I have to get emissions tested. Speaking of emissions, does eliminating the VTCS butterflies trigger a CEL on the stock ECU?
You'll need to swap back the OEM intake manifold for the emissions testing too and re-install all the plumbing since VTCS-related CEL errors wont be the only CEL errors you'll get with the Skunk2 manifold (eg. emissions control errors).
If you think unbolting the top half of the OEM intake manifold to access your injectors is a hassle, you're in for a real world of pain swapping the lower half of the intake manifold.
11-07-2017, 03:28 PM
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