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I question the power gains under 4500rpm strongly. It looks like the stock-turbo chart goes to WOT much later. Starts at 50wtq, clearly not at WOT, then a quick ramp up to WOT and 125wtq at 3100rpm, and then takes more time to build up to full boost. The Skunk2 run was clearly started much earlier and built boost earlier as a result.
Good point Sav. I just sent the guy a message to see if he can clarify this, because as you said, picking up over 50 torques at 2500rpm seems impossible.
For the time being, everyone else can just examine the dyne graph from 3500RPM and up until I get some clarification
And here it is. I'll go back and edit the other post to ignore everything shy of 3500rpm. It does give us a good glimpse past that though
I asked: "I have a question. Just posted this in the thread on miataturbo and someone said it looks like in the old dyne graph, the operator opened the throttle later than in the new one, which would now show a huge increase below 4000rpm over stock. They said it looks like in the old run someone didn't fully open the throttle until that "dip" around 3100. True? Otherwise I can't see how it picked up 50+ torques at 2500rpm with just the manifold and TB"
Original poster: " ya that spike at 3100ish is where the throttle was stabbed on that run. We had tried opening it up at different rpms and that was the best run of the night."
valid point. but even when it does come on, it seems to be at least slightly lower.
I'm not sure you can draw a conclusion without seeing datalogs with a MAP or boost trace for each pull. If you start a 3rd gear pull at 3000rpm, and the wastegate cracks slightly, it's not unreasonable at all to expect to wait until ~4500rpm for full boost. If that's the case, there are zeo gains under 4500rpm.
This was my run. I added points from a run when the throttle was opened earlier to where it became even with the dotted lines for a better comparison.
We didn't change any of the wastegate settings so the boost level should be the same for both runs. Was 12 psi tapering down to 10 by the end.
Yea looks much smoother and theres only one spot around 4600 where the power dips below its old. I'm just holding out for that square top comparison, I have one that I would need to port to match the Skunk 2 TB anyway so if the Skunk mani is going to be significantly better, I won't bother molesting my square top and just sell it. I'm definitely rooting for this thing to do better
While tuning we found this one part interesting...at 4500 for some reason the VE went really rich. if we were to tune it out there would be a huge spike on that area of the fuel map. But only at 4500...so we just kept the map smooth and went on to the higher cells which were fine.
Untuned or not, with VICS wired open anything above 5200rpm should be fair game no? Its got signifigant gains up top. Still looking for the squaretop comparison to see where it stacks up, I think itll outflow it honestly.
Untuned or not, with VICS wired open anything above 5200rpm should be fair game no? Its got signifigant gains up top. Still looking for the squaretop comparison to see where it stacks up, I think itll outflow it honestly.
The plot shown does not represent what a VICS is capable of in terms of peak or area. That is my point.
Also no mention of what correction factor/run conditions.
At first blush, many of us can see the manifold appears to be right in photos. But I like data.
I will reserve judgement until I either see or conduct something resembling a controlled test. Our manifold has not shown up yet.
The plot shown does not represent what a VICS is capable of in terms of peak or area. That is my point.
Also no mention of what correction factor/run conditions.
At first blush, many of us can see the manifold appears to be right in photos. But I like data.
I will reserve judgement until I either see or conduct something resembling a controlled test. Our manifold has not shown up yet.
Maybe yours hasnt shown up yet because they know youre going to test it, lol. THEY SKURRED
We ordered a second manifold so we can do ab A/B on Bullet too. That's a TSE EFR6258 kit on a blueprinted/forged NB1 longblock on corn.
The first one will go on Taxi, that's an 11.0:1 2.0L with medium large cams, +2 CNC head, blah blah. That's the engine that we made 167whp on pump gas and stock ECU (JDM + crystal mod) with AFPR.
Would be nice to hit 185whp on corn. Our previous best with milder cams and square top on race gas was 182whp with a 2.0L NB2 and +1 hand ported head.
Well we need to wait until there's more data, but at least we can say this won't be a flop.
In my eyes, part of the sales comes from the simplicity of it. For someone who's swapping engines (Example VVT in an NA chassis), this eliminates any worry about dealing with VCTS or VICS flaps. In addition, it is already tapped for different ports you might need. Seems to make a decent sales pitch even if it doesn't make gobs more power, but we'll wait to see.
I wonder if I can get 20whp up top from this or the squaretop without upping my boost. Currently have a debutterflied and ported at the TB VTCS manifold with a skunk2 TB and made 310/285 @17psi and 330/310 @20psi. What could I expect a squaretop to do?
We ordered a second manifold so we can do ab A/B on Bullet too. That's a TSE EFR6258 kit on a blueprinted/forged NB1 longblock on corn.
The first one will go on Taxi, that's an 11.0:1 2.0L with medium large cams, +2 CNC head, blah blah. That's the engine that we made 167whp on pump gas and stock ECU (JDM + crystal mod) with AFPR.
Would be nice to hit 185whp on corn. Our previous best with milder cams and square top on race gas was 182whp with a 2.0L NB2 and +1 hand ported head.
From my experience I think the Skunk2 will excel on highly ported, large cam NA heads that have been fully developed. Expect to see big power improvements high up in the rev range with the peak power far later in the rev curve. This means you will need to push to revs to make the most use out of the manifold. Also expect to see more harmonic undulations and a loss of power south of 5000rpm due to the larger runners. With my engine I'm still seeing the power push upwards past 9000rpm although mine has shorter runners than the miata Skunk2.
On a turbo engine I'd expect to see similar changes except at a lower level of development. The manifold will flow more air so it removes a restriction point if the valves and exhaust aren't the bottleneck.
Waiting for data too... my car is a bit of an N/A screamer that doesn’t wake up until 4.5-5k RPM, and pulls hard to 8. I’m only hitting 98kpa under max load, and I think it’s the shitty VICS intake.. I’d love to try this one...
10-17-2017, 03:01 PM
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