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Old 02-18-2016, 03:16 AM   #41
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The problem with the skunk2 is the return spring seem to break at about the same frequency as the OEM TB breaks shafts. The throttle sticks wide open when it does but at least you don't have to worry about sucking screws through the motor.
I had this happen to an early unit on Rover. It always had a sticky/notchy feel to it. Skunk2 replaced it with a "revised" unit, no sticky feel, no issues ~3 years later.
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Old 02-18-2016, 03:16 AM   #42
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The problem with the skunk2 is the return spring seem to break at about the same frequency as the OEM TB breaks shafts. The throttle sticks wide open when it does but at least you don't have to worry about sucking screws through the motor.
That would be a comforting thought as you plow into a wall. My Honda 70mm Skunk2 was absolutely junk. It was the alpha series TB which is cast but I believe they have the same throttle spring and TPS linkage as the miata specific one, both of which caused me endless problems. My idle adjustment was also useless and kept unwinding. For anyone retrofitting throttle bodies to manifolds I'd highly recommend the S90 70mm throttle body over anything from Skunk2. The build quality is vastly better, and all the above issues are fixed.

The S90 would easily bolt up to a squaretop with an adapter plate or tapping directly into the end plate. You'd need an aftermarket ECU though to connect the required TPS and Map sensors.
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Old 02-18-2016, 01:21 PM   #43
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Default Would port matching my Skunk2 to FlatTop lose power?

I would advise that it may be better to push in the clutch and let the engine bounce off the limiter rather than crashing into a wall. But that's just me.
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Old 02-18-2016, 01:30 PM   #44
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Welp y'all convinced OP to port match lol
So we'll be doing that soon
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Old 02-18-2016, 01:45 PM   #45
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I would advise that it may be better to push in the clutch and let the engine bounce off the limiter rather than crashing into a wall. But that's just me.
In theory, or on the street, sure. On track though, a fast driver will stay at WOT up until the very last few ms to keep the tire at optimum slip angle, then lift. Any longer and you fly off. Throttle sticks and event the quickest reaction is usually too slow. You fly off.

The Skunk2 TB is poorly designed and engineered. Pretty well made but that doesn't help. Between Andrew, myself and a few others, Skunk2 has had the info needed to correct the 8 or so flaws for about 4 years. IIRC, they have fixed one and band aided two others. The guys in customer service seem to care. They are powerless to effect change though and the owner does not care. Thus, the TB is as good as it gets until someone comes along and does it right. Still safer than a reworked OEM. The one and only $500 "prepped" OEM TB I bought from "the guy" for our STL broke about 20 minutes in.

A proper TB solution is on my long list. Probably never happen though, too many other projects..
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Old 02-18-2016, 01:53 PM   #46
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Are the skunk2 design issues inherent to the miata s2 throttle body, or all s2 throttle bodies. Although a properly designed bolt on throttle body is the "best solution" as madjak suggested an adapter plate for a known bulletproof throttle body is a damn good bandaid.
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Old 02-18-2016, 02:05 PM   #47
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Almost all Junk2 stuff is universal chinese stuff that they "engineer" adapters to basically.
We were just laughing at how the bolts that came with OP's for the IACV adapter were both wrong, both too short. Had to source our own.

I always laugh when the owner/advertiser/pr guy for that janky company says they "engineer" stuff in house and all that.
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Old 02-18-2016, 02:55 PM   #48
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Skunk2's customer service is excellent and my TB hasn't broken in any sort of way considering that Savington told me to red loctite a few things.

Could be worse. vOv
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Old 02-18-2016, 06:25 PM   #49
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alright, more info, for science

same temps this time, or at least only 2* apart




same weight re-dyno on same road in same location, etc.



No power gained.
No power lost.
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Would port matching my Skunk2 to FlatTop lose power?-80-pre_s2_vs_post_s2_aits_86722107f34fada4948eb4fcffc4f957be398722.png   Would port matching my Skunk2 to FlatTop lose power?-80-pre_s2_vs_post_s2_dyno_comparo_b654ea25a73f2e13887f0c4c621508b9f91769ba.jpg  
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Old 02-18-2016, 06:49 PM   #50
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Originally Posted by sixshooter View Post
I would advise that it may be better to push in the clutch and let the engine bounce off the limiter rather than crashing into a wall. But that's just me.
I'd like to think my reaction speed would be quick enough to get the clutch in but as Emilio said even an extra half a second of WOT comprimising the braking zone and I think I'd be off the track. There is no way to predict it so reactions would be slow. Hopefully the spring on the accelerator pedal has enough in it to push the throttle partially closed. A lot of race cars run double springs for this reason.

When I get the time I'll line up the S90 against a stock manifold and see whats involved in getting it to fit. 70mm is getting pretty large for a stock motor though and thats the smallest they make.
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Old 02-18-2016, 07:05 PM   #51
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Originally Posted by Dunning Kruger Affect View Post
Skunk2's customer service is excellent and my TB hasn't broken in any sort of way considering that Savington told me to red loctite a few things.

Could be worse. vOv
Care to share all the "few things"? - I'm concerned I may have missed some.
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Old 02-18-2016, 07:58 PM   #52
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Originally Posted by 18psi View Post
No power gained.
No power lost.
Not sure how you came to that conclusion without pressure altitude data.

Quote:
Originally Posted by Lokiel View Post
Care to share all the "few things"? - I'm concerned I may have missed some.
I'd be glad to share my S2 TB tech info with you, assuming you purchased the TB from me.
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Old 02-18-2016, 08:11 PM   #53
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Not sure if splitting hairs and trolling or attempting to actually help.
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Old 02-18-2016, 08:23 PM   #54
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Originally Posted by Savington View Post
:
I'd be glad to share my S2 TB tech info with you, assuming you purchased the TB from me.
I've pre-purchased the EFR6258 manifold and downpipe as well as bought brake ducts and matching hoses from TSE - does that get me any lovin' ?
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Old 02-18-2016, 09:08 PM   #55
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I've pre-purchased the EFR6258 manifold and downpipe as well as bought brake ducts and matching hoses from TSE - does that get me any lovin' ?
Sure, shoot me an email.
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Old 02-18-2016, 09:11 PM   #56
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Not sure if splitting hairs and trolling or attempting to actually help.
SAE corrections are based on both ambient temperature and barometric pressure, so if you aren't doing the A-B on the same day, you absolutely need both measurements to accurately compensate. You're talking about a party that's been shown to add ~2-3whp at best to an optimized setup, so your data needs to be virtually perfect to even see the difference. Splitting hairs? Yes, but at <2% gains, you need to.
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Old 02-18-2016, 09:27 PM   #57
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Originally Posted by emilio700 View Post
In theory, or on the street, sure. On track though, a fast driver will stay at WOT up until the very last few ms to keep the tire at optimum slip angle, then lift. Any longer and you fly off. Throttle sticks and event the quickest reaction is usually too slow. You fly off.
Yeah, you're right. 0.5 seconds eats up a lot of real estate at 100mph. And I may not even figure it out in that amount of time.
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Old 02-18-2016, 09:44 PM   #58
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On the 70mm Honda Skunk2, the TPS connector fixes to the throttle shaft via a M2 sized screw that is just ridiculously undersized. I had it come loose even after loctiting it. I pulled this screw out and drilled the throttle shaft out larger, tapped and then fastened it in with a M3 bolt and loctite. After that I took out every bolt, checked it and loctited it back in, and put a locking nut on the throttle wheel stop.

I would think that the S2 for the Miata would be very similar in design.

Next event the little pins on the TPS connector bent and lost engagement with the TPS. I then decided it wasn't worth running so swapped it out with a S90.
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Old 02-18-2016, 09:50 PM   #59
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Quote:
Originally Posted by Savington View Post
SAE corrections are based on both ambient temperature and barometric pressure, so if you aren't doing the A-B on the same day, you absolutely need both measurements to accurately compensate. You're talking about a party that's been shown to add ~2-3whp at best to an optimized setup, so your data needs to be virtually perfect to even see the difference. Splitting hairs? Yes, but at <2% gains, you need to.
Fair enough, I'll leave the data up let the readers make their own conclusions
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Old 02-18-2016, 10:11 PM   #60
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Fair enough, I'll leave the data up let the readers make their own conclusions
A 130whp engine doesn't need a massive amount of air flow especially given the biggest restriction would be at the head / valves. Put that same setup on a ported head with bigger cams and valves and then it becomes a much bigger factor, as does the filter, size of the runners, casting marks in the intake etc etc. They all add up to restrict the flow of air.

The problem with this stuff is that until you get the car on a dyno and try it's all just theory. I've heard that a simple bellmouth merged into the OEM throttle body of a 180whp fully developed NA8 is worth 3-4whp. The car was on the dyno for 2 days, trialing different combinations of intake lengths and bellmouth sizes and positions. Move the bellmouth away from the throttle body by 100mm and it would lose the gain. This result would have cost thousands of dollars in dyno time and development but when you are chasing that last 5% you have to do the trial and error.

Put that same bellmouth and throttle body setup on a different intake or engine with different cams and the result could be the complete opposite.
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