No more broken throttle shafts
#62
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I really don't see the addition of some epoxy stopping a throttle shaft from breaking. I did it with the expectation that it will keep my engine from eating the screws, not keep the shaft from breaking.
#63
The goal of it isn't to stop the shaft from breaking, it's to stop the screws from falling out when it does and getting eaten by the engine, smashed up against your head stabbing it in, scraping up the side of the piston (it's gonna bounce something fierce in there) or mashing into or under a valve and bending it.
#64
From the link on Miata.net i mentioned posted by "2002tiitomx5"
"It's an aerodynamically induced vibration fatigue issue. The metallurgy of the shaft is inadequate for the operational requirements you are subjecting it to. At high airflow rates the butterfly valve is open with differential air pressure on upper and lower surfaces. With the valve open and only supported by the shaft bearings, the shaft is then allowed to flex up and down at some high hertz rate eventually causing fatigue cracking at the weakest points."
If there is truth to this maybe thats why the epoxy seems to keep them from busting so much. maybe it changes the flow of the air around the plate
"It's an aerodynamically induced vibration fatigue issue. The metallurgy of the shaft is inadequate for the operational requirements you are subjecting it to. At high airflow rates the butterfly valve is open with differential air pressure on upper and lower surfaces. With the valve open and only supported by the shaft bearings, the shaft is then allowed to flex up and down at some high hertz rate eventually causing fatigue cracking at the weakest points."
If there is truth to this maybe thats why the epoxy seems to keep them from busting so much. maybe it changes the flow of the air around the plate
#65
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From the link on Miata.net i mentioned posted by "2002tiitomx5"
"It's an aerodynamically induced vibration fatigue issue. The metallurgy of the shaft is inadequate for the operational requirements you are subjecting it to. At high airflow rates the butterfly valve is open with differential air pressure on upper and lower surfaces. With the valve open and only supported by the shaft bearings, the shaft is then allowed to flex up and down at some high hertz rate eventually causing fatigue cracking at the weakest points."
If there is truth to this maybe thats why the epoxy seems to keep them from busting so much. maybe it changes the flow of the air around the plate
"It's an aerodynamically induced vibration fatigue issue. The metallurgy of the shaft is inadequate for the operational requirements you are subjecting it to. At high airflow rates the butterfly valve is open with differential air pressure on upper and lower surfaces. With the valve open and only supported by the shaft bearings, the shaft is then allowed to flex up and down at some high hertz rate eventually causing fatigue cracking at the weakest points."
If there is truth to this maybe thats why the epoxy seems to keep them from busting so much. maybe it changes the flow of the air around the plate
The only thing that keeps it from breaking is better/stronger/thicker metal.
#68
Has anyone ever seen the return springs break on a stock throttle body? I know all about the shaft and screw problems, but I've never heard of the springs breaking. One of my friends had the springs break last time we were at the track, 3 weeks or so ago, and he just called to tell me that he had the exact same failure again today with a new (used OEM) throttle body. I checked the throttle body myself last time and the shaft and screws were perfectly fine- only the springs broke. I haven't seen any pictures yet of the one that failed today. We thought it was just a freak failure last time, but now I'm confused.
Details of the car:
Brand new 99 chassis PTE build- the first spring failure was at the car's first event after the cage and engine swap. Today was the car's second time at the track.
Unopened VVT motor with flat top and full exhaust
Stock redline
Roughly 140whp right now
I'm not positive, but I think it just has mazdacomp rubber motor mounts.
I'm talking about the two springs in the bottom left corner of this picture. The ones that wrap around the throttle shaft.
Details of the car:
Brand new 99 chassis PTE build- the first spring failure was at the car's first event after the cage and engine swap. Today was the car's second time at the track.
Unopened VVT motor with flat top and full exhaust
Stock redline
Roughly 140whp right now
I'm not positive, but I think it just has mazdacomp rubber motor mounts.
I'm talking about the two springs in the bottom left corner of this picture. The ones that wrap around the throttle shaft.
#71
was there ever a workable epoxy or braising method found to retain the parts? (not so much worried about if it breaks, just don't want to ingest anything). Read a bunch of places where it was talked about, but no actual what was done. Don't want to get/make an adapter plate to run the Skunk2 on my 1.6.
And no, the answer is not 1.8 yet. I still don't trust my tuning ability and would rather sacrifice a 1.6 if I make a mistake.
I am thinking epoxy over the screw heads/ends and then epoxy the plate to the shaft. I have some nice high temp/high strength stuff at work.
And no, the answer is not 1.8 yet. I still don't trust my tuning ability and would rather sacrifice a 1.6 if I make a mistake.
I am thinking epoxy over the screw heads/ends and then epoxy the plate to the shaft. I have some nice high temp/high strength stuff at work.
#73
was there ever a workable epoxy or braising method found to retain the parts? (not so much worried about if it breaks, just don't want to ingest anything). Read a bunch of places where it was talked about, but no actual what was done. Don't want to get/make an adapter plate to run the Skunk2 on my 1.6.
And no, the answer is not 1.8 yet. I still don't trust my tuning ability and would rather sacrifice a 1.6 if I make a mistake.
I am thinking epoxy over the screw heads/ends and then epoxy the plate to the shaft. I have some nice high temp/high strength stuff at work.
And no, the answer is not 1.8 yet. I still don't trust my tuning ability and would rather sacrifice a 1.6 if I make a mistake.
I am thinking epoxy over the screw heads/ends and then epoxy the plate to the shaft. I have some nice high temp/high strength stuff at work.
I only did epoxy on the one side on this one. The next one I do will have epoxy on both sides of the butterfly.
#74
It won't at least suck parts into the motor like a broken OEM but I think the risk of suddenly stuck open throttle with my Skunk 2 is just as bad if not worse than OEM.
#75
Fwiw, we are working on a new throttle body. Drawings made just got to work out a few more details before we built the first prototype. But yes, I understand everyone's frustration that at this late stage there is still no thoroughly engineered and properly manufactured throttle body solution for the B series.
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#76
Fwiw, we are working on a new throttle body. Drawings made just got to work out a few more details before we built the first prototype. But yes, I understand everyone's frustration that at this late stage there is still no thoroughly engineered and properly manufactured throttle body solution for the B series.