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| 250 WHP Supernatural 3.4 Build (Page 46/47) |
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La fiera
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MAR 01, 12:20 AM
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| quote | Originally posted by pmbrunelle:
I checked my car today for the supposed spark-on-boot behaviour, and I didn't see it.
I connected a spark plug to the coil wire, and I placed it such that it was visible from inside the cabin. I then cycled the key on-off (5 cycles). I did not observe any sparks. It was quite dark in the garage at the time.
I don't think we can generalise my results to all MS installs; each user should check this on his own setup. |
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I was thinking; my injectors are high up in the runners and E85 has its own oxygen and that makes a big problem.
All it takes is to have some residual fuel in the runners and an intake valve open.
In my case, I hit the start button, the spark plug fire (waste spark) and the residual fuel in the runners are ignited by the combusting fuel in the chamber.
Having the TB closed and the explosion expanding without a way out, the manifold weld gave out due to the energy of the explosion.
I never had this problem with non-oxygenated fuels, I switched to E85 and I started to have backfires here and there, but this one was severe.
Another thing, because of the duration of the camshaft I run much more advanced timing to keep the idle/low end throttle response crispy.
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La fiera
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MAR 20, 11:18 PM
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. [This message has been edited by La fiera (edited 03-20-2020).]
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La fiera
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APR 24, 09:04 PM
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La fiera
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MAY 10, 11:50 PM
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pmbrunelle
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MAY 11, 12:59 PM
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At 6:00 your car sounds like an old F1 car!
Your VE table is interesting... it shows a relatively "normal" engine that then suddenly "wakes up" at about 3000 RPM (we don't see the numbers at the bottom of the screen).
I guess the piston still sucks in a bunch of air at low RPM, but then whatever it swallowed comes right back out before the intake valve closes. Something like that?
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La fiera
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MAY 11, 01:33 PM
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| quote | Originally posted by pmbrunelle:
At 6:00 your car sounds like an old F1 car!
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 That's exactly the sound I was looking for and the only way to get it was with true dual pipes. My favorite F1 engine sound
is from the Matra V12 from the 70's and 80's used by Ligier.
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lou_dias
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MAY 11, 02:05 PM
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It did sound amazing when you were coming back!
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La fiera
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MAY 11, 07:54 PM
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| quote | Originally posted by lou_dias:
It did sound amazing when you were coming back! |
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That's because when I left I didn't go over 50% throttle. After 50% the secondaries opens and that is
when she screams. My AFR coming up that hill at WOT was over 16 and I have it target it at 12.2. So, it wants lots of fuel.
But yes, it sounds like an old Cosworth DFV F1 engine from the70's and I love it!
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Spadesluck
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MAY 11, 09:59 PM
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That looks like an ice chest sitting up there....love it! That does sound amazing, even crazier it is only a 3.4L!
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stradivarius151
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JUL 16, 04:07 PM
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| quote | Originally posted by La fiera:
That's because when I left I didn't go over 50% throttle. After 50% the secondaries opens and that is
when she screams. My AFR coming up that hill at WOT was over 16 and I have it target it at 12.2. So, it wants lots of fuel.
But yes, it sounds like an old Cosworth DFV F1 engine from the70's and I love it!
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Can you explain what's going on with the exhaust setup with regards to that sound? The firing order on the 3.4 is 123456, right? I see those equal length headers but are you doing anything funky with merging primaries to get even pulses? My apologies if this has been explained already, I haven't had a chance to pore through all the thread which I will do ASAP.
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