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Post by brian on Sept 21, 2007 13:52:54 GMT -8
According to the latest Fastrac, drop in ignition modules like the Petronix will be legal as of 11/01/07
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sweenrace
National Driver
.....rub'ns racin......
Posts: 450
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Post by sweenrace on Sept 21, 2007 14:54:21 GMT -8
points or electronic will be legal, right? rather than just electronic.
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Post by brian on Sept 22, 2007 9:04:26 GMT -8
Yes, the rule say "may use". Other than not having to adjust as often, I don't know if there will be any advantages to the petronix. I will be testing after the Runoffs.
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Post by hardingfv32 on Sept 23, 2007 10:27:21 GMT -8
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Post by brian on Sept 23, 2007 15:11:20 GMT -8
Haven't heard anything about cams and no one has requested that change. If the rivets come loose some have replaced with bolts and a threaded cam flange.
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Post by hardingfv32 on Sept 23, 2007 19:47:41 GMT -8
Oct Fastrack Pg 48:
Formula
Item 1. (FV) Add the following after the fifth sentence of section 9.1.1.C.5.21 (note section number is 9.1.1.C.5.23 in the rewrite)
to read as follows: The camshaft timing may also be changed in its relationship to the crankshaft by utilizing an adjustable cam
gear that retains the existing helical gear thrust angle and that is statically adjustable only (e.g., no dynamic adjustment mech-
anisms that respond to engine speed changes).
Sounds like a useful change.
Brian
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Post by dave FF 50-aka "Harm" on Sept 23, 2007 22:27:28 GMT -8
I use the Crane/Allison w light beam instead of the Hall effect units in my Ford's Bosch dist. With the points, I used to have to reset the gap every couple of sessions till the rubbing block wore down and then it would stay constant. With the electrics, the engine builder sets the timing and I never touch it till the next rebuild. I used to set the gap on the bench and found the lobes were worn unevenly--the gap varied a few thou from the highest to the lowest. Also, wear in the shaft bushings caused slop.
Advancing or retarding the cam will move the power band up or down the RPM band. Total hp will only slightly change, but where the peak power is will move. In the Fords, we normally RETARD the cam 3 degs to rise the power band giving us more top end, trading low end pull. In a Vee, will retarding the cam yield more top speed but give up accelleration out of the turn? In a Ford, we can change the gears for each track to compensate for the power band, but aren't the ratios fixed in a Vee (2 boxs availible?)? Will this mean a different engine for Laguna vs Thill (or at least different cam timing)? This sounds like a cost increase to me.
dave
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Post by brian on Sept 24, 2007 9:40:55 GMT -8
Yea, it sounds like a good idea if you do your own engines! It's a lousy idea if it means paying someone every time the nature of the track changes. Yes, it would be easier for engine builders to set cam timing but a nightmare for the competitors. I'm opposed and I build some engines.
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