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Old 06-04-2010, 09:09 PM   #8
Super73
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Join Date: Nov 2007
Location: Bay Area, Ca
Posts: 2,841
Re: Throttle stops.. Some one help me :)

I hear what your saying on using timing to take some shock out of the tires. I have done that before. The biggest problem I found with this, is too much and you start runing in to really running like crap and bogging bad also your fueling goes out the window unelss you sepnd time correcting for it. The last track outing, I had 19* timing on the hit for the motor ramping to full timing at 6,200 (forgot that tune was in there). Went to spray on it and being dumb, I took another 10* out from 2,800 on up. So it left with 9* timing, fell on it's face so bad it cut a 1.9x

Here is what a table looks like in HP tuners. Typically WOT on the motor is .84-.88 g/cyl (goes up a little on 1 stage to .87-.91).. You can see in this table I have my timing ramping down at 5,200 from 28* to 24* then at 5,600 from 24* to 20* as I have the bottle coming on at 5,800.

Take a look at the throttle position, wheel speed and rpm.. You can clearly see I had to pedal it at first. Once I felt it was hooked and I laid in to it no traction issues what so ever.

The computer averages the timing drop so If I have it go 4* over 400 rpm's it's 1* per 100 rpm. Samr goes for increasing timing. Say I pull 12* on the hit over a 400rpm span. It'll have 16* coming in and will add 3* each 100rpm.

There are other ways I can do things like moving the intake air temp to be bellow the plate system (currently in the filter/carb hat). I could than use another table that is a timing vs intake air temp. As the computer sees a temp drop, I could have it pull timing too.

Attached is a recording from one of the bottle runs where you can see the timing come down in the graph.


I'm not looking at leaving on the bottle out of the hole in these events. These events also aren't some sanctioned million rule deal. The only things are, Pass tech, No line lock burn outs and it has to be 73 or 65 earlier. There are no timers, it's a flag start and it's all grudge.
Attached Images
   
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------Motor---------------Bottle
60'---1.53---------------1.41
1/8---6.58 @ 105.92----5.87 @ 118.41
1/4---10.38 @ 126.97----9.24 @ 142.49
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