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Old 10-01-2010, 11:21 AM   #17 (permalink)
EdKiefer
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Quote:
Originally Posted by Meph View Post
Yep i rotate CW, my cam gears are correctly labeled too, I checked this as I was worried as well.

Ill take another read though the posting too.

What if I were to do it in two steps, shifting the cam events +4 degrees advanced (Intake +4 and Exhaust +4) then took the next step of lowering overlap (Intake +4 - 1 = 3 Exhaust +4 + 3= 7)

Would this theory work (+3 intake, +7 Exhaust) or would the ideal be more like intake -1 and exhaust +7



After all this messing around I assume resetting the base timing is a good idea, its triggered by the intake cam so Id have to adjust my ecu (standalone). Would any of the cam timing changes warrant advancing or retarding the ignition?


I'm starting to lean towards running +4 exhaust and leaving the intake at 0 so i wont have to redo my timing, and seeing if I can notice a differnece, or maybe try +6 ex and +2 intake giving me a +3 shift and a +3 ex / -1 intake

Sorry for all this mindless thought, Im slightly thinking out loud , hopefully it makes a little sense
Hard to say, but me I would try 4+ 4+ and note any gains (if you got any type of datalogger be great to test performance) . The I would try lowering the overlap way, but starting with stock 0, 0 as baseline . After noting that you can combine any improvements noted in each test .

The thing its going to be hard to tell improvements unless you do it on dyno for power in X rpm band or test mpg over time in each mode. There so many variables with 2 adjustable cam gears , IMO its hard to recommend a setting .

One thing to note, since your on turbo car you don't need a lot of overlap or long duration openings, especially on exhaust side as you don't want to blow intake charge right out exhaust on boost (not that this be problem on stock or mild cam) . I would not go more than 4deg on either cam without some good way to test .

Does this engine have ignition pickup on intake cam end ?
can't you just adjust it with timing light the few deg you move cam or is it not adjustable .
If thats the case yes you could just try advance on exhaust side first as test run .
Try 4+ on exhaust and see out come as thats easy .I would not combine both methods as your altering deg a lot then .(meaning I would try Ex -4+ , In 0 and then Ex4+ , In-4+ but not Ex 8+, In -4+ , max I would go would be Ex 6+ , In 2+ combined . Again I would focus on doing each separate to even notice which gives some improvement then if both did try combining , again this is tough call .

Last edited by EdKiefer; 10-01-2010 at 12:13 PM..
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