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Thread: VVL - Switching too Early?

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Posts: 1-10 of 21
2009-07-14 16:35:38
#1
VVL - Switching too Early?
Can someone please explain how switching too early can cause the ve motor to lose power? In a race situation, that is.

If say I am drag racing, wouldnt it be best to have the motor on high cams as early as possible? In any case once you pass the switch point in 1st gear you stay in high cams anyways for the 1320.

I even know of a guy setting up an ve and plans to drive it on high cams only.

Thanks.

Peace
2009-07-14 16:54:58
#2
in a race situation, if you are launching on the high cam, and staying on it on each gearshift, then yes it doesnt matter.

Being on the high cam as early as possible may not be the best thing, they do not provide good low down power. This is why VVL was invented.

driving on the high cams is fine, but it wont idle well (if at all), nor be nice to drive at all down low.
2009-07-14 18:00:45
#3
Originally Posted by lonewolf
in a race situation, if you are launching on the high cam, and staying on it on each gearshift, then yes it doesnt matter.

Being on the high cam as early as possible may not be the best thing, they do not provide good low down power. This is why VVL was invented.

driving on the high cams is fine, but it wont idle well (if at all), nor be nice to drive at all down low.


Thanks.

Not planning to lauch at more than 4000rpm, plus when I leave the line it may allow to drop to about 3500rpm (when load of car reaches motor, tranny) so will I need to turn vvl down to 3500rpm or just leave it at 4600 or 4800 (the points I have been playing with)?

Peace
2009-07-14 19:56:39
#4
just leave it at 4800 rpm's...you gotta let the low cams do their job first man...
2009-07-14 19:59:49
#5
I have mine at 5100 and 5300 with sr16 cams, shifting at 8000
2009-07-14 22:02:57
#6
Originally Posted by qwkse-r
just leave it at 4800 rpm's...you gotta let the low cams do their job first man...


Please explain. How do you explain the guy locking the cams at high cams only? Not sure how he is gonna make it idle.

Peace

2009-07-14 23:16:04
#7
my cams switch at 4500/5000 and i have pretty much the same setup as you dude, and pretty much the same power, my rev limit however is still at 6950 but when i shift just before the limiter it stays on high cam
2009-07-14 23:39:24
#8
Originally Posted by gtirwezz
my cams switch at 4500/5000 and i have pretty much the same setup as you dude, and pretty much the same power, my rev limit however is still at 6950 but when i shift just before the limiter it stays on high cam


Maybe that's why your only making 171whp. Rev the car higher to like 8k and move up your vvl points to where mine are at and I bet you will make more power. Probably like 185 or so. 171 is to low for your setup I think.
2009-07-14 23:42:01
#9
I was told by some knownledgable people that 5000 is the lowest I should go and guess what I tried lower and they were right! I can't see how your making even 171 shifting that low.
2009-07-15 02:15:33
#10
Originally Posted by niZmo
Please explain. How do you explain the guy locking the cams at high cams only? Not sure how he is gonna make it idle.

Peace



low cams make more power to about 5000rpm
high cams make more power over 5000rpm

if you go below 5000rpm at any point, being on the high cam is bad at this point.

as for the guy locking them on, then no idea how he is going to make it idle. I accidentally set one of the cams to come on at low rpm and it barely idled, let alone both.
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