technical power differences from 4* ext. duration
11-03-2005, 11:57 PM
#1
TECH Resident
Thread Starter
technical power differences from 4* ext. duration okay...
lets say you have a stalled A4 and want to keep stock 3.23's... you want the best performance at the track.
how much of a power difference peak, under curve and rpm axis are we ACTUALLY talking about with a split duration cam with 4* ext. same LSA.
Car...
4000 2.5 stall
3.23 gears
Lets use these two cams for the example in this thread...
identical except for the split.
224/224 113lsa
224/228 113lsa
which would provide the best performance and WHY?
lets say you have a stalled A4 and want to keep stock 3.23's... you want the best performance at the track.
how much of a power difference peak, under curve and rpm axis are we ACTUALLY talking about with a split duration cam with 4* ext. same LSA.
Car...
4000 2.5 stall
3.23 gears
Lets use these two cams for the example in this thread...
identical except for the split.
224/224 113lsa
224/228 113lsa
which would provide the best performance and WHY?
11-04-2005, 03:36 PM
#2
TECH Resident
Join Date: Dec 2004
Location: K-W, Ontario
Posts: 845
Likes: 0
Received 0 Likes
on
0 Posts
All things considered, I'd say the 228 degree exhaust will have more of an impact.
A little more overlap should make some upper RPM power...and if that's within
the gearing window, then you're going faster down the track.
More discussion about this topic in a thread called, "The Truth about LSA".
A little more overlap should make some upper RPM power...and if that's within
the gearing window, then you're going faster down the track.
More discussion about this topic in a thread called, "The Truth about LSA".
11-04-2005, 03:39 PM
#3
TECH Fanatic
iTrader: (14)
Join Date: Dec 2003
Location: Salisbury,MD
Posts: 1,729
Likes: 0
Received 0 Likes
on
0 Posts
Also, a little more higher rpm power may result as the increas in overlap (like Adrenaline mentioned) in addition to the earlier opening of the exhaust valve which may help reduce pumping losses by allowing more time for exhaust gasses to escape.
11-04-2005, 05:40 PM
#4
On The Tree
Join Date: Nov 2005
Posts: 184
Likes: 0
Received 0 Likes
on
0 Posts
Not a big hp difference but earlier opening/later closing will help scavenge on intake side increasing V.E. everywhere but at idle and below say 2K. This also has a tendancy of extending power band at high rpm(slightly).
11-04-2005, 11:34 PM
#5
TECH Resident
Thread Starter
thank you all, I read the LSA thread, I think I have to read it again to fully get all of it though. LOL
so, would the 228 ext. split still net the power in the 4000+ range for a good hit for the stall? and I assume it will make good power in the shift extension rpm's too.
so, would the 228 ext. split still net the power in the 4000+ range for a good hit for the stall? and I assume it will make good power in the shift extension rpm's too.