Overlap in cams is good for FI cars
02-08-2005, 12:25 AM
#11
3.0 BAR
Join Date: Apr 2003
Posts: 2,579
Re:Overlap in cams is good for FI cars
Originally Posted by Whitey
Did you read that the increased overlap might be preventing contamination from the reversion effects of the log manifolds?
p.s. Can the drunks go ---- up G.D and not the tech threads, thanks.
p.s. Can the drunks go ---- up G.D and not the tech threads, thanks.
And I woudn't have been able to spew all that out If I were drunk. But sorry bout the spelling.
02-08-2005, 12:47 AM
#14
0.0 BAR
Join Date: Feb 2003
Posts: 0
Re:Overlap in cams is good for FI cars
See, ---- like this is just better with pictures and diagrams. Where the piston is, what postition the valves are in. You know, english. It's just hard to draw pictures in your head with numbers like -4 and +2.
I guess it's just all new to me and I haven't read about how "normal" people even tune these things.
I guess it's just all new to me and I haven't read about how "normal" people even tune these things.
02-08-2005, 05:22 AM
#15
0.5 BAR
Join Date: Jul 2004
Posts: 169
Re:Overlap in cams is good for FI cars
Originally Posted by Stealthmode
See, ---- like this is just better with pictures and diagrams. Where the piston is, what postition the valves are in. You know, english. It's just hard to draw pictures in your head with numbers like -4 and +2.
I guess it's just all new to me and I haven't read about how "normal" people even tune these things.
I guess it's just all new to me and I haven't read about how "normal" people even tune these things.
It's not that hard to understand really.
02-08-2005, 10:09 AM
#17
1.5 BAR
Join Date: Mar 2004
Posts: 938
Re:Overlap in cams is good for FI cars
different engines will like different type of overlap or less of. It depends on the set up, which differs from one another. I tuned cars on the dyno that like increasing the over lap and some that don't. The only way to know if you are tunning your camgears right is to do it on the dyno. 98ctr
02-08-2005, 11:42 AM
#18
1.5 BAR
Join Date: Aug 2003
Posts: 1,341
Re:Overlap in cams is good for FI cars
Originally Posted by fork
This is confusing because more overlap causes less cylinder pressure. the reason people raise compression, use nitrous, or turbos is to increase cylinder pressure. now he says he uses more over lap and less timing. So thnk about having a car that has too much boost or compression, and you're detonating, you would use more overlap or less timing to fix the problem. How would more overlap (less cylinder pressure) and less timing cause more power. That doesn't make much sense unless the initial tune was so bad that the spark was blowing out. I don't know but taht doesn't make much sense to me.Maybe hes got it backward and hes actually getting less over lap.
The theory behind this is having the exhaust gases exit through the exhaust valves while opening the intake valves. The flow of the exhaust gases going out the exhaust valves are supposed to help draw air in through the intake valves at the same time.
Stan
02-08-2005, 11:47 AM
#19
3.0 BAR
Join Date: Jan 2003
Posts: 7,082
Re:Overlap in cams is good for FI cars
Originally Posted by fork
I don't know for sure that it's not true but why would haveing both valves open at the same time cause less exhaust to go back into the chamber.
02-08-2005, 11:50 AM
#20
1.5 BAR
Join Date: Aug 2003
Posts: 1,341
Re:Overlap in cams is good for FI cars
Originally Posted by Kyle
Originally Posted by fork
I don't know for sure that it's not true but why would haveing both valves open at the same time cause less exhaust to go back into the chamber.
Stan
