Hi everybody!
My name is Evgeny, and i am from Russia (sorry for my bad English).
So, i have a nice car Opel Astra J OPC with a20nft engine and we made some modifications with this car.
Spec list:
ZFR7163 turbo
ZZP Connecting rods
ZZP stage 2 cams
ZZP #82 valve springs
Wiseco 86.5 pistons
Deleted Balance Shafts
f40 transmission
Bryce_eng aluminium flywheel and clutch for 650nm+ of torque
Front mount evo9 intercooler, 2.5" piping
89mm custom Maf housing (84mm inside diametr)
3" exhaust.
Cortex ebc boost controller
LPFP DW300C with externaf fuel filter.
fuel ron100
Fully rebuild head and block
Opel injectors (stock), stock HPFP,
AEM X-Series OBDII Wideband UEGO
Here is some photos:
Here is the result on stock cams and valve springs:
As you can see torque curve drops down at high RPM. To achieve more torque at high RPM ZZP stage 2 cams and #84 valve springs has been installed. We asked ZZP to send us calibrations for the camshafts, and they sent it to us (of course, not for free).
Finlay we made some dyno tests,made some calibrations and here is what we got:
After we got such a bad result, I decided to understand in more detail what the numbers on cam position map mean.
Astra J opc stock Intake Cam Position and exhaust cam position maps (e39a)
The map contains only positive values. The minimum value is 1 degree, the maximum is 25 degrees.
Based on the data in this article: https://pages.mtu.edu/~mahdish/Docs/..._MScThesis.pdf the maximum angle of rotation of the phaser is 50 degrees (angle of rotation of the crankshaft). As we know, the camshaft rotates 2 times slower than the crankshaft, therefore it can be assumed that the angles of rotation of the phaser at camshaft degrees are indicated in the map.
Cams phasing is all about overlap and back pressure (turbo engines). To find out the overlap values we need to know the valve opening and closing timings in crank angle degrees, and lobe profiles. Intake and exhaust valve profiles for park position and completely phased position and Valve timing diagram for the stock GM Ecotec LHU engine (https://pages.mtu.edu/~mahdish/Docs/...ScThesis.pdf):
However, one important question remained. What value corresponds to the parking position of the phaser? 0 or 25? It is known that at high boost values and high revs it is necessary to reduce the overlap to reduce the back pressure. If this is true, then in the stock map, at high loads and revolutions, the overlap should decrease (the phaser tends to the parking position). If my assumption is correct, then 0 is the parking position of the phaser, and 25 is completely phased position. Am I right or not?
If i am right then look at the maps by ZZP:
ZZP increased overlap at high loads and revs for St2 cams. For a better understanding, I approximately drew stage 2 cam profiles for stock and for ZZP maps (High load and rpm):
large overlap...
So, before we start real testing i wold like to find out the correct direction. What value corresponds to the parking position of the phaser? 0 or 25? Or completely different?