From SRT forums-all the cam specs you ever needed and more!

[turbovanman²]

From Christian, aka DRASTIC on the SRT forums-


SRT-4
duration @ .050: 172/175
Valve Lift: .327/.261
LSA: 113

2.0L Neon
duration @ .050: 174/173
Valve Lift: .347/.315
LSA: 110 int: 108 exh: 112

DOHC 2.4 N/A
Duration@.006": 232/240
LIFT: .324/.256
LSA: 113 intake: 115 exhaust: 111

please note, the duration is not anywhere near correct in terms of in correlation to the .050" ratings...


Brian Crower
Stage 2
duration @ .050: 186/184
Valve Lift: .350/.310


Stage 3
duration @ .050mm: 194/186
Valve Lift: .389/.383


Crower 2.4
Stage 1
DURATION @ .050: Int: 186°/Exh: 184°
Valve Lift:Int:.357 / Exh:.308

Stage 2
DURATION @ .050: Int: 196°/Exh: 188°
Valve Lift: Int: .385 / Exh: .382

Crower 2.0
stage 1
duration @ .050: 197/197
Valve Lift: .383/.383

stage 2 (Nitrous cam)
duration @ .050: 196/196
Valve Lift: .403/.403

Stage 2 (Forced induction Cam)
duration @ .050: 186/184
Valve Lift: .416/.410

Stage 3 (street/strip cam)
duration @ .050: 204/204
Valve Lift: .410/.410

Stage 3 (Race Cam)
duration @ .050: 210/210
Valve Lift: .420/.420


CRANE CAMS
10s
duration @ 1mm: 200/200
Valve Lift: .354/.354LSA: 110

12s
duration @ 1mm: 204/204
Valve Lift: .364/.364
LSA:112

14s
duration @ 1mm: 204/196
Valve Lift: .364/.354
LSA: 110

16s
duration @ 1mm: 208/208
Valve Lift: .374/.374
LSA: 110

18s
duration @ 1mm: 216/216
Valve Lift: .394/.394
LSA: 112


WHICH CAMS NEED VALVE SPRINGS:
BC 3s
Crower 2.4: stg2s
Crower 2.0: stg1 and up
Crane 16's and larger

all else are fine w/ stock springs



VALVE SPRINGS:
Crane Valve Springs
Outside diameter: 1.065
Inside diameter: 0.725
Seat pressure: 60lbs@1.535
Open pressure: 255lbs@1.063
Coil bind: 0.987
Rate: 413
Maximum net lift: 0.472

Brian Crower Valve Springs
Seat Pressue: 1.500" @ 92 lbs
Open Pressure: 1.100" @ 195 lbs
Coil Bind: 0.920"

Ferrea Valve Springs
Stage 1
S10107 Dual Spring
Inside diameter: 20.8 mm
Outside diameter: 28.0 mm
Seat Pressue: 90lbs@37mm
Open Pressure: 200lbs@27mm
Rate Inch: 279lbs
Coil Bind: 23mm
Max Net Lift: 12mm

Stage 2
S10108 Dual Spring
Inside diameter: 20.8 mm
Outside diameter: 28.0 mm
Seat Pressue: 105lbs@37mm
Open Pressure: 235lbs@27mm
Rate Inch: 330lbs
Coil Bind: 23.5mm
Max Net Lift: 12mm

The Stage 1 and 2 spring requires Ferrea Titanium Retainer #E11074 and BOTH, Ferrea spring seat locator # SL1062 and factory supplied spring seat locator.


SOHC Crane Springs in the DOHC head
Outside Diameter: 1.065
Inside Diameter: 0.725
Seat Pressure: 85lbs@ 1.535
Open Pressure: 244lbs@ 1.135
Coil Bind: 1.014
Rate: 397
Maximum Net Lift: 0.440

DCRValve Springs w/ Moly Retainers
120lbs @ 1.535 @ base
290lbs @ 1.035 @ max lift and .060 from coil bind.
10,000 rpm tested at over 65lbs of boost!
$300 set

TUNING CAMS
EXHAUST
advancing: widens powerband
retarding: narrows powerband

INTAKE
advancing: narrows powerband
retarding: widens powerband

MORE CAM GEAR TUNING
ADVANCING BOTH GEARS:
doing so will shift the entire powerband to the higher rpms. for stock/s3 turbos, this would be a good idea. w/ an already fast spooling turbo, giving up 2-300 rpms is worth the added gains to up top.

RETARDING BOTH GEARS:
doing so will shift the entire powerband to the lower rpms. this will result in a torquier low-midrange, but will fall off slightly up top. 50trim and up owners could benefit from shifting their powerband to the left, and gaining some midrange power where they lack it.

HOW TO TUNE:
the dyno is the only way.
start off by tuning your AFR's to a solid 11.5:1 afr (many people differ on the afr, but this is a happy medium that wont set you too far lean if something happens).
once done doing so, jump to your intake cam and start adjusting. go by 2* increments. retard your intake 2*. if you gain power, add an additional 1-2* until you see the power gains stop. if you lost power right off the bat, retard them doing the same procedure.

once done and you like it, check your afr's once again just to assure that the afr's are in check. now start your exh cam.

advance your exhaust cam 2*. if you gained power, add 1-2*. if you didnt, retard it 1-2* and see of the result. follow the above procedure.

if you like how the results of both cams are, but want a tad bit faster spool, retard both cams 1* at a time.
if its the other way around, and want the power to not drop off as much, advance both 1* at a time.



advancing intake, retarding exhaust results in a smaller LSA; thus a torquier powerband.

retarding intake, advancing exhaust results in a broader LSA; thus a broader, higher RPM gained powerband.


CAM GEAR SELECTION
UR CAM GEARS
price is roughly 340-390. only cam gear on the market that will fit under the cover. tolerances on the dowel pin are closer than that of the fidanzas, but that should not matter if you are tuning anyways. if stealth is all worth it to you, then shell out the $$ for these.


FIDANZA
can be readily had from many vendors here. price goes from 170-200. all cracking issues w/ them prior have been fixed and updated a yr ago. their new updated hardware (allen keys instead of hex) are made to supposedly clear the side mount. too close for comfort...save yourself the headache, and shave the mount. oh, and upgrade your hardware, theyre junk

AEM 2.0's + JEFFB#2 spacers
these are my favorite. can be had from 125-200 used/new from the 2.0 neon guys. all youll need to do is get ahold of the JEFFB#2 spacers and youre golden.
super easy to tune w/ only 3hex bolts vs. the standard 5allen keys. it saves muchhhh time when on the dyno.

VALVES
REV (+1mm int, +1mm exh as well as +2mm)
SI (+1mmint/exh). go roughly for 12.50/valve
DCR +1 avail and +2mm for exh

larger valves help contribute to a little faster spool, and more power to be made at less boost.




i will be adding more throughout time as i find necessary.
this section hasnt had a thorough, and solid info thread w/ correct info in yrs practically.
im trying to get mod status for this section, since alot of stuff needs to be stickied and updated. so if you found this thread helpful, shoot ekool or castrol of the sorts a pm, and let them know. id appreciate it.


christian

__________________
CHRISTIAN.
custom 47lb AGP setup.
413hp, 446tq 91pump!
Crower S2's, ported int/exh on the head, 70mm TB, and fresh stock rebuild added.
420-430hp on 91pump or bust!