Which GT3 cams for 996 Turbo tuned
#17
12-13-2009, 09:14 AM
Same here Rob... I have spoke with my guy here in UK and they have fitted these before with no issues, I have also sent Todd an email regarding this, he will know for sure.
#18
12-13-2009, 09:51 AM
The old myth of wrong duration on Turbo cams is somewhat a myth nowadays. People seem to think Turbo motors don't like overlap because it keeps the valves open and boost pressure escapes, blah blah blah. Maybe at lower boost levels and power levels without a freeflowing intakes and exhaust.
When you start getting big flow exhaust, bigger turbos with bigger exhaust housings, it has been proven and written by many builders, NA hi-lift and longer duration cams will produce better results on even on turbo motors such as these. The scanvenging effect on higher boost levels will ultimately help the effiency on a turbo motor.
Why do you think a high HP EVO motor uses a 11-12mm lift over long duration vs using a stock cam? Why has the Supra world been using bigger HKS and newer style cams over stock cams? Its because the bigger cams and overlap duration makes more power on a highly modified motor.
Anyone have a DYNO before/after from cams?
When you start getting big flow exhaust, bigger turbos with bigger exhaust housings, it has been proven and written by many builders, NA hi-lift and longer duration cams will produce better results on even on turbo motors such as these. The scanvenging effect on higher boost levels will ultimately help the effiency on a turbo motor.
Why do you think a high HP EVO motor uses a 11-12mm lift over long duration vs using a stock cam? Why has the Supra world been using bigger HKS and newer style cams over stock cams? Its because the bigger cams and overlap duration makes more power on a highly modified motor.
Anyone have a DYNO before/after from cams?
#19
12-13-2009, 10:23 AM
I am currently investigating the Valve/Tappet issue... I find that very strange, but will come back to you on this!
I am more than positive the GT3 Exhaust Cams are all the same, might be a superseded part number though... If I do remember correctly, 996 GT3 MKII Cams.
I am more than positive the GT3 Exhaust Cams are all the same, might be a superseded part number though... If I do remember correctly, 996 GT3 MKII Cams.
#20
12-13-2009, 10:24 AM
The GT3 exhaust cam can be used with the 996tt cam housing. The GT3 intake is too big for the same housing.
#21
12-13-2009, 10:34 AM
The old myth of wrong duration on Turbo cams is somewhat a myth nowadays. People seem to think Turbo motors don't like overlap because it keeps the valves open and boost pressure escapes, blah blah blah. Maybe at lower boost levels and power levels without a freeflowing intakes and exhaust.
When you start getting big flow exhaust, bigger turbos with bigger exhaust housings, it has been proven and written by many builders, NA hi-lift and longer duration cams will produce better results on even on turbo motors such as these. The scanvenging effect on higher boost levels will ultimately help the effiency on a turbo motor.
Why do you think a high HP EVO motor uses a 11-12mm lift over long duration vs using a stock cam? Why has the Supra world been using bigger HKS and newer style cams over stock cams? Its because the bigger cams and overlap duration makes more power on a highly modified motor.
Anyone have a DYNO before/after from cams?
When you start getting big flow exhaust, bigger turbos with bigger exhaust housings, it has been proven and written by many builders, NA hi-lift and longer duration cams will produce better results on even on turbo motors such as these. The scanvenging effect on higher boost levels will ultimately help the effiency on a turbo motor.
Why do you think a high HP EVO motor uses a 11-12mm lift over long duration vs using a stock cam? Why has the Supra world been using bigger HKS and newer style cams over stock cams? Its because the bigger cams and overlap duration makes more power on a highly modified motor.
Anyone have a DYNO before/after from cams?
The whole experiment had a price tag of about 60K. At the time no cam builder was doing anything with the intakes and little with the exhaust. We discovered that all Porsche cams had harmonic distortion. We also found the mix of lift and duration between the turbo and the many GT3 cams was not ideal for our motor.
I will not disclose all information because as of yet what we have appears to still be the state of the art. We totally eliminated all harmonic distortion and as a result was able to run a redline of 9400 rpm's with spring pressures far lower than the spring pressures being used on any other engine builder/tuner that we are aware of.
Last edited by cjv; 12-13-2009 at 11:18 AM.
#22
12-13-2009, 10:47 AM
Here is some information for anyone who is interested about the stock 996tt intake cams. The exhaust cam info is pretty easy to find.
Lift is .402" secondary cam lobe .118"
Duration .040 234 degrees .050 230 degrees
secondary cam duration .040 128 degrees .050 120 degrees
cam base circle 1.378
The cam specs on the GT3 street cams are:
Duration......... Intake 286.0 Exhaust 285.0
50/1000's Lift.. Intake 235.0 Exhaust 226.6
0 Lash Lift...... Intake 484.0 Exhaust 437.0
For our own build we used more duration/lift on the intake and less duration/lift on the exhaust
Lift is .402" secondary cam lobe .118"
Duration .040 234 degrees .050 230 degrees
secondary cam duration .040 128 degrees .050 120 degrees
cam base circle 1.378
The cam specs on the GT3 street cams are:
Duration......... Intake 286.0 Exhaust 285.0
50/1000's Lift.. Intake 235.0 Exhaust 226.6
0 Lash Lift...... Intake 484.0 Exhaust 437.0
For our own build we used more duration/lift on the intake and less duration/lift on the exhaust
Last edited by cjv; 12-13-2009 at 11:16 AM.
#23
12-13-2009, 11:00 AM
Join Date: Jun 2009
Location: Warsaw
Posts: 56
Rep Power: 18 
GT3 catalouge offer
996 105 212 95
and 996 105 245 90 M96.70 Remark 04-
So it`s mean the best GT3 exhaust cams are from 2004 Gt3?
996 105 212 95
and 996 105 245 90 M96.70 Remark 04-
So it`s mean the best GT3 exhaust cams are from 2004 Gt3?
#24
12-13-2009, 11:06 AM
This all depends on year and model.
#25
12-13-2009, 01:43 PM
Ok... so we are starting to get somewhere now
Chad, (ref Exhaust Cams only)... my main concern here are these Tappets which can be Radius or Flat!!!...
Does this mean GT3 Cams (GT3 MKII) can also be different?... and if so how do they differ?
Chad, (ref Exhaust Cams only)... my main concern here are these Tappets which can be Radius or Flat!!!...
Does this mean GT3 Cams (GT3 MKII) can also be different?... and if so how do they differ?
#26
12-13-2009, 01:44 PM
Join Date: Jun 2009
Location: Warsaw
Posts: 56
Rep Power: 18
Who can write correct part number ?
Especialy that in parts catalouge there are only two possibility choice
http://login.dealerskins.com/SiteSpe...rameset_en.htm
Especialy that in parts catalouge there are only two possibility choice
http://login.dealerskins.com/SiteSpe...rameset_en.htm
Last edited by dominik...; 12-13-2009 at 01:50 PM.
#28
12-13-2009, 02:16 PM
Ok... just checked on my PET
GT3 Exhaust Cams (as Dominik mentioned)
1999 - 2005
996.105.212.95
996.105.245.90 - M96.79 (which is MKII GT3)
Nothing listed against the 95 Cams, but suspect these would be MKI GT3
As for Tappets
996.105.041.91 - M96.76 (which is MKI GT3)
996.105.041.92 - M96.79 (which is MKII GT3)
GT3 Exhaust Cams (as Dominik mentioned)
1999 - 2005
996.105.212.95
996.105.245.90 - M96.79 (which is MKII GT3)
Nothing listed against the 95 Cams, but suspect these would be MKI GT3
As for Tappets
996.105.041.91 - M96.76 (which is MKI GT3)
996.105.041.92 - M96.79 (which is MKII GT3)
#29
12-13-2009, 02:21 PM
Join Date: Jun 2009
Location: Warsaw
Posts: 56
Rep Power: 18
thank you
Turbo tappets is
996 105 041 72, who can compare this one to GT3 Mk2 996 105 041 92?
Turbo tappets is
996 105 041 72, who can compare this one to GT3 Mk2 996 105 041 92?
Last edited by dominik...; 12-13-2009 at 02:27 PM.
#30
12-14-2009, 08:23 PM
Registered User
Join Date: Aug 2009
Location: Houston Tx
Age: 39
Posts: 2,496
Rep Power: 186 
just curious wouldn't it be better to purchase one that is already made for our car as in the regrinds that protomotive and others stock? or 9ff or is there something im missing maybe price? but i doubt it as OE porshe parts are not cheap
Last edited by OS Inspector; 12-14-2009 at 08:24 PM. Reason: typo stupid laptop keyboard