Evolution of my 996 Turbo
#50
After me TOM WHERE YOU BEEN MAN!>>!>! Call me!
Joe you are sick man, how's everything?? We didn't even get to meet up this past summer, been a while hope all is well with you and the car.
I wanted a damn ride, but I guess our schedules confilct, see you i'm sure this spring/summer!
Joe you are sick man, how's everything?? We didn't even get to meet up this past summer, been a while hope all is well with you and the car.
I wanted a damn ride, but I guess our schedules confilct, see you i'm sure this spring/summer!
#51
I just now saw this thread, Joe. The build looks and sounds spectacular! I really can't to hear how she runs at the strip. It looks like wait was well worth it, my friend.
Congratulations!
Congratulations!
#52
Thanks Scott!
#53
The GT3 exhaust cam will fit in the turbo cam housing, however the intake cam will not. Besides, the GT3 cams are NA cams and you simply don't need NA duration spans on a turbo motor.
Just guessing, if you are modifying a turbo vario cam, there is a very good chance Laurie and Web Cams are doing the work. It wasn't but a couple of years ago that no cam manufacturer's would touch them. Web was the first. I believe that is the route Todd at Protomotive used with Scott's build.
Are you using CP pistons? I believe this relieved design has become somewhat a staple of their's now.
Last edited by cjv; 12-27-2008 at 03:50 PM.
#54
joe,
The GT3 exhaust cam will fit in the turbo cam housing, however the intake cam will not. Besides, the GT3 cams are NA cams and you simply don't need NA duration spans on a turbo motor.
Just guessing, if you are modifying a turbo vario cam, there is a very good chance Laurie @ Weber Cams is doing the work. It wasn't but a couple of years ago that no cam manufacturer's would touch them. believe that is the route Scott went.
Are you using CP pistons?
The GT3 exhaust cam will fit in the turbo cam housing, however the intake cam will not. Besides, the GT3 cams are NA cams and you simply don't need NA duration spans on a turbo motor.
Just guessing, if you are modifying a turbo vario cam, there is a very good chance Laurie @ Weber Cams is doing the work. It wasn't but a couple of years ago that no cam manufacturer's would touch them. believe that is the route Scott went.
Are you using CP pistons?
#55
Yes CP pistons.Evoms tried the GT3 cams during mock up of the motor.The problem came in that Evoms and myself wanted to keep Variocam.The problem with the GT3 intake and exhaust cams when used with variocam is not piston to valve clearance but actual intake valve to exhaust valve clearance (clipping).This would not have been a problem with the stock or slightly larger turbo valves but with GT3 valves and variocam it is a problem.The cams are coming from Germany.
Regardless, you are in good hands. Again, you have my best.
#56
Yes CP pistons.Evoms tried the GT3 cams during mock up of the motor.The problem came in that Evoms and myself wanted to keep Variocam.The problem with the GT3 intake and exhaust cams when used with variocam is not piston to valve clearance but actual intake valve to exhaust valve clearance (clipping).This would not have been a problem with the stock or slightly larger turbo valves but with GT3 valves and variocam it is a problem.The cams are coming from Germany.
Due to my lack of knowledge regarding your build, are you using GT3 heads and cam housings or turbo heads that have been valve modified with turbo cam housings?
#57
GT3 heads machined for turbo cam housings
#59
Correct ,I should clarify...... the cams were GT3 exhaust and welded and reground turbo intake cams .The pointers are only on the intake cams.Even with the stock turbo intake cam and the GT3 exhaust cams the valves will clip,which is why the car is running stock intake and exhaust cams at the moment.We needed someone who could make a match set with the pointers and the correct specs for the GT3 heads and the Variocam.
#60
Correct ,I should clarify...... the cams were GT3 exhaust and welded and reground turbo intake cams .The pointers are only on the intake cams.Even with the stock turbo intake cam and the GT3 exhaust cams the valves will clip,which is why the car is running stock intake and exhaust cams at the moment.We needed someone who could make a match set with the pointers and the correct specs for the GT3 heads and the Variocam.
I believe that is what Protomotive did with Scott's car. Not sure if it was a GT3 exhaust and modified turbo intake. Two modified turbo cams may have been used. Not sure if Scott knows or not. I believe Web Cam did the vario cam weld and regrind.
This is really a tricky area because the type metal must be a match with the Porsche tappets metal otherwise premature wear (flattening of the cam lobes) is a big risk. Either that or you have to build both the tappets and cams from billet. Our cams utilitized custom designed/profiled for a turbo motor billet cams and tappets based on the GT3 cam housing fit. It was very difficult, time consuming and costly. About 60K later we got the cams right.
Last edited by cjv; 12-27-2008 at 04:40 PM.