Help selecting the best turbo cam!
Originally Posted by trtturbo
You can still have basically stock driveability using a mid 220's cam on a 115.
We did a 226/220 on a 115 and the cam was very near stock idle.
We did a 226/220 on a 115 and the cam was very near stock idle.
I see a few schools of thought regarding turbo cams:
1. Standard split- Large exhaust duration compared to intake, which allows more exhaust gas to spin the turbine. Let the boost do the work on the intake side, and couple it with a wide LSA to minimize reversion. This is your z06 and GT2-3 cams.
2. Reverse split- Run a larger duration intake to allow more air and fuel in, and run a smaller exhaust duration to minimize overlap and thus reversion. This allows a tighter LSA to be run. An example would be the 226/220-115 cam above.
3. A comp tech rep said that they size it like a N/A cam, then they reduce the duration 10* and biased the exhaust about 4*. The reason they don't like reverse splits, because they feel its the old school way, since turbines are far more efficient now.
4. Single pattern- I'm not sure as the reasoning behind this, so maybe some one fill me in.
I'm sooo confused!!!
All comes down to what you want to do with the car, and the power level you need to hit your goals.
Too much exhaust duration can increase backpressure (for a single turbo setup) to the point where you have to dial down the tune.
Too much exhaust duration can increase backpressure (for a single turbo setup) to the point where you have to dial down the tune.
Originally Posted by Pro Stock John
All comes down to what you want to do with the car, and the power level you need to hit your goals.
Originally Posted by Pro Stock John
Too much exhaust duration can increase backpressure (for a single turbo setup) to the point where you have to dial down the tune.
Joined: Nov 2001
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From: LT1 land...the "409" of the 90s!
This is the cam speced out for the shop truck. NOT an LS1 but many of the same rules apply 
Duration (intake/exaust) 221/214
Lift (intake/exaust) 540/532 (1.5 will be using 1.6)
Lobe Center Separation 115
Intake Centerline 112
The cam was custom chose for towing and play power.
Duration (intake/exaust) 221/214
Lift (intake/exaust) 540/532 (1.5 will be using 1.6)
Lobe Center Separation 115
Intake Centerline 112
The cam was custom chose for towing and play power.
