compression for Turbo
Originally Posted by fsttyms1
6 to 7 is a good reliable #
Good luck on getting your compression that low. But to be perfectly honest, you will be fine at around 9-9.5 compression for 10psi of boost. Anything higher and you may want to drop it down to about 8.5 compression. And turbocharging an automatic seems kinda pointless and dangerous to me. Now I am far from a FI expert but on an automatic, unless getting off the gas pedal between shifts, boost pressure would not be able to be relieved through some sort of BOV and the back pressure in the charge pipe could possibly cause damage to your motor and/or turbo. Anyone with more knowledge please chime in, and correct me if I am wrong.
Originally Posted by JimmyTLS
Good luck on getting your compression that low. But to be perfectly honest, you will be fine at around 9-9.5 compression for 10psi of boost. Anything higher and you may want to drop it down to about 8.5 compression. And turbocharging an automatic seems kinda pointless and dangerous to me. Now I am far from a FI expert but on an automatic, unless getting off the gas pedal between shifts, boost pressure would not be able to be relieved through some sort of BOV and the back pressure in the charge pipe could possibly cause damage to your motor and/or turbo. Anyone with more knowledge please chime in, and correct me if I am wrong.
He was talking about psi not compression ratio. Currently a CL-S is seeing 8lbs of intercoolered boost through a supercharger. The CL-S motor runs at 10.5:1 compression.
The two current CL-S turbo set-ups are around 5.5 psi for street driving, although they can increase the boost closer to 8 psi for the track or dyno.
Turbocharging an automatic is a little different because there is no closing of the throttle between shifts, so there is no blow-off valve. Turbochargers on automatic transmissions are not uncommon though, infact many cars can come from the factory with an automatic transmission and a turbo.
Originally Posted by mrsteve
He was talking about psi not compression ratio. Currently a CL-S is seeing 8lbs of intercoolered boost through a supercharger. The CL-S motor runs at 10.5:1 compression.
The two current CL-S turbo set-ups are around 5.5 psi for street driving, although they can increase the boost closer to 8 psi for the track or dyno.
Turbocharging an automatic is a little different because there is no closing of the throttle between shifts, so there is no blow-off valve. Turbochargers on automatic transmissions are not uncommon though, infact many cars can come from the factory with an automatic transmission and a turbo.
The two current CL-S turbo set-ups are around 5.5 psi for street driving, although they can increase the boost closer to 8 psi for the track or dyno.
Turbocharging an automatic is a little different because there is no closing of the throttle between shifts, so there is no blow-off valve. Turbochargers on automatic transmissions are not uncommon though, infact many cars can come from the factory with an automatic transmission and a turbo.
I am not saying that turbo automatics are dangerous...I am saying a turbo with OUR automatic transmissions are dangerous. I debated this over and over as well, and reality finally set in that the only sensible FI for the TL is either the comptech SC or nitrous.
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