S4 & S5 engines compared?
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From: Kansas City
S4 & S5 engines compared?
Sorry...I tried searching for these differences. I was wondering, what are the benefits(like why more/less psi or compression etc.) to having either the S4 engine or the S5 engine? Also if they would have any negative sides too. Thanks. 
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From: BC, Canada
Originally posted by dr0x
NA or turbo?
S5 has weaker/lighter internals, allowing for the higher revs. S4 has heavier/stronger internals. S5 has bigger ports, better turbo. I believe all turbo ii motors had a 8.5:1 CR and NA had 9.0:1. Kind of sad the s5 motor only makes 20bhp more than a s4.
NA or turbo?
S5 has weaker/lighter internals, allowing for the higher revs. S4 has heavier/stronger internals. S5 has bigger ports, better turbo. I believe all turbo ii motors had a 8.5:1 CR and NA had 9.0:1. Kind of sad the s5 motor only makes 20bhp more than a s4.
S4 NA: 9.4:1 CR
S4 TII: 8.5:1 CR
S5 NA: 9.7:1 CR
S5 TII: 9.0:1 CR
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From: BC, Canada
Also, the irons's had more meat on them in the S5's, allowing for larger porting, and extra meat around the dowel pin area, which was prone to crack on S4 Turbo engines.
The rotor housing coating procedure became changed drastically. The S5 housings last A LOT longer before showing flaking of the chrome surface.
The EGR was removed from all S5 engines, and the port air induction into the block was changed.
There are a few more, but those are the major ones.
Power:
S4 NA: 146 hp
S5 NA: 160 hp
S4 TII: 182 hp
S5 TII: 200 hp
The rotor housing coating procedure became changed drastically. The S5 housings last A LOT longer before showing flaking of the chrome surface.
The EGR was removed from all S5 engines, and the port air induction into the block was changed.
There are a few more, but those are the major ones.
Power:
S4 NA: 146 hp
S5 NA: 160 hp
S4 TII: 182 hp
S5 TII: 200 hp
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From: BC, Canada
Originally posted by dr0x
Was the sidewall on the not thinner on the s5? And wow, NA's have more compression than I thought.
Was the sidewall on the not thinner on the s5? And wow, NA's have more compression than I thought.
Sidewall refers to tires.
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From: Bay area
Originally posted by scathcart
sidewall? be more specific. The rotor housings were not any thinner, and the irons were thicker.
Sidewall refers to tires.
sidewall? be more specific. The rotor housings were not any thinner, and the irons were thicker.
Sidewall refers to tires.
My guess is that he's referring to the strength of the rotors themselves, the S5's are lighter but as a result cannot handle as high of combustion chamber pressures. I think it was crispeed that said he ran S4 rotors because they can take more boost?
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the S5's are lighter but as a result cannot handle as high of combustion chamber pressures.
The reason (in a turbo application) to run s4 rotors is lower compression ratio; this favors higher boost for more safety. I have heard that some tuners in japan etc. prefer to use s4 t2 rotors in high power FD's etc. due to extra safety margins(s4 t2 rotors are lowest compression of all).
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From: BC, Canada
Originally posted by pengarufoo
My guess is that he's referring to the strength of the rotors themselves, the S5's are lighter but as a result cannot handle as high of combustion chamber pressures. I think it was crispeed that said he ran S4 rotors because they can take more boost?
My guess is that he's referring to the strength of the rotors themselves, the S5's are lighter but as a result cannot handle as high of combustion chamber pressures. I think it was crispeed that said he ran S4 rotors because they can take more boost?
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