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Frequent flyer Gold
Posts: 421
Location: Brisbane,qld | what do you think about a 12 -20 psi supercharged 6g74 with stock bottom end, aren t they good for 500 hp or roundabouts, the conrods are a bit beefier than the 75; being 300 cc smaller woulnt make that much difference, can anyone ad to this, give thier opinions...........?? |
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Frequent flyer Gold
Posts: 1093
  
Location: An island off southern Tasmania. | Almost every supercharged 6g74 has failed at 8 psi or more if it had stock internals.
500hp with stock internals? For a little while i guess....6G75 is a far better engine. |
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Frequent flyer Gold
Posts: 421
Location: Brisbane,qld | I just thought with the beefier conrods it would be a wee bit stronger going off how skinny the 75s are,so would the 75 be good for 7.5 psi? |
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Frequent flyer Gold
Posts: 1093
Location: An island off southern Tasmania. | wsbtt - 11/8/2011 06:47
I just thought with the beefier conrods it would be a wee bit stronger going off how skinny the 75s are,so would the 75 be good for 7.5 psi?
My stock engine was running 7.5 for quite a while.
Bear in mind with supercharging 7.5 psi is at redline maximum.
How much time do you spend on redline? I find most of the time it sits between 2 psi and 4 psi.
Stock internals on just about any engine give up at 8 psi plus....regardless if its a holden,ford mitsubishi...whatever.
On the TMR380 the best thing you can do is the 7th injector mod described elsewhere.
In any event it's not the conrods that fail...it's pistons and bearings. |
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Frequent flyer Gold
Posts: 421
Location: Brisbane,qld | no probs, thanks for the info |
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Posts: 18
Location: Sydney Australia | Administrator - 11/8/2011 09:44
wsbtt - 11/8/2011 06:47
I just thought with the beefier conrods it would be a wee bit stronger going off how skinny the 75s are,so would the 75 be good for 7.5 psi?
In any event it's not the conrods that fail...it's pistons and bearings.
FWIW we've found that a good way to make bearings last is to run tighter tolerances, what are the 380 stock tolerances?
shoot for 0.015" mains and 0.002" Rods seems to be keeping our engines together |
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6g74
