12.05:1 Static - Dynamic ?? & What is good for boost ?
10-20-2011, 06:58 PM
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12.05:1 Static - Dynamic ?? & What is good for boost ? Ok I don't want to boost this motor but I was wondering what I have : Static or Dynamic ?
Question # 2 : I have this complete motor from oil pan to throttle body , water pump , Optispark , etc. sitting on my garage floor.
GM LT1 5.7 Litre. 355CI Bore 0.030".
JE SRP Forged Pistons (10.3:1 compression).
Manley Sportsman Forged Rods.
GM hotcam Kit (hotcam, LT4 springs, 1.6 Roller Rocker).
Aluminum heads.
And I'd like to try boost ( forced induction ) but not turbo ( cost of custom made Exhaust keeps me away ).
I have driven ( summer 2011 ) my actual motor , over 11,000KM problem free.
Winter is coming ad I need a new project.
I have driven the old motor for over 10,000KM summer 2010 and who knows how many miles exactly it has since this motor was in another car before ( a member here ) back in 2002 or 2003 and the guy sold it saying it had back then 3,000miles .
Installed in the Mazda in 2003/4 and I don't think it has been driven more then 5,000 miles.(none working speedo back then ) so if I want to try boost , what would be a good "static or Dynamic" compression ratio I should be looking for ?
I want something that I can run pump gas "91" and drivable .
Does my 10.3:1 motor will be a good candidate ? Again , Static or Dynamic ?
I kept it in case if my new stroked LT1 exploded so I have a complete "ready to run" back up but it didn't happen so I think for beginning of 2012 the "stroker" may end up on the stand and the old one back in the car.
I knew this past summer if I had a major problem with the drivetrain I can switch back to my old setup in a week end , re-flash the PCM and all that practically for free.
Does 3,000 USD will supercharge my car if I do 99% myself ( except the tune ) I do not fabricate tho , I buy and install basically.
Thanks .
Question # 2 : I have this complete motor from oil pan to throttle body , water pump , Optispark , etc. sitting on my garage floor.
GM LT1 5.7 Litre. 355CI Bore 0.030".
JE SRP Forged Pistons (10.3:1 compression).
Manley Sportsman Forged Rods.
GM hotcam Kit (hotcam, LT4 springs, 1.6 Roller Rocker).
Aluminum heads.
And I'd like to try boost ( forced induction ) but not turbo ( cost of custom made Exhaust keeps me away ).
I have driven ( summer 2011 ) my actual motor , over 11,000KM problem free.
Winter is coming ad I need a new project.
I have driven the old motor for over 10,000KM summer 2010 and who knows how many miles exactly it has since this motor was in another car before ( a member here ) back in 2002 or 2003 and the guy sold it saying it had back then 3,000miles .
Installed in the Mazda in 2003/4 and I don't think it has been driven more then 5,000 miles.(none working speedo back then ) so if I want to try boost , what would be a good "static or Dynamic" compression ratio I should be looking for ?
I want something that I can run pump gas "91" and drivable .
Does my 10.3:1 motor will be a good candidate ? Again , Static or Dynamic ?
I kept it in case if my new stroked LT1 exploded so I have a complete "ready to run" back up but it didn't happen so I think for beginning of 2012 the "stroker" may end up on the stand and the old one back in the car.
I knew this past summer if I had a major problem with the drivetrain I can switch back to my old setup in a week end , re-flash the PCM and all that practically for free.
Does 3,000 USD will supercharge my car if I do 99% myself ( except the tune ) I do not fabricate tho , I buy and install basically.
Thanks .
10-20-2011, 07:41 PM
#2
From the calculator above, it would be 12.05 static CR. Dynamic CR calculations would use your camshaft intake closing point ABDC (after bottom dead center) @.050 lift plus 15* and your rod length.
On that 355 at 10.3:1 CR and 91 octane, how much boost?
On that 355 at 10.3:1 CR and 91 octane, how much boost?
10-20-2011, 07:52 PM
#3
Hey Martin,
The 385 LE2 wasnt enough power for you?
Im sure that thing was retarded in that RX7. Im sure it had alot of traction issues i can only imagine a what a blower and even more power will do!
IMO juding by your 385 at 12:1cr its way to high to try and bring down and a new set of slugs would definetly be in question to change out along with the camshaft to be blower friendly. You would be alot better off using the 355 and putting a set of 62-65cc TFS or AFR heads on and getting it down to 8.5-9:1cr safe enough that you could crank up the boost and the motor take it. You could also try and sell the 355 to offset the cost of pulling that 385 apart and putting in some blower pistons. Just depends which way you want to go with it.
The 385 LE2 wasnt enough power for you?
Im sure that thing was retarded in that RX7. Im sure it had alot of traction issues i can only imagine a what a blower and even more power will do!IMO juding by your 385 at 12:1cr its way to high to try and bring down and a new set of slugs would definetly be in question to change out along with the camshaft to be blower friendly. You would be alot better off using the 355 and putting a set of 62-65cc TFS or AFR heads on and getting it down to 8.5-9:1cr safe enough that you could crank up the boost and the motor take it. You could also try and sell the 355 to offset the cost of pulling that 385 apart and putting in some blower pistons. Just depends which way you want to go with it.
10-20-2011, 08:49 PM
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I have no idea yet, I'm just exploring options for now.
.
How are you doing ?
It did put a lot of "Grinds" anywhere I went including my own face.
Not too bad with warm Drag Radial to be honest but you still have to chose when and where to floor it.
More "Grinds".........
To be honest if I do something I'll pull the pefect running 6.3L LT1 on the stand as is for emegency.
This motor is pushing almost 392 RWHP on a DynoJet with 387 Ft-LBS of torque with some tiny 1 1/2" shorties , single line exhaust and a baby camshaft and I know it is running good.
If I can Supercharged the Mazda and don't beak the Bank I may try it.
Money is always what's slowing me down......
.
How are you doing ?
Not too bad with warm Drag Radial to be honest but you still have to chose when and where to floor it.
More "Grinds".........
IMO juding by your 385 at 12:1cr its way to high to try and bring down and a new set of slugs would definetly be in question to change out along with the camshaft to be blower friendly. You would be alot better off using the 355 and putting a set of 62-65cc TFS or AFR heads on and getting it down to 8.5-9:1cr safe enough that you could crank up the boost and the motor take it. You could also try and sell the 355 to offset the cost of pulling that 385 apart and putting in some blower pistons. Just depends which way you want to go with it.
To be honest if I do something I'll pull the pefect running 6.3L LT1 on the stand as is for emegency.
This motor is pushing almost 392 RWHP on a DynoJet with 387 Ft-LBS of torque with some tiny 1 1/2" shorties , single line exhaust and a baby camshaft and I know it is running good.
If I can Supercharged the Mazda and don't beak the Bank I may try it.
Money is always what's slowing me down......
