Alum 5.3l Road Race build
09-21-2011, 08:26 PM
#1
Staging Lane
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Alum 5.3l Road Race build Hey guys,
I'm currently building a road racing bmw with an LS powerplant. It will be mated with a 4speed dogbox and a lightweight racing flywheel/clutch.
I want a 5.3l engine, H/C/ITB and some RPM, ~7500rpm, to overcome the power deficit from a 5.7l, as long as I get 3000-3500rpm powerband I will be more than happy. At some point it just takes to much torque to get that powerband with limited rpm.
After reading a few threads I will clarify my reason and thoughts on the build-up so I don't get flamed.
-First it would let me start with a cheap base to get the car dial in before I upgrade for more power
-I know everyone says to go for cubes and torque, but torque breaks drivetrain, the lower torque from higher rpm would be a good thing for me
-Since I think 7500rpms is somewhat reasonable, I don't think the price difference between the extra mods to handle rpm will be much more than the price difference for an LS1
-These higher rpms would make it easier to match the gearing with the BMW stuff vs sub 7000's
-I want to play with the motor stuff myself, always feel easier to do so on a 500-700$ block than a 2-3-4k bigger block.
My question is more towards the bottom-end, will the stock stuff (with upgraded bolt) handle those rpm, or I will need to go forged.
Thanks for your helpful inputs. (I've read the other threads of 8500rpm dreams, I understand my goals are easier to achieve and that cubes won't be my solution)
I'm currently building a road racing bmw with an LS powerplant. It will be mated with a 4speed dogbox and a lightweight racing flywheel/clutch.
I want a 5.3l engine, H/C/ITB and some RPM, ~7500rpm, to overcome the power deficit from a 5.7l, as long as I get 3000-3500rpm powerband I will be more than happy. At some point it just takes to much torque to get that powerband with limited rpm.
After reading a few threads I will clarify my reason and thoughts on the build-up so I don't get flamed.
-First it would let me start with a cheap base to get the car dial in before I upgrade for more power
-I know everyone says to go for cubes and torque, but torque breaks drivetrain, the lower torque from higher rpm would be a good thing for me
-Since I think 7500rpms is somewhat reasonable, I don't think the price difference between the extra mods to handle rpm will be much more than the price difference for an LS1
-These higher rpms would make it easier to match the gearing with the BMW stuff vs sub 7000's
-I want to play with the motor stuff myself, always feel easier to do so on a 500-700$ block than a 2-3-4k bigger block.
My question is more towards the bottom-end, will the stock stuff (with upgraded bolt) handle those rpm, or I will need to go forged.
Thanks for your helpful inputs. (I've read the other threads of 8500rpm dreams, I understand my goals are easier to achieve and that cubes won't be my solution)
09-21-2011, 10:20 PM
#2
look at these cams from comp 54-408-11,or comp 54-455-11.will a ls truck intake fit under the hood?if not use a ls6 intake.stock rods and pitons should work for what you want to do.
09-22-2011, 12:34 AM
#3
Your logic is skewed. For the amount of money you're going to spend on an ITB setup you could have a very nice engine with a traditional style intake that will make much more power throughout the entire power band.
Your top end setup will determine your power band, not the size of the engine (extremes 302 --> 454 excluded). You could have a nice high DCR cam with nice flowing heads in the lower ranges on a 5.3 that makes more torque than a 5.7 with stock heads and an extremely large cam.
Your top end setup will determine your power band, not the size of the engine (extremes 302 --> 454 excluded). You could have a nice high DCR cam with nice flowing heads in the lower ranges on a 5.3 that makes more torque than a 5.7 with stock heads and an extremely large cam.
09-22-2011, 05:13 AM
#4
Staging Lane
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Your logic is skewed. For the amount of money you're going to spend on an ITB setup you could have a very nice engine with a traditional style intake that will make much more power throughout the entire power band.
Your top end setup will determine your power band, not the size of the engine (extremes 302 --> 454 excluded). You could have a nice high DCR cam with nice flowing heads in the lower ranges on a 5.3 that makes more torque than a 5.7 with stock heads and an extremely large cam.
Your top end setup will determine your power band, not the size of the engine (extremes 302 --> 454 excluded). You could have a nice high DCR cam with nice flowing heads in the lower ranges on a 5.3 that makes more torque than a 5.7 with stock heads and an extremely large cam.
My point is since it's a 100% track duty car weither my lower end of the powerdand is at 3k rpm or 4k rpm doesn't bother me, if it's a little bit higher there's a little bit less torque for same power and it's easier on the drivetrain.
