Probably a real dumb question but ....

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Turbo440Dart said:
The best advice I can give you is make sure you have someone there to tell you to stop turning it up. I think @TT5.9mag wanted to tie my hands behind my back at the dyno since I kept turning the knob.
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Well that's a good idea!!!
I don't like wasting money lol
 
Turbo440Dart said:
The best advice I can give you is make sure you have someone there to tell you to stop turning it up. I think @TT5.9mag wanted to tie my hands behind my back at the dyno since I kept turning the knob.
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What I wanted to do was lean that thing out. But my hands were tied.
 
Does the use of forced induction negate the need for compression?

We are doing a 9 to 1 comp. 528ci hemi build with twin turbo's next year.
Big cubes, big blowers and cheap GAS is all we can afford.

Race fuel is way too expensive 'these days' for a pensioner like me...:eek:

Lots of room in a boat for the add-ons.:drama:
Water cooled inter-cooler would help make BIg power methinks?
lots of room.jpeg
 
At any compression over 10:1 the pressure the turbo puts out has to be very limited. 13:1 requires for street use with a carb and without computer control requires 100%+ octane fuel, adding more compression via a turbo requires more octain and ignition control. I run a supercharger on my slant six with with a boost referenced fuel pressure regulator, and a pressure referenced ignition control modual, at 8.5 compression I still run 94 to 100 octain depending on the boost I want.

IMG_7288.jpeg
 
Spudmaster said:
At any compression over 10:1 the pressure the turbo puts out has to be very limited. 13:1 requires for street use with a carb and without computer control requires 100%+ octane fuel, adding more compression via a turbo requires more octain and ignition control. I run a supercharger on my slant six with with a boost referenced fuel pressure regulator, and a pressure referenced ignition control modual, at 8.5 compression I still run 94 to 100 octain depending on the boost I want.

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That's really cool, good info.
 
polyjohn said:
Does the use of forced induction negate the need for compression?

We are doing a 9 to 1 comp. 528ci hemi build with twin turbo's next year.
Big cubes, big blowers and cheap GAS is all we can afford.

Race fuel is way too expensive 'these days' for a pensioner like me...:eek:

Lots of room in a boat for the add-ons.:drama:
Water cooled inter-cooler would help make BIg power methinks?
View attachment 1716179120
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It negates the “need” for compression if you can meet your power requirements with lower compression and boost. It’s all just cylinder pressure. Weather you get there mechanically with compression or later with boost it really makes no difference. Think of boost as just a multiplier of what’s there. More compression does the same thing it does in an NA engine. And like I said above, we met my power goal in the boat without an intercooler and the tune up is safe. I have enough turbo to make 1800hp and the engine is built to live at 1500 or so, but it’s a 21 foot boat and 800 is enough to scare the **** out of my passengers and myself. So that’s where it’s staying and will live a long time at that power level.
Spudmaster said:
At any compression over 10:1 the pressure the turbo puts out has to be very limited. 13:1 requires for street use with a carb and without computer control requires 100%+ octane fuel, adding more compression via a turbo requires more octain and ignition control. I run a supercharger on my slant six with with a boost referenced fuel pressure regulator, and a pressure referenced ignition control modual, at 8.5 compression I still run 94 to 100 octain depending on the boost I want.

View attachment 1716179141
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Are you saying you can’t run big compression and big boost? Why does the “pressure the turbo puts out have to be very limited”? There are no hard and fast rules. You can run 15:1 compression and 50 pounds of boost if you want, just need the right fuel.
 
TT5.9mag said:
It negates the “need” for compression if you can meet your power requirements with lower compression and boost. It’s all just cylinder pressure. Weather you get there mechanically with compression or later with boost it really makes no difference. Think of boost as just a multiplier of what’s there. More compression does the same thing it does in an NA engine. And like I said above, we met my power goal in the boat without an intercooler and the tune up is safe. I have enough turbo to make 1800hp and the engine is built to live at 1500 or so, but it’s a 21 foot boat and 800 is enough to scare the **** out of my passengers and myself. So that’s where it’s staying and will live a long time at that power level.

Are you saying you can’t run big compression and big boost? Why does the “pressure the turbo puts out have to be very limited”? There are no hard and fast rules. You can run 15:1 compression and 50 pounds of boost if you want, just need the right fuel.
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Now that's more interesting lol.
 
TT5.9mag said:
Do as I say and not as I do, I know but I have my reasons.
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This is my 9.2:1 489 twin turbo big block Chevy. Runs on pump gas 91 octane, non intercooled, blow through carb, in my boat. It makes around 800 at 7psi and idles like a stock big block. If I could get e85 at the dock I’d run that. If I could fit an intercooler I’d run one. But sometimes you make compromises and those compromises will limit output. We hit my power goal pretty easily and didn’t see any reason over complicate it. Start with a goal in mind (hp) and pick a fuel to run, then set the compression to the fuel. Then turn the boost up till it makes the power you want.
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In a boat application can you run a water to air intercooler with water from the lake? I know probably yes but I don't know about boats
 
Mean416 said:
In a boat application can you run a water to air intercooler with water from the lake? I know probably yes but I don't know about boats
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Absolutely you can and lots of guys do and it works awesome because the lake water is usually well below ambient air temp. My problem is space, I want to keep everything under an engine cover, and to pull another water source from the jet I’d have to drill and tap the bowl. When it needs rebuilt that will happen. Right now we met my power goal on low boost and it’s safe because it’s a blow through carb and the temps are completely reasonable.
 
TT5.9mag said:
Are you saying you can’t run big compression and big boost? Why does the “pressure the turbo puts out have to be very limited”? There are no hard and fast rules. You can run 15:1 compression and 50 pounds of boost if you want, just need the right fuel.
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Look at the diesels. They start at high compression, and run upwards of 90 lbs boost. It's the total package
 
Spudmaster said:
At any compression over 10:1 the pressure the turbo puts out has to be very limited. 13:1 requires for street use with a carb and without computer control requires 100%+ octane fuel, adding more compression via a turbo requires more octain and ignition control. I run a supercharger on my slant six with with a boost referenced fuel pressure regulator, and a pressure referenced ignition control modual, at 8.5 compression I still run 94 to 100 octain depending on the boost I want.

View attachment 1716179141
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Hi, would you mind if I send you a PM regarding your build?
 
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