10:1 compression gen 2

[Basspro302]

Just a thought the more compression the bigger pulley you can run to make the same power. Less chance of belt slip and dealing with 10rib kits and overdrive crank pulleys. As you have a vortec kit I would have gone with factory compression.
I would consult whoever is tuning the car tho

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[WildHorse]

Haha ikr. I'm gonna say not serious

You'd be wrong. This isn't the 70's guy. Some of yous seem to think coyotes have top fuel over square size cylinders, huge and lazy intake ports/exhaust port. Not the case. More boost, the more restriction, and the more heat.

 

[Veteran]

There’s a YouTube by Flores of Lund that goes through the whole compression saga.

 

[engineermike]

I'd like to see 2 all out builds. One at 12 to 1 and one at 9 to 1. If the 12 to 1 engine could support the same amount of boost and being able to use MBT the 12 would win. But can you use MBT even with E85 and 30 Lbs of boost?

That’s easy, just compare gt350 to gt500 builds. The bore, stroke, heads, cams, etc are all very close if not identical, but one has 9.5/1 and the other 12/1.

 

[Jackson1320]

Just a thought the more compression the bigger pulley you can run to make the same power. Less chance of belt slip and dealing with 10rib kits and overdrive crank pulleys. As you have a vortec kit I would have gone with factory compression.
I would consult whoever is tuning the car tho

You are correct with more compression you will not need as much boost to make the same power so you can run a larger pulley and not worry about slip. There are pros and cons though. It’s not all pros

 

[Nawsad123]

I have the aluminator crate motor sc 9.5:1 compression. Lower compression means more boost (ie smaller pulley) and tuned to e85. Thatll be your 750 to the wheel no problem

 

[Wheysted]

I have the aluminator crate motor sc 9.5:1 compression. Lower compression means more boost (ie smaller pulley) and tuned to e85. Thatll be your 750 to the wheel no problem

What kind of power are you making ? Did you notice a difference. How much more boost did you have to add to compensate?

 

[Nawsad123]

What kind of power are you making ? Did you notice a difference. How much more boost did you have to add to compensate?

On the stock motor, made 680 to the wheel. Still breaking in this new motor, but will be putting on a 3.33 pulley to compensate abd increase boost by about 3-4 psi, all on pump gas. I should be back to the 680, if not slightly above

 

[engineermike]

How much more boost did you have to add to compensate?

When dropping from 11 to 10, you should expect to lose about 4% of your torque. 1-1.5 psi will restore that, but even at the same power level the result will be lower peak cylinder pressure and engine stresses.

 

[Wheysted]

When dropping from 11 to 10, you should expect to lose about 4% of your torque. 1-1.5 psi will restore that, but even at the same power level the result will be lower peak cylinder pressure and engine stresses.

Okie that's good go know probably gonna run a 3.3 on pump and 3.1 on e85

 

[Jackson1320]

Okie that's good go know probably gonna run a 3.3 on pump and 3.1 on e85

What kind of boost are you looking for?

 

[Wheysted]

What kind of boost are you looking for?

Maybe 15/16 psi?
Running a vortech.. going for 700 on pump and 850/900 on e85

 

[Jackson1320]

At

Maybe 15/16 psi?
Running a vortech.. going for 700 on pump and 850/900 on e85

16psi you are in the ballpark

 

[Wheysted]

At

16psi you are in the ballpark

Okie great now just gotta figure out which pulley

 

[Jackson1320]

Okie great now just gotta figure out which pulley

Get a overdrive balancer and you will not need as small of a pulley and less chance of belt slip

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