350ci 470HP Peak at 6000RPM

[Tom68]

Borrowing from the go faster thread.
SBC Carb'd.
You can make 470 at 6000 if you're actually making a lot more higher up in the revs.
A 470 peak comes at higher than 6000 with a SBC.

The question is why.

I think it's just inlet manifold choices, single planes are too short in the runner for a 6000 rpm peak, a modified dual plane should do it but they start laying down and you may have to overdo the rest of the motor to get it.

470 peak at 6000 shouldn't be a problem with an injected LS 5.7, plenty of manifolds with a 6000 rpm tuned length.

I guess that means with a SBC you could use an TPI, or an IR intake, or a crossram to achieve it.

[KnightEngines]

Plain Jane Vic jnr, team G or 300-25 will do it - with a bit of a rub.
300-25 needs the least rubbing.

[steve cowan]

The Holley strip dominator is a excellent manifold, very nice casting.
On a 350 cube engine they would work nice as cast in my opinion.

[mag2555]

Sure you can!
As long as no where in the whole overall length of the Intake tract your not knocking on the NA sonic brick wall velocity wise then it's easy.
All your heads need to be flowing and your Intake passing is between 230 and 240 cfm@28" to have that 470 hp take place on a 8 cylinder motor.

[6.50camaro]

It was done in 2007, "Son of sledgehammer" engine build. the peak hp was at around 6200 according to the dyno graph, close enough for me.

[Tom68]

6200 is pretty close but we know you can do it over 6000.

[Tom68]

Sure you can!
As long as no where in the whole overall length of the Intake tract your not knocking on the NA sonic brick wall velocity wise then it's easy.
All your heads need to be flowing and your Intake passing is between 230 and 240 cfm@28" to have that 470 hp take place on a 8 cylinder motor.

The runner length appears to be the problem, the Accell TPI would do it.

[F-BIRD'88]

A tunnel ram will do that.
and more torque too where you need it.

[F-BIRD'88]

Here is a dyno test of a 350 sbc with both a dual plane and single plane tested.
It is 454 hp dp and 463 hp single plane.

In both cases you need to gear the #3600 car to rev it up thru the traps to make full use of the engine power.
Think 4.56 (short tire) 4.88+ (taller tire).
Needs a 4500-5200 stall converter
A 350. 470 hp to 500 hp will be THE SAME STORY.
This is a easy build. It will run 11's.

[F-BIRD'88]

And with a tunnel Ram it will pick up POWER AND TORQUE right where you need it and go quicker.
Even in Calgary. This street strip easy build is street friendly.
Either way on which intake used.
Use that. "Calgary cam" Howards solid street roller cam I speced for you for this car. and 3000' elevation.

[1980RS]

Borrowing from the go faster thread.
SBC Carb'd.
You can make 470 at 6000 if you're actually making a lot more higher up in the revs.
A 470 peak comes at higher than 6000 with a SBC.

The question is why.

I think it's just inlet manifold choices, single planes are too short in the runner for a 6000 rpm peak, a modified dual plane should do it but they start laying down and you may have to overdo the rest of the motor to get it.

470 peak at 6000 shouldn't be a problem with an injected LS 5.7, plenty of manifolds with a 6000 rpm tuned length.

I guess that means with a SBC you could use an TPI, or an IR intake, or a crossram to achieve it.

Neither my Air Gap or my Holley 300-36 dual plane ever laid down, both will pull up to 7K easily. As a matter of fact the Holley 300-25 was only 1.5 mph better than that 300-36 dual plane and that intake ran 117mph.

[Tom68]

Borrowing from the go faster thread.
SBC Carb'd.
You can make 470 at 6000 if you're actually making a lot more higher up in the revs.
A 470 peak comes at higher than 6000 with a SBC.

The question is why.

I think it's just inlet manifold choices, single planes are too short in the runner for a 6000 rpm peak, a modified dual plane should do it but they start laying down and you may have to overdo the rest of the motor to get it.

470 peak at 6000 shouldn't be a problem with an injected LS 5.7, plenty of manifolds with a 6000 rpm tuned length.

I guess that means with a SBC you could use an TPI, or an IR intake, or a crossram to achieve it.

Neither my Air Gap or my Holley 300-36 dual plane ever laid down, both will pull up to 7K easily. As a matter of fact the Holley 300-25 was only 1.5 mph better than that 300-36 dual plane and that intake ran 117mph.

Thinking dyno hp curve sp v dp when I wrote that, the dp may have more avg hp but the sp will be still climbing after the dp has levelled off.

[mag2555]

That’s true, but then the question that you seem to be dodging is what is a lot more hp in your definition, or conversely what is the lowest rpm where you want peak torque to be made.

[skinny z]

That’s true, but then the question that you seem to be dodging is what is a lot more hp in your definition, or conversely what is the lowest rpm where you want peak torque to be made.

Speaking for myself, let's say peak TQ at 4000. Peak HP at 6000. And able to carry to 6500.

Here's one example that says it's doable. 472@6000.

472@6000.jpg

[1980RS]

Borrowing from the go faster thread.
SBC Carb'd.
You can make 470 at 6000 if you're actually making a lot more higher up in the revs.
A 470 peak comes at higher than 6000 with a SBC.

The question is why.

I think it's just inlet manifold choices, single planes are too short in the runner for a 6000 rpm peak, a modified dual plane should do it but they start laying down and you may have to overdo the rest of the motor to get it.

470 peak at 6000 shouldn't be a problem with an injected LS 5.7, plenty of manifolds with a 6000 rpm tuned length.

I guess that means with a SBC you could use an TPI, or an IR intake, or a crossram to achieve it.

Neither my Air Gap or my Holley 300-36 dual plane ever laid down, both will pull up to 7K easily. As a matter of fact the Holley 300-25 was only 1.5 mph better than that 300-36 dual plane and that intake ran 117mph.

Thinking dyno hp curve sp v dp when I wrote that, the dp may have more avg hp but the sp will be still climbing after the dp has levelled off.

I look at it this way. If my car loses 1mph with the dual plane in the 1/4 mile with the dual plane, but picks up a half tenth in the 1/4 mile over the single plane even though that intake is still pulling a little harder on the big end, I will take that trade off any day of the week.