[Dailyguy]

I have a 5.7 wit
1 7/8 longtubes
Stage 2 cam with non mds
3inch straight piping from headers back

All in the corner of my room. Will a 6.4 manifold ported at the throttle body to 87mm and intake heads for more flow give me more hp or low-mid rang power??

 

[weaselsmopar]

I have the ported 6.4 intake and throttle body on my 5.7. it would help more if your heads were ported also. The intake will get rid of the dead spot the car hits at higher rpms. Also if your looking at the ported intake at hhp that is a stripped intake with no parts at all.

 

[Dailyguy]

I have the ported 6.4 intake and throttle body on my 5.7. it would help more if your heads were ported also. The intake will get rid of the dead spot the car hits at higher rpms. Also if your looking at the ported intake at hhp that is a stripped intake with no parts at all.

Would the heads be too big if i get them ported?

 

[Dailyguy]

I have the ported 6.4 intake and throttle body on my 5.7. it would help more if your heads were ported also. The intake will get rid of the dead spot the car hits at higher rpms. Also if your looking at the ported intake at hhp that is a stripped intake with no parts at all.

Also whats the dead spot?

 

[weaselsmopar]

Would the heads be too big if i get them ported?

No it would just be much closer matched to the intake. You don't have to do it.

 

[weaselsmopar]

Also whats the dead spot?

When doing hard pulls with the 5.7 intake you lose power in the higher rpms. Where as the 6.4 intake switches modes so it keeps the power much better.

 

[CE9311]

I have a 5.7 wit
1 7/8 longtubes
Stage 2 cam with non mds
3inch straight piping from headers back

All in the corner of my room. Will a 6.4 manifold ported at the throttle body to 87mm and intake heads for more flow give me more hp or low-mid rang power??

Personally I feel unless there are a lot of other mods like boost, ported intakes are a scam. Specially if they "port" the intake runners because there is 0 chance of all the intake runner being done.

Far as the ported TB, 6.4 uses same exact size as 5.7 makes 100hp more....



Regardless, if you are not planning on boosting the 6.4 intake is a great mod and well worth the effort. I gained .2 in the 1/8 in consistency. Runners set at 4700-4800 rpms.

 

[vjo90rs8]

When doing hard pulls with the 5.7 intake you lose power in the higher rpms. Where as the 6.4 intake switches modes so it keeps the power much better.

the 6.4L intake gives more low-end power by starting off in long runner mode. It switches to short runner mode at higher rpms (requires special wiring in 5.7L applications). The 5.7L intake is always in short runner mode.

 

[CE9311]

the 6.4L intake gives more low-end power by starting off in long runner mode. It switches to short runner mode at higher rpms (requires special wiring in 5.7L applications). The 5.7L intake is always in short runner mode.

Incorrect, the stock 5.7 Intake is always in a long runner setup.

 

[vjo90rs8]

That is incorrect, look at all the dyno charts. No gain between 5.7L and 6.4L manifold at high RPMs. It’s all at low rpms. Long runners make more power at low end, short runners at high rpms.

what's up with the 392's intake manifold?

So what is this new intake manifold all about? Variable intake? Can someone explain it to me in layman's terms? I am getting tired of saying that "I don't know" when people ask me. Thanks in advance and sorry if it is a dumb or repeat question. P.S. I am not talking about variable...

www.challengertalk.com

 

[CE9311]

That is incorrect, look at all the dyno charts. No gain between 5.7L and 6.4L manifold at high RPMs. It’s all at low rpms. Long runners make more power at low end, short runners at high rpms.

what's up with the 392's intake manifold?

So what is this new intake manifold all about? Variable intake? Can someone explain it to me in layman's terms? I am getting tired of saying that "I don't know" when people ask me. Thanks in advance and sorry if it is a dumb or repeat question. P.S. I am not talking about variable...

www.challengertalk.com

5.7 intake shares the same "long" intake runner design as 6.4, except the lack of the SRV valving. This is a physical design and is not based on a "dyno" graph.

Also several people have seen gains up top specially when paired with a good cam and extended redline like the 6.4.

 

[vjo90rs8]

The 392 intake gives 0 gains up top (or very small), people swap it for low end power.
long runner mode shows gains over 5.7L intake at low rpms, less power a high rpms.

 

[Eric40962005]

The 392 intake gives 0 gains up top (or very small), people swap it for low end power.
long runner mode shows gains over 5.7L intake at low rpms, less power a high rpms.

View attachment 300315

Those number specifically say long runner only why would you use the intake and not incorporate the short runners at higher RPM. You need to do some research before you start just making claims.


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[vjo90rs8]

The dyno graph was in support of my argument that the 5.7L intake is a short runner intake. Another member experimented on the dyno (short only, long only, 4800rpm short runner activation).
The 6.4L intake is in long runner mode by default and is shows that the gains are down low compared to 5.7L intake and lost up top compared to 5.7L intake.

 

[Eric40962005]

The dyno graph was in support of my argument that the 5.7L intake is a short runner intake. Another member experimented on the dyno (short only, long only, 4800rpm short runner activation).
The 6.4L intake is in long runner mode by default and is shows that the gains are down low compared to 5.7L intake and lost up top compared to 5.7L intake.

That is not accurate at all. The 5.7L is not a short runner intake. they balance it to have decent low mid to high end power.


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[Eric40962005]

The dyno graph was in support of my argument that the 5.7L intake is a short runner intake. Another member experimented on the dyno (short only, long only, 4800rpm short runner activation).
The 6.4L intake is in long runner mode by default and is shows that the gains are down low compared to 5.7L intake and lost up top compared to 5.7L intake.

It’s more close to a long runner. He showed you a cross section of the 5.7L intake. Just because there’s gains down low does not stipulate one intake being a long runner vs a short runner. They are 2 totally different intakes designed for 2 different engines.


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[vjo90rs8]

another dyno switch 6.4L manifold switched to short runner mode at 4800.

392 Manifold: long by default, short at 4800
5.7L manifold: shorter than long runners of 392 and close to short runners on 6.4L. If you don’t want to call it a short runner intake we can call it a “short-mid runner” for comparison purposes since we don’t have actual measurements.

 

[Eric40962005]

another dyno switch 6.4L manifold switched to short runner mode at 4800.

392 Manifold: long by default, short at 4800
5.7L manifold: shorter than long runners of 392 and close to short runners on 6.4L. If you don’t want to call it a short runner intake we can call it a “short-mid runner” for comparison purposes since we don’t have actual measurements.
View attachment 300316

There’s a literal picture of it right there. If you think that’s a short runner idk what to tell you.


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[Eric40962005]

another dyno switch 6.4L manifold switched to short runner mode at 4800.

392 Manifold: long by default, short at 4800
5.7L manifold: shorter than long runners of 392 and close to short runners on 6.4L. If you don’t want to call it a short runner intake we can call it a “short-mid runner” for comparison purposes since we don’t have actual measurements.
View attachment 300316

If you think because the numbers are so close at the top end, let me guess that’s your reasoning of it being a short runner? You don’t understand what’s going on here. No other intake would help it on the top end…. That’s all she’s got.


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[vjo90rs8]

What picture? The one you posted is not a 5.7L intake. You can see the white valve connected to a shaft, that looks like a 392 manifold or 5.7L Ram manifold with active runners.