MRR23,

It seems you are getting aggrivated and I understand, but let me tell you, I mean no harm!

I was only getting at the design of the manifold leads to the restriction. Yes, filling the cylinders at higher rpm. Like you said, how much cfm it can flow. It becomes a restriction.
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The whole FAST/6.0/LS6 intake manifold comparison were doing here is out of context with the subject I think. Comparing x manifold to y manifold doesn't show how we are "intake manifold" restricted. The design is a restriction in itself.

Plus what your missing is dyno graphs don't show everything.

The thread you linked where Gomer pretty much concluded reverse split camshafts suck. I made a smart *** comment, but look into what i said. Just because its not a dyno queen camshaft doesn't mean it sucks. Graphs/Track results are a whole different ball game.

I'm sure you understand this concept.


Ok! If the head is demanding X amount of air but the manifold can only suppy Y amount, then you have an intake restricted motor. Therefore, you crutch the intake.

 

Here, I'll simply all of my B.S.

-The head is demanding more air than the intake manifold can provide.
-We have a high flowing exhaust if setup correctly.
-Head flow #'s by themselves, show a restriction in the exhaust.

I guess my point is, with a certain setup, a few degree duration favoring the exhaust could be exceptable. Yet, I still do not see the need for 8* like seen from the ASP KICKER.

I'll let you respond, then I'll post up a question and go from there.

I'd like to thank you for your help.
Only if we could get some other truck members involved!

 

this has been a very informative thread for me! thank you mrr23, sportside and marc

 

Mrr23.

Another thing!

I will stand by you in that we shouldn't give up our bottom end for the top end as seen with the different brand manifold comparisons.

I think, we were focusing in on different aspects of the manifold "restriction" and I gave off a wrong approach.

 

no prob. it's all talk. but for some reason, you keep insisting the intake is a restriction. how do you know for certain? i keep giving proof that it's not. and all you keep saying is that it is? have you done the vacuum test i explained above? i've submitted proof that the truck manifold is better than the LS1 manifold the corvettes and f-bodies came with. and you keep saying the the manifold is restricted. can you stop saying it is and start proving it is?

trust me on this. Crane and VHP has done way more testing on the LS1 than you and me will ever do. and they have come up with the acclerated lift technology. it works. it's stomping a mudhole in the other cams out there with less duration than the competition.

 

well then explain the 'restriction' you are refering to. i don't see one in all those tests i just put up from CHP other than the small cam compare. that one throws everything off. i guess for some reason it's the exception to the rule.

 

not really. i know you don't. it's just something you can't get a grasp of. and so you are asking bunches of questions about it. i don't mind answering.


and so the aftermarket has made a couple of intake manifolds improving on the design. unfortunately the cost of one doesn't warrant the gains given. we are going to be putting heads on the wife's car soon. but i will not be changing the intake. it's just worth the cost at this point.

and i'm glad you are aware of that. mainly because you can't see below 3k rpms. unless you lock the tranny in 3rd. my 00 formy can be started off in 2nd. i've done some pulls with it starting from 10 mph.

yeah i read that.

again you are still focusing on the intake side as being the issue. do the vacuum gauge test and report back. really though, i'm trying to stop you from spending $900 on an intake. and trying to stop you from making the wrong cam choice.

and it's a good thing you are asking all these questions. that way you don't end up buying the wrong cam. but look into what marc_w did. he had a 220/220 cam. to him, it lacked enough low end to warrant him swapping cams. and when he did, he went to a smaller duration cam, 212/218, with the wide split. now he talks about how much better it drives. and he does tune his vehicle. PM him about it.

 

Look at the dyno graphs of LS1's. Power begins to fall off. This is a clear sign.

The intake manifold becomes a restriction and bottle necks the engine. It can not meet the demands of the cylinder head.

This is why tq is usually at its peak around 4800rpm or less. And hp at 6200-6400rpm's or less.

Most all EFI motors are intake restricted. Power drops. In the carb world, some of the setups will climb to 7400rpm. Like I said, the design is the restriction.

 

Im familair with Marc's results and he went with the 210/218 at .050

Do you really think the the duration split gave him his results? I bet backing off 10* of intake duration had a much large effect. Moving the intake duration back 10*; I'm sure, brought his power band back down to his likings.

 

Yes, and he backed down the intake duration 10*. If you are referring to the tq jump, I'm sure that the decrease in intake duration had a large effect than the standard split (210/218). His swap brought down the power a few or more hundred rpms, I'm sure.

I'm quite aware of his results.The TR220 is alot bigger than the ASP KICKER. And, valve events, overlap, lobe profile also play a role in his better driving characteristics.