Modding a 4.6 vs a Coyote

[05stroker]

Not really. A 20psi coyote will out power a 20psi 3v.

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By how much?

With a 3v at 20 psi and a 5.0 at 15 psi, what would be the difference?

Edit: With the same c/r.

 

[Department Of Boost]

That's what I was thinking. When it gets to the 750-800 rwhp range I think they even out a bit. Think about it this way though, stetch ran a 9.27 to my 9.38 with 14-16 psi turbo vrs my 20 psi centri and my car was heavier by at least 300 lb. At this level there seems to be a 4-5 psi difference on the same power. It is from 15 psi up where things seem to become more equal. IMO

Well turbo's are always going to have less parasitic loss. There is a couple of psi in just turning the blower.

Then there is the 300lb. And all the other variables.

Where the coyote shines is at the 8, 10, and 12 psi over the 3v. They make insane numbers for the low boost. I think due to better flowing heads and the VCT on the 5.0.

I think the compression ratio has a lot to do with the extra power.

I was looking at JPC's head flow numbers this morning. Their full tilt boogie Coyote heads don't flow much different than their full tilt 3v heads do (they have the 3v flowing more). At least on the intake side, they didn't have exhaust numbers for the Coyote heads.

I'm not sure how much the VCT factors in. In theory you can run "bigger" cams in the Coyote and still get it to run down low.

 

[Department Of Boost]

Not really. A 20psi coyote will out power a 20psi 3v.

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By how much?

With a 3v at 20 psi and a 5.0 at 15 psi, what would be the difference?

Edit: With the same c/r.

This^^^^^^

I've never seen anything like an apples to apples comparison so I'm working off of guesses here.

 

[lito]

A coyote head will always out flow a 3v head. The problem with that statement is trying to match psi as an equalizer, it will never be. Same psi, the coyote engine will be moving more air, always. Even if you match displacement, compression, etc. Boost is not an equalizer

Billy, I have no idea how much would be the difference, so many variables.

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[05stroker]

A coyote head will always out flow a 3v head. The problem with that statement is trying to match psi as an equalizer, it will never be. Same psi, the coyote engine will be moving more air, always. Even if you match displacement, compression, etc. Boost is not an equalizer

Billy, I have no idea how much would be the difference, so many variables.

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Thanks for the info, we may have a local comparison brewing, I will find out this fall.

 

[Department Of Boost]

A coyote head will always out flow a 3v head. The problem with that statement is trying to match psi as an equalizer, it will never be. Same psi, the coyote engine will be moving more air, always. Even if you match displacement, compression, etc. Boost is not an equalizer

From what I can get with a quick search the fully ported 3v heads flow as much as the fully ported Coyote heads do. At least on the intake side. I can't find any exhaust flow numbers for the Coyote heads.

 

[foxxxtman]

Well, if it means anything, I wasn't trying to stir up a pot of shit lol! Looks like I'm going to have to think about this one long and hard before I do anything. My first step regardless is to get me a 4 banger daily drive so I can sit my mustang (whether it be the current one getting forged or a coyote) in the garage so that I'm not on a timeline when I want to do my own modifications and I could leave it in the garage when it's shitty weather outside. I probably should soulsearch and decide if I want to go auto too, if I do then it would be trade for a coyote hands down vice having to also do a tranny swap in the 3v. From what I've seen auto seems to be best for the strip in most occasions and that stock auto tranny is good for some pretty decent HP. I do enjoy a manual transmission too though for going out and banging gears.

 

[lito]

Thanks for the info, we may have a local comparison brewing, I will find out this fall.

You are raising compression and heads should flow more (if they are doing it more efficiently than before) so you should be better. One thing that crossed my mind now. How big are your headers?

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[05stroker]

You are raising compression and heads should flow more (if they are doing it more efficiently than before) so you should be better. One thing that crossed my mind now. How big are your headers?

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1 3/4 to 3" collectors and 3" from there to the rear.

 

[Department Of Boost]

1 3/4 to 3" collectors and 3" from there to the rear.

Kooks?

 

[05stroker]

Kooks?

ARH.

 

[lito]

From what I can get with a quick search the fully ported 3v heads flow as much as the fully ported Coyote heads do. At least on the intake side. I can't find any exhaust flow numbers for the Coyote heads.

http://www.jpcracing.com/rgr-jpc-cnc-stage-3-coyote-5-0-cylinder-heads/

Easy search. Now, are these numbers or any other numbers any good? I don't know, I just know that a 3V head would never match an FGT head and the coyote ones are even better, you may have more room for improvement on a 3V head for port work? maybe, I don't know.

In essence, what I meant is that the coyote is a better engine, it will move more air, more efficiently so if you match psi, the coyote should always win, remember boost is just a measure of restriction.

 

[stkjock]

I'm very much a layman, however, I just don't see how a 4V head the flows more air than a 3V head cannot produce more power all things being equal (near impossible to do IMO)

In essence, what I meant is that the coyote is a better engine, it will move more air, more efficiently so if you match psi, the coyote should always win, remember boost is just a measure of restriction.

/\ +1

Post #2 of the thread...

no

5.0>4.6 boost to boost

 

[fdjizm]

Oh noess.. 720hp instead of 750hp le 4.6 is teh sux0rs!!!!!!!!!!!!!!!
What a piece of shit hunk of non efficient metal it must be! -.-

 

[stkjock]

Oh noess.. 720hp instead of 750hp le 4.6 is teh sux0rs!!!!!!!!!!!!!!!

well, no one knows if it's that small of a difference. I'd suspect it's more.

What a piece of shit hunk of non efficient metal it must be! -.-

no one is saying that the 3V is junk, just the Coyote is mo betta.


it's like saying,

meh... I'll throw this gold away because I have a bunch of platinum sitting her..

.


just silly

 

[Department Of Boost]

http://www.jpcracing.com/rgr-jpc-cnc-stage-3-coyote-5-0-cylinder-heads/

Easy search. Now, are these numbers or any other numbers any good? I don't know, I just know that a 3V head would never match an FGT head and the coyote ones are even better, you may have more room for improvement on a 3V head for port work? maybe, I don't know.

In essence, what I meant is that the coyote is a better engine, it will move more air, more efficiently so if you match psi, the coyote should always win, remember boost is just a measure of restriction.

Wow, I guess I was just not paying enough attention when I looked at those numbers (I was on the couch trying to filter out my wife watching The Walking Dead). I should have paid more attention. I’m up now with coffee in me. Now I’m paying attention.

3v Intake 315cfm
4v Intake 342cfm

3v Exhaust 225cfm
4v Exhaust 249cfm

So were looking at roughly 10% better cylinder head flow from the Coyote. Which is nothing to sneeze at. I'd take it if someone were giving it away.

Now starts my section on WAG (wild ass guesses). Just bear with me here, this is all theory and basic assumptive math. Not anything near science, but you work with what you have. This for example is how you start building custom valve stacks in race dampers. You figure out where you are at, you guess where you want to be, then you guess how to get there, you do the math, you build it, then you test it. And you don’t end up shooting bulls eyes every time. But it’s better than firing off rounds with your eyes closed.

So you have two motors, one 3v, one Coyote. All things being equal (this is assuming the 3v is stroked to 302, mine is not). Both motors have a 3.4L Whipple on them spinning the same speed. Let’s say using a 1.857 blower drive ratio (because this is what I’m running on my 3v and some of these numbers will therefore have some basis in fact). The 3v is on the edge of 93 octane at 20psi and 17deg of timing. The 3v makes 752hp (all #’s are rear wheel).

The Coyote motor in theory flows 10% more air. So the boost will be 10% lower at 18psi. If you don’t change the blower speed all things being equal both motors will make the same power, a screw blower is the “meter” in the system. The Coyote will do it at 2psi less though. But in this case you are pushing the limits of pump gas though so on the Coyote you speed the blower up to get your 2psi back, which puts more air through the motor. That 2psi is worth roughly 75hp (752/20x2).

So in this case as long as you are changing blower speed to maximize the available limits of the fuel you are looking at about 75hp between the two motors.

Now if you are running lets say e85 and you crank the blower speed up to lets say 25psi on the 3v you are looking at somewhere around 1065hp (+100hp for the e85 +213hp for the 5psi). If you put that same blower with the same blower ratio on the Coyote you will still see the same power (1065) but at lower boost (22.5psi or so). So in reality the Coyote won’t make more power at the same blower speed, as long as you don’t run out of blower (which you won’t in this case). You will just make it at less boost.

Now all of that assumes a screw blower that has enough headroom to make that power without being over spun is being used (it’s not even close to that in this case, 15,826rpm). If you run turbo(s) and I’m not quite sure how a Centri works as resistance goes up, you will get different results. If the power adder pushing air into the motors efficiency is affected by how the motor moves air then a freer flowing motor (the Coyote) will in theory gain a higher percentage than 10%. I don’t have a WAG for this because I don’t have any data on how turbo(s) or Centri blowers behave when met with resistance. It’s pretty safe to assume that a Turbo or Centri will behave “better” on the better flowing motor though because they are not “positive displacement”.

Lastly if you are in 05stroker’s situation where he is running out of blower you will get different results. When the blower starts running out of breath it starts acting more and more like a NA motor. You can’t put enough air through the motor to keep up with the RPM’s/displacement. You will either see boost flat line early in the RPM range or it will hit a high point early and drop off slightly from there. In this case you are trying to get everything you can. You have stretched your blower out, you have stretched the fuel out and in theory you have stretched the motor out. In this case the more efficient motor will win out. Will it win out to the tune of 10%? IDK. Probably has a curve in there that is based off of how stretched out the blower is, etc. But lets play devils advocate and say with everything set on kill the Coyote makes 10% more power, I think that is slightly optimistic, but I’ll play. So at 22.5psi you are making about 1065hp. But the blower is giving up. If you get 10% more with the Coyote you will see an extra 106hp out of the Coyote for a total of 1171hp. Nothing to sneeze at, but I think the 10% is a bit optimistic, and that is assuming you power adder has given up. If you step the size of the power adder up so it’s not stretched out things start to even out again in the HP department. The 3v will just always do it at about 10% more boost.

So obviously across the board a Coyote is the better base motor to start with assuming that everything is equal, including cost. But if you factor in cost and you are going for 750hp+ and you have plenty of power adder the 3v is going to do the same thing for quite a bit less money (stock block, less cams to buy, etc). If you start playing with 1000+hp it sounds to me like even if you are running a Coyote, even one with a hot rodded block you are an borrowed time (unless you fill the block some or all). You are still on a stock 3v block at this point, and it probably won’t come apart on you.

No real conclusions, like anything too many variables to make a blanket statement like “X is better than Y across the board”. Unless you remove cost from the equation then it’s a no brainier (until about 1000-1100hp), the Coyote is the “better” motor hands down. All random thoughts of course.

Thoughts? Especially on the turbo/Centri and how they react to restrictions.

I have to get to work now.

 

[Department Of Boost]

I'm very much a layman, however, I just don't see how a 4V head the flows more air than a 3V head cannot produce more power all things being equal

And your layman’s impression is correct. Assuming that you are not using a screw blower and or are not running out of power adder. But if you are using a screw blower the 3v will make just as much power as the 4v, it will just be at a higher boost level.

I picked the screw blower as an example because it is the only power adder that I am 100% sure is not affected by the motors resistance. I did it to “prove out” a thought process and remove a variable. In different situations with more variables (turbos/centri) the results will be different.

(near impossible to do IMO)

Pretty much. Unless you gathered a whole pile of money and built two dedicated "identical" motors it's all theory. And really, who's going to do that test? You can't even get a good header camparo anymore.

 

[stkjock]

And your layman’s impression is correct. Assuming that you are not using a screw blower and or are not running out of power adder. But if you are using a screw blower the 3v will make just as much power as the 4v, it will just be at a higher boost level.

well then all things are not equal....

Pretty much. Unless you gathered a whole pile of money and built two dedicated "identical" motors it's all theory. And really, who's going to do that test? You can't even get a good header camparo anymore.

yea, precisely whey I made my comment

 

[Department Of Boost]

well then all things are not equal....

True dat! I had to remove at least one variable for arguments sake though. In some cases the boost you are making doesn't matter. If you are running e85 and not making enough boost to lift a head (28psi or so) who cares what the boost is?

Money no object and I don't have to do the work I'll take the Coyote until about 1000hp. Then I would get worried about putting blocks in it all the time. But of course if money is no object that kinda doesn't matter either. But money is always a factor for most mortals.

At the end of the day the 3v is a jumped up truck motor. The Coyote is a dumbed down race motor. The Coyote is one bad mofo.

 

[stkjock]

well my solution is just to run a 5.4L 4V