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one thing that i read that baffled me is that supposedly the 4V uses the same rods, and can safely rev to 7k

maybe someone can shed some light on this as to whether or not the rods on the 4V are marginally better than the 2Vs.....im guessing they are though
 

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Boom.
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You would need to have some major airflow mods (heads, cams, intake, headers) to be able to take advantage of those relatively high RPMs. On a stockish motor there doesn't seem to be any reason to go that high.
 

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Discussion Starter #5
Palmguy said:
You would need to have some major airflow mods (heads, cams, intake, headers) to be able to take advantage of those relatively high RPMs. On a stockish motor there doesn't seem to be any reason to go that high.
Guy on mod depot made solid gains to 6500 rpm on a dyno with VT stage 1 cams.

Stock pi heads/intake/manifolds
 

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Kentwood said:


Guy on mod depot made solid gains to 6500 rpm on a dyno with VT stage 1 cams.

Stock pi heads/intake/manifolds

Wow...got a link for that? I don't feel like searching through the forums. That's cool...:)
 

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Discussion Starter #7
I can't find the thread, it was along time ago

but here is his graph




SCT Tune before and after


Stock PI longblock/heads/intake - Comp cap springs


He had a 75mm accufab TB and plenum.


He may have had some shorty headers but I'm 99% sure it was stock manifolds.


He did have an aftermarket exhaust and h pipe.




Still impressive though......the pi intake flows alot better than people give it credit for.
 

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I would say that 6300-6500 is a safe range for a maximum. There are people revving higher, but I don't think I would chance it unless I was ready for another buildup.

Russ
 

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I don't remember exactly what year it was that Ford started putting the same rods in the Cobra motors as in the 2V. I do know that all the 4Vs in 02 on up used the 2V rods. With exception of the 03/04 Cobra that is. Whether is was done on the 4Vs back to 99 I don't know.
 

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id think you could set a shift point at 6100-6200, even if its not worth reving there and go with that, puting some work on your heads and intake (pi intake) would definitly make it worthwhile to rev up there

but from the word of mouth of afew very renowned 4.6 guys, stock npi bottom end, 6300 to 6400 is about the point you have to worry
 

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Discussion Starter #11
JoeyICU said:
id think you could set a shift point at 6100-6200, even if its not worth reving there and go with that, puting some work on your heads and intake (pi intake) would definitly make it worthwhile to rev up there

but from the word of mouth of afew very renowned 4.6 guys, stock npi bottom end, 6300 to 6400 is about the point you have to worry
as you can see by that dyno graph, with some vt cams that engine is still pulling to 6100 with stock heads and pi intake
 

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with pi cams id think it would still get power that high, the npi intake is really the biggest hold back, that and the stock cams, but yeah, dont wanna kick a dead horse, im gonna try to see what i can get from the engine i have as it sits because im poor and pressed for time, college is nice and sucks at the same time
 

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JoeyICU said:
with pi cams id think it would still get power that high
Nope...somewhere around 4700 for the peak with unported NPI heads, PI intake, and PI cams.
 

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Anyone remember that graph...NPI heads, PI intake, PI cams, a '02 GT MAF and a tune by KD. No need to shift at 6500 or anywhere close to it with PI cams. I would have to plug in numbers to tell exactly where to shift but it isn't anywhere near there. Probably something around 5400.
 

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with my sct tune with 02 gt maf and stock npi cams and npi intake the car run outs of power after 5100 rpm. the tune is set to shift at 6000 rpm. will change out to pi intake (maybe pi cams also) once i find the right gasket.
 

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casper, are both your 1-2 and 2-3 shift points set at 6000?

96bird, based on that dyno graph, the 1-2 should be at around ~6000 and the 2-3 around ~5550 in order to keep the pre-shift HP equal to the post-shift HP
 

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guitar maestro said:
casper, are both your 1-2 and 2-3 shift points set at 6000?

96bird, based on that dyno graph, the 1-2 should be at around ~6000 and the 2-3 around ~5550 in order to keep the pre-shift HP equal to the post-shift HP
Like I said I could have plugged in the numbers....
 

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You guys should read the tech articles on MD for Max Acceleration

MD

One of the things you guys aren't thinking about is how long it takes for the trans to actually complete the shift. The EEC commands the shift at a certain point. Then the time it takes the trans to complete that shift is a totally different point.

This also depends on your transmission. The earlier AODEs and 4R70Ws like in the 94/95 MN12s take a little longer to shift than the newer trans. A stock trans will shift slower than one with a Jmod. And a completely built Jerry spec trans will shift even quicker.

Now the SCT programming and depending on the programmer will speed up the time it takes for the shift to complete also.

So for instance you have a stock trans and shifting from 1 - 2 at WOT from the command point to the completed shift could take up to a full second. In that time at full throttle your rpms continue to climb at a very fast rate. So if a commanded shift at 5200 takes place it could be at 5800 or higher before the shift is completed. So setting your shift at 6100 like someone mentioned would end you up with a failed shift since it would hit the rev limiter.

Take for instance Casper's shifts, his 1 - 2 is set for 5700 but it isn't completed until close to 6000. Also remember your stock tachs are worthless when up that high so don't count on them to be accurate.

Then you also have to take into consideration of what your rear gears are. Say you have a set of 3.73s or 4.10s. In that same amount of time it takes the trans to complete said shift your rpms are climbing even faster due to the gear multiplication. So now instead of only 300 - 400 rpms from the command to complete it could be as high as 1000 or more.

And finally, you want your shifts to happen so that when the shift is completed and you are in the next higher gear that it is in the engines power band. So if this means you have to wait until what seems like the car is nosing over or losing power to shift then that's what you have to do. Since the vehicle is still accelerating and will accelerate quicker keeping the next gear in it's power band. Read the articles I link and they will explain it.
 

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im pretty sure when people refer to seting the shift points at a certain rpm, the general idea is that when we say shift points, it means the end result, where it actaully shifts at, not the rpm the eec actaully commands the shift

j-mod will drop a shift about 150-200 rpms, it speeds it up that quickly!

go j-mod
 

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Lonnie said:
I don't remember exactly what year it was that Ford started putting the same rods in the Cobra motors as in the 2V. I do know that all the 4Vs in 02 on up used the 2V rods. With exception of the 03/04 Cobra that is. Whether is was done on the 4Vs back to 99 I don't know.
They started to do that crap in '99 or '00..from '93-'98 the rods in the 4V were of a better quality-I've had both here to look at,and they're visibly different.
JL
 
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