5th gen intake manifold swap is possible....
Originally posted by Dave B
True, but more energy is lost and the truth is the MEVI is not as good as the 2K-2K1 manifold. By simply looking at the HP and TQ curves you'll see why those short runners are more effective. The 2K-2K1 manifold makes more power (peak) and takes that power straight to 6500rpms. The MEVI only peaks at 6000 and falls slowly after that. There is an advantage to a dual stage runner design.
Dave
True, but more energy is lost and the truth is the MEVI is not as good as the 2K-2K1 manifold. By simply looking at the HP and TQ curves you'll see why those short runners are more effective. The 2K-2K1 manifold makes more power (peak) and takes that power straight to 6500rpms. The MEVI only peaks at 6000 and falls slowly after that. There is an advantage to a dual stage runner design.
Dave
There are more differences between the VQ30DE and the VQ30DE-K than the intake design. The VI on the 5th gen appears more effective because the engine was designed to use it to begin with.
The closed loop fuel maps on our 4th gen cars were not designed to use the MEVI.
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The MEVI, although it is a dual-frequency resonating design just like the 5th gen's, does not make as much peak torque as the 5th gen manifold because of the WAY it is designed.
The 5th gen manifold uses two distinct runner lengths. The two "manifolds" are isolated from each other, so in either the low or high rpm settings, the air has a clear path from the plenum to the intake ports. On the MEVI, however, the low and high rpm runners are joined. What ends up happening is when the manifold is set to the low rpm (long runner) setting, the compression (shock) wave moves from the main plenum down the long runner when it suddenly encounters the "merge" section where the short high-rpm runners are. At this point, the compression wave loses some of its energy as it negotates the "T". The wave actually splits into an expension wave (not good) that goes up towards the (closed) butterflies while the reduced-energy compression wave continues on towards the intake ports. It is because of this that the MEVI shows less peak torque. In fact, every resonance-induced torque peak is reduced on a MEVI-equipped car when compared to a stock 4th gen engine. Take a look here at Dave B's dyno plot: http://mywebpages.comcast.net/stevte...DaveB_MEVI.jpg Every torque peak (3400, 4500, and I bet also the 2200 rpm peak that's not shown here) is lower with the MEVI.
Theoretically speaking, if one could lower the location of the MEVI's butterflies to be flush with the long runners and change the shaft location so each runner opened up so that they lined up with the long runners, the phenonemon I detailed above would be eliminated. The torque peaks would then be identical to the stock 4th gen manifold while getting the high-rpm gains as well. However, since that ain't gonna happen...the torque losses with the MEVI are very mild, and are more than made up for by the substantial gain at redline compared to the stock 4th gen manifold.
The 5th gen intake manifold is a superior design, but the subsystems designed for it (idle air assembly, EVAP, EGR, etc) are also much different on the 5th gen. Considering the tremendous effort it would take to adapt the 5th gen manifold to the 4th gen, the MEVI is the only real choice we 4th geners have for a variable intake.
The 5th gen manifold uses two distinct runner lengths. The two "manifolds" are isolated from each other, so in either the low or high rpm settings, the air has a clear path from the plenum to the intake ports. On the MEVI, however, the low and high rpm runners are joined. What ends up happening is when the manifold is set to the low rpm (long runner) setting, the compression (shock) wave moves from the main plenum down the long runner when it suddenly encounters the "merge" section where the short high-rpm runners are. At this point, the compression wave loses some of its energy as it negotates the "T". The wave actually splits into an expension wave (not good) that goes up towards the (closed) butterflies while the reduced-energy compression wave continues on towards the intake ports. It is because of this that the MEVI shows less peak torque. In fact, every resonance-induced torque peak is reduced on a MEVI-equipped car when compared to a stock 4th gen engine. Take a look here at Dave B's dyno plot: http://mywebpages.comcast.net/stevte...DaveB_MEVI.jpg Every torque peak (3400, 4500, and I bet also the 2200 rpm peak that's not shown here) is lower with the MEVI.
Theoretically speaking, if one could lower the location of the MEVI's butterflies to be flush with the long runners and change the shaft location so each runner opened up so that they lined up with the long runners, the phenonemon I detailed above would be eliminated. The torque peaks would then be identical to the stock 4th gen manifold while getting the high-rpm gains as well. However, since that ain't gonna happen...the torque losses with the MEVI are very mild, and are more than made up for by the substantial gain at redline compared to the stock 4th gen manifold.
The 5th gen intake manifold is a superior design, but the subsystems designed for it (idle air assembly, EVAP, EGR, etc) are also much different on the 5th gen. Considering the tremendous effort it would take to adapt the 5th gen manifold to the 4th gen, the MEVI is the only real choice we 4th geners have for a variable intake.
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Since our engines use a MAF sensor, the engine always knows how much air is entering the engine and adapts continuously to compensate. Therefore, the additional airflow of the MEVI doesn't "detune" the motor any more than, say an intake or exhaust would. The engine will retain a pretty decent tuning with these sorts of n/a mods. The only thing you can really say is that the factory program is a bit conservative in that it puts in too much fuel...that can be addressed via a programmed ECU (JWT, etc). However, a MEVI-equipped car wouldn't benefit any more than a non-MEVI n/a motor in terms of a reprogrammed ECU fuel mixture-wise. Now when it comes to an extended redline that a hi-po ECU could offer, a MEVI car would see a LOT more benefit than a non-MEVI car.
Originally posted by mzmtg
There are more differences between the VQ30DE and the VQ30DE-K than the intake design. The VI on the 5th gen appears more effective because the engine was designed to use it to begin with.
The closed loop fuel maps on our 4th gen cars were not designed to use the MEVI.
There are more differences between the VQ30DE and the VQ30DE-K than the intake design. The VI on the 5th gen appears more effective because the engine was designed to use it to begin with.
The closed loop fuel maps on our 4th gen cars were not designed to use the MEVI.
Originally posted by Keven97SE
The MEVI, although it is a dual-frequency resonating design just like the 5th gen's, does not make as much peak torque as the 5th gen manifold because of the WAY it is designed.
The MEVI, although it is a dual-frequency resonating design just like the 5th gen's, does not make as much peak torque as the 5th gen manifold because of the WAY it is designed.
You may have a point there. But, the differences in output are too small and the effort required to equalize them too large.
It's not that big of a deal...
Originally posted by infinitiblast
So you notice the clearance issue too ehh?? wont fit are you sure?
So you notice the clearance issue too ehh?? wont fit are you sure?
Old Timer
Joined: Aug 2002
Posts: 1,430
From: Huntsville, TX
I have taken extensive photos of both plenums on my two cars. I will have the pics posted later this evening. I was able to install the 2K1 FSTB on my 97 with minor rubbing. Looking at it from the side, it appears there is no way the hood would close, but it did. I know rubbing with the motor is entirely different than rubbing on a FSTB, but I think it may be possible. I'll keep this post updated.
David
David
Originally Posted by Dave B
Well, I would love to be able to fit the 5th gen manifold to the 4th gen. If I knew for sure that it worked, I'd get it ASAP. The intake butterflies could easily be wired into a rpm switch and everything else can be "fabbed" to fit the 5th gen. Bolting it on to the 4th gen block is still slightly uncertain. I think the 4th gen could stand to gain about 15 fwhp with 5th gen intake with a much deeper powerband (the VQ powerbands are already deep). I don't think the 4th gen will make as much power as the 5th gen VQ because I believe the 5th gen has some slightly deeper breathing cams. If I could make power to 6400 (600 rpms than I'm at now), I'd be VERY happy. 15fwhp more with 150lbs less weight, a 4th gen with the 5th gen intake manifold could be a deadly combo. I am VERY sure a modded 4th gen like this could nail very low 14s at near 98-99mph with a traction and weather.
Dave
Dave
And dave I knew deap down inside you would love the 5th gen manifold
Originally Posted by Dave B
What's wrong with the MEVI? You know better than to ask this question 
Look at the graphs of the MEVI vs that of the 2k-2k1. You'll see that the 2k-2k1 manifold makes peak power at 6400-6500rpms where as the MEVI makes peak power at 6000rpms. The short runners of the 2k-2k1 manifold simply flow better than the resonance tuned MEVI. My VIM only netted me a peak gain of ~6fwhp. My orginal post was before we knew anything about the MEVI. Also, we didn't know that the MEVI would loose the VQ torque from 2500-4800rpms. This is a slight problem because of the stock fuel cut of 6500rpms which forces us to shift early therefore we have to accelerate with less power on the early portions of 2nd and some of 3rd. With a raised rev limter, we will be able to get out of this less powerful portion of the rpms.
That's my excuse
Dave
Look at the graphs of the MEVI vs that of the 2k-2k1. You'll see that the 2k-2k1 manifold makes peak power at 6400-6500rpms where as the MEVI makes peak power at 6000rpms. The short runners of the 2k-2k1 manifold simply flow better than the resonance tuned MEVI. My VIM only netted me a peak gain of ~6fwhp. My orginal post was before we knew anything about the MEVI. Also, we didn't know that the MEVI would loose the VQ torque from 2500-4800rpms. This is a slight problem because of the stock fuel cut of 6500rpms which forces us to shift early therefore we have to accelerate with less power on the early portions of 2nd and some of 3rd. With a raised rev limter, we will be able to get out of this less powerful portion of the rpms.
That's my excuse
Dave
I am going to get 00VI because of this post
Senior Member
Joined: May 2004
Posts: 106
That is the sh I it But now that the " I wonders" are out of the way how about a parts list or a "Write UP" I have a spare 4th gen 96 engine at my parents garage and as soon as X-mas has passed my personal gifts will start to come in. So please help out a no Vi guy out! 
But let Me also say that I'm glad that you got it done! So when will you dyno it and do you have a base line dyno already? Either Way 
But let Me also say that I'm glad that you got it done! So when will you dyno it and do you have a base line dyno already? Either Way
Originally Posted by krismax
Good info about the 95-99 cams against the 00's
And dave I knew deap down inside you would love the 5th gen manifold
And dave I knew deap down inside you would love the 5th gen manifold
Cam height is different on the DEK exhaust cam. Both the DE/DEK intake cams and the DE exhuast cam are 43.940-44.130mm, however the DEK exhaust cam is 44.465-44.655mm.
Also, the DE intake valve duration is 8-degrees longer, 232 vs. DEK 224, because the valve closes later. Otherwise, the opening and closing points and exhaust cam duration are the same.
So, a 4th gen intake cam and 5th gen exhaust cam could be somewhat better combo for high RPM.
Also, the DE intake valve duration is 8-degrees longer, 232 vs. DEK 224, because the valve closes later. Otherwise, the opening and closing points and exhaust cam duration are the same.
So, a 4th gen intake cam and 5th gen exhaust cam could be somewhat better combo for high RPM.
Originally Posted by spirilis
I thought the only cam differences between VQ30DE and VQ30DE-K was a slightly LESS AGGRESSIVE exhaust cam profile?
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