VQ35DE INTAKE SHOOTOUT: FWD IM vs. Z33 vs. Z33 + MD Spacer

Subscribe
Jun 6, 2006 | 07:59 AM
  #1  
Read my dissertation and ask questions if you’d like. The results will surprise you.


Contenders:
1. VQ35DE FWD Variable Intake Manifold (Dyno Tuned 3-stage)
2. Custom Z33 manifold (287 hp version)
3. Custom Z33 manifold plus addition of Motordyne Engineering 5/16” spacer (w/ thermal gasket)


Z33 manifold fitment on A32 Chassis:
Custom Z33 redesigned for fitment (elbow removal , adapter for 70 mm TB)
All three plenum interior surfaces polished, runners honed, and upper exterior buffed
Engine/transmission dropped ½” to allow fitment of Z33 manifold with MD spacer
Drop has had no adverse effects to powertrain or chassis after 2500 miles
Hood closes with a bit less than 1/4" space between hood and intake (my CF Hood does not have underhood bracing)

Pics Here

Polish

Stut tower to intake view

Both Intake Manfolds

BASELINE:
-VQ35DE Swapped onto 1996 Nissan Maxima (VVT removed)
-JWT ECU Dual Fuel/Timing Maps (performance/nitrous)
-STOCK VQ30DE Exhaust Manifold
-Custom 3” Y-pipe (magnaflow muffler)
-’01 Pathfinder 70mm throttle body
-Fidanza Flywheel (11 lb.)
-’01 AE VLSD 5-speed w/ Raxle Axles

No changes to vehicle since baseline dyno. All runs conducted as consistently as possible (A/F, operating temperature, etc.). The MD spacer was added with the vehicle strapped to the dyno.

Baseline:

Green: VI Closed
Red: VI Open
Blue: Old VQ30DE days

The three intersecting points used for optimal VI actuation:




Z33 Custom Manifold Results:

Blue Line: Z33 Manifold
Red Line: Z33 Manfiold + Motordyne Engineering 5/16” Spacer




Baseline FWD IM VIAS closed vs. Z33 + MD:




Baseline FWD IM VIAS open at 5800rpm vs. Z33 + MD:

Z33 + MD:
HP: 238.5 @ 5750
TQ: 238.1 @ 4750

FWD
HP: 235.9 @ 5400
TQ: 244.1 @ 4500






Statistical Results

Gray Portion in Table Depicts Z33 + MD gain/loss when compared to baseline.

Stats Here


Highlights:

-FWD IM makes 25 ft/lb of torque more than Z33 (no spacer) @ 3500 rpm
-FWD IM makes 17 ft/lb of torque more than Z33 (no spacer) @ 4300 rpm
-FWD IM makes 20 hp more than Z33 (no spacer) @ 6900 rpm
-Z33 makes ~18 hp more during the VI change point @ 5800 rpm

Side Note:
Dropping the engine has been my best handling mod ever. It is very apparent that the lower cg does miracles when it comes to cornering. Additionally, the front strut bar now fits without a problem. There also appears much less wheels spin now. While I have no 60 ft. time test prove this, the lower weight placement on the front nose of the car will offset a sizeable amount of torque transfer to the rear of vehicle during acceleration. Less squatting on the rear means more weight on the front tires, and thus better gripping. None the less, it can still make the tires smoke if desired.

Conclusion:

VVT must do miracles for you 5th gens and 350Z. Based on my mod setup and dyno results with quasi controlled environments, the Z33 manifold is simply inferior to the FWD IM. The Z33 Manifold requires the help of the MD Spacer to come close to performing as well as FWD IM. The dyno proved what my butt dyno suspected. Could my exhaust be the culprit? Headers have been sitting at home and are waiting to be installed, but I don't expect much change. If it does help in my high end with the Z33 IM, it will surely help my high end even more with the FWD IM. All these dyno time is getting expensive.





The Z33 Manifold may have not given me much power, but it has plenty of underhood appeal to make up for the loss. Can you say *bling*?




Reply
Jun 6, 2006 | 08:11 AM
  #2  
Wow, these are the kinds of threads I pray for.. good analysis man.
Reply
Jun 6, 2006 | 08:33 AM
  #3  
This is the thread I have been waiting for. Do you have the MREV++ IM? Thats was going to be my project to use with the 3.5. Looks like the stock IM is the way to go.

Looks like we need to get Jime's results of his setup in to compare once he is finished. He has the MREV++.
Reply
Jun 6, 2006 | 08:35 AM
  #4  
Jesus, thank u MexiMax. I'm loving how more and more people are doing HW on Maxima mods. I've talked to Nismology about the 2 IMs, and we concluded that the Z33 IM SHOULD be superior due to its ability to reach 105% VE, but that is with the aid of the VVT doing their work. Without VVT (like it is the case with the majority of people doing the 3.5 swap on their 4th gens), the Z33 IM isnt being optimized to its full potential and thus it appears to be inferior.

So bottom line- If you are keeping VVTs for your swap, the Z33 IM should gve you much better results assuming that you can get the Z33 VTC maps. If you are doing the swap with no VVTs (me), the Z33 IM might not give you what you might expect.
Reply
Jun 6, 2006 | 08:50 AM
  #5  
Quote: Do you have the MREV++ IM?
Its a 287 hp upper and lower.

Interestingly, the MD Spacer's increase in power and torque closely resemble what MREV++ , albeit without VVT. Maybe my honing and polishing created enought volume to represent MREV++ results
Reply
Jun 6, 2006 | 09:58 AM
  #6  
Very nice...time to get the EU and control the VTC pulleys. Nissan designed the 350Z IM with the VVTC, so that's the important piece missing.

How'd you lower the engine?
Reply
Jun 6, 2006 | 10:01 AM
  #7  
How would you control VTC on the 4th gen ECU? Where would the cam sensor go?
Reply
Jun 6, 2006 | 10:07 AM
  #8  
The VQ35 ECM sends an "ON/OFF pulse duty signal" to the IVTC valve, I'm thinking to use the Sub Injector maps' two channels. Definitely wouldn't have the target angle feedback, but it might be possible. SR20DEN was finding some weird issues when trying to log the signals, but hopefully he can find something useful.

No idea what you mean about the cam sensor...[edit]oh the VQ30 cam sensor on the VQ35 cover..yeah that's a biggie[/edit]
Reply
Jun 6, 2006 | 10:19 AM
  #9  
Very interesting. I am waiting for Jime to chime (in)

From my experience, I ran much more consistant times with the Z33 (no spacer), vs. the stock (VI always opened).

The best I could muster with the stock IM was a 14.0 w/ a 2.2 60ft, most of the traps were 98-99mph, These runs were done with a 2-3 gallons of gas in the tank.

A few months ago with teh Z33, I ran multiple 14.0-14.1's with 2.3 60's, and one 13.8 w/a 2.3 60ft. Also trapped about 3 mph higher in the 1/8th. Best 1/4 mile trap was almost 103mph. Conditions felt the same. Although this time was with HS headers added, (I didn't really feel much of a gain from those) These runs WERE done with 3/4 tank of gas.
Reply
Jun 6, 2006 | 10:20 AM
  #10  
Quote: Very nice...time to get the EU and control the VTC pulleys. Nissan designed the 350Z IM with the VVTC, so that's the important piece missing.
Unfortunately for me, my VQ35DE has no VVT equipment. I do however have a very healthy amount of dope that does more than make up for the lack of VVT.

BTW, the VI actuation caused flow disruptions that caused unpleasing hp fluctuations, particularly when spraying. No such thing with the Z33 IM


Quote: How'd you lower the engine?
Left Hand Side: Re-drilled mount-to-chassis attachment points (1/2” lower)

Front/Back: 1/2" aluminum Spacer and kept rubber bushings, (Longer bolts required)

Right: Sacrificed old mount to use as spacer. (Longer bolts required)


I did loose 1/2" ground clearance, but nothing to be alarmed about. Another way of dropping would be to redrilling the actual mount attachment points, and dropping the engine relative to the cross-member, but this leaves the exhaust piping unprotected.
Reply
Jun 6, 2006 | 10:24 AM
  #11  
Nice work. This should be made a sticky.
Reply
Jun 6, 2006 | 10:33 AM
  #12  
What if it was possible to run without cam sensors(w/CEL of course), ie just CPS(POS) and CPS(REF)?

Quote: Where would the cam sensor go?
Reply
Jun 6, 2006 | 10:35 AM
  #13  
Quote: What if it was possible to run without cam sensors(w/CEL of course), ie just CPS(POS) and CPS(REF)?

Disconnect your cam sensor and see if the car even starts. I am pretty sure the 30 ECU's like feedback from that sensor to check with the timing.
Reply
Jun 6, 2006 | 10:39 AM
  #14  
Probably true, but I had one fail/throw a CEL, yet drove home, ie no limp mode. Not sure if it was just for a second and then worked though.

The FSM makes it sound like the cam sensors are backups to the crank sensors....
Reply
Jun 6, 2006 | 10:55 AM
  #15  
Quote: Probably true, but I had one fail/throw a CEL, yet drove home, ie no limp mode. Not sure if it was just for a second and then worked though.

The FSM makes it sound like the cam sensors are backups to the crank sensors....
All the crank sensors can tell you is where in the stroke that the pistons are.

You need to know cam position to tell you which stroke you are on (ie. compression or exhaust) for ignition and injector firing.
Reply
Jun 6, 2006 | 10:57 AM
  #16  
Yeah, I just tried to turn on my car w/o the cam sensor plugged in and it would just keep cranking(car would not turn on). I wont have my car for the next 2 days so you will have to do more testing
Reply
Jun 6, 2006 | 11:06 AM
  #17  
Thanks guys....just hoping.

What about cutting two holes for the VTC pulleys to stick through in the VQ30 timing cover and using some kind of ghetto cover to keep oil in. Something like those black covers on there now, but with a bulge?

NM...don't want to ***** up the thread like usual. Sorry meximax.
Reply
Jun 6, 2006 | 11:19 AM
  #18  
Fu*ing interesting guys
Reply
Jun 6, 2006 | 11:52 AM
  #19  
I find the handling improvement to be the most interesting thing really. I'm suprised 1/2" made ANY difference in your handling....

allen
Reply
Jun 6, 2006 | 02:08 PM
  #20  
good analysis but vtc is a must.
Reply
Jun 6, 2006 | 03:34 PM
  #21  
Well I wish someone would hurry up and figure out how to use the VTC's with the 3.0 ECU? Even if they could figure out how to use it with the EU I would be happy. Keeping the VTC's is just an unattainable goal for most people on these forums. Kudos to the few that have done it.
Reply
Jun 6, 2006 | 03:49 PM
  #22  
Would it be too much to ask for the runfiles?

Once your headers go on, it will be even more interesting.
Reply
Jun 6, 2006 | 04:13 PM
  #23  
Quote: Would it be too much to ask for the runfiles?


mdeezy@gmail.com
Reply
Jun 6, 2006 | 04:33 PM
  #24  
Quote: Would it be too much to ask for the runfiles?
Not a problem, I'll e-mail them to you later on. By the way, you need to open up a runfile database, and share it. Any chance you have runfiles for a VQ35DE (FWD IM), 5-speed with VQ30 headers?

Quote: Once your headers go on, it will be even more interesting.

I will post a Header's dyno, but not before I shorten the lower intake manifold's runner length in an effort to shift my torque curve a bit to the right. Peak horsepower at 6500 is the goal. As for low-end torque?
Reply
Jun 6, 2006 | 04:44 PM
  #25  
Quote: Well I wish someone would hurry up and figure out how to use the VTC's with the 3.0 ECU? Even if they could figure out how to use it with the EU I would be happy. Keeping the VTC's is just an unattainable goal for most people on these forums. Kudos to the few that have done it.
That's going to be tough when the 3.0 ECU needs to read the 3.0 cam sensor.
Reply
Jun 6, 2006 | 05:20 PM
  #26  
Please send me the run files too..! Thanks for the dyno work.

DandyMax @ auracom. com (no spaces)
Reply
Jun 6, 2006 | 05:47 PM
  #27  
I'd love to see this on a 5.5 ecu.
Reply
Jun 6, 2006 | 05:56 PM
  #28  
what about pathy vtc's similar to vq30 the covers and sensors
Reply
Jun 6, 2006 | 05:57 PM
  #29  
It be better on a Z33(VTC map) tuned 5.5g ecu.
Reply
Jun 6, 2006 | 06:35 PM
  #30  
Oooh........good idea.

Quote: what about pathy vtc's similar to vq30 the covers and sensors
Reply
Jun 6, 2006 | 06:48 PM
  #31  
Quote: Well I wish someone would hurry up and figure out how to use the VTC's with the 3.0 ECU? Even if they could figure out how to use it with the EU I would be happy. Keeping the VTC's is just an unattainable goal for most people on these forums. Kudos to the few that have done it.
this may be a dumb question but couldn't you just use the ecu from the 3.5 to run the motor and vtc, and use the 4th gen ecu for everything in the cabin?
Reply
Jun 6, 2006 | 07:04 PM
  #32  
Quote: this may be a dumb question but couldn't you just use the ecu from the 3.5 to run the motor and vtc, and use the 4th gen ecu for everything in the cabin?

Somebody is already doing that I think. Can't recall who it was.
Reply
Jun 6, 2006 | 08:18 PM
  #33  
Quote: this may be a dumb question but couldn't you just use the ecu from the 3.5 to run the motor and vtc, and use the 4th gen ecu for everything in the cabin?
Wow, thats a wiring nightmare..
Reply
Jun 6, 2006 | 08:35 PM
  #34  
Quote: Wow, thats a wiring nightmare..
wiring is easy
Reply
Jun 6, 2006 | 08:43 PM
  #35  
Quote: what about pathy vtc's similar to vq30 the covers and sensors
Please elaborate further???
Reply
Jun 6, 2006 | 08:55 PM
  #36  
Quote: Somebody is already doing that I think. Can't recall who it was.
Here you go:

http://forums.maxima.org/showthread.php?t=400371

From reading, it seems he is actually using just the 3.5 ECU and removed the 3.0.
Reply
Jun 6, 2006 | 09:28 PM
  #37  
Quote: Please elaborate further???
Do some simple research

Just gotta find a way to drill in the timing covers.
Reply
Jun 7, 2006 | 09:08 AM
  #38  
Yeah but I think this will become much more costly but the effects no doubt will be greater.
Reply
Jun 7, 2006 | 12:16 PM
  #39  
Quote: wiring is easy
for most people its a headache
Reply
Jun 7, 2006 | 01:55 PM
  #40  
Quote: for most people its a headache

I think it's probably more scary than anything else just because a lot of it is usually unknown. If everyone really understood wiring then there would probably more people using 5.5 ECU if they had the money. The CVTC will make the difference in car power.
Reply