dwapenyi

iTrader: (3)

I saw a commercial on speedvision for this compny called Edelbrock. See where I'm going with this? They make custom aluminum intake manifolds for hot rods and such. Couldn't we get a group together to show interest and have Edelbrock make a Gen 5 like manifold for our Gen 4s?? That would be the end all NA mod for the gen 4, addressing its main weakness. What y'all think?

DW

BlkStnValyMaxima

iTrader: (1)

Edelbrock has been around for ever in the Muscle Car scene. If they were going to break into the import market, I'm sure they would start with Honda's, just like every other company.

Jeff92se

iTrader: (82)

It's not just the manifold. (but that alone would be expensive) The valve is vaccuum actuated but the hose is connected to a little solenoid or something. And that is ecu controlled.

jran76

Last time I checked Edelbrock already made hundreds of parts for imports, but you're right mainly civics, eclipse's, etc. Read a import mag and you will probably see a ad...

dwapenyi

iTrader: (3)

Putting in an ECU activated vacuum mechanism would probably make the costs alot higher, especially since our ECU probably isn't even thinking about a variable intake manifold. Why not a simple RPM switch? 4200 rpm, switch to the shorter runners? That's bound to be better than what we have now.

DW

Jeff92se

iTrader: (82)

I guess that would work but you still need a vacuum source(no big deal) and rig a vaccuum lever(from a 4-gen or 5-sp ve 3-gen). But a rpm switch is different than a vacuum sourced switch.

mzmtg

iTrader: (11)

Think about the cost. A part like that could end up costing as much as or more than forced induction...

1MAX2NV

iTrader: (5)

Like Jeff said RPM switch probably won't work. It will work if you go WOT all the time. If you are just at 50% throttle and pass the rpm setting. Switching to the other intake runners might affect your gas mileage and drivability.

mzmtg

iTrader: (11)

The whole theory of variable intake runner length is based on resonance. The resonant frequency of the intake system is affected only by RPM (the frequency of each valve opening event), not by load. This is why these systems are switched according to RPM and not vacuum.

Jeff92se

iTrader: (82)

I don't know if you would want the level opening if you are just reving the engine(no load) or crusing in a high gear(no load). In these cases, the rpms are high but the vaccum signal should still be high.

When I rev my 3-gen VE(at idle/no load) I admit, I can get the valve to pop though. But I believe it's at a higher rpm than a load condition.

I'm just totally guessing here. I would have to take a look at my FSM to see what signals the the ecu is using for the switch activation. If it was purely rpm, I don't understand why it would require such an elaborate device to control it. Again just a guess.

mzmtg

iTrader: (11)

Well, the system on your VE is variable valve timig not variable intake runner length like the 5th gen VQ.

So, that's a whole differnt ball game.

Jeff92se

iTrader: (82)

We have both. VTC and varible intake volume tech. Where do you think Nissan got these ideas?? hehe

Weasel

iTrader: (2)

Variable intake manifolds already exist for non-US 4th gens. Road Beast's car has one and so do some Australian cars. I'm sure you could import this part for less than Edelbrock would need to make one.

Jeff92se

iTrader: (82)

Pics please!

MardiGrasMax

iTrader: (14)

Its simple.

Just use an RPM switch and full throttle switch. Slap it on a dyno and play with the switch rpms. That will work. The 5g manifold actuator is pulled open by vacume. The electrical switch part is just an on/off valve controlled by the ECU.

Keven97SE

Here ya go. Pics courtesy of the middle eastern/australian Maxima guys. The manifold is different from the 5th and 3rd gen manifolds. The secondary plenum is located ~half way down the runners. You can see the individual butterfly valves inside the runners on the second pic. I can't tell exactly how it works from the pics, though.

Keven97SE

And here's the second pic showing the runners.

Keven97SE

And finally here's a pic of the upper manifold off the car. See the honkin secondary plenum sitting on top of the runners? Kind of an odd looking manifold but apparently it works. JDM 4th gen Maxima 3.0's are rated at 220 HP. Same engine as ours otherwise, too.

Jeff92se

iTrader: (82)

Ah Kev? I don't see any pics.

Keven97SE

Lemme try this again. First pic showing engine bay with variable intake manifold from a JDM 4th gen.

Keven97SE

Alright. Before I b!tch slap my PC, would somebody enlighten me as to how one attaches a picture? Although I assumed I just needed to paste the http://...jpg address into the "Attach File" area, that doesn't seem to work for me. Jeff, can you help? Thx.

Keven97SE

Hey, lemme try this now:
Pic 1 Engine bay): http://www.sx7r.com/roadbeast/My%20engine%20pic.jpg

Pic #2 (butterfly valves): http://www.sx7r.com/roadbeast/Stille...20Mani%201.JPG

Pic #3 (upper manifold): http://www.sx7r.com/roadbeast/Middel...t%20intake.JPG

Jeff92se

iTrader: (82)

That last post worked Kev. Sorry I haven't tried the maxima upload thingie.

dwapenyi

iTrader: (3)

This is interesting. Nissan had a variable intake manifold for the 4th gen, but they couldn't get it on the US version. I guess they couldn't get the US spec Maxima to pass emissions with the variable manifold or something.

DW

MardiGrasMax

iTrader: (14)

WHOA!!!

I just looked at those pics. Thats a direct bolt on for sure. Add in th JDM cams and heads and WE HAVE OUR SELVES A WINNER!!!

Dave B

JesusH, can someone figue out how to import this freaking intake manifold. THIS IS THE KEY TO RUNNING 13s NA IN A 4TH GEN MAXIMA.


Dave

dwapenyi

iTrader: (3)

These pics really tell the story. I saw only the the 3rd picture before and was scratching my head trying to understand how it could fit on the VQ, but the 1st picture shows it.

I can see what's gonna happen, and it doesn't look good.

Someone may import that intake manifold and fit it to a 4th gen VQ USA engine. They'll find that the US VQ ECU just can't deal with it, so they'll have to use the ECU from a Bahrain or NZ 4th gen Max. But if they do use that ECU, bye bye US emissions. Bummer

Damn, road beast, and all you NZ maximas, I am much more envious of your VQ motors

QUestion, if the 4th gen VQ in NZ or Barhrain style develops 220HP, what does the 5th gen do out there, and the VQ3.5?? Those must be absolute monsters!

DW

Keven97SE

I compared the picture with a pic from my service manual. So far, it looks like the overseas variable manifold IS a direct bolt-on. One little change I noticed is that the variable manifold has no holes for the canister purge volume control, but that's a minor thing...you could find a way to mount it somewhere (just needs to sit on top).

The lower manifold looks to be EXACTLY the same as ours. Check it out: http://www.sx7r.com/roadbeast/Lower%20intake.JPG

Keven97SE

I doubt it had anything to do with emissions. There's no reason why a variable intake manifold would cause emissions failures, assuming the fuel curves in the ECU were matched appropriately to the increased air flow rates at high rpms.

Think about what cars were out back in late 94 when the 4th gen was introduced. 190HP was huge back then. Heck, even a V6 in an import family sedan was a big deal back then. There was no reason to introduce a new motor with 220 HP. That would have been overkill. Nissan needed to be cost competitive also, so they axed the variable intake manifold for the US market. I'm assuming all this, of course, but it makes sense.

dwapenyi

iTrader: (3)

I hope to God you're right. That would be AWESOME if it could work. The reason I say emissions is because maybe the Bahrain or NZ maximas don't have as many O2 sensros etc, and other watchdogs montiored by the ECU for emissions.

DW

Dave B

I would think the US-spec would be able to keep up with the varible intake because the US-spec has no problems keeping up with a ton more air when you add the Stillen SC. The ECU seems pretty smart and the fuel injectors can keep up. The stock 4th gen valvetrain appears to be fine to 6600rpms with no valve float. If the stock cams can keep up with the SC, I don't see why it couldn't keep up with a variable intake. The only hard part will be developing the rpm switch.


Dave

dwapenyi

iTrader: (3)

It's not so much a question of the ECU keeping up, but more of an issue of whether the ECU can even acknowledge the presence of the variable intake. Since the US 4th gen came with a fix manifold, then Nissan could have made a special ECU just for this US model. Like putting SCSI drive into a 1970s PC. It ain't goona happen even though the CPU and motherboard could proabaly deal with and benefit from the SCSI drive performance.

DW

NZ Max

We dont get the VQ35DE (yet anyyway)

I doon;t have time to post now, but in a few hours ill be back.

dwapenyi

iTrader: (3)

OK. What's the output of the VQ30DE-Kaizen motor?? 222-227hp here in the US.

DW

MardiGrasMax

iTrader: (14)

The ECU will keep up and have no problen acknowledging the extra flow, IMHO. THE MAF sensor will detect the extra air flow and adjust a/f ratio instantly. Its no different than adding a high flow intake and exhaust to move more air. The MAF sensor tells the ECU "hey I got more air comming past me", the ECU says "ok, I'll adjust the fuel injector pulse width" and they all live happily ever after

Dave, rigging up a full throttle switch and rpm switch to control activation is easy part for me, the parts will cost a few hundred bucks though. The hard part will be finding these manifolds and importing them in quantity.

1MAX2NV

iTrader: (5)

FYI, I noticed three slight variation on the 4th gen upper intake manifolds. There might be more variations, but I only have on hand a 97, a 98 and a 99.

98 is different than other years. This is a 98. Notice the extra little vacum tube near the TB.

1MAX2NV

iTrader: (5)

Here's a 99 cali-spec compare to a 98. The one tube is smaller than other 4th gen. Besides these small variation. All 4th gen seems to be the same.

1999


1998

Anachronism

So if this is possible - anyone want to take a guess at (total) cost and approximate horsepower increase? Just ballpark numbers would be cool.

Jeff92se

iTrader: (82)

Lowend-might not see much. Maybe some more punch(good) but the VQ doesn't need help here.

Highend: Hopefully, this will give the VQ the upper-rpm breathing/pulling power this sweet engine should have. This could be a 10hp+ difference in the 5500rpm+ range. But it would depend where the stock vq rev limiters are. No good if the ecu is gonna cut off the fuel/timing too soon.

The thing is, this euro manifold doesn't look to be much bigger than the usa vq. Maybe Tony can comment a little more. Tony, does the port size and runner I.D. look bigger to you?

Keven97SE

This variable manifold should be good for ~20 HP or more. When you look at the specs for the 5th gen motor, the primary difference is the intake manifold. That motor runs 32 HP more than the 4th gen. I think some of that gain is also due to the improved fuel system and muffler, though, so +20 HP for the manifold alone is probably a reasonably conservative guess.

If one was able to upgrade the intake manifold on their 4th gen, I would expect there to be no change in the character of the motor below 5000 rpm, the rpm at which most likely you'd tune the butterfly valves in the manifold to open. Below that rpm, the intake manifold is pretty much the same as ours, implying that torque/HP would be the same. Above 5000 rpm, though, the torque falloff would be far more gradual. At 6500 rpm, I'd expect ~20-25 more ftlbs of torque. The car would definitely pull harder past 5000. Wouldn't feel any different below that, though. The upgrade would only be "felt" when racing the engine (ie racing or highway passing).