good luck.. tho i heard this would actually loose power.. but prove me wrong

 

Well I bought a MD 5/16" spacer....I'll wait to see the results from reptile718...

Get some DYNO #'s!!!!

Take a Baseline without anything
another with the lower plenum
last with the spacer+lowerplenum.

Depending on how mush dyno time you can get, I would make 2 runs with each individual set-up.

 

It might be a couple of weeks before I get any results, just bought the lower plenum and still need to buy a spacer. What I would like to do is run a dyno w/o any of these mods, install the spacer and run it again, then remove the spacer and lower plenum and install the revup lower plenum do another run, and finally install the spacer on the upgraded lower plenum and run it. Sounds like a lot of work and $$$, prob. why no one else has done this, just a lot of speculation.

 

Okay, after doing some more research I found out why putting spacers on the lower REV-UP plenum is pointless and why adding a spacer to our factory lower plenum's would provide a better gain. After inspecting both pieces on photograph you can clearly see that our 03-05 lower plenum intake runners are about an inch longer than the new REV-UP engines lower plenum. What this means is that having shorter intake runners creates more space for air to be stored in the plenum its self which would be exactly what a spacer would due to a normal lower plenum. By adding even more space (a spacer to a REV-UP lower plenum) for air to roam around in will be too much for the stock ECM as well as the engine its self, everything must be balanced. The reason Nissan developed this intake is for the higher demand of air the REV-UP engine requires due to the raise in RPM, hence the name. In theory I believe that the longer the intake runners the more gain in TQ you will have but the shorter you get the more HP you can create by having more air stored in the lower plenum. The ideal solution for this problem is for both the intake runners and air space on the plenum to be balanced which is what Motordyne came up with, lol, and why we show more gains on our plenum by adding a spacer then a REV-UP engine adding a spacer. I believe this is why the MREV kit switches out the REV-UP lower plenum (short intake runners, more air stored) for our plenum's (larger intake runners, less air stored) and adds a spacer (increasing the air stored) balancing the equation. I hope this makes sense to most of you, it does to me but its hard to explain. All in all there are pros and cons to this story. For someone looking to gain HP (racing) and doesn't mind loosing TQ in low to mid range (passing) then this is the mod for you b/c at high RPM your 03-05 Nissan would be doing what a REV-UP engine would do and suck up a lot of that much needed air. In addition the higher you can raise your RPM on the 03-05's the more HP there would be to gain, once again no surprise b/c this is what the REV-UP engine would do and we already know it has 300 HP compared to our 287 HP. Also I would think that this mod would increase MPG as well due to the fact that more air is available for use during the whole power band. I have gathered all this info from dyno sheets, other members posts, photographs, ect. Feel free to argue, you might be right. I am no expert and am open to other opinions. Just want to help others and try to offer some sort of an explanation before they buy this mod and expect more then what they get.

 

yes.. thats why guys with REV-UP motors are getting Non rev-up motor lower plenum with spacers... even more air gain.

 

I have not really looked into the effects of this lower plenum on an FI engine but my guess would be that there is a lot to gain w/ little to loose from this mod considering the fact that a lot of low to mid end torque is already gained from supercharging or turbocharging your engine so to sacrifice some torque (plenty of) for a higher gain in HP would be a smart choice. The only problem would prob. be the ECM, I know it must be re flashed for any of these FI mods to work correctly and I am afraid that maybe too much air stored in the plenum with a forced induction will cause problems. I would like to see dyno results from an 05 Track and up with the REV-UP engine going from stock to FI and compare them to some of our numbers with the normal plenum's. Has anyone already done this, if so I would be interested in their numbers!

 

logical

 

After staying up most of the night doing research I have decided to sell the lower intake plenum from the REVUP engine, since I dont race, plan to keep my car NA and use as a daily driver I really dont need it. Only real gain for me would be an increase in MPG. If there are any FI guys or racers that would like more HP w/o need for buying a spacer PM me and let me know. Some people on this forum have already installed theirs and are very happy with the results. Performance Nissan sells them for about $250.00 and the rep I spoke to from there has it on his Z and enjoys it.

 

I am looking for far less than $250 so let me know!

 

Rev-up plenum on a non rev-up motor loses power from 2000 to 6200rpm's. It only makes power from 6200-6600 redline and thats way too narrow of an increase of 3-5whp to make it worthwhile. Dont just look at peak look at the area under the curve guys. You non-rev up motors just do spacers and be done with it.

 

You are right in a sense, however if you upgrade your ECM to run at higher RPM your HP gain will be greater or if you are FI you can create more forced air mass flowing through your intake plenum giving you some crazy power in the upper RPM which if you are running FI I would imagine is where you want it. Only sacrifice is loosing a little TQ but on an FI or higher RPM engine it really would not matter. Other benefits are better MPG and you don't have to buy a spacer. Pretty good mod actually but it all depends on what you are looking for or preference. If I am not mistaken on an 03-05 287hp engine with the upgraded lower plenum running a simple ecm re flash to 7100rpm (still in safe zone) you can see gains of around 11-13 HP which is not bad for the price of these plenums.

 

No way-your saying a non-rev up motor with a 7100rpm limit will make 11-13 hp with a rev-up plenum? Show me proof, its not happeneing. Your failing to realize that the rev-up motors have different cams (more peak power) and valve timing on the exhaust not just intake they can take advantage of the upper powerband we cannot. Rev-up plenum on non revup motor is BS.

Edit btw im talking NA-afaik nobody has done this on a FI Z yet, but I know many are planning it.

 

When I referred to a gain or 11-13 hp you have to also take into account the TS upgrade which alone provides good results depending on the mods you have on your vehicle. Sports Z magazine did a dyno on this part and got some good results, your more then welcome to look it up.

 

But then you dont know how much you gained with just the lower plenum. I gained 9whp and 12 ft/lbs with my flash, so on their test car the flash could have provided 90% of the gains-proving what I said the revup plenum is just not worth it. And it doesnt matter if you can rev to 7100rpm's our peak hp is at 6200 rpm's thats not changing.

 

thats just it man the test car did not have a flash, it was just stock with the lower plenum install only and produced good gains on the top end, better then the kentics plenum. There is someone else on this site who put this mod on their car and added some motordyne goodies and got really good results, he has yet to put it on the dyno but I am sure it will prove this once and for all.

 

ill post something when I find out

 

hi im thinkin bout bying yer spacer..

i have 06' so would i use a pre 06 lower plenum and your isothermal spacer kit to get max HP?

for giggles how would it run with the upper plenum remove alltogether??

 

It wouldn't run if you removed it... unless maybe you could drive it at nothing but WOT 100% of the time.

It sure would sound interesting with the runners uncovered though.
Might sound a little more like F1!

 

Wouldnt run cuz your TB would have nothing to connect to, neither would your MAF-car wouldnt even start.

 

oo ok thanx.. hydra did you get my quetion?