http://www.my350z.com/forum/showthread.php?t=158576





Kinda reminds you of the first generation Yamaha SHO 3.0L IM's, huh?

Personally I would put the TB at the front already. Everyone and their grandmother is putting out IM's with nasty bends at the back just because the stocker is located there. Oh well. It looks good, gotta give all the aftermarket Z manifolds that.

 

It does but it's missing the secondary high rpm runners and butterfly valves


I don't see how this design would help at all...

But at least the G & Z guys have shops making new parts for them and us Maxima folk get stuck with mostly left overs.

 

I think all these guys are underating the stock G/Z manifold. If I had a Z I'd just buy a spacer and call it a day.

But I'm sure it still makes more power than our intakes.

 

Yup. I'm gonna have to my own. Not shelling out 800+shipping (over 1g when it gets to Canada) for Kinetix.

 

wow, that looks cool

 

Piece of cake to make that fit FWD VQs...hopefully it makes power.

 

Piece of cake to make any made-from-scratch G/Z manifolds fit our cars, power's the real criteria. At least on a FWD you wouldn't have that nasty TB flange bend, it'd just be a short, straight tube on the side.

 

Me and Krismax thought about trying to put my SHO intake manifold on my Maxima for some fun.

But it would require alot of work and probally not worth it...

 

Geez at $1300 it cost more than my whole engine.

 

none of these Intake manifolds will be any good if you look inside the 350z IM you will relize the horned runners are very short.

 

As I said, there was a lot of R&D into the OEM 350z manifold and IMO its only flaws are starving the two front cylinders (thanks to the slope, i.e. little hood clearance) and TB location. But I don't think it's impossible to improve upon it.

Horned runners now that's an interesting idea. But the actual runner length of the G/Z manifold isn't *that* short because you have to take into account the lower.

Where did they say 1300$?

 

On their website, they have them for sale $1299. For $200 more they are powdercoated, for $300 more they are polished, for $500 more I will personally hold your hand while you install it.

****! I will take two of them suckers.

http://www.speedforceracing.com/prod...y_g35imani.php

 

1300 bucks? This is getting ridiculous. We're paying for looks. I don't care if it looks like retarded, as long as it actually makes power. They need to start designing all go no show pieces.

 

Hmmm, looks a bit familiar.

 

J series..

 

Looks like a good manifold for torque, I predict a drop in high RPM horsepower.

I could use one of those though regardless.

allen

 

Dunno about the high RPM drop off... he said they made the plenum slightly larger than the engine displacement.

 

Did you do anything to your intake other than remove the butterfly? Thinking I might put on my surgeon's gloves and see what I can do to the stock one, can't see spending $800 let along $1300 for something I can play with myself. I could do a lot of experimenting for that kind of money.

BTW Stock one is approx 5L

 

I paid $80 shipped for my spare stock upper+elbow.

 

I didn't just remove the butterfly valve, I grinded the whole plate off so there is no divider at all, air freely flows. Tilley did this. Baseline was 233whp/230wtq, and after this getho mod he was at 238whp/223wtq. I noticed a slight low end loss and a slight top end gain. Honestly I doubt it did much to improve my times. The stock intake has many flaws and I don't think I want anything to do with it next year.

Right now I'm seriously mulling over building a complete Aluminum upper from scratch. I've got a few ideas, mainly to equalize the airflow between all 6 cylinders. I think that's the problem with all the aftermarket manifolds; they're overly complicated. We have inline, round lower ports, should take advantage of this.

All the fastest all motor cars seem to have air horns no matter what the plenum design is.

Also it's possible to 'decide' the peak torque you want with runner length/diameter. Seen several formulas. Just need to make sense of them. A 5000 rpm peak torque would be awesome (where you 'land' around 5k after a shift, where the beef of the powerband is from 5 to 7k).

No matter what the plenum design is, it should equalize air between all the cylinders. And no dead air pockets.

 

He was referring to the plenum itself. It's not total size it's the plenum alone, no runners and TB elbow. They call it a "surge tank". I think peak VE occurs at peak torque, that's where the plenum volume/shape is being the most effective.

 

What about making an upper that just a cover? Then make the lower include individual trumpets ala older M5 intake manifold? The upper cover would leave you the option of putting the TB plate almost anywhere.
Here are pics of the new M5 version. It's the older version I was talking about but can't find pics of http://www.germancarfans.com/photos....001/bmw/1.html

 

I looked at the M3's IM. They have individual TB's but all the best NA intake manifold designs seem to "imitate" ITB's. At least that's the impression I'm getting. So air horns is a must. But you don't need to touch the lower. Machine a flange (not too hard considering the 3.5 has round ports vs oval for the 3.0) and have the horns immediately 'complete' the runners, then plenum, TB...

 

True, but they appear to have increased the runner length. The may have cancelled each other out, who knows until we see a dyno.

allen

 

Seems like a paradox doing both but whatever... I'm waiting on that dyno.

 

I wonder if they'd sell me one of those flanges.....anybody capable of making one for a reasonable price on the .org?

allen

 

The flange doesn't have to be machined that way. A rectangular 3/8 one would do the job just as well IMO But I guess it adds to the 'bling factor.

 

and these aftermarket will use the same stock lower to .

and yes in the 350z IM stock theres air horns in there the new rev up IM has even shorter horns now.

 

Kris, I remember someone posted pictures of the inside of a stock 350z IM, but that was the 287 HP version. Where did you see pictures of the 300 HP 05+ engine IM?

 

did you see the MREV mod over at my350z.com? It replaces the plenum on the 300hp engine with one from a 287 hp engine and uses a spacer. It gives huge area under the curve, and sacrifices very little top end.
The stock 350z manifold is not that bad of a design. If I had one, I would add a spacer which gets 90% of the gains of a manifold and looks stock.

 

Exactly. But that thing is way too huge to fit under our hoods.

By the way, I found a picture that compares the 287 hp to the 300 hp plenum:



The above one is the 287 hp version. Kris was right, still air horn style opening but shorter. Yet the plenum is the same size, so larger chamber/shorter runners. Same angle, same edge shape.

 

Did I read somewhere that the 350z stock upper intake manifolds will not bolt to the Maxima 3.5L lower IM?

thanks,
allen

 

Yes you did, if you want to use a Z upper you need a Z lower.

 

You also need a ridiculous giant hood buldge to fit that thing in your car.

 

hmm...i'd be willing to make a cutaway hood to fit the 350z manifold if it gave some great gains..

 

I wouldn't. This car is going to keep its 99% stock appearance till it dies. I am convinced that an IM that gives even better gains than an OEM 350z IM can be made to fit under our hoods.

 

At least give it a mild drop, that could be the 1%...

 

That is the 1%.

 

There is a major flaw in the design of that intake manifold pictured in the first post. On the pic of the Accord V6 pictured later on in the thread there is a cross member at the end of the manifold. This is needed to equalize the air volume across the cylinders. Without it, the air volume can be unequal and cause lean or rich conditions in each cylinder. It can be easily fixed by attaching the two ends together like on the Accord or by making a balance bar to go across the top. An example of the balance bar is on the 300zx manifold.

 

Or they could simply design a manifold that does not biase any one cylinder. There's really no need for those complicated, 1k$+ designs.