We gonna try and run 4" !! I already test fitted a polished 4" 45..... It fit beautifully!

 

I really want to see this, but I am tired of being let down by all these speculative threads.

 

Can somebody explain the theory behind why this should yield more power? That is, I'm looking for a technical explanation (i.e., Bernoulli's principle, air resistance, etc) on why this works.

 

I picked up .2 in the quarter mile with the PGM 90mm on my Titan. The throttle responds is Extream, no lag at all. I say it had the same performance boost as adding headers.

 

+1 on post 42 and 43

 

I will try(I'm no brain shark).lol
On the Titans and most vehicles made today are restricted by a few things.
1.air/airflow(restrictive), 2.TB/Intake(small/restrictive), 3.Exhaust(crusted bends/substandard cat/diameter), 4.Tune(tuned good enough to get by and fuel milage)
So being car nuts we change stuff and to go faster.
1. ColdAir intakes= a small increase HP/TQ by creating a denser mixture in the cylinders, which makes for a more volatile mixture plus allows for a more even flow of cooler air with less restrictions. With the 4" coldAir intake on the Titan some are seeing almost 300gps of air flow.
2. TB's, most will work for the application intended by the manufacture. But with the Titan it uses the same diameter as the Z. By increasing the size it allows more cooler/denser air into the intake of the truck. By using the sharply tapered adaptor plate at the intake manifold it funnels the air into the intake system creating more pressure in the intake manifold. Witch inturn creates more volume of air in the intake manifold. IN MY OPNION!

 

We will keep ya'll update dated as we work on this project.

 

Didn't SG motor sports already prove a 90mm tb gave huge gains?

http://www.sg-motorsport.com/?p=693

"The first test we did involved physically removing the upper plenum in the middle of a dyno run, to see exactly what kind of power the engine would produce with the intake runners entirely open to the atmosphere. We found 25+ wheel horsepower. Following that incredible discovery, we built an extremely large plenum out of aluminum to see if plenum volume was the issue. No gains were found, so the next logical step was to increase airflow into the plenum. A large 3.5” hole was opened in the top of the plenum with a velocity stack that would allow airflow additional to what was coming through the factory throttle body. That 25 wheel horsepower came right back, so we concluded inlet flow was more of an issue than the actual plenum flow. The engines power output at this point was 334whp."

&

https://my350z.com/forum/na-builds/4...ideo-pics.html

"The stock ECU with a Haltech standalone running MAP sensor was able to work with the GM throttle body. HOWEVER, it would throw a code every time the engine was started as it detected a throttle fault, and the code would have to be cleared to take the DBW out of failsafe mode. Once that was cleared, we dyno'd with the Carbotron plenum and 90mm throttle body."



Why would anyone be skeptical of a larger throttle body? The easier it is for an NA engine to breather the more HP. This is a very common mod on domestics looking to squeeze out every last NA HP...

Speaking of which I have a custom intake manifold being built that will have a 90mm neck and ls2 throttle body plate. :hide:

 

I think the biggest restriction is the neck between the TB and the plenum. Adding the 90mm TB might give some gains but the bottle neck effect of the oem plenum or any plenum for that matter, will restrict flow even with the tappered adapter plate.

Best solution would be to have a 4" plenum opening and the 87-90mm Tb.

 

they proved that a built motor (* ? I lost track in their threads which car had a built motor and which car didn't) that can rev (a huge limiting factor with a DE at least), with cams*, a proper set of headers and a custom intake manifold with a 90mm throat will benefit from a larger intake and 90mm throttle body when tuned with a standalone. To really see the benefit of the throttle body alone, it would take a stock throttle body being then used on that exact setup, tuned, and then swapped out. That would tell you it's rough power worth

this thread is an entirely different concept however as its retaining a stock plenum which has a considerably smaller throat. The engine can only inhale what it's smallest orifice allows it to. So will this work? on a car with no cams, no headers? who knows, gotta wait and see

 

and thats the biggest difference with the titan. The TB opens directly into the manifold, just like LS motors. We have to neck down for the curve.

I still make a ton of power thru the stock TB and to realistically utilize that big of a TB would mean custom intake manifold, new charge pipe and new intercooler.

Hopefully the OP sees gains without having to change anything.

 

I want to thank everyone for their opinions on this mod.

 

Yep and forced induction is a whole different ballgame vs an NA car. Forced induction lets you get away with a less efficient design and still make tons of power, because air goes to the path of least resistance and filling the plenum is not an issue. An NA car literally has to suck it's air in, making manifold design, etc ultimately more complex

 

The SG motor had Nismo R tune cams(very mild) and an open exhaust off the headers reving out to only 7250, or 750rpms over stock. The dynos are back to back with the only change being the intake and TB. They made 327 from a basically stock engine. Now I agree this is not a simple bolt on but I only mention it because I think it proves the TB/IM/Intake as a restriction in the goal for max NA HP...I mean I have seen on these forums a stroked out 4.15l engine making the same HP, granted the area under the curve was probably much greater I think it proves the limitation of the intake manifold, tb, and intake. I mean if nothing else they gained 25whp by taking the entire plenum off and tuning. I think that proves the restriction.

I would assume the gains from having a larger intake, maf and TB would be because of the Venturi effect. http://en.wikipedia.org/wiki/Venturi_effect : The Venturi effect is a jet effect; as with a funnel the velocity of the fluid increases as the cross sectional area decreases, with the static pressure correspondingly decreasing. According to the laws governing fluid dynamics, a fluid's velocity must increase as it passes through a constriction to satisfy the principle of continuity, while its pressure must decrease to satisfy the principle of conservation of mechanical energy. Thus any gain in kinetic energy a fluid may accrue due to its increased velocity through a constriction is negated by a drop in pressure. An equation for the drop in pressure due to the Venturi effect may be derived from a combination of Bernoulli's principle and the continuity equation(for the guy who wanted to name drop j/k ).


You can get a custom intake manifold made for 1k-1.5k with whatever size elbow and tb plate you want with velocity stacks inside, length custom runners(most would go with shorter for more higher rpm hp), etc.
That carbotron you can probably buy now for 2kish as he has already made one and has the molds/jigs.
For 3k you can get individual throttle bodies and if you copy SG's build you can hit 372whp NA(supposedly)


I think just adding the TB as shown in the above posts will be worth a few Hp and should make the engine slightly more responsive with a tune obviously..

 

Torgus, thanks for your response, but they actually didn't help at all. I have basic knowledge of fluid dynamics but when I posted I wasn't thinking clearly as it was getting late.

Anyway, after reading SGSash's quoted post, I was able to clarify things. Thanks anyway, though.

 

The original 90mm for the Titan, PGM info Here:

http://www.clubtitan.org/forums/show...ct+Giant+Mouth

http://www.clubtitan.org/forums/show...ct+Giant+Mouth

 

"a service that modifies a GM 90mm TB to speak Japanese. "

What exactly does this mean? If this could get us past the ecu going into limp mode because of the DBW issue using the ls2 TB that could be huge...

 

This has been figured out on the Titan, I see no reason it will not work on the Z.

 

its been figured out thru Uprev.

 

Too bad the 'company' which made the LS2 MAFs for the titans only made 12 and are out of business...at least that is what I last read about them. Are they back in business or is someone else now making the kits?

Also, I can't use uprev with my ecu so I need a hardware fix that will let me run the ls2 TB with an 03 maxima ecu...even with a full standalone it will throw a code...

SG Motorsports couldn't get it to work correctly. That is the only 3.5DE I know of having an LS2 TB attached and semi 'working'.

Do you have a link of how to use the LS2 TB with UpRev on a 3.5DE ecu? It is amazing how incompatible Nissan made the different ECUs even different 3.5 ECUs which should basically be all the same...