I had a 2002 Ford Taurus come into work today, and saw that the intake manifold was made out of some kind of injection molded plastic, basically like ABS, but I'm sure it had some other resin in it to keep it from melting... I couldn't believe it, from the throttle body mounting to the lower runners, all plastic... Imagine, no polishing, no chance to bore or extrude hone to find more power, heck, you'd have a hard time putting a Direct Port Nitrous setup without stripping the plastic out... We may be cursed, but at least were not damned...

 

LOL. Wait until the 2000-2001 VQ30-k guys read this

 

I believe Nissan used the composite starting in 2k. At least the 2k that I test drove had a composite intake. Nissan does not suffer from bad mechanical design, it suffers from poor exectution ie parts and assembly (oil and tranny leaks). It'd be like constructing a federal penitentary in Manhattan, and then realizing later that organized crime built it. Nothing wrong with the structure, but the project was poorly planned and executed.

Inexpensive parts fail but they cause motor oil and gear oil to be lost. So I would answer your question negatory. Could Nissan do a better job with suppliers? Sure.

btw the Taurus is a very good vehicle. Very few people that I know drive one (only 2), simply because it lacks individuality. But as far as price, with the rebates, it's a car that delivers alot of value. Ford did something Nissan never does, they incorporated features that focus groups told them they wanted, such as adjustable pedals.

 

Yeah, Nissan used it for 2 years on the 2k/2k1 and then got rid of it.

Piece of ****.

Problem is you can't examine or fix the butterflys in the variable intake. That meant that Nissan (in my case) just denied there was a problem - you know the old "can't see anything wrong here." I'm certain that even though they never admitted there was a problem, they knew there was and changed them because of it.

 

So, you got a metal replacement, like the 2K2s, or another plastic one?

DW

 

another composite one.

My complaint is mainly that if it wasn't one composite piece they could diagnose a failure.

 

My 2K developed a big lag at 4500 rpm in each gear (5 speed). Dealer said that nothing was wrong, suppose to be that way.. I said sounds like a VI problem to me, they said "we can't touch that plastic intake". I sold the car... That got rid of the lag...

 

Composites are the wave of the future. Hop aboard.

 

Maybe so but the dealer service organization doesn't know it..........

 

Hmm, I haven't really messed with too many 5th gens, but the one's Ive seen looked like the intake manifold was anodized or painted black... Not calling anyone out, I just didn't know... It seems like a bad design to me, especially if you want to add any performance, but I guess with all the new emmisions systems they keep adding, eventually mod's will be a thing of the past...

 

http://www.dupont.com/automotive/new.../handmfeb.html

http://media.siemensauto.com/mediace...prjob_num=1166

http://www.basf.com/static/OpenMarke...c-Article.html

http://www.sae.org/automag/plastics/05.htm

Engineers don't create bad designs. Corporate ofiices turn good designs into bad designs.

 

Most dealer service organizations wouldn't know a good design if you rolled up the blueprints and shoved them up their ****.

 

Well said, but I'm still wondering why Nissan went back to a metal with the VQ35.


Hmmmmmmmmm


DW

 

I won't even go into what I went through . . . it's well documented in the stickies. But that sure sounds like the problem I had.

 

Doesn't the 2K2 motor have a variable intake system of some kind? I would have to guess that moving parts are better left to cast aluminum housings. In order to have rotating or translating parts, there would have to be bearing surfaces. These surfaces would need a base that does not deflect much. Aluminum does deflect much less than Nylon at temperature.

I wouldn't count out composite intakes and other components just because the 2K2 went with an aluminum intake manifold. The new Alfa Romeo coupe has a composite hood...and if you look at the G35, you'll notice the radiator support is made from a BMC composite.

 

Lets not ask why but instead just be happy that they did.

 

My brother in law has 98 Taurus - stock. I was helping him change an oxegen sensor. Even though it has the same size engine (3.0) as the Max everthing looks very 'wimpy'. The exhaust is smaller,the throttle body is very small and so is the stock intake tube. The intake runners seem very short compared to ours, but his were metal. The Taurus also has two cats on the Y-pipe but no main cat .

 

Yeah, but when you say stock, do you mean Vulcan or Duratec? It's the Duratec that uses the composite intake. The Vulcan is an OHV motor, but that bad-boy has more than proved itself over the years.

Taurus is a great car, but too bad they gave it rear drums. Still, would you rather have a Sentra or a Taurus? I guess in high school, it'd be a Sentra. If you were an old dude like Cal Ripken maybe a Taurus.

 

A plastic hood, or even carbon fiber, I would be happy to have, but a plastic variable intake manifold? Call me old fashioned, but I'd rather have metal Besides, I would think that metal transfers heat better than the plastics, so the motor would be less likely to suffer from heat soak.

And yeah, the 2K2 Max has a variable intake manifold.

DW

 

"The low thermal conductivity of the nylon manifold also helps improve engine performance. The nylon manifold insulates the air inside it from heat, and thus allows high-density intake air to flow into the engine."

Taken from this article:
http://www.basf.com/static/OpenMarke...c-Article.html

 

Wow. Sounds promising, then.

DW

 

The Vulcan now has a composite intake too. I would know, I drove one for 3 weeks


Dave

 

 

How many of those are VI manifolds like 2K and 2K1 VQs?????????

 

What VI manifolds?

 

ld be happy to have, but a plastic variable intake manifold? Call me old fashioned, but I'd rather have metal Besides, I would think that metal transfers heat better than the plastics, so the motor would be less likely to suffer from heat soak.




You don't want the intake manifold to heat up !! You want COLD DENSE AIR going in ...

 

I think he already realized that he was in error.

Why don't you transform and roll out somewhere else.

 

VI stands for Variable Induction. The manifold has two different air paths. At the low to mid rev range, the long path is used. This maximizes low to Mid range power and torque. At high rpm the the short path kicks in maximizing high end power. This type manifold was used on 3rd gen VE engines and 5th gen VQ engines. 2K and 2K1 VQ engines use a plastic VI manifold with the 2K2 VQ35 going back to aluminium. 4th gen VQs use an aluminium non-VI manifold thus power drops off on the high end since these manifolds are designed for mid-range power and torque. An after market VI is available for 4th gen VQs in a group deal on this forum. These are brought in from Japan and were originally on 4th gens sold in the mid-east thus they are called MEVI. These are aluminum also. Hope this answers your question...

 

I'm not sure. But, the manifold for the V8 in the Jaguar XK-series and the Rover/BMW V6 are variable...both manifactured from fiberglass reinforced Nylon 6,6.

Sidenote: Heh, for some reason I thought your VI was the Roman numeral 6.