Skirmich

I saw a Ridgeline Review today on YouTube and it was one of the few that actually removed the Engine Cover to show the bare engine, With horror I noticed the new Manifold was made from plastic...

That is cheap, very cheap to say the least...... I know Honda did this to save weight but it actually ends up looking pretty cheap on Honda Side, The Magnesium Manifold was pretty light and it was strong.
Now we have something that might brittle with heat and break.

RDX10

The biggest issue I think may happen is if cold water splashed on to it while it was hot it could easily deform.

Skirmich

Makes me wonder if the new MDX or Pilot also has it?

justnspace

iTrader: (1)

Y'all do know that guns are made out of plastic right!?
It's technically a polycarbonate, but still considered a strong plastic.

If the manifold is polycarbonate, what's the problem?

myron

iTrader: (4)

I don't know what you would be doing with a manifold that might cause it to break. And I am sure they didn't use 0.001" thick plastic cup type of plastic for this

thoiboi

Umm...


I'll just leave this new thread from 2G RL right here:

https://acurazine.com/forums/second-...ded%2A-949753/



TL;DR?

here's the pic:

1killercls

My Audi has a plastic intake manifold... :dontcare:

fsttyms1

Manufacturers have been using plastic for years

There are a bunch of reasons to go to plastic (they arent cheap brittle things like you might expect, most have fiberglass infused to aid in strength), It can be stronger, lighter, They dont absorb as much heat as alum/mag and they also absorb sound better making the engine quieter all of which make it much more attractive to manufacturers.

justnspace

iTrader: (1)

and i repeat, guns that go BOOM are plastic.

cu2wagon

But the plastic part isn't containing any significant pressure. It's all structural.

FWIW, this plastic manifold will likely be a-okay. I seem to remember the hatchbacky Impreza going to a plastic manifold and all the Subie boys were initially. But then it was okay.

This will be okay too.

Just take deep breaths and remember that it will be alright.

justnspace

iTrader: (1)

well, that's beside the point...
guns are still plastic....lol

TacoBello

So Nissan has been using plastic manifolds for years now. Without issue, I should add.

If my engine is going to explode, like the one posted above, I'd prefer plastic also. Why? Because plastic will blow out before any other damage potentially happens. That nice cast one... who knows what else happened inside the engine with all that pressure. Either way... the odds of an explosion like that happening are VERY small. And cost of replacing a plastic manifold? I can get one for much less from Nissan, than a metal one from Honda.

The manifold just has air flowing through it... who cares if it's plastic

Also, the manifold will not deform with it being hot and then sprayed with cold water. It doesn't even get that hot.

C'mon guys...

cu2wagon

Caveat: Forced induction is another story...

But, see again: Subaru.

YMMV.

myron

iTrader: (4)

So what are you trying to say with this picture? That engine can blow up? Has nothing to do with the manifold being plastic, and that one exploded being aluminium so I don't see the connection at all

TacoBello

Not really... see my Turbo Hyundai. Plastic manifold. Hasn't blown up yet

thoiboi

Here's your original question:
so i showed you a manifold that broke

and you don't see the connection?

cu2wagon

Yeah. I have no basis, but I feel like metal manifold would take more boost than plastic. Just in general...

But like I said, that was the "sky is falling" response when Subaru started using plastic manifolds. It was for sure the death rattle of aftermarket tuning for the industry!!!

But that didn't really seem to be the case.

Still relevant almost 50 years on.

AZuser

If high powered cars like the SRT Viper and McLaren MP4-12C are using plastic intake manifolds without problems, I doubt Honda would have any.

Besides, Honda's plastics are more superior to other manufacturers plastics

TacoBello

I've come across plenty of boosted 370s, putting out in the range of 500-650hp that all run plastic manifolds... Boost pressures are fairly low.. even a crazy high boost application, pushing 25psi... well 25psi in terms of force is not all that much. at 25psi though, the 370s are getting to 900-1000+ hp. The guys do start changing the manifolds then, but not because they're weak, but because there are higher flowing/more efficient options available, resulting in even moar powah!!!

p.diddy

iTrader: (3)

A bunch of worrying over nothing. I'm sure the engineers knew what they were doing. Honda isn't the first and won't be the last to run plastic manifolds.

cu2wagon

Uhhhh.... I think I know better than those silly Honda engineers. Thank you very much.

myron

iTrader: (4)

it would make more sense to me if you posed a picture of a plastic one broken to prove a point. This way you just proved that they can break being metal too. So if the engine detonates, it clearly won't matter if it's metal or plastic

RDX10

I mixed up manifold with valve cover....you are right on it not getting hot enough.

Skirmich

Holy crap what happened to that engine? That's the real question.. If something that bad was bound to happen I dunno what type of material would endure the explosion.

To my original Point.. I feel that Honda is Cutting costs where it shouldn't.. Honda V6s are only placed in the highest of trims or their high end cars (Since the Ridgeline is the only Truck Honda sells and its asking PREMIUM for it) I dunno why it should have cheap out on the engine and placed more weight to the car? Remember that the new Ridgeline is using HSS and ACE Structure compared to the Old One it WEIGHTS THE SAME... So If Honda wanted to lower the weight by using a plastic manifold why add useless crap like IN BED AUDIO?
And Look I know there are a lot of brands using Plastic Manifolds since years, Honda own 4 cyl engines use them a lot.. But back to my point, They are used on the CHEAPEST TRIMS which use the 4 cyl. Even the Odyssey which use a V6 isn't cheap..
Now you can say Nissan has be using it on the VQ35 but I do not own a Nissan nor would want to with their crappy CVTs.. I own a Honda (Acura) so I care about the new IDEAS Honda is getting about how to Prioritize Dumb things over using the Magnesium Allow Manifold which not only worked well, it gave the Engine a Premium Feel and to some that is way more important than IN BED AUDIO.

If using plastic would in any shape or form Lower the GVW or Get better MPGs? (I though of this as its main purpose since Plastic does not heatsoak as much as Metal) but since the New Ridgeline basically weights the same what is the point? Its getting better MPGs because of the DI Engine, Trans and VCM not because they lowered the weight by using a Plastic Manifold.

Perhaps I am over analyzing this but in no way its a Rant, I cant do anything about it or Honda care about my opinion.. This is just a TOPIC of Conversation so do not get mad or anything.

Oh Sickest TL

iTrader: (3)

^ I'm pissed lol

cu2wagon

I'm super pissed over here.

One other thing to consider... the almighty $$$

Which do you think costs less: a plastic manifold or a magnesium manifold?

For an additional point, how many times less expensive do you think the cheaper option is?

And for the last point, how many vehicles with the plastic manifold does HoMoCo produce a year?

For extra credit, do the math to multiply the cost difference by the number of units produced. Express your answer, rounded to the nearest ten thousand dollars (your choice of currencies, but please specify). In 500 words or less, explain why you think the choice to move from magnesium to plastic does or does not make sense from a corporate finance standpoint.

Your answers are due to me by 11:59 pm Friday night. Late answers will not be accepted and will not be graded.

thoiboi

Counterpoint: magnesium is a naturally occurring metal out of the earth. Plastic involves manufacturing and chemicals


I'll stick to magnesium

Oh Sickest TL

iTrader: (3)

approx 34.50 canadian doll hairs in savings per manifold

cu2wagon

True, it's naturally occurring... They just mine those manifolds right out of the mountains, right?

fsttyms1

Sooooo since when did "Honda V6s" become placed in the higher end cars? Honda isnt a premium or luxury brand So you think just because its a plastic intake manifold now they have become cheap?? I think someone should tell BMW that then as they use them too. They use them, even on the new M series vehicles. I dont think it makes them cheap because they use them.

So if honda didnt reduce weight where they could do you think the new ridgeline would weigh the same as the old? Its stronger, more features, electronics etc.. Everything adds up. Weight reduction needs to happen as well. A pound here a few lbs there, all adds up. With cafe standards tightening up every little bit adds up. Same goes for mpg. You cant just look at 1 vehicles mpg rating. You have to add them up across the whole line up. Thats how they meet cafe regulations. Also need to look at NVH. manufacturers are finding ways to make the vehicles even more quiet and smooth. Plastics are used to help reduce resonances, vibrations/sounds that may other wise be heard in a alloy manifold. There are many things to consider as to why it may be better than an alloy manifold. I think you are just over analyzing it

Serious question. Other than your reasoning of it being a dumb idea, why do you think its dumb? Just because its plastic? So why did the magnesium give it a premium feel or should i say what gave it that, especially over a newer composite design? Is it still more premium even if it doesnt perform as well as the plastic?

Here is a good read for ya

Plastics Under the Hood

Why Does My Car Have a Plastic Intake Manifold?

Skirmich

Fatty that are some really good reads right there....
So basically it all comes down to manufacture costs and CAFE Restraints?

I didn´t think the plastic manifold was dumb, I just think it wasn´t worth it look at the 3rd gen MDX that kept the Magnesium Manifold but They added features and the weight was shaved by a whopping +/-300lbs compared to the previous gen, This weight difference is noticeable in all levels of performance and MPGs.

Also I do think using Plastic instead of any Metal is Cheap, I like my Engines in Full Metal Jackets.. What is next? Plastic SH-AWD Diff Case? Plastic Gas Tank? (Oh wait that already happened)

RDX10

Skirmich, while I do feel Honda is currently undergoing some massive cost cutting with their current Acura lineup, I don't necessarily think this is a major part of it. Just look at the interior quality to get a good feel for that.

Despite the MDX selling for 50-70k here, it is still doing remarkably well compared to the otber competiton so they must still be doing something right!

YeuEmMaiMai

I believe that GM was using plastic intakes starting in the early to mid 90's

gatrhumpy

iTrader: (1)

rockstar143

iTrader: (6)

thoiboi...i was actually trying to remember where that intake that cracked was posted to repost here.
Immediately thought to post that to show that plastic or not, a failure can occur.
Great minds

thoiboi

I don't see the connection... why would you post that?

fsttyms1

I guess im just try to figure out why does the intake mani need to be metal to you? Is it just a look thing to you? If it isnt weaker, and actually improves the engine why is it still cheap? Why isnt it worth it?
The BMWs (even the M series) use it, do you feel they are cheap or any less of a car because of it?

Personally id be more upset that they still use a Timing Belt, not a Chain and SHOC which to me lessen(make it cheap) the vehicle more than a plastic/composite intake manifold.

rockstar143

iTrader: (6)

Would you just fucking MOVE ON already?

cu2wagon

The thing is, "plastic" is cheap.

What they need to do is start making those parts out of "high density composite thermosetting polymer resin".

Now, all of a sudden, it's like the underhood is chocked full of science! And we use science to make luxury, so...

thoiboi

See, now we're cooking with fire...