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I got a chance to take a B9 out for a test drive yesterday, and found some interesting results. . .

 

One of the most disturbing is that when I tromped on the throttle, it took like 2 seconds before the engine actually started putting out power. It just seemed to sit there thinking about it. . . I was told that it is a system designed to protect the tranny from excessive forces from the engine. . .

 

It felt like those old SciFi movies where the engines had been tampered with and when they were pushed to full, there was this winding down sound, and they chugged to a halt. . . when lesser throttle was applied, it ran OK, but if you ever need to "push the envelope" to get out of a bad situation, you are stuck. Other than that, it was nice in most respects. the two other problems are the stereo is round faced, so aftermarket units are not an option, and I looked under the hood. . .

 

OK, when did Subaru start using plastic intake manifolds? I can understand that this is probably to save weight, but I'd much rather have the extra weight than a huge hunk of plastic acting as my intake. I'm sorry if I'm old fashioned, but I like my engines to be made of metal.

 

If I ever get the cash to get one of these, I will first find out if that plastic intake can be swapped for a metal one. Oh, and they are thinking of putting a turbo on this for next year? Bull. The car is not designed to be able to take a turbo. With the hesitation built in to protect the tranny, and the plastic intake manifold, a turbo would last about 6 months. . .at most

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I think I'll stick with my 96 OBW 5sp until the tailpipe falls off.

 

Hey, Mattocks, did your suby come standard with that spoiler? How many miles you got?

 

I bought it used, but it did come with the spoiler when it was new. Right now I have 119,000 miles on it. I just put a new muffler on it, and it is LOUD :D

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Wow - don't like weight reduction, cost reduction, inflow resistance, lower center of gravity...

 

Plastic intake manifolds are on many cars. There is a LOT of plastic under the hood of many cars and guess what - none of it has melted.

 

Agree the intake gases in a turbo would be hotter, but probably not hot enough to melt that plastic.

 

I'd guess that if they add a turbo next year it would be with an entirely new intake manifold and the issue of plastic is a moot point.

 

Remember, Subaru has had turbo cars for more than 30 years, I think their engineers know what they are doing.

 

We did no experience the hesitation you spoke of, but will certainly be looking out for that on Tuesday when we pick ours up.

 

Mike

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personally any car with a plastic intake can take a flying leap.. seen too many fords, dodges, etc with those plastic intakes, suck the gaskets around 60k miles..

 

 

if its got a plastic intake the B9 can take a flying leap too..

 

just my .02

 

It baffles me something like that would be made of plastic..

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It baffles me something like that would be made of plastic..

 

Surprised the hell outta me too. . .

the hesitation is only when you tromp on the throttle. I only tested it at low speeds, so it may not be an issue on the freeway. Midrange throttle gave the best pickup. There is a lot I like about the B9, but plastic on the engined is not one of them (I plan on keeping it a long time if I get one. . .) I'm not as worried about melting as I am about it ageing and getting brittle. Plastic does not last as long as metal. If I can retrofit metal parts for the plastic ones, I'll be happy. . . the hesitation I can compensate for (or use the sportshift to get around it. . .)

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Dont forget about carbon fiber (real CF) intakes, They are used in very high horsepower engines especially if turbocharged, for their properties; stronger then steel and lighter then aluminum and extreamly low heat transfer rates. Some composites used intakes and other various parts of the car are actually stronger then aluminum and lighter weight. As said previously, the biggest reason to use a composite intake is to reduce the heat transfer from the engine into the intake air. We run intercoolers to cool down turbocharged air and everything after the intercooler that is made of metal simply heats the air back up, ever touched your hand on the top of your aluminum intake manifold after driving for 5 mins, you'll burn yourself, its like touching your exhaust manifold. Try touching a composite intake. My '05 Legacy 2.5GT has the same composite material as the B9 and I am prowd of it!

 

 

To add to this I am working on makeing a carbonfiber intake manifold for my ER27TT if anyone cares;)

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Wow - don't like weight reduction, cost reduction, inflow resistance, lower center of gravity...

 

Plastic intake manifolds are on many cars. There is a LOT of plastic under the hood of many cars and guess what - none of it has melted.

 

Agree the intake gases in a turbo would be hotter, but probably not hot enough to melt that plastic.

 

I'd guess that if they add a turbo next year it would be with an entirely new intake manifold and the issue of plastic is a moot point.

 

Remember, Subaru has had turbo cars for more than 30 years, I think their engineers know what they are doing.

 

We did no experience the hesitation you spoke of, but will certainly be looking

 

out for that on Tuesday when we pick ours up.

 

Mike

 

Ford started using plastic manifolds on their 4.6L V8 in 1996. They issued a recall on "severe duty" models such as Interceptors and taxis a while back to replace the intake with a modified unit that has an aluminum crossover. I just received a copy of a class action suit, (I own a Grand Marquis as well as a Forester), which seeks to increase the waranty on the plastic part on all models to seven years. The suit is successful, and the waranty increase will go into effect in October. It is not so much if the plastic manifold will fail on the 4.6L, as when.

 

I will *not* buy another car with a plastic manifold. Ford has been building cars a hell of a lot longer than Subaru, and they screwed up!

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OK, when did Subaru start using plastic intake manifolds? I can understand that this is probably to save weight, but I'd much rather have the extra weight than a huge hunk of plastic acting as my intake. I'm sorry if I'm old fashioned, but I like my engines to be made of metal.
I guess you will not be flying in any light planes or helicopters, either. Nor race cars.

 

What you call plastic most folks call composites. They're called composites because they are a mixture of materials. For example, there are companies now that inject aluminum infused with carbon fibers to make it stronger. People race around the world in boats made of carbon, kevlar, and glass fibers in a resin matrix, either polyester or epoxy. Burt Rutan flew around the world non-stop, and one of his guys flew into space in a "plastic" aircraft/spacecraft.

 

In fact, just stick with the car you have! The dollar value of plastic parts in most new cars exceeds the cost of the steel in that car.

 

Most automotive manifolds - and at least two thirds of them these days are "plastic" appeared in the 70's in European cars. They can be much more complex, allowing better berformance; they deliver a denser charge, since they don't heat up as fast; and they can weigh 3-5 lbs less. They cost about the same as aluminum depending on production volume but allow increased design flexibility and lower shipping and assembly costs.

 

Most American manufacturers used glass fiber reinforced Nylon 66. This material has been used in everything from rifle stocks to military equipment. It is incredibly tough stuff; resists chemicals; and isn't too expensive.

 

There are always late technology adapters who won't buy anything new until they've been whipped. Some other people are pioneers and buy every new technology available. But most of us are in the "early majority" that will buy a product once the benefits seem to be proven and the cost is reasonable. Plastic manifolds don't even move the technology meter. No late market adopters will buy a Tribeca. In fact it's not clear just who will buy one, and I predict rebates by Christmas.

 

Ford has made a habit of beating their vendors to death over price. No one should be surprised about any quality problems they have. I'm from a "Ford family" but only one of the last six new cars we've purchased has been a Ford. Even though our 1994 Econoline runs well with 161,000 miles, we just bought a Chevrolet Express.

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Ford started using plastic manifolds on their 4.6L V8 in 1996. They issued a recall on "severe duty" models such as Interceptors and taxis a while back to replace the intake with a modified unit that has an aluminum crossover. I just received a copy of a class action suit, (I own a Grand Marquis as well as a Forester), which seeks to increase the waranty on the plastic part on all models to seven years. The suit is successful, and the waranty increase will go into effect in October. It is not so much if the plastic manifold will fail on the 4.6L, as when.

 

I will *not* buy another car with a plastic manifold. Ford has been building cars a hell of a lot longer than Subaru, and they screwed up!

 

WOW somebody is compairing a ford to a subaru, big differance there buddy! My wife used to work for ford recall center before we got married, I am certin that she would have had a lifetime carrer there if I didnt join the military seeing that all their crap breaks down. The junk that rolls off the floor from ford usually 9 time out of 10 already had at least 5 recalls issued before being sold. Ford is a mass vehicle, low quality car company, why do you think they can mark their cars and trucks down about $10,000 and still make a profit on them? My wife had a 91 ford tempo and if it didnt get into a reck I was going to junk it. It wasnt even 10 years old and bairly ran, whereas my 84 brat is in about 10 times better condition then that ford.

 

Here ya go it from ford but its a comparison of composite and aluminum intakes in almost every aspect. Not for those who dont know how to read.:grin:

http://www.epa.gov/ORD/NRMRL/pubs/600r01059/600r01059.pdf

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Off Topic but I test drove a new Legacy the other day and I was impressed that saleswoman chose a course that was full of curves. Then she said, " too bad you didnt come yesterday when it was raining." Just thought that that was a great sales technique.

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Isn't there a relation between plastic intake manifolds and variable-length intake runners as well?

 

It's easier - or possible - to make these more complex designs as a molded part. The interior walls are smoother and there is better control of internal corner radii as well.

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Just wanted to drop a note about "plastic." I should first say I have no idea what the specifics are concerning the manifolds.

 

But plastics cover a WIDE range of properties. I think the most common image we strike up is a plastice bottle or cup. But plastics can be used in things ranging from high temp applications, to structural support, to soft items like clothing or diapers (pampers and huggies are made either entirely out of plastic). classifying plastic to a narrow range of properites is like saying "metal" only bears certain characteristics. Do you want a manifold made out of sodium?

 

If plastics are being used in the manifold, I'm sure it's not the same plastic that's used in a soda bottle.

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