Why no dual intake?

[MCarsFan]

It's not a question I am asking to undermine or bash. An honest question and I'd love a theoretical answer.

I have noticed that all American sports cars of recent time (all Corvettes including C6 ZR1, C7 Z06, camaros, other mustangs, boss) all have a single intake design whereas all european sports cars, mclarens, new ferraris, audi, BMW, Mercedes all have a dual intake design.

I'm curious why one is preferred over the other. I would expect in a car like GT350 with a 5.2 liter displacement, dual intakes would be the norm no? Most 4-4.4 liter twin turbo V8s use a dual intake and those are "turbos" which means there is far more air entering the combustion chamber than a naturally aspirated engine. So in a NA engine that is 5.2 liter, a dual intake is probably more important?

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[J_Maher_AMG]

Almost entirely down to cost/complexity, both in relation to design, tuning, manufacturing, etc.

A dual intake system and other features like ITB's would be ideal for the Voodoo, but then we'd be looking at potentially a 10-20 thousand dollar increase in base price maybe.

 

[MCarsFan]

Almost entirely down to cost/complexity, both in relation to design, tuning, manufacturing, etc.

A dual intake system and other features like ITB's would be ideal for the Voodoo, but then we'd be looking at potentially a 10-20 thousand dollar increase in base price maybe.

Thanks, I didnt know that ITBs was a requirement for dual intake systems. Are you sure about that? For instance, E9X M3 had a 8300 rpm V8 that was naturally aspirated and it has ITBs but only a single intake like the Vodoo whereas the S63tu from BMWs F10 M5 has a 4.4 liter twin turbo V8 with dual intakes but no ITBs.

I am not saying you are wrong about the cost factor, I just dont think dual intake design means you have to have ITBs.

 

[Stuntman]

Where did J say that ITBs were a requirement for dual intakes?

I agree with him that it has to do with cost and complexity. You can have a single or dual intake on cars with single, dual, or ITBs. Why spend more money on two smaller inlets when one larger one is sufficient, cheaper, and easier to manufacture? I wouldn't be surprised if s voodoo made more power with ITBs and a properly designed plenum.

 

[J_Maher_AMG]

Thanks, I didnt know that ITBs was a requirement for dual intake systems. Are you sure about that? For instance, E9X M3 had a 8300 rpm V8 that was naturally aspirated and it has ITBs but only a single intake like the Vodoo whereas the S63tu from BMWs F10 M5 has a 4.4 liter twin turbo V8 with dual intakes but no ITBs.

I am not saying you are wrong about the cost factor, I just dont think dual intake design means you have to have ITBs.

As Stuntman mentioned, they're not exclusive to one another, as you can certainly have one or the other without necessitating both. My point was that a dual intake setup, along with ITB's would probably do wonders for our cars. But they are definitely far more costly from a design/manufacturing standpoint, and also would take longer to design due to their more complex nature. Given that time was a constraint for the team working on the Voodoo project, I imagine simple elegant solutions were prioritized.

 

[MCarsFan]

Where did J say that ITBs were a requirement for dual intakes?

I agree with him that it has to do with cost and complexity. You can have a single or dual intake on cars with single, dual, or ITBs. Why spend more money on two smaller inlets when one larger one is sufficient, cheaper, and easier to manufacture? I wouldn't be surprised if s voodoo made more power with ITBs and a properly designed plenum.

Thats the purpose of this post. Yes, they are cheaper to manufacture, but are they really on par performance wise?

 

[J_Maher_AMG]

Thats the purpose of this post. Yes, they are cheaper to manufacture, but are they really on par performance wise?

Probably not... if dual intakes/itb's and other various aspects that you don't see on our car weren't worthwhile, you wouldn't see them used on Ferrari's and McLaren's, etc.

IMO, of course they would be beneficial, it's like wondering if a lighter crank shaft would be beneficial, as it is/should be a fairly obvious answer. But when we're talking about a 50K car as opposed to a 250K supercar, luxuries such as fancy intake setup and other aspects are the first to be thrown out during the design phase.

Cost is the answer, and the only reason we don't see some of those better features in our car.

 

[10splaya22]

Thats the purpose of this post. Yes, they are cheaper to manufacture, but are they really on par performance wise?

I would think so, no point in adding complexity without a benefit. It doesn't make sense to design anything to be more complicated when a simpler version nets the same performance.

Most of the twin turbo V8's have twin intakes because they are twin turbos...one intake per turbo. Of course there are many factors that go into the design of the intake system like airflow needs, packaging, cost, etc. Just because it looks cooler isn't a good reason to have it.

 

[nastang87xx]

Cost and packaging.

 

[Epiphany]

Cost and packaging.

How dare you offer up such a concise response!

Tear it up MCarsFan!

 

[icormba]

I'm kinda glad the GT350 has a single intake/throttle body. My 2 previous cars had dual intakes and in reality... you basically need to buy 2 of everything in relation.

1990 Nissan 300Z
2009 Nissan 370Z

 

[xXANCHORMONXx]

Round and around we go!


Mustang6G, Monday morning.


"Hey guys, serious question."

Why doesn't this car have a flat bottom? I mean a lot of cars have a flat bottom but this car doesn't. Why would they do that? It seems silly to me that they would stop at the oil pan.

 

[GT_Dave]

Round and around we go!


Mustang6G, Monday morning.


"Hey guys, serious question."

Why doesn't this car have a flat bottom? I mean a lot of cars have a flat bottom but this car doesn't. Why would they do that? It seems silly to me that they would stop at the oil pan.

But, But then where or how would you mount your jacking rails ??

 

[xXANCHORMONXx]

But, But then where or how would you mount your jacking rails ??

 

[Ctease]

I take a different view. Ferrari DOHC heads used to be very fat. So the room inside the V was small. They were forced to have vertical shaped manifolds and runners. As DOHC system shrank in size. It allowed more room in the V. Ferrari kept the vertical shaped runners and downdraft carbs but were forced to have separate right and left grouping. Then a switch to fuel injection the shape vertical runner shape was kept. Instead of having ITB FI to directly replace the individual carb barrel. They used two plenums and dual throttle body.

I think Ferrari like all good engineers were lazy. They had vertical runners so why change to center plenum and circular shaped runners. It would require more work and learning curve.

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