Intake spacers?

[GaryDE]

Do these spacers really do anything? Or just snake oil?

2020+ F250/F350 7.3L Super Duty aFe Power Silver Bullet Intake Manifold Spacers 46-33024 - 5 Star Tuning

Intake Manifold Spacers offer thermal insulation between the cylinder head and the intake plenum – keeps the air in the intake cooler and denser.

5startuning.com

 

[MT N8IV]

This is my own opinion with nothing exactly scientific to back it up other than how naturally aspirated engines work, I would say the gains, without a tune to specifically compensate for increased air volume, would be negligible at best. Now if this were for a diesel engine I'd say it might have a better chance but still not enough to warrant without a tune.

The reason I say negligible is due to the way a naturally aspirated gas engine on a tuned port injection setup measure/mix the air/fuel prior to introduction into the cylinder. Regardless of how much air is available it is still going to take a set amount based on the strategy in the PCM. With a diesel, since it is only the fuel that is regulated and because the air is compressed some (due to turbo) ,in a sense, it will gulp as much air as it can within parameters set by the PCM as well. Then the actual fuel introduced at injection time is either increased or decreased based on the amount of air introduced. Please keep in mind, this is my very poor attempt at explaining and there are more things to take into consideration.

Now, with a tune, it will set the calculations for more air to make more power which would, in a sense, show gains. In the end, you have to believe what the sellers are claiming or calculate the volumetric flow rates not only on the actual piping leading in but also exiting. Just like water, you can only get so much air into a pipe before it bursts as more volume equals more pressure. Beyond that, you have to figure that even if you could allow more volume in what about volume out? That increased volume, even if it was coming in is limited by the volume out. So without a tune, without a larger volume flowing out from the exhaust and possibly increased inlet tubing, I am not sure how much of the intake tubing "space" is utilized on the 7.3, but ultimately if it were me I'd err on the side of this being negligible on its own.

Somebody with a much better understanding of the 7.3 and engines in general would be able to explain a bit better and may even say it would work.

 

[GaryDE]

This is my own opinion with nothing exactly scientific to back it up other than how naturally aspirated engines work, I would say the gains, without a tune to specifically compensate for increased air volume, would be negligible at best. Now if this were for a diesel engine I'd say it might have a better chance but still not enough to warrant without a tune.

The reason I say negligible is due to the way a naturally aspirated gas engine on a tuned port injection setup measure/mix the air/fuel prior to introduction into the cylinder. Regardless of how much air is available it is still going to take a set amount based on the strategy in the PCM. With a diesel, since it is only the fuel that is regulated and because the air is compressed some (due to turbo) ,in a sense, it will gulp as much air as it can within parameters set by the PCM as well. Then the actual fuel introduced at injection time is either increased or decreased based on the amount of air introduced. Please keep in mind, this is my very poor attempt at explaining and there are more things to take into consideration.

Now, with a tune, it will set the calculations for more air to make more power which would, in a sense, show gains. In the end, you have to believe what the sellers are claiming or calculate the volumetric flow rates not only on the actual piping leading in but also exiting. Just like water, you can only get so much air into a pipe before it bursts as more volume equals more pressure. Beyond that, you have to figure that even if you could allow more volume in what about volume out? That increased volume, even if it was coming in is limited by the volume out. So without a tune, without a larger volume flowing out from the exhaust and possibly increased inlet tubing, I am not sure how much of the intake tubing "space" is utilized on the 7.3, but ultimately if it were me I'd err on the side of this being negligible on its own.

Somebody with a much better understanding of the 7.3 and engines in general would be able to explain a bit better and may even say it would work.

Thanks, I was thinking along the same lines. I also wondered about the claims of reducing heat transfer. The factory intake is plastic, so..... Be interested in some actual dyno numbers.

 

[MT N8IV]

Yeah, the heat reduction is something that I think is extremely marginal at best. I wouldn't expect anything more than a few degrees reduction, if any, but who knows. aFe wouldn't make completely bogus claims but I am sure they don't shy away from embellishing a bit either.

 

[Smindustries]

Old-school trick to reduce carburetor heat soak. It has no modern application except to separate consumers from their money.