Well, would there be any gains to switch out the stock air filter and have each S.U. have their own exposed air filter with ram horns?

Without putting the car on a dyno, I doubt anyone would be able to "seat of the pants" tell you. Even air horns w/no filter only gives marginal improvement over filtered air. Other than appearance, I would see no advantage.

FWIW,

Frank

I've heard that the factory air box was actually a very good design, and taking it off to use separate filters doesn't improve things. I don't know if that is true however.

What I do know, being a vehicle design major, is that alot of work went into the design of most everything under the hood. I'm sure the engineers considered the separate filter-no airbox route and dismissed it for some reason. I know I've had problems with engine temperature, and it may be that they used the box to ensure cooler air went into the engine rather than warmer engine compartment air.

That's all educated speculation.

The former owner of ZTherapy, Scott Bruning, believed the stock air cleaner performed better then the individual air cleaners. This was on the Just Su's or Datsun Z Tune-Up Dvd from ZTherapy.

Dave Ruiz

For what it's worth , the K & N part number for he stock air filter is E-2910. I have been running K & N filters for many years on other vehicles and on my 240Z since I have owned her. I bought mine from Summit , but any parts store that carries K & N can order one for you. One thing about them . If you have an injected engine , be sure to follow the instructions provided to service the filter and use only there spray for this. Otherwise you will ruin the filter and if you apply to much spray it can cause problems with the throttle body. I am not a injection guy but three of our vehicles are injected. I am a SU guy. Old School.

Does it sound any better with the double compared to the single?

Without putting the car on a dyno, I doubt anyone would be able to "seat of the pants" tell you. Even air horns w/no filter only gives marginal improvement over filtered air. Other than appearance, I would see no advantage.

FWIW,

Frank

On the dyno - removing the top of the air cleaner, and the filter netted 4HP in the peak power band.

Haven't found any individual filter units that allowed enough room for air horns on the S.U.'s

FWIW,

Carl B.

hey carl beck, i rigged my SU's to have the airhorns. i wanted to keep the venturis after watching the ZTherapy video.

After looking at a photo Alan sent me of a 432 air cleaner, I though about doming the area across from and concentric to the horns while retaining the removeability of the assembly, I just haven't done the math to figure the proper doming.

Will

My setup. I ran it by Z Therapy and they said it would work well. Uses the TWM air horns sold by MSA as well. FWIW my cars AC compressor gets in the way of the stock air box so the previous owner modded the air cleaner.