got a question...looking for a little bit more power otta my 5.9L magnum and was looking at throttle body spacers and a cold air intake...just was wondering if u install both of those do you have to increase exhaust flow or can u put em on and still have manis...i have a straight pipe just took the muffler out and put a pipe in its place....just wondering if i absolutly have to upgrade to headers or not

 

Spacers do not even work in theory on our type of intake and have been proven to not do a damn thing on the dyno.... they can somtimes work on tbi injection or direct runner setups but not with a large open keg full of air going in different paths like ours...
Dont waste your money.

 

put a muffler back on or a cat and you will likely get some of the low end your losing back....headers dont make a huge different on these trucks it seems...I have them and had them when I bought the truck but many who bput them on say the increase was slight....
roller rockers a 50mm throttlebody and a properly setup CAI will likely be a better increase with you exhaust flow increase...

 

Listen to Augie on the spacer, don't waste your money.
The CAI will give you a little improvement over the stock air box but it's only worth it if you can get it cheap.

 

I got my CAI from this guy on eBay

http://www.ebay.com/itm/Spectre-Cold...item33738d306e

 

As said TB spacer is junk..

Just make sure the CAI is actually getting cold air into it, any open filter just sitting under the hood is going to get heat soaked.

 

tb spacer = $80 paper weight

 

You need an engine with a really big appetite for air ... think racing above 6K and probably higher ... or are running a poorly designed intake in the first place, to be able to use a TB or Carb spacer's increased plenum volume.

Neither really applies to the Magnum engine in a truck.

Sometimes a phenolic spacer (or some other insulating material) can help if there are issues with intake air (actually fuel/air) temperature in a more mundane engine. Not really an issue with Fuel Injection ... a carb with a float chamber where fuel is heated by heat soak to the carb body is where that belongs.

But the above is why you sometimes see them used on Dyno runs in engine buildups, and usually with a single-plane manifold on there to get maximum HP above 5252 RPM. Or if they are using a Carb or Throttle Body that is really too big, it can act like a restrictor plate and get back some intake velocity for mid-range power lost by the out-there parts selection. Probably matters more to the magazine's bragging rights with their parts-the-want-to-sell-you-list than a practical street application.

Even the racers don't get around to playing with plenum volumes (beyond a calculated start point) until the rest of the engine is decided and buttoned up. And then they just play and see what works, and they tailor it to a very specific RPM band they feel they need to run. If you're not at that point, it's pure guesswork with just as much chance to hurt as help. Why spend for that?

So 'No Earthly Use' then on these trucks. Save your money.

A Cold Air Intake isn't going to help in stop-and-go traffic on a summer day ... two minutes underhood and the plumbing is hot ... but they offer some benefit at highway speeds. More if there is forced induction and heat is already a big problem. Don't be afraid to insulate it.