Ok guys im newer to this diesel game and im getting ready to order an intake but I cant decide between the Riffraff or the Tymar from Beans. It appears to me the only differnce between the 2 is that the Tymar costs more since it has the whole steel pipe thing going where as the Riffraff makes use of the factory flex pipe. Which way do I go?

 

Tymar came up with the idea first. Then the DIY crowd figured out it was a 6637 filter and started just sticking that filter in ourself. The Riffraff kit has rounded up the parts for you. Seems like the only difference I remember is the Tymar comes with a stand off bracket which many say is not needed. It's your money. Either one will work.

 

Thanks for the heads up. I take it the factory tubing doesnt hinder performance enough to warrant needing metal tubing all the way to the turbo then?

 

Also, the Tymar uses a Donaldson Filter which is supposed to be more water resistant than the Napa 6637 therefore if it gets wet, it will still flow better air than the 6637.

 

I made mine with a 4" elbow mated up to a 3 1/2" piece and that connects right to the turbo boot. Is that the way the tymar is?

 

Riff Raff also sells the pre-filter sock. Theres a place where you can purchase the bracket seperately too

 

I have researched this a few years back. The Napa 6637 is a Donaldson filter (actually has a Donaldson sticker on it) and no matter where you buy the filter (tymar, beans or Napa) it isn't the water resistant filter. That is either a marketing ploy by Tymar from back in the day or just an internet myth. Donaldson does make a water resistant filter exactly like the 6637 but it is about 3 times the cost of the 6637/tymar filter.

 

Thats the way it looked to me when I saw it on Beans website, I could be mistaken though

 

go with your wallet, but I went with Riff Raff

 

i bought mine from beans. its the same filter you get at napa and the tubing doesnt go all the way to the turbo. it only goes to the bracket in the middle.

 

My vote is Clay, Ryan Bean is to full of himself.

 

PSDFan- the name of this game is to simply chuck the stock airbox and fit a "6637 style" air cleaner element in it's place. You can buy the washable/reusable type, which becomes water resistant when treated with air cleaner oil OR the cheaper, one use only, disposable type. I don't like washing and oiling air cleaners, so I use the Duralite disposable from Dieselfiltersonline along with the sock from Riffraff which I lightly treat with Scotchgard to ensure it's water repellent.

The entire intake ducting/battery tray/airbox configuration varies between PSD year models. Likewise, the later 7.3s have more sound deadening insulation under the hood, which can cause clearance issues with the 6637. To fit mine ('02 model) all I needed was a 3-1/4" long piece of 4" diameter straight pipe that connects the 6637 to the stock flex tubing and a good compression clamp for the neck of the air cleaner. But in order to position the 6637 low enough to clear the hood insulation, I had to trim the high side off the bottom of the intergral battery tray/air box support (easy). So I at least retain the air inlet duct pipe that comes in from behind the radiator support bracket. Earlier PSDs don't have this one piece battery tray/air box setup, so that MAY not be neccesary.

So basically, decide whether you want the reusable OR disposable 6637 and buy one. Then yank the stock air box completely intact, see how the 6637 fits and determine what you need to join it to the stock flex. You may need an elbow or you may not. Retain as much of the air inlet duct pipe as you can to keep at least some air flow from the grill. Later, if you're feeling so inclined, you can fabricate an airbox (see previous post) that isolates the 6637 from hot engine air. Every 8 degree drop in intake air temp yields approx 2 extra ponies. Radiators run at 175 to 190 degress. Do the math.

Also, go ahead and do the CCV bypass (if your year model needs it) while you're doing the 6637. That way you're done with the air train. All you need for that is a 3-1/2 to 4" long piece of some more 4" straight pipe, a couple of hose clamps and some oil grade hose.

Of course if I were building a sled puller, I'd run 4" pipe all the way from the air cleaner to the turbine. Otherwise, the flex tubing should be adequate! At any rate, the 6637 is probably the single best performance improvement you can make to a PSD.

 

I do plan on doing the CCV mod at the same time im just trying to figure what to do with the hole that will be left in the underside of my intake tube when I reroute the ccv hose. Any one have any suggestions?

 

the CCV breather coupling with the inlet hole goes away. you replace that housing with the second piece of 4" pipe I mentioned. See guzzler's website for the instructions. piece of cake.

 

although your '94 may be plumbed a little different. not sure. compare to guzzler's install.