I've always been a little worried about using other air filters besides the Fleetguard filters made for the factory air box.....Especially after reading some of the stories of people posting how a lot of the performance air filters were bad & would shorten the life of the engine.....I had a K&N in for just a short time & I noticed there was an increase in power, but went back to the Fleetguard after hearing that the K&N didn't provide good air filtration.....After seeing the writeup here on Mopar1973Man's website for the BHAF I was thinking about installing one of these.....I was just wondering how good the air filtration is compared to the stock filters? Does the BHAF give in increase in performance or help with the EGT's? Are there any of these filters that are better than the other such as Wix or Fleetguard?

The BHAF provides more flow (because of more filtering surface area) and it lasts longer (since the more surface area means more filter that has to get dirty). I doubt it has much of an effect on EGT. Filtration is the same or better than the fleetguard airbox filter you have been using. I bet the fleetguard BHAF even uses the same media as the fleetguard airbox filter. They are not performance filters that have huge pores to get then engine dirty but "increase performance", they are stock filters for applications and we use them to cheat using the more surface area they provide to give us more performance without losing filtration by using some "high performance" filter. If you are partial to Fleetguard then the part number for the Fleetguard BHAF is AH19037 http://mopar.mopar1973man.com/personal/2002/bhaf/bhaf.htm

Well my first BHAF lasted 128K miles and 7 years before I gave in to change it... A dead give away to the performance of a air filter... Take your rubber intake boot and wipe it clean first then spray a light coat of WD40 and then take a ride down a dirt road somewhere for 10-20 miles. Pull the intake boot and wipe it out with a clean white paper towel and take notice to dirt found... Like what happen to me was plastic lid of my stock air box was deforming with the unhood temp causing a dust leak. So looking at the BHAF is a completely sealed unit no way for dirt to enter. It pure size makes it a excellent choice ofr dirt roads because jus the vibration of a dirt road will shake out most dust and dirt... So in a lot of ways it self cleaning. You don't need a Outerwears pre-filter either but some people like them...

Like what happen to me was plastic lid of my stock air box was deforming with the unhood temp causing a dust leak. So looking at the BHAF is a completely sealed unit no way for dirt to enter. It pure size makes it a excellent choice ofr dirt roads because jus the vibration of a dirt road will shake out most dust and dirt... So in a lot of ways it self cleaning. You don't need a Outerwears pre-filter either but some people like them...

the same had already happened to my truck's filter box when i purchased the truck at 125k miles. i could put a filter in, have it perfectly seated, and after my next drive one of the sides(the one facing the front of the truck)will be collapsed in with a wide open gap. have been running BHAF for 3+ yrs. i did not buy the OUTERWEAR. everyone looks at the filter and think its done, because its not bleach white. it was no longer bleached white after 2 months

After seeing the writeup here on Mopar1973Man's website for the BHAF I was thinking about installing one of these.....I was just wondering how good the air filtration is compared to the stock filters? Does the BHAF give in increase in performance or help with the EGT's? Are there any of these filters that are better than the other such as Wix or Fleetguard?

I never saw any "gains" that were measurable. I did "feel" like the system breathed easier and spooled better I also heard discussions on other forums where there was a lot of debate about whether there is an actual increase in air flow due to the increased volume and surface area. It got pretty heated and never saw a winner there :P So hard to say unless someone has a better doc/link with info on actual gains. I think most of us who run them feel they are better than stock - but hard to prove apart from what you notice. Apart from performance - I like the looks of them (THEY are big) ..... and I like the outerwears - gives them a nice look also and keeps the filter clean and washable

Thanks for info....It does make sense that it would help the engine be able to breathe easier with these filters....I wonder how much increase you would see if you did the BHAF & put a larger intake manifold on?......

Thanks for info....It does make sense that it would help the engine be able to breathe easier with these filters....I wonder how much increase you would see if you did the BHAF & put a larger intake manifold on?......

Only as good as the exhaust... So if you do a bunch of mods to the intake remember to do the exhaust too... This also mean to include your turbo exhaust housing because putting all the intake mods in and having a 9cm2 HY35 turbo is not going to change it much... This could be measured by having both boost pressure and drive pressure gauges in the cab. Typically boost and drive pressure should run equal most of the time till you hit your choke point then the drive pressure rises rapidily...

Thanks for info....It does make sense that it would help the engine be able to breathe easier with these filters....I wonder how much increase you would see if you did the BHAF & put a larger intake manifold on?......

What do you mean by increase ? Power ? I don't think any air intake will boost your performance to a point your like ' wow' ....... that will basically come from fuel ............ the air/turbo/exhaust etc allow you to push more fuel

Only as good as the exhaust... So if you do a bunch of mods to the intake remember to do the exhaust too... This also mean to include your turbo exhaust housing because putting all the intake mods in and having a 9cm2 HY35 turbo is not going to change it much... This could be measured by having both boost pressure and drive pressure gauges in the cab. Typically boost and drive pressure should run equal most of the time till you hit your choke point then the drive pressure rises rapidily...

yeah :banghead: frigging hy35 ........... why why why .......... get a 4" straight exhaust with good resonator

What do you mean by increase ? Power ? I don't think any air intake will boost your performance to a point your like ' wow' ....... that will basically come from fuel ............ the air/turbo/exhaust etc allow you to push more fuel

yeah :banghead: frigging hy35 ........... why why why .......... get a 4" straight exhaust with good resonator

i'm not really talking about a big noticeable power increase....just a little....i've just heard that some people who have put those CFM+ intakes on the 2nd Gen's have noticed a small increase in power because of better air flow.....i know it probably wouldn't be worth it unless you were planning on putting a better exhaust in.....

i ran one of those K&N filters for about 500 miles....I noticed that the truck was more responsive.....i took it out after i found out it wasn't filtering out the dirt.........

--- Update to the previous post...

Only as good as the exhaust... So if you do a bunch of mods to the intake remember to do the exhaust too... This also mean to include your turbo exhaust housing because putting all the intake mods in and having a 9cm2 HY35 turbo is not going to change it much... This could be measured by having both boost pressure and drive pressure gauges in the cab. Typically boost and drive pressure should run equal most of the time till you hit your choke point then the drive pressure rises rapidily...

is this the case with all the HY35 turbo's or is it just some of them.....it seems like i remember there being a difference between the 6-speeds & the automatics or something?

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is this the case with all the HY35 turbo's or is it just some of them.....it seems like i remember there being a difference between the 6-speeds & the automatics or something?

01-02 auto tranny rigs came with the HY35, all manual rigs and early 24valves came with the HX35 turbo.

oh ok....so you basically have no choice on an 02 automatic if you want to get better performance....wonder if they did that to cut down on horsepower to save the tranny & not put as much stress on it? i've never had any transmission problems....hopefully never will...

the smaller exhaust housing is needed to spool the turbo in the automatic trucks.

The HY was put on for emissions and throttle response. When you step on it and have no boost it will smoke, so having a smaller exhaust housing will make the turbo light sooner and have boost so it won't smoke. They still had the HX on the early 24V autos. You can get the HX to spool just as good by tightening up the valves. As for exhaust size, Mike has pulled some heavy loads lately and has the same low EGT's that I see while pulling a heavy load and he has a 3" straight pipe, I have a 5". This goes to show that the 3" outlet on the turbo will bottleneck it and you won't gain anything from putting a bigger exhaust on, you need a bigger turbo.

The HY was put on for emissions and throttle response. When you step on it and have no boost it will smoke, so having a smaller exhaust housing will make the turbo light sooner and have boost so it won't smoke. They still had the HX on the early 24V autos. You can get the HX to spool just as good by tightening up the valves.

As for exhaust size, Mike has pulled some heavy loads lately and has the same low EGT's that I see while pulling a heavy load and he has a 3" straight pipe, I have a 5". This goes to show that the 3" outlet on the turbo will bottleneck it and you won't gain anything from putting a bigger exhaust on, you need a bigger turbo.

and have a bigger exhaust...why have a bigger exhaust housing and have a stock exhaust?

--- Update to the previous post...

and having cooler air coming in helps.

The HY was put on for emissions and throttle response. When you step on it and have no boost it will smoke, so having a smaller exhaust housing will make the turbo light sooner and have boost so it won't smoke. They still had the HX on the early 24V autos. You can get the HX to spool just as good by tightening up the valves.

Can you tell me about the valve adjusment or where to get the specs for that?

is this the case with all the HY35 turbo's or is it just some of them.....it seems like i remember there being a difference between the 6-speeds & the automatics or something?

I don't remember which years but all the automatics like from 2000-2002 I think have HY35 turbos... All manuals trans came with HX35...

I don't remember which years but all the automatics like from 2000-2002 I think have HY35 turbos... All manuals trans came with HX35...

2000 may have been the switch year:shrug:, I know for a fact that 99 autos have HX on them as I have 2 friends with them.

2000 may have been the switch year:shrug:, I know for a fact that 99 autos have HX on them as I have 2 friends with them.

Yes, there are guys with HX's and HY's with 2000 autos on this site.

--- Update to the previous post...

If you look at post #10, Guesswho512 shows his findings from the cummins manual. This means we have a lot of play around the standard 10/20 (Intake/Exhaust lash) and we can take advantage of it by making the valves tighter, therefore the valves can stay open longer. By setting the exhaust lash tighter, the gasses escape faster and the turbo lights faster. Now I cleaned my turbo shaft so that might have done it also. I am going home tomorrow and am going to set my valves at the max and the min tolerances and show the effects and then I will know for sure how much the valves helped turbo lightup.

http://forum.mopar1973man.com/showthread.php/2923-runnin-the-valves

My 01.5 automatic RE47 has the HY turbo. Yes, I can hear it whisle fairly early even if not a lot of punch that soon.

I could tell a very slight difference with the BHF from stock but I mostly love the looks. I do believe 98.5-2000 all have hy35 and auto 01-02 have hy's but 01-02 w/ manual tranny have the hx35. I may have my years messed up with the 2000's...i am just trying to remember what I read.

I definetely see lower egt's and better throttle response from the bigger filter. The truck has more top end power as well. Mine dont last as long as Mike's though. I change them every 30 or 40 k miles.