Cheap Mods On A Stock Truck Thread.
 

post 'em boys. p/n's and links if you got 'em.

cheap mods on a stock truck-

1-remove the aneroid fuel control housing (AFC) (you will need a chisel or left handed drill bit to remove the break off screw) this device controls pre-boost fuel. this is done under 10psi of boost.

2-slide the fuel plate forward then back it up 1/16th to 1/8th of an inch. (you can play with this until your butt dyno says you got it where it wants it)

3-reinstall AFC and slide it all the way forward. (this is also butt-dyno adjustable. i got my best results with it all the way forward)

4-remove the 8mm plug on the top of the AFC. you'll see a starwheel. cranking this towards the engine makes it go forward. forward = more pre-boost fuel = more smoke.

5- go to NAPA. buy this filter: p/n FIL2790. this is known as a BHAF. remove the stock airbox and put this in it's place. bend up some sheet metal as a heat shield.

well there's a start. i'm a crappy teacher tho. lol!

you could also do some wastegate adjusting.

either buy the boost elbow........ or if you wanna go the cheap way, get a small 1/4in. hose clamp and clamp off the hose going from the back of the afc housing to the turbo. This will in result., increase the boost pressure that the turbo will push.

Lance

you can change the diaphram washer in your afc housing also. you can drill you banjos out bigger also.

Grind down the stock fuel plate.

thought about doin that once before but wasnt sure how much bigger to go w/out causin some kinda leaks.

How much bigger did ya go??

Lance

i took the washer with me to the hardware store. the washers are the same size. the new one is thinner than the stock one. the one i purchased does not have a lip on it like the stock one does.

Johnny, Nice post! Don't know if you got my messases on Dieselram, but i sent them back, didnt think they were working. I wasn't ignoring you

By the way......

Gauges :w:

na man............. I was talking about the banjos. How much bigger can ya go with em and did it really make a difference???

Lance

it did make a difference. not sure how much but i did notice a good bit of difference. i cant remember how big i went. i removed the banjo completely now. i have a fitting screwed in there now with a 1/2in fuel line hook to it.

hey guys, ive posted up some tonight and this week, though i just got my 94 little over a week ago. i am not new on things EXCEPT the p pump. tomorrow (well later today/saturday) im planning on doing my fuel plate and was thinking/and advised that a 100 plate is best way to go. ANYHOW, i have a friend who does metal work, and am thinking maybe to go to him with the stock plate and have him make me a copy (or two even) so i can grind it down without fear of messing anything up...

so any detailed advice on the p pump mods is greatly appreciated, as i plan on bombing the truck ASAP. already have gauges installed (did em day after i got the truck) so i can monitor any changes-

thanks in advance,
-jeremy

jeremy-

i ground my stock plate myself. first and only one so far tho. i used a cone shaped carbide bit in my 90* die grinder at work. i took my time doin git. let the grinder feed itself instead of me pushing it. just make sure you get all the burs off it so the arm isn't catching on it. i'm pretty happy with it. it's kinda like a 10 but the hook at the top is smaller. i'm also including a general reference sketch of the basic profiles. it's been floating around various forums for years.

Thanks for more info johnny- havnt gotten around to doing the plate today, though it will be soon :D

Jeremy, it is not hard to do at all. Just take your time and you will be fine.

not sure of what you mean here .do i cut off the pressure from the waste gate completely or restrict it, thanks

whats the deal with the afc washer?

you can do either, but if you get rid of the wastegate circuit on your turbo you'll have to learn to drive by your boost gauge. keep the boost under 35 psi!!

the boost elbow screws into the turbo side of the line feeding the wastegate actuatator. there's a little allen head screw on in. i'd recommend this route myself.

so what do i do with the allen scew ? and you say driving by the turbo boost sounds too confuseing i may forget to on many accasions

here's a DIY boost control valve that gives you infinite control over the wastegate.

http://img126.imageshack.us/img126/4...trollerwv5.jpg

it may be confusing. that's why they ccreated wastegate systems. Lol. basically you'd have to keep your eye on your boost gauge and make sure to keep it under 35 psi.

with the allen screw on a boost elbow you screw it in and out. this increases/decreases the holding pressure of your wastegate valve. the harder the valve holds the more boost you build.

the valve set up that chris just posted would be used insead of a boost elbow and would cost you about $5 to build.

Not to mention a boost elbow creates a more drastic response from the wastegate actuator because the spring loaded check ball BLOCKS the signal to its threshold. When it opens, the gate acts fast and can cause boost creep, surges etc.....though it's usually not felt. The needle valve version still allows a linear boost signal, but bleeds off a little pressure so the actautor sees only a percentage of the pressure. This in turn makes the compressor build more pressure until the wastegate sees enough to open. If you put a pressure gauge on the actuator side of the hose you'd see the actuator is still seeing 17-20 psi while tru intake pressure is closer to 35-37. I don't like boost elbows because they are not dynamic with the engine. Order up any aftermarket boost controller like a turbosmart or whatever, and you'll see they operate the same way with a bleed orifice. Those that think this little bleed-off is costing them boost are over-concerned. The amount of actual air mass lost through the orifice, or valve, in the case of a DIY model, is so minute in relation to total air mass throughput, it really is an un-measurable amount. Boost elbows are a cheap and easy gadget to sell along with a plate that originated years ago in the diesel aftermarket. Boost CONTROLLERS, however, are a much better design, and you can duplicate that $80 aftermarket controller with $5 from ace hardware just like Chimpo said.

Chris

So, you mount the valve in the cab?

You definitely could...just by placing another line on the exhaust of the needle valve to air out into the engine bay, and run longer lines to and from the wastegate actuator. You could adjust it on the fly that way. I didn't go that route, mine is mounted on the turbo...set it and forget it after a little trial and error. In all reality, I don't run one anymore. My secondary turbine is large and drive pressures aren't high anyway, nor is the turbo overspeeding. I used my wastegate actuator to control a butterfly valve in one of the turbine volutes of the secondary to force all the exhaust through one volute for better spoolup down low. Then the butterfly opens by boost signal and allows flow through both volutes. Call it a basic variable geometry turbine if you will....but not really in the true sense of the word. It's a wastegate in a better place :)

Chris

hey chris,

what's your opinion on this? i have a banks bighead wastegate. should i:

1- keep it as is? it's adjusted as far as it can be.

2- add a bleed off valve to it?

3- add a bleed off valve and put the stock one back on?

or anybody have any thoughts on this? i still have my stock actuator so it'd be an easy swap if it's worth it.

Leave th big head on, it has a higher operating threshold as well as a better pre-load spring for higher boost. The stock gate actuator can flutter under boost of 30 or higher, not that it WILL, but it can as mine did. I would, however, add a valve to it. you can always close the valve entirely for normal operation, or start to adjust it if need be. 35-37 psi is easily attainable with the stock HX35, and I would use every bit of it. If you engine is modded enough to provide the drive energy then it can benefit from the extra air. An important mod for the stocker as well, especially at the ceiling of it's map, is to open up all 6 cylinders to the wastegate. Stock The gate only relieves 3, and causes some pretty high drive pressure on the front 3. If you don't know about this or haven't done this yet...it's a highly recommended mod. You'll lose the pulse separation in the twin scroll turbine, but the trade-off is worth that loss.

Chris

are you talking about getting rid of the separation in the turbo mounting flange?? i haven't done that yet. that doesn't increase lag?

Ok, so does anyone have any hard dyno figures with just doing the air filter, fuel plate moved forward all the way (99%), AFC (we just call'em aneroids here) moved all the way forward, 2 turns forward on aneroid adjusting screw, boost controlled to 35lbs?

How carried away can I get with my stock auto trans?

I would say thats about it with the auto tranny....

I hope you have a pyrometer and boost guage at the very least.

Well, we'll eliminate the aneroid as a variable since it won't do anything to the horsepower figure, nor the preload screw or tension wheel. The power output will vary depending on what year 12 valve you're talking about, and I don't have any hard figures for you, but with a stock plate forward, and a good free flowing air filter, you might gain 35 or 40 horsepower. If you go one step farther and open up the exhaust better you might see as much as 250 or so on a 94-96, and maybe 275 on a 97-98. Torque should go up a few hundred as well. As far as what the stock trans will hold, that's subjective. I could drive 700 hp on a stock trans and make it last, or I could drive the trans wrong with 250 and make it smoke. Generally, 300 is probably pushing it a bit without a little modification to the trans for longevity and strength.

And Johnny, sorry I didn't see your post till now, for some reason I didn't get an update in my subscriptions......but....ther are two ways to do it. Either remove some of the scroll devider at the inlet, or remove the backplate, open the wastegate, and with a 3/4" or larger drill, bore down through the existing wastegate hole and continue through the devider there. I found when I was playing with the stock HX35, that removing about a 1" square area from the inlet was sufficient to equalize pressure in the scrolls, and a lot easier than the latter version of drilling. As for lag, you won't feel it, but the engine will very much like equal drive pressures on all the cylinders. You'll lose the pulse effect, but it's a small trade off.

Chris

thanks, chris. no problem on the time frame. i know you're busy trying to live in every state in the union. :poak: :ha: :ha:

i'll definitely look into this. i haven't ever had the back of that wastgate off. should be interesting. :U:

oh yeah, i made that needle valve for my wastegate line. NICE :up:

this isnt a real big horse power thing but I heard it helps everything work together better if you have the stock turbo where the waste gate has the hole in the side of the outlet drill a hole through the center section because it only waste gates half of the turbo. one thing I have learned is do not do the free gsk swap its not worth the trouble.

Why no more than 35#'s of boost?

Boost pressure is relative to turbo rpm and depending on your location (altitude) 35ish has been accepted as the ceiling for safe turbo rpm's. Notwithstanding, any more pressure than that and you lose boost efficiency because of compression heat from the HX35. There are those that boast 40, 45, and 50 psi out of their 35's, but don't listen to them. Sure the turbo will make it if you spin it fast enough, but it doesn't take a rocket scientist to know the danger zone you're in. at 35 psi, that turbo is spinning 130,000 rpm...by the map anyway, and at 40 it's cooking along at 145,000. The highest efficiency for the HX35 occurs at 24 psi, which funny enough, is about where they size it at for the 5.9. Push it harder, and the laws of diminishing returns start to encroach upon you.

So over 24psi is a waist with the HX35?
Really then about 32psi you should get a bigger turbo right?

Drilling the banjo's on a 12v is a complete waste of time.The stockers are used on way more trucks over the 600hp frame than one realizes.If your going to go down that route you may as well just go aftermarket with your fuel system.

iv got a 97, with a 215 pump. i pull a 35 foot trailer and i was thinking of going to a #100 plate. i was wondering how bad will that kill my milage??? and what can i do to get my hx35 up to around 25psi. will the plate do that because a guy told me he did the #0 plate and it put him up to around 35 to 40psi ???

get a boost elbow i got one for 40 from a shop on here but saw it on ebay foe 20 free shipping

you payed how much for a boost elbow?:run::itsok: im sorry i have to on my work bench in the shop you could have had

ildsmokey97 would you recommend clamping that hose or would not be a good idea

- drill 15/16" through both volutes on the exhaust housing
- boost regulated to 35psi
- stock airbox with 3" hole will be fine (or a clamp-on filter...either way)
- grid heater delete w/handmade intake horn
- 3000 rpm shim modification
- 4" downpipe
- TC lockup switch/adjust bands to spec
- WEIGHT LOSS PROGRAM
- grind fuel plate to a flat "0" profile, put it full forward
- contrary to popular opinion, adjust the AFC tension to get the best boost response from your setup - the more fueling mods you have the tighter the spring will probably need to be.


something also on the "cheap"-
- injectors (extrude honed)
- larger exhaust housing on the turbo