Max Safe Boost ?

[jstyer]

As you can see by my signature, I have the Bank's Git Kit on my 01. 5 ETH/DEE and have been adjusting the Big Head Actuator and now have maximum boost in 5th and 6th of approximately 30 lbs and in the 20's in lower gears.

I presume the lower boost in 1st thru 4th is due to the 4. 10 gearing, since it red lines very quickly and the load isn't as great (or last as long) in the lower gears. I could be wrong.

I would like to know what is the maximum safe boost I can get before I lunch my turbo.

Thanks

 

[Todd T]

my HX eats 30lbs for a snack.



I produce 35PSI on a regular basis empty or loaded, and maintain 28-30 on big pulls, loaded.

 

[Devildog]

I see 42 lbs everyday on my stock turbo, no problems to report.

 

[EScott]

I top out at 35#'s pretty regular, with nothing more than a grin to report...

 

[Steve St.Laurent]

I was hitting 34 psi daily for 40,000 miles and have been hitting 41 psi daily for 15,000 miles now.

 

[jstyer]

More work

Well based on this information, it's time to lift the hood and turn the adjustment in a few more turns.

Thanks guys

John Styer

 

[Chris N5CWM]

More isn't always better..

Your boost may be optimised for the ammount of

fueling the Banks kit is set up for. If you add

more boost, theoretically you should also add more

fuel (bigger injectors etc). There is a point of

diminishing returns. There was a post regarding

this a few months ago. Do a search and see if you

can find it. The only good more boost will do

in most cases is impress your buddies when you

peg the boost gauge... unless you add fuel as well!



-Chris

 

[K_Arts]

Currently I am running DD2 injectors, an EZ box on the middle setting, Bill K's TC and VB and Piers and an HX-35 turbo with the wastegate completely capped off and I can only see 25lbs of boost on a flat road and 27lbs of boost up a hill.



It doesn't sound like much boost, but it sure will give you whiplash when you romp on the "GO" pedal.



Kev

 

[Max Wedge]

I just came across a boost elbow that has an adjustable set screw in the side--should I replace the boost elbow that came with my EZ box that is NOT adjustable. I am seeing 26 psi no load WOT now.



Would this adjustable elbow improve anything, or just be wasted?



Max

 

[Todd T]

you could do that Max, normally you shouldnt have to tweak on them though.



what type airbox and filter are you running. you may be starving for air and that is the reason for low boost.

 

[Max Wedge]

Originally posted by Todd T



what type airbox and filter are you running. you may be starving for air and that is the reason for low boost.

I have the stock air box minus the "fender adapter" and with 6

1 1/4" holes drilled in the back side, with K&N filter.

 

[Todd T]

that shoud be suficient, it is not uncommon to have to fine tune your wastegate actuator. it could be bleeding off some boost.



this is getting into the "grey" area though. if you dont know what you are doing then leave it alone.



try the other elbow and adjust it if you think you can squeeze some more out of it, first. take them both off and blow through them. if you can tell an obvious difference then swap them.



boost is tied directly to the amount of fuel you are adding. without going back and looking at your signature, all i can say is with an EZ you would only pick up about 6PSI over stock. that should land you in the 28-30PSI range. also keep in mind the truck will must likely not sustain that kind of boost. it will just flash up that high and fall back a few pounds and stay.



UNLESS..... you have alot done to it, I. E.

a very agressive fueling box and or injectors.

 

[Max Wedge]

this is getting into the "grey" area though. if you dont know what you are doing then leave it alone.



Heck Tod, if I knew what I was doing, I probably would have left the truck alone At least thats what my wife says



Thanks for the info. I am trying to keep all my bombing mods Stealth--you know what I mean. Here is a list of the mods:



TransGo VB modifaction w/ 94 psi line pressure @1800 in OD

130 psi WOT



Ray's banjo-bolts--bigger holes . 187 compared to . 130 stock

Power Edge "EZ" w/boost elbow that came in kit-non-adjustable

K&N Filter with the holes drilled in Factory Air Box



2000 3500 QC 4x4 Auto 4. 10 all options--very heavy

EGT's empty WOT up hill 1100

Max boost empty 26 psi



Just thought maybe the adjustable elbow might make a difference if I could get boost up to around 30 psi--but probably not enough fuel to make a difference.

 

[Sixspeed]

If you were to run to high a boost pressure would it be possible to stretch your head bolts or blow your head gasket. I think that Cummins says the max boost is 25lbs. Just asking.

 

[LSMITH]

Sixspeed, there have been some blown headgaskets and such, but all of them that I know of have been at serioulsy high (over 50PSI) and lots of times involved propane too. There are a ton of members running over 40 PSI on a daily basis with no ill effects seen.

 

[Vaughn MacKenzie]

K_Arts , only 25psi boost with all that??? I could easily surpass 25psi with the boost module when my truck was bone stock RV injectors sent it to 33psi. DD2s take it a bit past 35 (needle pegs on Autometer gauge).



I think you could stand to tweak your wastegate actuator or look for leaks. Maybe this is related to the problems you had running 4" exhaust??



Vaughn

 

[work2muchplay2little]

I'd agree with Vaughn, you should probably be seeing mid 30's with your set-up. Might want to check the the boost pathway - all the couplings/gaskets between turbo and head. A spray bottle with diluted dish soap can help find those leaks if present. The other possibility is a bad boost pressure gauge. How are your EGT's running? I've talked with the guys at DD regarding max boost - 65 psi is pushing the limits for a stock engine. Generally, 1 psi per 10 HP is the rule of thumb.

 

[KatDiesel]

One part of the factor is Kevins altitude. Although something doesn't sound right, I could make 25 psi stock (PE turned off).



Have you pressure tested the air system? How bout your gauge? Tested it? I can't remember where you have your boost tap at? on the block? You should have more boost then that I would think. Wonder if your ECM has anything to do with it? Maybe the MAP sensor "numbers" are different with the upgraded ECM?? Your still running that right?