How is boost controlled?

Is boost controlled by just the waste gate?

Does a stock lb7 have an electronic boost controller?

1. How is boost controlled?

2. Is boost controlled by just the waste gate?

3. Does a stock lb7 have an electronic boost controller?

1. by exhaust pressure, or simple terms how hard your on the throttle.
2. yes, it is not like the 04.5's and newer which have a different turbo
3. no, the 04.5's and newer do, its control is located in the ecm

Ok, thought so, waste gate control only.
So I have a Hypertech programmer. It came with the truck when I bought it.
When I program it for the 90hp tune it’s just modifying the fuel map with no boost increase. So how am I getting an extra 90hp without a boost increase?


I know how waste gates work and this is a non-adjustable one on the lb7.
So as soon as you start making boost the waste gate is opening up (ever so slightly) until you are making enough boost for it to be fully open.

I’m thinking about installing a manual boost controller but am concerned that the new fuel map will not provide enough fuel for the added boost. I don’t want to run lean.

So can anyone answer how the Hypertech can get the truck to make 90 extra HP with no boost increase?
And does anyone know is its safe to add a boost controller with the 90hp tune?
I assume max boost should be around 30psi…

TIA

Ok, thought so, waste gate control only.
So I have a Hypertech programmer. It came with the truck when I bought it.
When I program it for the 90hp tune it’s just modifying the fuel map with no boost increase. So how am I getting an extra 90hp without a boost increase?


I know how waste gates work and this is a non-adjustable one on the lb7.
So as soon as you start making boost the waste gate is opening up (ever so slightly) until you are making enough boost for it to be fully open.

I’m thinking about installing a manual boost controller but am concerned that the new fuel map will not provide enough fuel for the added boost. I don’t want to run lean.

So can anyone answer how the Hypertech can get the truck to make 90 extra HP with no boost increase?
And does anyone know is its safe to add a boost controller with the 90hp tune?
I assume max boost should be around 30psi…

TIA



the turbos on the lb7's peak out at 32 psi. I have mine dialed into 25 psi with PPE boost valve
http://www.thedieselpage.com/reviews/jkboostvalve.htm

I personally wouldn't attempt to run my own truck @ 30 psi

do you have gauges on your truck? a pyro and a boost gauge?

32 is peak, thanks!
So 25psi it is, don’t need to burn up the turbo.

No pyro only a boost gauge.

You can turn it up higher than 25psi, you will be loosing alot running @ 25psi, I know everyone says don't go above 30 but I have been for almost 2 years now it seems ok, right around 30 I'd say is safe. You will notice a huge power increase from 25 to 30!

I’m thinking about installing a manual boost controller but am concerned that the new fuel map will not provide enough fuel for the added boost. I don’t want to run lean.
Yes, you DO want to run "lean". Diesels aren't like gas engines. At idle, you have no air restriction, but very little fuel. On a gas engine, this would be so lean it wouldn't even run.

It doesn't hurt a diesel to run lean, in fact, they run cooler (lower EGTs). That is why you would want extra air-- to cool your EGTs, and prolong the life of the engine. There is enough extra air from the factory that you can add quite a bit of power without any extra air. That is how Hypertech does it. Adding more boost will cool your EGTs, and it might pick up some power, if you have enough fuel to take advantage of it.

[quote=DAVe3283 = In Red [/quote]

“It doesn't hurt a diesel to run lean, in fact, they run cooler (lower EGTs). That is why you would want extra air-- to cool your EGTs, and prolong the life of the engine.”

Ok so LEAN is good.

“There is enough extra air from the factory that you can add quite a bit of power without any extra air. That is how Hypertech does it.”

So this would mean I don’t need to add any extra boost because you are saying there is enough already?
So because there is 20psi already by changing the mapping it will yield the extra hp?

So Hypertech is leaning out the mix in order to get the HP #’s?
But why is it suggested not to use the max HP setting when towing?
The max HP setting would yield the lower EGT if I understand this right?
Lean = better EGT


“Adding more boost will cool your EGTs, and it might pick up some power, if you have enough fuel to take advantage of it.”

Adding boost will get my EGT down, great.
Pumping up the psi is more for cooling and not really for HP?

What happens if there is more boost then fuel to keep up?
You say I want to run lean but that is scary to me.
My limited knowledge comes from gas engines.

what he meant is that hypertech designed their tuners to work on the principle that our engines already suck in enough air to run much more fuel than the stock map gives the motor.....that is why the higher tunes run your EGT's way up into the 1400's, at least my predator 65 and 85 tunes do.

anything over 1260 for sustained times will melt your turbo, so be careful.

Ok that makes more sense

The amount of boost in a diesel is dependent on the amount of fuel there is to burn you could remove the wastegate line on a stock tune truck and it would go nowhere near 32psi.


1375 degrees is the safe sustained egt's but they can go much higher for short periods of time


I have been running 30+ psi on my IHI for a long time they are very tough and can take alot of abuse

^^ Ditto. Pressure is also relative to the amount of fuel your dumping in. I know with my 6-gun I get around 22psi on level 3. Put it on SL and I'm at 28-29psi. I don't have a PPE valve

I disconnected my wastegate and with my Hypertech on stage 3 I hit a max of 26psi, with the PPE boost valve I hit 24psi. When I got EFI Live I took a peek at the hypertech and how it tunes out trucks...I was surprised. I won't tell what I found, as respect to the company, but it did make me wonder.

I sled pull and pulls last 15-20sec, my 1600* pyro max's out, maybe 26-27psi boost.

^^ Ditto. Pressure is also relative to the amount of fuel your dumping in. I know with my 6-gun I get around 22psi on level 3. Put it on SL and I'm at 28-29psi. I don't have a PPE valve


How is this?
If your waste gate opens at 20psi or even 18psi no amount of fuel will get you a solid sustained 26psi. Maybe spikes but that’s it.
It’s not physically possible. Your spring opens when it opens.
Unless diesels are that much different than gassers…

I disconnected my wastegate and with my Hypertech on stage 3 I hit a max of 26psi, with the PPE boost valve I hit 24psi. When I got EFI Live I took a peek at the hypertech and how it tunes out trucks...I was surprised. I won't tell what I found, as respect to the company, but it did make me wonder.

I sled pull and pulls last 15-20sec, my 1600* pyro max's out, maybe 26-27psi boost.


My EFI live will be here today (I hope) or next week and will be playing with it ASAP.
If you don’t mind pm what you found.

My EFI live will be here today (I hope) or next week and will be playing with it ASAP.
If you don’t mind pm what you found.
You'll find out when you get your efi live, efi is just more refined. there is nothing wrong with the hypertech, its done me well for the 2yrs I had it.

Got the PM thanks!
My EFI Live is a scan only for now.
Got it to read injectors and what not.
If they are all good then maybe i'll get the upgrade..

bloody hell mine boosts to 10psi no wonder it's like a driving a dodge............good job my banks big waste gate just arrived.

How is this?
If your waste gate opens at 20psi or even 18psi no amount of fuel will get you a solid sustained 26psi. Maybe spikes but that’s it.
It’s not physically possible. Your spring opens when it opens.
Unless diesels are that much different than gassers…


I agree. I dont fully understand how it can. But I can tell you I have no reason to lie. Stock I see 20-22. Solid 22 on level 3 which is where I run every day. When in SL its 28. (have seen a spike of 29) I didn't buy the truck new, and I know the previous owner had a tuner on it. Whether or not he messed with the wastegate I have not really investigated. I do know it does not have a PPE or any other kind of valve on it.

You do kind of have me wondering now though. I have never really thought about it. The wastegate must be different somehow. Pressure is pressure. It should open theoretically. It looks factory. There is no way to "modify" a factory gate that I am aware of.....