Stock Turbo Limits.....

[fords4life]

I hooked my truck up to NWSUPRD's new AE today so I could check things out. I have no guages yet so I was curious to see what boost was like. I loaded it up once, and then did another run from a rolling start. I saw 32psi both times, and it held in the 30-32 range while floored. My wasegate never opens at WOT, only when downshifting or letting off the pedal. I have heard that 26-28 was pushin it for stock, but has anyone else seen 32 on stock injectors, stock oil, and a 30hp old school Hypertech chip?

My other question is....I see some people say that 25psi is what the stock turbo should be limited to. Why is this? What is the weak point in the stock turbo that causes it to fail at higher boost numbers? As far as I know the chip is the only mod to this truck besides an AFE filter. It has 99,6XX miles on it and I've owned it for the last 15k. I have boost launched less than 10 times, not sure of the previous owner. It has been floored on many occasions getting onto the freeway and passing people on 2 lane roads.

I'm just curious now since I wasn't expecting numbers anywhere near 32.

[Dirk]

I've never seen boost that high on a 30hp chip.

What pressure was your HPOP putting out?

[fords4life]

Originally Posted by dirk0

I've never seen boost that high on a 30hp chip.

What pressure was your HPOP putting out?

I thought he logged it, but he didn't. I am hopping to go back in the next week or so and run it again. We need to run his truck too and get some data on it, but couldn't cuz he blew an IC boot. So, hopefully I'll know that in a few days.

[Dirk]

I would also like to see boost pressure readings from a gauge. At that pressure, if the truck was reading that high.. it would be defueling like crazy.

[fords4life]

Originally Posted by dirk0

I would also like to see boost pressure readings from a gauge. At that pressure, if the truck was reading that high.. it would be defueling like crazy.

That one might be awhile....no $$$ for the guages for at least a month, gas is killin me.

So you're thinking that maybe AE is reading incorrectly? That would mean the pcm is reading incorrectly, or a faulty sensor, but then wouldn't the truck be defueling? It definitely doesn't feel like it's defueling. The boost stayed pretty consistant and only dipped when the truck shifted and picked right back up.

Just in case it sounded like it, not an argument...just thinking out loud, asking questions cuz I don't know and tryin to learn...

[Lord Tauk]

You wont hear the wastegate, that sound you're hearing is air pressure reversing it's direction back out since there are no blow off valves in diesels. I've never seen that high of pressure through my MAP sensor with AE, but I have a fooler. If it's saying 32 PSI, then that's what it is going to be unless it's malfunctioning.

Take a look at the map sensor's hose, it's the one that's near the oil filler cap that goes towards the passenger side, it might be in a plastic shroud but it's just a rubber hose. Take note of any MAP foolers or anything like that on there..

Also for grins, take a look at the wastegate hose on the turbo, it's red and should have a 90 degree rubber fitting, if there's anything else other than a red hose and a rubber connector then you got a "Delay" thing on there, or it's blocked off. Unplugging that hose would also eliminate the wastegate from opening.

You didn't mention having any codes or seeing any CEL? I think you should be getting a turbo overboost code. Without a fooler or some sort of way to keep the MAP sensor from seeing too high of boost you'll defuel at that high of boost. I highly doubt AE is reading incorrect, if anything is wrong your MAP sensor is the one to look at.

Lastly I think it's safe to say the stock turbo is good around 25PSI, beyond that it is out of it's range or not doing any good, plus 32PSI is way too high for a stock turbo to be running at often.

[strokin_early_99]

I would bet it was manifold absolute pressure, that included barometric pressure, approximately 15psi. I say that because the manifold gauge pressure will only go as high as 24psi and then it defuels. If you have a boost fooler on it then it will never see more than 24psi since that is what it is designed to do.

Just my $.02

[Lord Tauk]

That too! I forgot about that, however I don't recall seeing a sensor that read it from 14PSI, I just remember selecting the sensor that shows the 14.whatever figured at 0.

I had assumed you setup the correct sensor when you were running the live meters, obviously you'll have some subtracting to do if you started with 14PSI instead of 0!

[fords4life]

No codes besides an imbalance during a CCT on #8, not surprising.
No CELs

There is a red tube/rubber 90, goes into a wye that has a fitting on the turbo pedestal(i think) and then goes to the stuff mounted on the turbo.

The turbo is a Garrett....on the back side of the compressor housing(intake side) there is a 1.00A/R on the housing. Also has a barcode sticker on the intake side.

I think it's stock, but don't have anything to compare it to....I was never told it was replaced, thought maybe you could use the info.


If it had a boost fooler, wouldn't AE be reading the "fooled" reading meaning it would be reading less than the actual boost?

[fords4life]

Originally Posted by strokin_early_99

I would bet it was manifold absolute pressure, that included barometric pressure, approximately 15psi. I say that because the manifold gauge pressure will only go as high as 24psi and then it defuels. If you have a boost fooler on it then it will never see more than 24psi since that is what it is designed to do.

Just my $.02

HHHMMMMM We were reading manifold absolute pressure......that being said, what reading in AE would be true boost? The other question is....is it an automatic 14/15 psi? If that is the case, then I'd only be making 18psi...that doesn't make much since either...