Engine/Transmission (1994 - 1998) lots of smoke still.............

[SEmerson]

On my 97 I just added a pdr hx40. I still have tons of smoke. I start to smoke at 25 psi and up. Is this just because I am waste gating out too early? Mid pedal is fine. But past 3/4 pedal is very dark back there.

 

[Jim Fulmer]

There is a few things here to consider, one is what is your total boost?



You have allot of fuel depending on how it's setup, most of the time when your fueled that heavy it just won't clean up totally or if it does it takes allot of air. Once upon a time long ago I was at 450 ish on fuel with Twins and still had just a little haze at 55-60 psi.



Jim

 

[SEmerson]

I am hitting about 30 and you cant see behind the truck.

 

[BPonci]

smoke

You better watch out for Mr. Smokey! You should be around 36 to 40 psi at top boost. What is your wastegate cracking open at? What rpm are you starting to roll into it?

 

[nfox]

Lots of Smoke!!

I would check for a boost leaks, by pressurizing the sytem and checking it for leaks.

 

[SEmerson]

Here is where I am at now. I have alot of pre spool smoke. Inspit of using the heavyest spring in the pdr kit. It is turned in so the wheel is 3/4 back looking in the hole. The whole time I need to really baby it to keep it sorta clean. Even babying it I get a heavy haze. Full pedal it really heavy smoke at any rpm. I am at 36 psi full boost. This is where the gate opens. I beleave I am leak free, But I will made a cap and guage to test it soon.



What can I adjust and what should I expect? The only turned up cummins I have ever been in are mine. (other that a few with just a mild plate). So I really don't know what is normal and where I am at. Or what to expect.



Comments welcome

 

[Forrest]

Not sure, wonder if it has something to do with an injector/s. I just had on an HX55 hybrid & now have a PDR40-16 & don't get the smoke you have. As a matter of fact, the PDR40 runs super clean.



It even sounds like the HX55 ran with less smoke than you're mentioning.



I'm running the stock AFC spring & EDM injectors, the Mach 3's, which are cut to more fuel than 370's, but they produce less smoke than the 300's.

 

[JGheen]

Especially with your timing @ 16* and the PDR-40, you should have not as much smoke. That's a weird issue, not sure what to think.

IMO, I think 36lbs. of boost is a little low for your 40. Maybe try adjusting the wastegate to open around 45-50lbs. and see wht happens. It just seems like your not giving the engine enough air somewhere.

 

[nfox]

Boost numbers

On a PDR40 your top boost shouldn't exceed 40psi. Even with my setup with the PDR40, i really don't get smokey until about 2800rpm on up. I would pressurise the boost system to check for leaks. Let us know what you find out.

 

[SEmerson]

I did check my time tonight. The truck is much faster with the 40. I will try to make a cap tomorrow to check for leaks.

 

[Forrest Nearing]

you need more oxygen... crank the boost up to 40ish and it oughta clear up... you'll still probably have a little haze, but 30psi just isn't enough

 

[JoshPeters]

I'd be very cautious running even 40psi boost. I'd talk to Piers about that HX40, and what he recommends before overboosting it.



Josh

 

[JGheen]

Why would you run an HX-40, if you can get that same boost pressure out of an HX-35? I have heard HX-40 are good up to 50 psi and that is where they are most efficent. Maybe I am wrong, but just what I have read.

I'm just saying this cuz if an HX-35 is most efficent @ 38 psi of boost, why pay $1200 for an HX-40 that is only going to give you 2 more psi? I doubt 45-50 psi is going to hurt the 40. Maybe Peirs will jump in and straighten these questions out... ... .



SEmerson, what boost numbers did you see with the 40?

 

[Cooker]

Originally posted by JGheen

Why would you run an HX-40, if you can get that same boost pressure out of an HX-35? I have heard HX-40 are good up to 50 psi and that is where they are most efficent. Maybe I am wrong, but just what I have read.

I'm just saying this cuz if an HX-35 is most efficent @ 38 psi of boost, why pay $1200 for an HX-40 that is only going to give you 2 more psi? I doubt 45-50 psi is going to hurt the 40. Maybe Peirs will jump in and straighten these questions out... ... .

It is not a matter of pressure, it is about volume. At the same boost pressures the 40 will flow more air than the 35. Assuming a truck is overfueled to start with, more air volume equals more HP at the same or possibly even less pressure.



As far as efficiency maps, the 40 and the 35 are very close.



If I am not mistaken Piers sets his 40's to around 36-38 PSI of boost. 40's will not live a long life at anything above 40PSI.

 

[JGheen]

Originally posted by Cooker

It is not a matter of pressure, it is about volume. At the same boost pressures the 40 will flow more air than the 35. Assuming a truck is overfueled to start with, more air volume equals more HP at the same or possibly even less pressure.

But how can air flow improve if you are not increasing the volume of everything else as well(intake manifold, intercooler and/or port volume)? I would think the bigger turbo would give you more pressure being it is stuffing that same post compressor volume with more compressed air. As an example, I have heard that the Banks twin ram intake manifold is supposed to flow more air than the stock single ram. Well apparently, it only distributes the air more evenly among the cylinders, not starving the #5 and #6 cylinders for air and does not increase flow since the port volume of the air entering the engine has not changed.

 

[chrleb1]

If you still have the stock EGR intake manifold, i would change that out. If you look at the casting of the cali and an out-of-state manifold, you will notice a big difference. The housing size of the turbo will make a difference too. If you are running a 12 housing, maybe you should have a 14 or 16.

 

[KLockliear]

What plate is in it and where is that set? Has the rack or anything else in the pump been played with? What altitude do you live at?



A cam would help.

 

[SEmerson]

chrleb1

I have a egr but it is blocked and the air horn is hogged out. The whole setup is for looks only.



KLockliear

I live at 1700 feet. I have a #6 setback a little from stock. Pupm is original 180. With a 4k and 191's in it

 

[ADSmith]

Originally posted by JGheen

But how can air flow improve if you are not increasing the volume of everything else as well(intake manifold, intercooler and/or port volume)? I would think the bigger turbo would give you more pressure being it is stuffing that same post compressor volume with more compressed air. As an example, I have heard that the Banks twin ram intake manifold is supposed to flow more air than the stock single ram. Well apparently, it only distributes the air more evenly among the cylinders, not starving the #5 and #6 cylinders for air and does not increase flow since the port volume of the air entering the engine has not changed.

It can flow way more at the same boost pressure because there is less backpressure on the exhaust side of the HX-40 than there is on the 35. This allows the cylinder pressure to be much lower when the intake valve opens, which means more fresh air gets in.

 

[SEmerson]

Originally posted by ADSmith

It can flow way more at the same boost pressure because there is less backpressure on the exhaust side of the HX-40 than there is on the 35. This allows the cylinder pressure to be much lower when the intake valve opens, which means more fresh air gets in.

Another factor is air temp. A hx40 will product about 150 degree cooler air. So at the same volume and the same psi there is many more oxygen molecules.