Turbo upgrade

[Will L.]

I’ve no knowledge on air or exhaust throttles on diesels. I understand how they can lower rpm, both with it’s disadvantages.

Close exhaust while rest of engine wants to keep going is going to trap heat and increase soot build up.
Restricted intake air is how to make a nice smoke machine- haha.

A super elaborate computer controlled set up restricting everything in porportion makes sense that it could work.

But to zombie day/ junkyard rig any computer controlled engine you can always rip things down to basic mechanical feed and Control any diesel by fuel input alone and same for any gas engine by air.

If you have any examples or info on the ones using air exhaust, I would love to read up...

 

[Big T]

Thats right it’s the basics. Now I feel like I should go back to school. Especially now where there are Diesel engines using air throttles and exhaust throttles.

That would be awesome if you could get a kit built for the center mount turbo guys to give them more options. I’ve seen a couple hummers for sale around here lately. All out of my price range but I’ve always thought it would be fun to own one.

I’ve got a buddy at work that has a wicked wheel on his 7.3 and swears by it. Most of the info I found on the wicked wheel says that it started out as a fix for the fords where the turbo would surge and wasn’t ever really for performance so that always made me wonder if it was worth anything on the 6.5.

So I guess what I’m looking at for my truck as it is would be leave it and just go with a better tune or go with the ATT and probably not see any gain with daily driving because of low rpm but towing would be where I see the gain as long as I run it in lower gears. The hx turbo would probably be about the same but I my see higher egt’s with it over the Att. Plus make darn sure the fuel system is up to the task before any upgrade goes in place. I think I’m getting a grasp on all the great info here

If you stomp on the ATT, you’ll never notice the low rpm deficiency. It is significantly better than stock. And as Will pointed out, you’ll never need an after cooler.

 

[royunion]

The obd1 does not use the koko procedure.

Yes it does. The proper name is called TDC OFFSET Learn - But it does not work key on key off. It needs a Tech 2 to do it. It is found on page 5-44 of the GM 6.5L Diesel Engine EFI/Mechanical Systems manual (16015.20-4)

 

[royunion]

@royunion

"It is safe to buy algae laden fuel so long as you know that is what it is and you should treat ALL bulk bought fuel like it has algae in it and you then filter it first in a buffer algicide treated tank to kill the algae first. "

Only when the bugs clump together do they plug the filter. We are talking mold, bacteria, yeast that are all smaller than the micron rating of the filter, pass through, and grow everywhere in the system.
.

This correct . . . that why I said run an additive that has biocide characteristics religiously at https://www.thetruckstop.us/forum/threads/turbo-upgrade.47733/post-564037

If you let algae or the possibily of it fester = it is bad news

 

[JayTheCPA]

Just for clarification about turbo lag . . . As Big-T notes, turbo lag is really not a big deal to anybody other than the driver that wants to get from red light to red light as quickly as possible. Even with some lag, the 6.5 is very driveable in all conditions.

Personally, I see a *lot* of commentary about people not liking lag. But, so what. In the 6.5's case, the motor still generates power even when its turbo is not able to boost. In the bigger picture, most people want a linear power delivery. In my world, they also love automatic transmissions and expect the world to revolve around them rather than how to live in the world around them.

Another area where people confuse lag is with the transmission where it allows the RPM's to drop into the territory where the motor cannot deliver much power (either from the too-tall gear, or less than optimal RPM range).


So far I have driven one (and only one) vehicle where lag actually made the experience annoying: an early generation Audi TT (US version) gasser. That setup was pretty much bi-polar where the motor was either extremely sluggish or in race-mode with no smooth transition between. Apparently Audi decided to keep that setup for a while as a buddy had a later generation (Euro version) and commented the car still had that behavior.



And for that Wicked Wheel, the reason it came to life was that people played with the OE exhaust plumbing on their 7.3 DI and threw the system out of balance. Sure, larger exhausts allowed for more power, but this change alone (plus maybe an intake mode as well) created surge in the turbo's compressor.

 

[royunion]

@royunion
Maybe you can expand on the topic: Stanadyne DS4 and GM PCM.... yea, quite a piece of work.
https://www.thetruckstop.us/forum/t...4-and-gm-pcm-yea-quite-a-piece-of-work.40940/

I am familiar that write up. What so many analysis situations of the DS4 and PCM forget to factor in is the inlet fuel pressure to the DS4 determines the potential for how it may perform

This post says it well https://www.thetruckstop.us/forum/t...m-yea-quite-a-piece-of-work.40940/post-509873

Aside from going to a Heath tune on the PCM - if the STOCK engine is kept cool with a good radiator, intake air is kept cool with an inter cooler (I have one on the center mount turbo engine), with tight good vacuum, and you have high inlet fuel pressure like 9 to 15 psi a decent newer binary like a 97 and up the engine will pull strong - but only as I have seen - with good 44 cetane and above fuel

Most of the time the PCM is holding the engine back when it thinks something is amiss - it could be coolant temp, tans temp, IAT, fuel temp - one never knows - I just know if I keep everything cool it runs the best

I do not do PCM programming and Bill Heath is truly an expert there, but on the test stand the DS4 is checked at 5 psi to assure it works properly at the minimum it is supposed to have for fuel. At 15 psi inlet pressure - the engine runs like a completely different animal and if the return valve is not working properly the engine will act up and may do a runaway if the IP is not set absolutely properly

Towards the end of the engine family life GM finally recognized and understood the importance of the fuel inlet pressure being higher - and the late 99 to 2002 OEM fuel lift pumps pressure have a higher spec pressure - not that it matters because ALL those solenoid buzz pumps simply do not pump the pressure reliably.

Those lift pumps can be checked for pressure cold - and it will report the proper pressure and then when they get warm - it drops. One has to remember - the only thing driving them is a SPRING- and that means fatigue quickly happens - it does not pump fuel so much as PUSH it.

The bottom line is you need exhaust gas velocity and heat to spin a turbo. The wicked wheel is more resistance to trying to pump more air and that is why it is said to only produce higher end boost, but no Diesel fuel is really going to do what CNG, Propane and Hydrogen will bi-fueled as inlet air to the engine if metered properly

That kind of fueling will spin the turbo to its max and I can get 10 psi of boost out of the Stock Turbo only because the PCM limits the boost and I am not going to mess with the stock programming.

Besides it is scary to me how fast and powerful that thing will pull and accelerate - after all it is a van.

I had a 15 psi rotary type lift pump on it and it ran like a rocket barely touching the accelerator - but it also wanted to surge a bit at idle, so I put on a 9 psi rotary type lift pump and it was enough to keep it running and idling properly with good enough performance like an OEM engine is supposed to have

Someone rebuilt the DS4 and did not set the throttleplate properly or its spring is weak

I do not believe in doing mods - because the PCM software has Gremlins - and I am with Will L on a no vote for the wicked wheel - but at the same time it is "not a bad investment". It is just that focusing on boost is not really what makes a diesel perform.

The only thing I can say is when I put on the inner cooler - I could tell the difference in overall performance but I cannot say if it was just the cooler intake air or if the PCM was also involved.

I recently bought a spare PCM from a 2002 6.5 and swapping it in - makes it run even better again

96 to 99 every year the binary changed slightly

 

[Deere65]

@Will L. on the air and exhaust throttles. deere is using them on FT4 engines and the main purpose of both them is to do the same thing which is to raise exhaust temp before and during dpf regen. The 4 cylinder engines use both if it has a vgt turbo and only the air throttle with a waste fated turbo. On the vgt model the exhaust throttle is used to raise temps and create back pressure for egr. The 6 cylinders run compound turbos where one is a vgt and other is a standard non waste gated turbo. These only use the air throttle. The 4 cylinder engine use in cylinder fuel dosing and the 6 cylinders dose fuel directly to the DOC. The concept of either throttle does the same thing. Why they used one over the other I have no idea. The next time I get to talk to one of the engineers I’ll try to get the answers. A lot of this stuff is kept top secret. They only give me just enough to get me by

 

[Will L.]

Ok thanks. I will try to find info and look into them.

 

[Will L.]

I would Need specific engines if you dont mind. All the ft4 deere engines I found are still electronic over common rail electronic injected engines where the electronics tell the injectors add fuel to raise or lower rpm. So still fuel controlled throttling.
All the air and exhaust closures that occur happen by electronics for the purpose of emmisions,not throttle control.

 

[Deere65]

I’m sorry I wasn’t so much saying that the air throttle is operating relative to throttle position and controlling rpm as I was more just stating that they are now controlling the air entering the intake with the use of an electronically driven butterfly valve where the turbo is still able to make boost either with the use of a vgt or by closing the exhaust throttle so now we don’t have max air all the time but are still able to maintain rpm/power and yes it is used for emission control. I guess my statement made it sound like I was saying a diesel was being controlled like a gas engine. Sorry about that

The engine models that would use these throttles would be a 4045 and a 6068. There are others but these are the most common engines