Turbo 4 Liter

[SkylinesSuck]

Yeah, we built a Viper a while back that had twin 98's on it. Built for the half mile made over 3k to the wheels. So I am somewhat familiar with the inappropriate turbo disorder. This one is nice as it spools up fully below 2000 rpm.

LoL, dayum. Okay, I'll quit referring to my dinky little HX40 than

Are you currently using the knock sensor to tune with your setup? I wonder how hard it would be to tune it to be useful with our 4.x's and not pick up lose tools on the floorboards instead. Tuning something forced infection without a knock sensor always mystified me.

 

[Brianj5600]

LoL, dayum. Okay, I'll quit referring to my dinky little HX40 than

Are you currently using the knock sensor to tune with your setup? I wonder how hard it would be to tune it to be useful with our 4.x's and not pick up lose tools on the floorboards instead. Tuning something forced infection without a knock sensor always mystified me.

Sparkplugs tell you a lot. There is a lot of information about reading both fuel and timing.

@Jezza do you log crankcase pressure to help detect irregular combustion? I have read that detonation causes the rings to lose seal and spike crankcase pressure even with a vacuum pump.

 

[SkylinesSuck]

For the kind of boost pressure and hp I'm thinking of being scared to tune without a knock sensor, picking up the spark plugs off the ground to read after you just grenaded the motor might be less than effective

 

[Jezza]

LoL, dayum. Okay, I'll quit referring to my dinky little HX40 than

Are you currently using the knock sensor to tune with your setup? I wonder how hard it would be to tune it to be useful with our 4.x's and not pick up lose tools on the floorboards instead. Tuning something forced infection without a knock sensor always mystified me.

There is a procedure where you set the noise range for the knock sensors. Typically other noise from the vehicle is not an issue because the engine is isolated with rubber mounts. Solid or semi-solid mounts can be an issue sometimes on setups that are more sensitive. The knock works really well when it is setup properly and is especially helpful detecting damage causing conditions before they become an issue. This is a screenshot of my knock logging trace. You can clearly see the sensor detecting more noise when the boost and rpm increase. A lot of that is engine noise like valvetrain, piston noise etc. As long as the noise stays under the preset knock noise floor it is ignored as background engine noise. The trace in knock 2 makes it clear that some knock was present and had I enabled the knock feedback at the time it would have pulled timing and adjusted the fuel mixture to attempt correction.

 

[Jezza]

Sparkplugs tell you a lot. There is a lot of information about reading both fuel and timing.

@Jezza do you log crankcase pressure to help detect irregular combustion? I have read that detonation causes the rings to lose seal and spike crankcase pressure even with a vacuum pump.

I also read plugs when I am leaning on something especially the first time. The stupid common coil makes checking plugs on the dyno time consuming. Especially when there is a turbo in the way, and its 1 million degrees. Knock is nice because it can help detect knock before it becomes an issue. Also properly setup knock works all the time, so if you put in a bad tank of fuel it can constantly make changes instead of burning up a hole.
I don't log crankcase pressure as I feel like by the time you see a noticeable increase in pressure there the damage is already done and the engine will sound like a Subaru. In my experience what usually happens if you detonate too much too hard or too long the ring lands on the pistons will crack away from the piston body and the rings will loose seal. Then the cylinder pressure will escape into the crankcase. I don't have a vacuum pump on here, because there is not much blow-by to speak of. I do have the crankcase vent routed to the turbo inlet, and I also have a Toyota Supra PCV valve between the back valve cover breather and the intake manifold.

 

[BigKID]

I worked on my custom shifter a bit today and finished getting it installed. I also made a new bronze bushing to replace the plastic shifter bushing that was looking a bit tired. I reduced the shift throw by 25 percent. It fits way better with the console. I no longer have binding issues when it is in 2nd or 4th. Very crisp shifting.

Is this for a stock NV3550 or have you upgraded transmissions? Just curious how it is holding up to the current power level.

 

[Jezza]

Is this for a stock NV3550 or have you upgraded transmissions? Just curious how it is holding up to the current power level.

Yep, it's just the stock 3550. It seems to be okay so far. I am only running at 300 whp right now, so hopefully it will live for a while. I was careful on the dyno only to do pulls in 4th gear which is 1:1 and just locks the input and output shafts together. On the street I use the boost by gear and in 1st, 2nd and 3rd I pull most of the boost out and ramp in to 4th.

 

[SurfinLife]

As promised here are some pics of the Turbo setup. I am still running the stock exhaust manifold and the stock y-pipe with the cats. I cut the y pipe after the y and welded a v-band to it. The up-pipe is 2.5 inch and the down pipe is 3 inch all the way out the back.
Don't judge the welds on the intercooler. That's the way it came from eBay lol.

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Wow, love it. I really like your location for the turbo. I think I will relocate mine..

1. What IAT sensor did you install? Looks like you put it directly into the manifold. Yes?

2. Do you have a wastegate? If so, I would like to see a pic.

I am interested in this infinity you speak of. I took the HPT route and find it limiting. I am thinking of changing out the PCM from a Gen III to something else, just to have a proper PCM firmware that works with turbos.

Would be interesting to see a pic of your spark table. Post here of PM me if that works.

Thanks in advance.

 

[Jezza]

Wow, love it. I really like your location for the turbo. I think I will relocate mine..

1. What IAT sensor did you install? Looks like you put it directly into the manifold. Yes?

2. Do you have a wastegate? If so, I would like to see a pic.

I am interested in this infinity you speak of. I took the HPT route and find it limiting. I am thinking of changing out the PCM from a Gen III to something else, just to have a proper PCM firmware that works with turbos.

Would be interesting to see a pic of your spark table. Post here of PM me if that works.

Thanks in advance.

Thanks. I was originally going to place the turbo rear facing behind the alternator as piping would have been a bit easier, but I like the look of it being forward facing on top.
The intake temp sensor I am using for the Infinity is their part number 30-2010 it is the same as the GM part 25036751. I have it located in the pipe between the intercooler and the throttle body. The factory intake air temp is still in the intake manifold and still connected to the factory computer. I left as many sensors connected to the factory computer as possible. It only has 10 codes currently and most of those are for the injector and coil circuits.
I have an external Tial 44 wastegate. It is located just below the alternator in front of the turbo. Currently I have it dumping externally, but I may recirculate it at some point.
HP was a huge disappointment for me. I expected way more. I have tuned other vehicles with similar software as well as others with HP, and the lack of coverage for the Jeep was shocking. There is no real way to have a stable tune work long term with the current version of HP. I am working on making a post regarding the Infinity. There is quite a bit to it.
Spark table attached.

 

[SurfinLife]

Awesome. I haven't put mine on a dyno yet, so it's nice to see that my spark table wasn't to different from yours... I inputted this table into my PCM and I have another big smile on my face.... love the jeep even more now

 

[SurfinLife]

I am having a new issue now though.. and after intense diagnostics, It's looking to be a crankcase pressure issue. Since this Jeep doesn't use a PVC system, did you install one? Part number?
I left my valve cover open to atmosphere, vs back into the manifold..... this needs to change because I am setup for more boost....was using only 4-5psi, and now I'm up to 7-8psi and anytime I come to a stop after wot and boost, I have a hard time idling... found out the engine will run lean. If I turn off the engine and wait 5 seconds before restarting, all is back to normal until I boost again....
Are you able to log your map sensor? Meaning, with HPTUNERS I setup a PID to record the barometric pressure side of the 2bar map, and I've never logged this before my issue so I have no reference....but I notice that the baro at start will be 102.3kpa as long as I start away from boost, throughout my drive. When I hit wot/boost, the baro will rise with the boost pressure and remain high, even after I return to idle. Is this normal? Just trying to see if that is throwing off my fuel map and making it lean, or if it's a side observation that's not related. I've replaced the map with a new one, same thing happens.

So, do you mind sharing your method of managing crankcase pressure? I see the valve cover air inlet to the intake pre turbo, but what about to the manifold?

Thanks.

 

[srimes]

When I hit wot/boost, the baro will rise with the boost pressure and remain high, even after I return to idle. Is this normal?

That's a no. MAP sensor should report what the MAP is in real time. Your MAP is in the manifold after the throttle body, right?

 

[SurfinLife]

That's a no. MAP sensor should report what the MAP is in real time. Your MAP is in the manifold after the throttle body, right?

It's in the stock place.... I just upgraded to the SRT 2bar.
To be clear, the kpa will move up and down with pressure as per norm, but the barometric side of the sensor will stick with the highest kpa I went up to.

In the attached pic, you can see 102 is norm all below 1.00 (100kpa), but when I come out of boost, you can see after 3k the baro number carried down below 1.00

Maybe there are 2 separate issues happening here??

 

[srimes]

Not sure what I'm looking at here. Is it the red line graph?

Sounds like the baro reading is from before the throttle body. When you get off the gas and the throttle slams shut the manifold will pull vacuum but the turbo will still be producing pressure until it gradually slows down and bleeds off pressure, unless you have a blow off valve. But it "shouldn't" be a problem as most stock turbo cars don't had a BOV. Unless your tune isn't able to handle it.

How long does it take for the pressure to drop? Or does it just die? If you back off the throttle slowly can you keep it running and does the baro go back to normal?

 

[SurfinLife]

Not sure what I'm looking at here. Is it the red line graph?

Sounds like the baro reading is from before the throttle body. When you get off the gas and the throttle slams shut the manifold will pull vacuum but the turbo will still be producing pressure until it gradually slows down and bleeds off pressure, unless you have a blow off valve. But it "shouldn't" be a problem as most stock turbo cars don't had a BOV. Unless your tune isn't able to handle it.

How long does it take for the pressure to drop? Or does it just die? If you back off the throttle slowly can you keep it running and does the baro go back to normal?

This is a screen shot of the software from HPTunners. This is used to record a drive/run. The red line is the whole drive. I am trying to show that the graph (chart) has the recorded numbers for the Baro side of the MAP (in this case), with RPM and MAP manifold pressure.
As I mentioned, the MAP is in the stock location post throttle. Don't confuse the terminology, dodge has a 2 part MAP sensor, Manifold pressure + atmospheric outside pressure.
Yes I have a BOV and its a MUST, or the engine would run away and not idle, or make a detrimental turbo flutter sound. So pressure drops immediately. Not an issue.
The chart shows the numbers being populated all over the RPM and Manifold pressure (20= vacuum, 160= 7 PSI boost) so i know the one side of the MAP is working. 102kpa was taken from the KOEO state and maintains until i go into boost, then it carries that number all the way down into vacuum. This is strange to me, and Google can not help so far, as most people don't scan and record this. The Baro will return to normal only after I turn off the engine and restart, because this is when the PCM rechecks the baro level. I am on my 3rd sensor since my first sensor failed. Since the issue stays, im trying to look deeper and found this baro number situation... maybe its normal, and maybe its not an issue, no one can confirm this yet. So, if you have a turbo, a GEN3 PCM setup and you can take a reading of the baro, then reading can be compared.

I have been running with a turbo for 3 years and never had a post boost rough idle issue before.
I have don't a large check on every part of the jeep, and replaced EVERY sensor, but the lean, rough idle continues.
So i disabled the 02 sensors for the PCM stops trying to add fuel and really messing up my tune.

I know that my crankcase pressure (CCV) system was removed and used to go to a catch can, but it would fill with water very fast from colder winter weather.

Today I went out and purchased a PCV so I can once again hook my valve cover to the manifold (crankcase will have vacuum again) and keep my boost pressure from back filling into the crankcase. But since this baro number sticks and carries, im thinking that this new value is keeping my PCM thinking its in a boost state, and keeps adding fuel, even at idle, which is a big problem for idling... sometimes up to 20% more. This is the new issue... Other than making a better breathing crankcase.... also i am getting oil leakage from the pan gasket, which also indicates i have high crankcase pressure building. Which is why i was asking how he setup his crankcase balancing system on the turbo jeep in this chat, as I have to come up with something custom.

 

[Juggernaut]

This is a screen shot of the software from HPTunners. This is used to record a drive/run. The red line is the whole drive. I am trying to show that the graph (chart) has the recorded numbers for the Baro side of the MAP (in this case), with RPM and MAP manifold pressure.
As I mentioned, the MAP is in the stock location post throttle. Don't confuse the terminology, dodge has a 2 part MAP sensor, Manifold pressure + atmospheric outside pressure.
Yes I have a BOV and its a MUST, or the engine would run away and not idle, or make a detrimental turbo flutter sound. So pressure drops immediately. Not an issue.
The chart shows the numbers being populated all over the RPM and Manifold pressure (20= vacuum, 160= 7 PSI boost) so i know the one side of the MAP is working. 102kpa was taken from the KOEO state and maintains until i go into boost, then it carries that number all the way down into vacuum. This is strange to me, and Google can not help so far, as most people don't scan and record this. The Baro will return to normal only after I turn off the engine and restart, because this is when the PCM rechecks the baro level. I am on my 3rd sensor since my first sensor failed. Since the issue stays, im trying to look deeper and found this baro number situation... maybe its normal, and maybe its not an issue, no one can confirm this yet. So, if you have a turbo, a GEN3 PCM setup and you can take a reading of the baro, then reading can be compared.

I have been running with a turbo for 3 years and never had a post boost rough idle issue before.
I have don't a large check on every part of the jeep, and replaced EVERY sensor, but the lean, rough idle continues.
So i disabled the 02 sensors for the PCM stops trying to add fuel and really messing up my tune.

I know that my crankcase pressure (CCV) system was removed and used to go to a catch can, but it would fill with water very fast from colder winter weather.

Today I went out and purchased a PCV so I can once again hook my valve cover to the manifold (crankcase will have vacuum again) and keep my boost pressure from back filling into the crankcase. But since this baro number sticks and carries, im thinking that this new value is keeping my PCM thinking its in a boost state, and keeps adding fuel, even at idle, which is a big problem for idling... sometimes up to 20% more. This is the new issue... Other than making a better breathing crankcase.... also i am getting oil leakage from the pan gasket, which also indicates i have high crankcase pressure building. Which is why i was asking how he setup his crankcase balancing system on the turbo jeep in this chat, as I have to come up with something custom.

Do you have a table or a switch (enable /disable) for baro learning? On the NGC3 05/06 years, there is. The pcm will learn baro at KOEO and again at what it deems to be WOT or atmospheric pressure. It does this as a sanity check for the KOEO baro learn performed by the MAP in case conditions change.

 

[SurfinLife]

Do you have a table or a switch (enable /disable) for baro learning? On the NGC3 05/06 years, there is. The pcm will learn baro at KOEO and again at what it deems to be WOT or atmospheric pressure. It does this as a sanity check for the KOEO baro learn performed by the MAP in case conditions change.

There is the option to disable baro learning, and a table that can be adjusted for throttle voltage delta max learning... I did lower the voltage numbers, but I wont know the effects until I turn the 02 sensors back on (CL vs OL at the moment).

 

[Jezza]

Not sure about the NGC baro correction, but on the JTEC there is a table for altitude correction. You have to clear the values from that table and change them all to 1. The PCM updates baro at wide open throttle and moves the baro value up with boost. If you don't disable the altitude correction table it will affect the tune. The baro value will still move up as you drive and hit higher boost values, but having the table at the same values will leave the tune unaffected.

 

[Jezza]

For crankcase ventilation I have the front port which is wide open to the hose running to my intake pipe between my air filter and the turbo. The back port has a restricted hole in it stock. I didn't change the port at all, but I did add a Supra PCV valve between the back valve cover port and the intake manifold.
This is the valve I used

https://www.ebay.com/itm/3924161508...d=link&campid=5337789113&toolid=20001&mkevt=1

 

[Juggernaut]

There is the option to disable baro learning, and a table that can be adjusted for throttle voltage delta max learning... I did lower the voltage numbers, but I wont know the effects until I turn the 02 sensors back on (CL vs OL at the moment).

Not sure about the NGC baro correction, but on the JTEC there is a table for altitude correction. You have to clear the values from that table and change them all to 1. The PCM updates baro at wide open throttle and moves the baro value up with boost. If you don't disable the altitude correction table it will affect the tune. The baro value will still move up as you drive and hit higher boost values, but having the table at the same values will leave the tune unaffected.

Jezza is on to it. The NGC is a little different than the JTEC as there is no altitude correction table. Disabling baro learn is an attempt to accomplish the same thing. Give it a try and report back.