12v twin setup tuning help needed

[TheSilverBullet]

Ok guys here's my setup
180 motor
NE diesel pump flowed 410cc with 181s now has full cuts timing is 20*
Stock lines feeding 5x18s
Cam is 192/215 458 lift
Pistons are fly cut and bowls enlarged roughly 16 to 1
Head is milled off and ported valve angles changed dual springs titanium keepers I think it flowed 220 on the bench
3 piece manifold port matched to the head
Secondary is a billet 62/74/12 air gate with adj elbow
Primary is 80/96 1.31 ar

This truck is smoky all the time, it hazes black at 65 it's a nv5600 with 354s. I build 60 at the manifold, 30 off the primary and roughly 85-90 pounds of back pressure. It seems kinda sluggish when you wot at about 18-2000 rpm. Then once it gets it's **** together it seems like it falls off at like 3200, where that's roughly where my boost numbers are coming from kinda hard to keep your eye on everything lol. I think this truck should have way more power it doesn't feel fast and it should let the tires loose in about every gear I think. In 3rd it will bark um for bit 4th maybe but you don't hear it. Now as far as back pressure I know my t3 spacer is divided idk if it should be open or what. This is my first twin setup and have never been around one before. Any help is appreciated. Got a kid with 6.4 and chip talking smack really want to blow his doors off.

[TheSilverBullet]

Forgot to add egts are really high like beyond my 1600 degree gauge.

[CorneliusRox]

Have you checked your fuel pressure? You should be making good power way past 3200rpms. That's where I'd start.

And if you go up against that 6.4L, it should be on a highway. It'll be hard to keep up with a tuned 6.4L with an auto down low.

[TheSilverBullet]

My fuel pressure is not what it should be, it's low. I put isspro ev2s in this summer and had the sensor mounted solid off the pump, well I had it idling and it quit because it shook the guts out of it a new one is in order.

As far as the race it's going to have to be a rolling start because of my six speed and slow shifting dual disk. My main concern is back pressure right now

[Headcase98002]

Replace the full cuts with something more streetable. That is where I would start.

[TheSilverBullet]

Originally Posted by Headcase98002

Replace the full cuts with something more streetable. That is where I would start.

I think I am going to put the 181s in this weekend and the valves need set since cam is new.

[straight 6 roar]

Full cuts, cam, pistons, large turbines, and even possibly the porting are going to slow things down in the low rpm but something is not right with your back pressure. Have you checked for boost and drive leaks? The hot pipe commonly leaks where it connects to the top turbo. It should be close to 1:1 at 60psi boost.

[Big Blue24]

I would advance the timing to 25*, remove the full cuts and go back with either the 181's, a set of 024's or 191's, or something slightly larger like 025" dv's. I would also tune the AFC to reach full travel around 60 psi boost, using a stock governor spring is a pretty good setup for slowing down the AFC so it can run lean and mean on the bottom end/mid-range. Overfueling on the bottom end is more detrimental to spool-up than most would ever realize until they try leaning out fuel delivery on the bottom end.

All said and done, with the decompressed pistons and extensive head work, you might not have enough compression and swirl to ever run squeaky clean, but black smoke at 65mph is definitely ridiculous for turbo diesel at cruise and can be tuned out.

[Drothgeb]

You have my build more or less. You should be making tons of power. I have no problem building 85-90psi of boost, with 45psi out of the primary. Run's pretty clean too!

I agree with both of the above post plus, that's a pretty big turbine on the secondary. I still run a 62/65/12 and have no problems driving the primary. Drive pressure is +/- 15 psi over full boost.

[TheSilverBullet]

I have had the timing at 24* but it made me have no bottom at all. I was also way over fueled on the bottom. It runs about 850 degrees ate 65 which I think is a lil warm and when u goose it, it has no problem climbing to 14-1500 rapidly.

[Hammer]

For s street driven 12v the bottom charger is way to big and you have too much exhaust wheel on the top charger.Have you ever seen John_P's "Red Rocket" and the turbos on that 12v?.You would be very surprised how small of a set he runs(bottom charger is a S400) to get his into the 800's on fuel only.When I asked him why way back when he didn't run a bigger charger on the bottom his reply was,it was tried and when street driving it was way to smoky and didn't spool soon enough to fit his driving style.

I know there are many guys here who swear by those big bottom charger with large exhaust housings but on a truck that has the timing fixed it creates a huge issue with spool time and temps.IMO,a smaller bottom charger with a tighter exhaust housing(something in the 1.10-1.23AR range) would allow the truck to wake up a bit.

[Ghostman]

Originally Posted by Hammer

For s street driven 12v the bottom charger is way to big and you have too much exhaust wheel on the top charger.Have you ever seen John_P's "Red Rocket" and the turbos on that 12v?.You would be very surprised how small of a set he runs(bottom charger is a S400) to get his into the 800's on fuel only.When I asked him why way back when he didn't run a bigger charger on the bottom his reply was,it was tried and when street driving it was way to smoky and didn't spool soon enough to fit his driving style.

I know there are many guys here who swear by those big bottom charger with large exhaust housings but on a truck that has the timing fixed it creates a huge issue with spool time and temps.IMO,a smaller bottom charger with a tighter exhaust housing(something in the 1.10-1.23AR range) would allow the truck to wake up a bit.

I must agree.

[DieselheaD]

Originally Posted by TheSilverBullet

I have had the timing at 24* but it made me have no bottom at all. I was also way over fueled on the bottom. It runs about 850 degrees ate 65 which I think is a lil warm and when u goose it, it has no problem climbing to 14-1500 rapidly.

Those temps sound spot on. And dont expect torque soon with that big secondary turbine

[YOUNG GUNS15]

Figure out who or where to get a 1.10 AR housing for that 480, double check for boost leaks/ drive pressure leaks, and put your 181's back in. That should wake it up.

That 62-74-.70AR should be a great turbo, I disagree that the 74 is too big, especially shoved in that .70AR turbine housing. That sucker should spool like crazy, Especially at lower elevations.

[wfodiesel]

Agreed

[TheSilverBullet]

Ok I moved the afc housing all the way back. I did have it alway the way forward. Smoke control is a lot better, driving still hazes decent running down the highway. It lights a lot better now. Egts are still kinda crazy, carries 1250 up a hill. I do agree with changing the housing but wondering how much it will hurt my top end? Pump has a 4 gsk in it.

About a week or so ago I pulled a 32ft dual tandem gooseneck with a skid loader. Together they weigh about 20k. I had to pull a pretty long grade and it instantly pegged my gauge I didn't think I could make it to the top without turning a piston into a blob lol. That being said a tighter housing would be nice I pull some with it and don't want to melt her down. Also curious if my waste gate isn't phucked and opening back up? Don't u guys think I should be pushing more than 28-30 pounds out of my primary?

[TheSilverBullet]

Also noticed soot around my secondary and the cartridge was loose, tightened all the bolts and also helped spool up

[Headcase98002]

Are you going I swap DV's?

[YOUNG GUNS15]

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He runs a 480 primary, it can be done correctly, just keep tuning.

[JQmile]

Originally Posted by TheSilverBullet

Ok I moved the afc housing all the way back. I did have it alway the way forward. Smoke control is a lot better, driving still hazes decent running down the highway. It lights a lot better now. Egts are still kinda crazy, carries 1250 up a hill. I do agree with changing the housing but wondering how much it will hurt my top end? Pump has a 4 gsk in it.

About a week or so ago I pulled a 32ft dual tandem gooseneck with a skid loader. Together they weigh about 20k. I had to pull a pretty long grade and it instantly pegged my gauge I didn't think I could make it to the top without turning a piston into a blob lol. That being said a tighter housing would be nice I pull some with it and don't want to melt her down. Also curious if my waste gate isn't phucked and opening back up? Don't u guys think I should be pushing more than 28-30 pounds out of my primary?

What gear were you in, and at what rpm? Should be at least 3,000rpm for that type of load on a modded truck.