Turbo survey

[RDBuck]

What seems to be the consensus on the best size turbo to use on our 1st gens? Not considering price but only performance up to cruising speeds of 75MPH. I know most of us will say the 14 wastegate but is there enough experience with the 12 wastegate to go for that added low end response without losing cruising economy? Will the 12 actually help cut down on smoke and improve emissions? I currently run a 16 and I frankly want better low-end response but I do cruise at 75 and don't want to change that either.

 

[Deezul1]

My friend with a strong 1st gen went from stock housing to 16cm to 12 cm wastegated with wastegate not hooked up and really likes the 12. I dont believe he would go back to the 16. His truck is pretty quick and is hard for me to beat. I think you would be pleased with the 12cm.

 

[Power Wagon]

I went from the stock 18 to a wastegated 12 (yes, the wastegate is hooked up, never run not hooked up!), and in our typicl wet winter, it required I re-learn how to drive to avoid making large arcs in the middle of the street unintentionally.



The boost comes in NOW, at almost any speed (I have an auto), with no real lag at highway speeds. It is dramatically better off the line and at mid-range. I did not notice any loss of performance at the top end, either.



If you intend to use Lucas injectors, and go for max performance, I would consider going to 14, or 16 if yer wanting to spend less. The 12 would be a bit restrictive for a 250 HP engine.

 

[Deezul1]

Powerwagon

Please explain why "never run with wastegate disconnected", I have done it both ways and am ready to learn.

John

 

[Power Wagon]

You should set the wastegate with as only as much boost as is needed to stay ok for EGT and not smoke. Creating excess boost is just unneeded restriction on the exhaust, which takes power to overcome.



In some applications, it won't matter, since a stock engine that never sees past 2000 rpm would probably not benefit much.



But if you're bombing at all, just make a habit of setting things to only as much boost as you need to accomplish the task. It's just an efficiency thing, and probably worth a fraction of mile per gallon and maybe a couple horsepower.

 

[JMorrow]

Originally posted by Power Wagon

You should set the wastegate with as only as much boost as is needed to stay ok for EGT and not smoke. Creating excess boost is just unneeded restriction on the exhaust, which takes power to overcome.



In some applications, it won't matter, since a stock engine that never sees past 2000 rpm would probably not benefit much.



But if you're bombing at all, just make a habit of setting things to only as much boost as you need to accomplish the task. It's just an efficiency thing, and probably worth a fraction of mile per gallon and maybe a couple horsepower.

I am with Power Wagon, I have a 12 on mine and would never go back to stock turbo. I have been up to 92 MPH with no problem.



John

 

[R.E. Miller]

Power Wagon.......

Since we are on the topic, I need some help. I have the 12 on my pick-up, and like it so far. Question is... . How do I adjust the wastegate? It was set at 32 psi, and I cannot even squeeze that out thankfully I typically see at normal cruise about 10psi and under load 20-25psi. I understand what you are saying Power Wagon, and so does my head gasket oil seeping yikes! I don't have any smoke problems, the smoke went down after I changed to the 12. I now only get a tiny puff at low boost. I would like to play with the wastegate so I can lower the boost and let my headgasket and bottom end relax a little.



Thanks for the help,

Russell

 

[Power Wagon]

The answer is a bit rambling, so bear with me. There are multiple styles of actuators, and multiple ranges of pressure.



BUt, here's how it basically works: The actuators havea strong spring inside that pushes the gate shut. It pushes against it via the rod, and the rod is normally adjustable length. On my truck, if you set the rod to be just tensioned a bit, it will open at about 12 to 15 psi. If you have it so that it's compressed 1/4 - 3/8's of an inch when shut, it appears to open at more like 25-30 psi.



Now, some rods have the end staked or welded and it just won't move. Others will move easily. You just adjust the lenghth of the rod, so that when you apply 20 PSI, there is no longer tension on the wastegate, and perhaps just starting to open. that'll get it opening in the very high teens.



You may want to remove the actuator... there is an E-clip that holds the end of the rod on, and 2 nuts that hold the body of the actuator to the bracket, clamp the rod very tightly in a vise, and then see if you can loosen the end, to screw it in or out. I believe out is more boost, in is less - but then it's been a while since I messed with it. You do not want to put force on the diaphragm inside by twisting against it. It can tear, or the attachment area begin to leak.





Mine screws in our out easily and has a locknut to keep vibration from wearing the rod and screw-on end from wearing out.



Just be aware that some actuators may not want to work at 18-20 psi, since they would have been designed for more like 30 psi. But this would not generally apply to any stock actuator.

 

[bvanetten]

Powerwagon,



All this talk of wastegates has got me thinking. I don't have one. Never have had one. Should I be worried? I plan on installing POD injectors in a couple of weeks. I'm hitting about 22 lbs boost now with a 2nd gen intercooler.



Bruce

 

[Snow man]

Im with powerwagon too,with the HX35,from what I've read,you dont want to make any more boost than you need,since the turbo becomes very inefficient at high boost,a few things happen when you use to much boost,first the drive pressure(exhaust backpressure in the exhaust manifold becomes very high,because your forcing all the exxhaust to go thru the turbo's housing at high rpm's,high load,if the wastegate functioned right,and opened,it would allow excess air around the housing,reducing drive pressure,and actually improving airflow at a certain point. Now on the intake side of the turbo,the HX35 is good to about 33-36 psi,above that boost level it starts to make a lot of heat,but not much more boost,so the air temp rises quickly as boost goes over 35,so there is no beneift to boost higher that 35 or so,with the stock turbo,now the HX40,or the B1,and other turbo's are still in their efficiency map at 40PSi,and higher,those turbo's will improve performance,and higher boost is a benefit,but if your runing the HX35,I would keep the boost at 35 or so,max. I can get 31 psi,with just the DD3's,and a boost elbow,but with the comp on level 5,my boost only goes up to 37-38 peak,this tells me,im way off the map of my turbo,and its inefficient at that HP,but im not $$ ready for the B1 yet,although i feel tis worth every penny.

 

[RDBuck]

turbo questions?

Snow Man you are losing me! What is the HX35, HX40, B1, DD3's and "comp on level 5"?

 

[R.E. Miller]

Help for you RDBuck.....

Snow Man in a 24 valver. The 24 valve lingo is DD3's= Diesel dynamics stage 3 injectors, comp on level 5= his fueling box that hooks into the computer that you can buy for the electronic engines like the 24v or ISB if you will. Level five is I think the highest level of increase fueling... ..... i. e. if you could do that on your truck you would need a new set of underwear



Generic Lingo here is the HX-35= the Holeset turbo that is on the 94-up rams, there are some exceptions. HX-40= the Holeset turbo that guys with mucho horsepower are moving up to, and finally there is the B1 term... a hybrid turbo built by one of our friendly members that is a whole story in itself. Basically, it is for sick amounts of horsepower and is said to be heavy duty, look over on the products/accesory forum for more info.



Hope this helps!



Russell

 

[RDBuck]

turbo education

Thanks R. E. Miller. That's what happens when you skip a generation, kind of makes me feel out of touch. The newer trucks must be like driving a rocket compared to my trusty 1st gener.

 

[Snow man]

Sorry RD,yes im a 24v guy now,but i still wish it was 12v,

 

[R.E. Miller]

Snow Man

Yeah, 12v's are nice, but isn't it cool to gain HP by pressing buttons he he he I can afford a new one but my friends have them. I love my 1st gen's, but everytime I climb into a new one, I wince

Russell

 

[Matt S]

I have a 12cm2 and love the response at the low end. I saw a difference of 5 horsepower between the 16 vs 12 housings on the dyno. I hit around 28 psi at WOT. No problems with cruising and mileage doesn't seem to be affected. I do not have ANY EGT problems with my set up with 225 hp at the wheels. Anyone have any suggestions on more power without EGT problems, I'm all ears.

 

[RDBuck]

Emissions

Matt S I see you are from Boston. I'm down on the cape in Chatham. Wondering if you have any problems with your set-up passing the Mass. state diesel emissions inspection?

 

[DieselBuzz]

Diesel emissions?!

Damn my ignorance! Is this new for '02? In May '01 when I got inspected they didn't go near the tail pipe. It was a good thing for me too. The previous owner, it seems, welded in his own muffler eliminator that leaks! It' not too bad, but I digressed from the turbo subject. Sorry

Art

 

[Roger rodbolt]

Originally posted by Matt S

I have a 12cm2 and love the response at the low end. I saw a difference of 5 horsepower between the 16 vs 12 housings on the dyno. I hit around 28 psi at WOT. No problems with cruising and mileage doesn't seem to be affected. I do not have ANY EGT problems with my set up with 225 hp at the wheels. Anyone have any suggestions on more power without EGT problems, I'm all ears.

Matt,

Did you lose or gain 5 horsepower with the 12cm housing? Did your dyno runs read the rpm for max horsepower, I was interested if the peak hp/rpm changed between the 16cm and 12cm housings. Thanks in advance!!

 

[Matt S]

I posted this under another thread with the 2 charts in hand. I think it was called 16 vs 12 on the dyno. I lost 5 hp on the top with the 12 but I gained 15 hp on the lower end of the scale. I liked and noticed the 15 more than I miss the 5. Makes the truck much nicer to drive in traffic.