I've got a Banks Wastegated Sidewinder kit on my truck right now.
As far as I can tell, I can get about 5PSI out of it at 1600RPM, with full throttle. I don't get the full 10PSI out of it until 2200+RPM.
I've already got the fuel as high as I can have it -- when I've got the engine maxed out at 1600RPM, I'm getting a haze of black smoke.
Thing is, I want more power, especially in the low end.
I've got some headstuds, but now I want to find a turbocharger which will at least double that(10PSI at 1600RPM), and hopefully give me a couple of PSI in the 1200-1600 range.
At 2500+, I don't care, because I never go that high -- so ending up with something that spools quickly and maxes out early is fine with me.

I know there's a turbocharger topic around here, but I can't make heads or tails of the graphs.

Any thoughts?

 

you should get 10psi out of a banks there must be something wrong with your turbo

 

You didn't read the post. I can easily get 10PSI out of it, but it takes 2200+RPM to do it. I want more pressure lower down in the revs.

 

Won't happen...This engine needs to rev up....Its not a six Banger.. Its a High speed Diesel V8....Stock Max Torque is somewhere in the 2600rpm range Max HP 3300rpm... If you don't rev it... You won't be able to spool a larger Turbo.

 

You can put a smaller turbo on there, that will spool faster, but it will have high drive pressure and choke down the top end. 5psi by 1600 is pretty good. These are high rpm engines, almost a necessity really with the compression ratio, add in boost and that is massive cylinder pressure in low rpms. There is a reason almost any diesel in the 500+wph catagory is turning 5k or better. To keep cylinder pressure in check. Now consider that they are 17:1 and we are 22:1

 

a turbo will only make boost under load.
cruising down the road i can see 0 boost at 1200 rpm, or 16+ lbs boost pulling a hill towing 20,000 lbs.

a wastegate limits boost to whatever the wastegate is set for. eliminate the wastegate and you will see 16+ lbs boost under load.

 

Where do you get this? I thought max torque was more in the 1,400-1,800 range.

 

NA peak torque is 1600 on a 6.9 and 1800 on a 7.3 iirc 2200 on a 7.3 turbo. Pretty typical numbers for a V8 diesel.

 

6.9: 155-175HP@3300 RPM, depending on factory injector pump calibration.there were also separate calibrations for high and low altitude locations.
318 ft-lbs torque @1400 RPM

7.3: 185HP@3000 RPM (natural asperated)
190HP@3000 RPM (turbocharged)

338 ft-lbs torque @ 1400RPM (N/A 88-92)
358 ft-lbs torque @ 1400RPM (N/A 92.5+ model years)
388 ft-lbs torque @ 1400RPM (turbocharged)

 

Cyl pressure wise, if I'm putting in air at 20PSI and enough fuel to use all that air, the cyl pressure should be the same whether I'm turning 600 RPM or 6000RPM: Each compression stroke is the same length. The only issue would be that at higher RPMs the cyl might not get up to 20PSI before the intake valve closes... but I doubt that would be too much of an issue.

With my turbo, I tried unplugging the wastegate, to see if it was opening before 10PSI. I had no change to the boost pressure below 2250RPM, when it would open.

Overall, I'm looking for a slightly smaller turbo, something that will give me the boost I want lower in the revs, at the engine's peak torque. If it loses efficiency and my pressure drops up high in the revs, I'm not too concerned.

 

the larger the turbo (as a rule) the more laggy it will be.the banks should be super snappy.

1.where is the timing set at?

2.injector info? (brand/code/miles/reman/new/unkown condition etc.)

3.whats the ip info?

4.what do you mean by this:
"when I've got the engine maxed out at 1600RPM, I'm getting a haze of black smoke."

how could you possible have your engine maxed out at such low rpm? (and why would you lug it so hard under load anyway?)

5.why is this?
"At 2500+, I don't care, because I never go that high"

if you don't let the engine rev a bit,then your going to be very hard on the engine with very high EGT's.
you just run this truck around empty im guessing? if so,then why would you want more power down low?

6.do you have heat wrap on any of the exhaust?
what about a turbo blanket?
^ both of those are very noticeable.

7.are you drawing in air from outside the engine bay?

8.what do you have for a transmission and gear ratio?

9.what does your truck weigh,and what is your average CGVW?

10.whats the exhaust info?

 

MacroBB, I have the same problem and I was wondering the same question. I have a non-wastegated ATS turbo kit on my f350. Red-lined, I've 8PSI max. When the tranny shifts, my rpms drop to 2300rpm and my boost drops to 4PSI. I was wondering if there's a drop-in replacement or if a turbo-shop can easily tune the turbo with different turbine and compressor to give me more boost at lower RPM.

 

The Factory reported output Numbers on this Engine are Not Very realistic for using them for Turbo related performance. There are way to many factors that play a roll in the way the Engine responds to Turbocharging. To say that the Max torque is measured at 1400 rpm in every situation would be incorrect. You need to look at all the mods to the Engine and its Exhaust system to determine the modified engines max torque rpm. If you want More Boost at Low rpm you will need a turbo with a smaller exhaust housing to spool faster or you need a more efficient turbo to move more air with the same exhaust gas volume and or a combination of both. Increasing the diameter of the exhaust pipe will help with spool up. adding fuel helps with power and spool up by increasing cylinder pressure. Stock cam is just to lazy to respond well and you get a lot more heat at low Engine speed. You said your Engine doesn't max out the boost until 2200 rpm. The Engine doesn't get to full volumetric efficiency until then so it can't take full advantage of the extra air until it reaches that point. You could get a bit more power with a Intercooler in the system too. You say you never rev it over 2500 rpm....Do you have a double overdrive?... What trans are you running? Look into a ball bearing turbo they spool faster than a oil bushing turbo too. Every little thing you do help spool will compound on the next to increase boost and spool faster than the MFG's stock configuration.

 

Alright, lets take this from the top.

It's fairly snappy; a couple of seconds for it to spin up to maximum pressure at a given RPM when I floor it.
27 degrees @ 2K rpm, when measured with a luminosity probe -> timing light, against the top edge of the timing strip of metal(not against the zero mark on it).
This is what I've found to give me the most power; I've adjusted several times back and forth to find it.
I've also checked a 'stock' vehicle that I *didn't* mess with, and it was at that timing value+-1deg.
All Stanadyne; varying codes. All have been set to 2000PSI +- 50 and spray patten checked.
Unknown. It's a 7.3 pump, came with the truck when I got it a few years and 20K miles ago. I know it's worn, but it is putting out enough fuel to do the job, as far as I can tell.
I've turned the fuel screw up to where I get a definite haze at full load.

I have 4.10 gearing + ZF5 + GVOD. In top gear, 60MPH @ 1600RPM.
It's not hard to totally max out the engine(pedal to the point where I'm smoking from the exhaust, but my tach/speed isn't going up) in top gear going up a big hill.
It's also quite easy to do it if I haul a trailer.

About half empty, half with 1/2-1 ton of scrap wood in the back.
Example:
http://imagizer.imageshack.us/v2/800...0/843/66kb.jpg
However, I'm looking for more power for pulling a trailer with. Last time I had to pull a trailer, I didn't have nearly as much power as I wanted.

I don't think I've spent more than around 30s over 2500RPM at a time, ever. It's a lot nicer feeling when in the 1600-2000 range.
Part of that seems to be improper IP advance curves(wear?), which I adjusted very recently, so it didn't get too advanced and start clattering and losing power up beyond the 2500rpm point... but I still have the gearing for the lower revs.

I'm really looking for it to give me good low end acceleration of a load, for those 30s or so before the EGTs end up hitting 1K+.


Not enough to worry about; I wrapped the downpipe to protect the cab, but that's it.
Nope; the plumbing was a bit of a hassle, so I just left it with an open filter going straight into the turbo.
I'll probably add an intercooler before trying to affect the temps going into the filter -- At highway speeds, I should be getting enough flow for it not to be a problem.

As explained earlier, 4.10 + ZF-5 + GVOD
6600lbs empty, on the scrapyard scale last I checked.
Other than that, I have no clue. Empty or with a load in the truck bed -- even one over a ton -- doesn't seem to affect my acceleration noticably.
If I pull my dad's 2-axle tilt-bed trailer, even empty, it's quite a bit slower. Googling, I'm guessing it weighs somewhere around 5000lbs, which would explain it.

Running the Banks stock up-pipe and crossover(which was multiple pieces and has been welded to prevent leaks).
Banks stock 2.75" downpipe, leading into 3" piping from the bottom of the engine backwards.
I have a 3" Thrush Turbo muffler, and exhaust coming out in front of the rear wheels.

--------------------
Goal wise, I have a second truck I intend to build up, as money and time permits.
I'm using my current vehicle as a 'reference', and I want to take it all one step further.
I just got some turbo piping for it, but I'm going to need to find a turbo, and I want to end up with something better than what I have now.
That engine will end up with a RD2-110 pump, torque cam, ARP studs(which I have for it already), along with any mods I have applied to my main rig.
Depending on how that rig progresses, I will probably put the 'best' engine into whichever truck I have as my 'main' rig, and then work on improving whatever's left.
Of course, the real restriction here is money -- new, expensive parts(like a RD2-110 pump) are hard for me to come by; cheaper bits and used stuff is more available.

Anyway, that's the deal.

 

when the truck is doing work, IE towing, you must have the transmission in the proper gear, at the proper RPM, let her rev a bit more, your gear vender should only be used, when on flat ground, or when not towing, OD will cripple your towing power. what are your EGT's? wrap your exhaust and blanket your turbo, put on an IC and add a bit more fuel, after all, power, just costs money