vanderchevy18
New member
Nope. Both are reverse.
IH Navistar T444E cam
- Thread starter powerlifter405
- Start date
it really depends on turbo response as to where the power starts. with ported heads and a stage 1 cam you don't lose anyting and start gaining everywhere.
powerlifter405
Active member
I'm planning on using the GTP38R w/ a GTX 4294 or get a t4 mount and use a GTX30 or GTX35 for the HP to provide near instant low end airflow/throttle response and get the mid range and upper w/ the GTX4294R or GTX4202R.
I was eyeing cams as another source of air flow but aside from my turbo selections I'm trying to keep things simple and reliable.
I debated porting, as if the motor is forged vs PMR I have no need to remove the heads. But If i'm starting from scratch I'll go the easy way out and I'll get one of Dave's built 7.3.
I"m really not sure where it stands as I"m in the planning phase.
How would a cam behave w/ a single GTP 38R or even a single GTX35 or GTX38, VS one of these coupled w/ the larger LP mentioned above?
vanderchevy18
New member
Dude a GTX4294 is an awesome single. You need to go bigger to compound it. That or use the GTX4294 as the HP turbo.
Groomzybanshee
New member
I agree if a bb 4294 is to laggy your doing something wrong.
Not correct... and I was corrected on this myself a few weeks ago...
http://sdforcedinduction.com/zen/index.php?main_page=product_info&products_id=86
Ultimate towing compounds (and almost silent) would be a gtx35 and a gtx4202. i would build a motor with good rods though because that has potential to build 1500+ft/lbs of torque in a hurry.
Groomzybanshee
New member
Most people don't get that Matt. They think others are running a 42 as a single so there fine but in reality not so much.
powerlifter405
Active member
I wasn't sure if the 75mm wheel would be too big to provide the lower end/mid range over lap I was wanting. I want a smooth transition between the two and I don't want to overfuel or have to use a heavy foot to get a larger 75mm moving in a compound set up, or even the 71mm in a single.
I am choosing the dual BB garretts for improved transient response time and larger center sections. When I spoke to both FI and MPD they both stated, if I'm wanting/willing to spend the extra $$ the garrett is better than the thrust bearing Sxxx-series or even the BB Precision units. FI flat out talked me out of the Precision.
I have the 2008 6.4 and thats plenty of power but I want the simplicity and mileage of the 7.3 but I like the responsiveness of the 6.4 twins.
I'm selling the 6.4 as we speak so i'm piecing my 7.3 build sheet together.
I've read both charles and Tarms' turbo set up and they seem to work good so that's where i'm drawing some ideas from.
Thanks for the info.
powerlifter405
Active member
Correct, I drove a school bus w/ the T444E and I had a 02 7.3. Two different turbos. I want to say the T444E is a Garrett 37D series
On a 7.3 engine with enhanced airflow like ported heads and a cam, the GTX 35 would be in it's efficiency range perfectly up to about 25-30lbs of boost. It would also spool up better than the 38r does. By the time the gtx35 is at 15lbs of boost the x4202 would be ready and willing to start adding airflow as it would probably be already in its efficiency range. If you really wanted to get cat's-azz with the setup, put a air to water heat exchanger between the stages and the air to air intercooler after the final stage of the compressor. The thing to remember in compounds is that you are dropping the pressure ratio of the chargers and the lb/min drops accordingly. The gtx4202/gtx35 combo would flow more like a gtx4294 as a single but with lower drive pressure overall. Since the 42 has a smalish turbine, I would run a 1.15 or the next size larger exhaust housing.
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ghohouston
Active member
To make things even more confusing, I worked on a 96-7 ish international box truck with a t444e, and it had a turbo just like an obs, but was intercooled iirc
powerlifter405
Active member
That was my guess when I was looking at the maps but i'm still eager to learn more.
Does one need the other? Cam vs porting? are they independant combing to equal a greater sum than each individually?
Now that you say that, how often for a DD application would a 7.3 see above 15lbs of boost? Aside from excellerating hard, under a towing load, etc.. When I"m empty just driving a long, I can't recall my 38R producing that much unless I was really in the pedal. The same thing for my 6.4. I can keep that under 12lbs all day long unless I get on the go pedal.
So your saying overall airflow, lbs/min of the 4202/35 would be similar to the 71mm 4294? But the gain would be a larger map, come on sooner, last longer, w/ lower drive pressures?
Just when i thought I had the most basic grasp of things, I get kicked in the nutts :doh:
I really wish there was a simple way to plug in the data but maps and info is scarce so i doubt that would ever happen.......
Back to fantasy land... After looking at the Garrett maps and seeing others w/ similar setups I figured that combo would give me great off idle response with minimal throttle input plus plenty of mid range 1800-2200 rpms on up.
My rpm goal is to be at 70-75 mph on a 32-33" tire w/ 3.55ish gears @ 1800 rpms. Highway speeds are 60-75 around here and my 02 7.3 was fine loping along at 1500 rpms so I'd like to use the natural torque band of the 7.3 to keep me moving vs higher rpms, when i'm a road trip.
My hope was to have plenty of air moving to burn what fuel is there=mileage/efficiency and prevent any lag when I need to slowly accelerate. Flooring it will get most any resonable setup going but I don't want to have to floor it it and i don't want just a "reasonable" setup. i want a solid, quick with minimal input when needed type setup.
Milford
New member
What kind of power would be expected on that setup tuned properly? 550-600 before your 35 is maxed out?
powerlifter405
Active member
I'm curious of the same thing. It appears the GTX3576 is just a hair smaller than the 38R but 3582 is a hair larger.
3582 is 62mm ind/82mm exd
3576 58/76mm
The 3582, one version appears to have a better map if I had to run just one of the 3582s as a single over the 38R but I bet Matt and Charles could chime in and decipher the maps better than I.
3582 would start making boost at 150-200 rpms lower than a 38r does at i'd bet, all things being equal. the 38r is a 65.x/88 compressor. and a compound setup with the 4202x would easlly make 600+ and be clean with 200% nozzles. you could push it higher than that though with a haze.
Milford
New member
Good food for thought. I always thought having a compounded 7.3 would be so sweet and now its becoming more and more common and parts are more readily available and tuning seems to be getting easier on them also.
Matt when you say 200% nozzle, what CC injector are you talking 250 or maybe a 300? I don't see(from what I have read on here) a 250/200 injector not being able to do 600 HP on compounds and live tunes running super clean and keep the lag to an extreme minimum. Is that doable?
Matt when you say 200% nozzle, what CC injector are you talking 250 or maybe a 300? I don't see(from what I have read on here) a 250/200 injector not being able to do 600 HP on compounds and live tunes running super clean and keep the lag to an extreme minimum. Is that doable?
powerlifter405
Active member
That was my guess that it would flow sooner but its good to know. I'm more interested in instant driveability vs over top end HP so i'm trying to spec my turbo set up based around the easiest/best DD vs spec the turbos for the inj size and HP goal.
I suppose if I wanted only HP, i could keep the 6.4 and payments, add a 71mm and have 625ish on tap. But I hate the payments and the mileage isn't as consistant as my old 7.3.
How do you think the smaller 3576 w/ a 4202 would work, w/ properly sized/tuned inj? Say a 250-200/200? I want to use a stock HPOP or maybe no larger than a SRP1.1.
I agree, it is a solid foundation and it is neat to see more progress being made on this platform.
