Ok guys, got it on today. It will be a week or so before I find out the actual gains in fuel mileage (if any) and the temperature outside needs to get back up to a standard. I will need about 1000 miles to get an idea of performance with the large housing.

Just the truck, no trailer, I can run 70 flat land at about 5 pounds boost, 65 at 1900 rpm at about 4 pounds. I beat in it in the hills a little, got the boost up to 28 at high rpm, pulling, most times to a 24 or 25 max boost at the rpm's I generally run with a load, 1800 to 2200. EGT's a tad higher, could only get it up to 1100 at one at the highest. That is not accurate until I have a load and steady wot to see what it will do, think it will be fine.

Spool up is I am sure longer but mine never did spool fast, so it is not noticable unless I am trying for fast acceleration, normal driving it is not noticable. Roll on boost at cruising speed is smooth and not noticable from cruise to wot. Cool down is the same or maybe a tad quicker, won't know for sure till I pull hard in hot weather. Cruise exhaust sound is a little louder at 2 or 3 pounds of boost.

On installation with the cast elbow from a '97, the exhaust had to be moved up and forward about 1 1/2 inches on a 45 degree angle. This was a commercial HX35 so I had to reclock both ends, and I reinstalled the silencer ring, so no more turbo noise. I have to reset exhaust down pipe as it is touching the frame on pull. I see no difference in smoke probably due to the electronics controlling the low boost fuel, but hotter weather will be the key to that situation.

Basically it still feels the same driving, no difference in general running. The boost pressures and EGT's are about what I expected (or hoped for) would not want them higher for my purposes. Actually it builds more wot boost than I figured. In the future a 4 inch exhaust will probably bring the high rpm boost down some.

 

Great report...interesting info.
The louder cruise exhaust sound should disappear when you get the downpipe away from touching the frame! I had a new downpipe rubbing on the transmission tunnel once...sounded like I had a stethescope held against the block!
RJ

 

Haulin'

Which housing was on this before? I can't believe it didn't kill the acceleration?? If you remember a while back I put a 14cm3 housing on my dad's 96 and the 0-60 acceleration was terrible, I have since fixed that problem (not entirely the housing) but it doesn't get up and go like the 12cm3. Yes, I know you are not building a "race" truck, so I am not looking at it that way-just curious.

 

Before the turbo was the totally stock 12 housing with a boost elbow from EZ. it stayed in wastegate most of the time so I felt that a larger housing would help it in the pulling/economy department. I did a lot of research on this before tearing into it. It looks like on my setup the 21 would have still been tame enough for the engine. But I got what I wanted, all the energy spent powering the turgo is now used for compression, not wastegate.

HOw can I put this, it is a little more lazy coming out of the hole due to longer lag, or better discribed, anyone who has driven a class 8 truck with a lot of power will know what I mean, it feels like a big engine unloaded does in the lower gears. But once it is spooled it feels like it got hit in the rear and the pulling I think is stronger than it was. Driving smooth for pulling freight or just going down the road, the truck feels the same as it did before. I don't have numbers, but the truck feels strong on acceleration, great seat of the pants.

Please bear in mind, this truck does not have a stock 235/460 engine in it. The cam is different and it runs a lot of fuel in lower rpm's and the FASS at over 18 pounds. The VP is calibrated differently and is the 2600 rpm motor. Defuels seriously by 2700. Actually compared to other trucks with this housing stock, I have not heard of boost pressures up to 28 pounds, so there is a definate difference. It (I guess) has the fuel curve to drive the turbo.

Now lets see if it gives better economy. I can get 13 loaded before the change, with an easy foot. I have two other combinations I can try if I feel bored in the future, the 21, and the 35/40 combo. Already have the wheel and housing from the 40. NO more changes until I get 4 inch exhaust. I doubt that four inch will change much at 1900 rpm though. I am more concerned with lowering boost while keeping good EGT's on heavy pull.

 

I was just about to mention the different cam in your engine...but you beat me to it. Sound like that thing is working great, Haulin.

Good Luck,
Chris

 

Haulin,

Where did you come up with the hx40 wheel and housing?

Aaron

 

Chris it is doing great, good mod for my engine. I got just about what I had figured. It has quite low cruise pressure with a load, 0 to 10 pounds and that with a rolling hills situation. On the harder hills running 1900 to 1800, pushes 24 pounds at the max. EGT's on a chilly day and night were max at 1150, never hit 12 so there is some leeway for higher elevations and tougher situations. A surprise though, it has more hill holding power, a few horse increase, did not expect that. No firm figures yet on mileage, chilly, windy day, wind kills economy on my rig, but it still got the best of mileage, 13 or better. Empty (7000 lb trailer) from Birmingham to Atlanta in mid 40's temps, I used the least fuel that I have seen. Loaded coming back into a strong head wind, still got 13.

Not sure that the economy will be earth shaking, but it is improved, light throttle the most, higher rpms, best improvement. Exhaust is definately lower in tone and louder than before. Smoke just about the same as with the 12cm. Soon as I can, will come the four inch stuff, I'll see where that goes. Good part is that 24 pounds of boost keeps it in good with the ECM on fuel delivery.

Aaron, I purchased a HX40 turbo from the same Dodge Mechanic in Cullman Alabama that ground the 53 of the block and it cracked. Turbo was the same idea, paid $150 for it, turned nice and tight, looked good, exhaust impeller was trashed, so junk. All together he took me for over $3000, not one of my best contacts. He will do that to the wrong person someday, get his.

 

Haulin'

I would have given him a long walk on a short plank-if you know what I mean. Ground the "53" off the block and sold it as good?? It even had a crack???

 

NO it lasted 6000 miles then cracked. It was new, that was true. Not worth a jail term for me. Now if I was in my 20's the way I did things then...

 

revenge is like fine wine... it's much better if it's aged properly

I'd wait a year or two and then extract my revenge...

not that I'd ever do anything like that...

Forrest

 

A little more info on the results of the 18.5 for towing purposes. It does improve economy and power. I noted that in good conditions the improvement on economy is not great, maybe a half mile per gallon. That is no wind, warm temperatures, cruising at 65 or so, just ideal conditions. The harder the truck is pushed the more improvement it has. Conditions that would give me 11 or so, hilly terrain, windy, etc, now gives over 12 mpg.

Highest EGT’s so far, 1200. Highest boost pressure is 30 in lower gears winding up like getting on the freeway in heavy traffic. In 3000 miles of chilly nights in the 40’s and heavy wind most of the time, no tank has been lower than 12 mpg, I think the lowest was 12.3. Ideal conditions would be like 80 degrees and no wind, have not had those conditions yet. The weather decided to go back to late winter for here about the same time I installed the housing.

I even got over 12 on the tank that I idled at high idle for a few hours, never done that before. For my engine this was a nice improvement. It makes me curious how it would work with other combinations, like a 40 with four-inch outlet and same sized housing. I am anxious to see what larger exhaust will do to it, as it is obvious that pulling hills, the flow is better with the increase of exhaust size.

The only negative that I have found is that it takes longer to cool down after running hard. Spooling is slower if you are looking for it, but normal driving it is not noticeable. The turbo is spooled by the time I am up in gears enough use heavy throttle. I have gained 5 mph or so on the steeper hills. That is when going into them at 65 or better and not having to shift. Hills that were dropping me to 60 mph are not staying at 65.

 

when I went from the stock turbo to the HX40-16, I noticed that the truck cooled down MUCH faster

if you go to an HX40, get the 16w turbine housing, trust me!