Just returned from 2 week trip pulling t.t. in mountains with above setup, it sure is a nice combo . I could stay in 4th o.d. nearly EVERY hill now, where I used to have to kick down to 3rd .On these few long 7% grades it would eventually drop down into 3rd, but maintain 65-70MPH with cruise set at 67-68MPH. , except when I got stuck behind slowpokes . I tried with and without cruise on, and preferred pulling with cruise on. What I found with MAD ECM now, is that with cruise on it can maintain speed with very little throttle movement, whereas when I would step on it with cruise off,I always seemed to push pedal too much. This would cause what I and others have also said, where more pedal doesn't do much more response wise, unless you back off a little or put to floor, then you have lots more power.

With cruise on it seemed to be always perfect, for making the right and instant adjustment to throttle to maintain speed, when going up any inclines. In 3rd and 4th gear power was awesome for passing, and EGT's would only get to 1150-1250f on hard pulls in 32c heat with boost at 34-35psi. Only twice did EGT's get to 1350f on those 2 very long grades at 34-35psi boost on HY-35, but would not get any hotter(pedal to floor). Coolant temp on the other hand did rise quite a bit more only on these 2 long hills, but stayed in safe zone to the far right. Never noticed any more smoke seemed to burn quite clean. Mileage was hand calculated strictly pulling at 14.4 lowest to 14.8 MPG CDN. With trailer and mix driving without averaged 17.8-18.8 MPG CDN. Very good mileage with this combo considering my driving style with the new found power, and all the passing.

These Mach 1.6's sure are everything they are promised to be and more, with little smoke, excellent mileage, and staying cool under load. If you can get used to the touchiness of the MAD ECM's throttle input, it is a very STRONG COMBO puller, as a Duramax with gauge pods, and some fueling box can attest to when I passed him on a big hill and he couldn't keep up.

 

What do you think ur power is at? Nice to hear that.

 

IM thinking of RV275 or the 1.6 ...Do you realy need to watch the EGTs or is it just on the long pulls ?? at times im up around 23K GCVWR and more power would be nice .also is your turbo an HY-- or an HX?
my truck is an 01.5 HO 6spd and I have a catcher and a 70/180 big hoss do you think the 1.6 might be to much? does the catcher hurt or help your EGTs?
sorry for all the ? im preping the truck for my MEXICO trip and would like to get it all figured out first.
thanks R

 

DO NOT STACK TIMING DEVICES!! CATCHER AND BIG HOSS IS A NO NO!!

If you run the Catcher, you should not use it with a device that advances timing in any way.

Consequences of excessive timing when towing heavy can be MELTDOWN, even with EGTs seemingly "fine" at 1150 or 1200.

Sell either your catcher or the big hoss. Don't use both. CAN I BE CLEARER? A guy who never tows MIGHT be able to get away with it, but probably not. You, on the other hand, grossing 23K will be into some awfully expensive stuff.

 

It will depend on which version CATCHER he has. If it is special version designed to be run with a box(without timing) it will be o.k, If it is standard version with timing, then it is not adviseable to run box with it towing, as that version of CATCHER already has timing programmed into it.

Rebal I run stock HY-35(auto) with disabled wastegate, yours is HX-35 a little bit more capable turbo on upper end. My normal cruising EGT's pulling trailer 19,000 lbs.GCW approx. are 750-800 pre-turbo in 4th gear o.d.mostly flat to slightly hilly. Cruising up moderate hills they would range 1000 -1100. Bigger hills egt's would go to maybe 1200- 1250 only near top of hill in 4th. Very long steep hills they peaked at about 1350f again nearing top(only did this twice), but never went over that in 4th o.d. I tried in 3rd gear direct lockup going up hill to see, and it was less than in o.d. by a hundred or so degrees.

Hard to believe you would need more power than what you have maybe your box is not working right? Clutch slipping? What are your boost pressures at under full load? Maybe they are too low to keep egt's down.

 

I dont have the catcher in at this time so the big hoss is it ...my EGTs are 1050 max preturbo on a 10% 2-3 mile grade. 29 lbs boost. if i install the mad ill pull the big hoss im looking to see if i want to run a mad with 1.6 or the 1.6s with the big hoss .i know the catcher makes lots of smoke and i can install it in my other 01 and my clutch is holding fine.
thanks R

 

I think with your weight you have, you would be better suited with the Mach 1.6's they are nice. Which MAD ECM version do you have? You MAY BE ABLE to run both , but find out first which version you have. Or do what I did and run just the MAD with injectors, or Big Hoss with injectors. You have a few options to try.

 

I think ill call bob and see if he sent me a special or just a standard mad ecm and try it with the 1.6s I could just swap parts and see what works best I just dont want to run my EGTs though the roof.
thanks for the input. R