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7.3 pulling heavy and high egts

 
  #16  
Old 07-07-2019, 02:26 PM
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Be sure to keep the RPMs up when on a grade, the added airflow cools the engine. While looking at the uppipes make sure the collector is properly mated to the turbo. High 20's on boost would indicate it's ok, but it's worth eyeballing it.
 
  #17  
Old 07-08-2019, 08:20 AM
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I think part of the problem is the large tires and transmission. Your gear ratio with 30" tires is 3:73 which is 1:1 when your transmission is in 3rd gear. In 4th or overdrive your effective ratio is around 3.00. I don't have access to the gearing calculators, but I would bet you are now running less than a 3:50 ratio. I run across a similar problem in my F-550, It is a tow beast as long as I stay in 3rd gear on very steep grades. Once it shifts to O.D. things start to heat up. The six speed manual guys have a much better set up as far as gaps between gears. The other unknown is what kind of work has been done to the transmission? What may have been a 20% drive line power loss may now be much higher.
 
  #18  
Old 07-08-2019, 08:27 AM
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The gap between drive and overdrive is pretty much the same between the auto and manual, the auto has a .71 OD and the 6 speed is .72.
 
  #19  
Old 07-08-2019, 09:02 AM
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Originally Posted by 00t444e View Post
The gap between drive and overdrive is pretty much the same between the auto and manual, the auto has a .71 OD and the 6 speed is .72.
Maybe I misunderstood the six speed ratios, I thought at Riff Raff East they dynoed 6 speed truck in 4th and the automatic trucks in 3rd overdrive off. That lead me to believe that 5th gear was a bonus for the manual transmission guys and the gap to 6th gear was much less than the automatic transmission. That is why I made the comment that the manual transmission guys have an advantage.
 
  #20  
Old 07-08-2019, 09:05 AM
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Originally Posted by CGMKCM View Post
Maybe I misunderstood the six speed ratios, I thought at Riff Raff East they dynoed 6 speed truck in 4th and the automatic trucks in 3rd overdrive off. That lead me to believe that 5th gear was a bonus for the manual transmission guys and the gap to 6th gear was much less than the automatic transmission. That is why I made the comment that the manual transmission guys have an advantage.
It might have been 4th on the shifter but it was 5th gear which is drive. The ZF6 shift **** reads L, 1, 2, 3, 4, OD.
 
  #21  
Old 07-08-2019, 09:08 AM
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Originally Posted by CGMKCM View Post
Maybe I misunderstood the six speed ratios, I thought at Riff Raff East they dynoed 6 speed truck in 4th and the automatic trucks in 3rd overdrive off. That lead me to believe that 5th gear was a bonus for the manual transmission guys and the gap to 6th gear was much less than the automatic transmission. That is why I made the comment that the manual transmission guys have an advantage.
The ZF6 has 6 forward gears and they are - L, 1, 2, 3, 4, 5. Some people refer to L as the 1st gear in the case, but most refer to 1 as the 1st gear in the case since L is only good to about 5-7 MPH. L is incredibly strong and will start moving anything, but once the tires start rolling, the truck should be shifted into 1st, 2nd and so on.

I hope this clears things up a bit.

As for the OP, if he wants to maintain the stock turbo then high RPM's will be required to keep EGT's manageable. If he chooses to get into the T4/SXE, then low RPM's and low EGT's are easily attained with stock injectors.

I feel that switching to the stock tune will get him low EGT's, but he will not be happy with the performance from the engine since he has been driving a different way for a while.

He needs to do what is right for his situation.
 
  #22  
Old 07-08-2019, 09:46 AM
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Originally Posted by 00t444e View Post
It might have been 4th on the shifter but it was 5th gear which is drive. The ZF6 shift **** reads L, 1, 2, 3, 4, OD.
Makes sense, thanks for clearing that up.
 
  #23  
Old 07-08-2019, 09:47 AM
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Sous, Thanks for clearing that up.
 
  #24  
Old 07-08-2019, 10:04 AM
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The shift kn0b pattern identifies gears as
R 1 3 OD
L 2 4


Here are the gear ratios on a ZF6

Reverse 5.23
L 5.79
1st 3.30
2nd 2.10
3rd 1.31
4th 1.0
OD .72


And here are Auto gear ratios

Reverse 2.18
1st 2.71
2nd 1.54
3rd 1.0
OD .71
 
  #25  
Old 07-08-2019, 01:03 PM
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Originally Posted by Wesley Green View Post
Here's the great ratios on a ZF6 as the shift **** identifies gears

Reverse 5.23
L 5.79
1st 3.30
2nd 2.10
3rd 1.31
4th 1.0
OD .72

Auto gear ratios
Reverse 2.18
1st 2.71
2nd 1.54
3rd 1.0
OD .71
Wesley, thanks for posting that information which only confirms that L is meant to start forward momentum and not a true forward traveling gear. Interesting to see the differences between the 4R100 and the ZF6 in regard to L, 1st and 2nd gears.
 
  #26  
Old 07-09-2019, 06:27 AM
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Originally Posted by tommyl View Post
Throw a 6.0 cooler in it and forget about all this other stuff!
Normally I would let this go, but future readers might heed it if they don't know better. With all due respect to you as a person and your effort to contribute - the thread is about high exhaust gas temperatures, and the purpose of the 6.0 cooler is to lower transmission temperatures. If you're like me, it's easy to get dragged down the rabbit hole when the discussion does an oblique to a related (but not on-point) topic.

bennyhick2 - Seriously.... Once you pull that chip, you'll be coming back here to ask why your EGTs dropped so much. The long answer starts here, and builds to the end: https://www.ford-trucks.com/forums/1...roduction.html
 
  #27  
Old 07-09-2019, 12:35 PM
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Originally Posted by Sous View Post
Wesley, thanks for posting that information which only confirms that L is meant to start forward momentum and not a true forward traveling gear. Interesting to see the differences between the 4R100 and the ZF6 in regard to L, 1st and 2nd gears.
It comes in handy starting out on hills when you can just ease off the clutch and get it moving. That is how it is in a big truck if you start out in 2nd or 3rd. Plenty of torque off idle to hold the rig from rolling backwards or stalling out,.
 
  #28  
Old 07-09-2019, 12:52 PM
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1150* is not that hot. 1250* I would back it off and drop a gear. Or in your case just lock out Overdrive and keep it at the 1/1 ratio. There is no magic solution besides turning the power down. On big trucks that are set at the very conservative rated hp (ie: stock and idiot proof), you have no choice but to downshift once or twice going up a hill with any sort of load on to keep the truck from bogging and stalling out. With modified engines with the fuel turned up you have to keep an eye on things. I can climb pretty much any mountain pass in 4th (ZF6) at 50-55 mph and keep the EGT's in the 1000-1100 range pulling an RV, which is basically a giant parachute hanging off the back.
 
  #29  
Old 07-10-2019, 06:23 AM
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Originally Posted by Brandonpdx View Post
1150* is not that hot. 1250* I would back it off and drop a gear....
Originally Posted by bennyhick2 View Post
...I usually shift down manually when I can to keep my rpms up. But I still have to keep backing out of the throttle to keep at 1150...
Downshifting is good advice, but I think we're already past that point. I've been here, as have many of my friends on this site - and I worked past it to have more power at lower EGTs. I'm not suggesting the OP abandon tuning... I just mentioned pulling the chip so he can see the result, then it can start a conversation on where to go from there.
 
  #30  
Old 07-10-2019, 10:56 AM
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His next move IMO should be to add a 4" exhaust and delete the EBPV, if that is still there. The wastegate being wired shut might not be a good idea either. I am not a big fan of wastegated turbos on diesel trucks anyway and consider them unnecessary clutter. (I use a 1.15 A/R turbine housing off a van and it helps a little.) On a small turbocharged gasoline engine where turbo response is more critical, sure. Anyway bottom line is he may not be able to use the throttle like a light switch when he is yanking his 10,000+ lb camper up a hill with the tuner on full blast. You start to bump up against physics at some point or another.
 

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