Towing compounds question

Signature600 said:
Lower timing also moves the power down towards lower RPM. For towing, you don't need power at 2500RPM, you need it from 1500-up. Lower timing will help that.

Chris
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I picked up a nice mpg gain on my old work truck 12v going to around 21* timing. It had 4.10 gears and was always around 2200 rpm plus going down the road.

Big drop in egt's also when towing heavy, all around a better truck than it was at 16*
 
alienturtle said:
that would cool to see. Im actually not against loosing the w2A and going with a large A2A if it will be more efficient than the W2A. I have no real world data to show one will work more efficient in my application. There seems to be a lot of variables involved also. how large are the coolers. water volume, how large of an intercooler ect
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I attached a picture, not sure if it can be seen. EGT 7 is pre CAC air intake temp and EGT 8 is post CAC air intake temp. Pre-CAC temp fluctuates more with ambient temp, but post-CAC is pretty much always always in the 100-110 range.
 

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jasonc said:
I picked up a nice mpg gain on my old work truck 12v going to around 21* timing. It had 4.10 gears and was always around 2200 rpm plus going down the road.

Big drop in egt's also when towing heavy, all around a better truck than it was at 16*
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That is a good point, but you had 4.10's and I had 3.55's. If I was running around at 2000-2500RPM I would have moved the timing.

What gears are in the OP's truck? That is needed to make a good recommendation on timing.

Chris
 
Vincejax said:
Lower timing would add torque, not power. And even on a stock application you would see torque peak at about 1600 and hp peak at around 2600. It will be more responsive across the board as well as more fuel efficient and lower egt with some more timing.
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Didn't I say it would "move the power down" That sounds oddly familiar to adding torque?

I'm going to ask you again, how much heavy towing have you done with a 12v?

Making power with them, is not the same thing as making towing power with them. I have towed with a 650hp 12v, and I have towed with a 400hp setup built for towing. I know which one I would do again.

Chris
 
Signature600 said:
Didn't I say it would "move the power down" That sounds oddly familiar to adding torque?

I'm going to ask you again, how much heavy towing have you done with a 12v?

Making power with them, is not the same thing as making towing power with them. I have towed with a 650hp 12v, and I have towed with a 400hp setup built for towing. I know which one I would do again.

Chris
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Information>Haughty conjecture
 
If you are towing heavy with a 12v you shouldn't be camping out at 1500rpm. If you are you're just lugging it anyway. Good for making noise and smoke but not any good for pulling a hill or accelerating a load. The factory rated hp is @2600-3200rpm for the 6bt engines depending on specific configuration... You say "12v's don't breathe" but you want to keep yours at 1500rpm :nail: Rpm's move air...
 
The marine 12v 300hp engines come factory at 20*
And best rated cruze mpg Ive found has been 2200 rpm.
 
Signature600 said:
That is a good point, but you had 4.10's and I had 3.55's. If I was running around at 2000-2500RPM I would have moved the timing.

What gears are in the OP's truck? That is needed to make a good recommendation on timing.

Chris
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im running 3.55s.

I appreciate everyones experience and input. There is certainly both sides of the table here. But im learning some things along the way. I may bump timing to the 17 range and see how it likes it.

Im still learning if the w2a or a2a will be better in my situation. im leaning toward keeping the w2a.

Sounds like the HX35/HX40 hybrid upgrade is not going to help me at all. Sounds like i will be better off just keeping my hx35

Signiture600. in your experience towing did you like the 100 fuel plate? i have read the 10 is good for a manual trans?

Again appreciate everything.
 
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I just bumped timing up to 21 degrees over 16 before, and power delivery is great. Still will make power if pulled down to 1500, egts only get over 1200 if stretched out past 3k rpm. Running an HT60/HE351 and 5x12s. Haven't had a chance to pull more than 5k with it with the timing bump but I see no advantage to having it lower.
 
alienturtle said:
im running 3.55s.

Signiture600. in your experience towing did you like the 100 fuel plate? i have read the 10 is good for a manual trans?

Again appreciate everything.
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I ran the 100 in everything, towing or high hp applications. However, I also always modded my AFC for more travel, and also ground on the AFC foot a bit as well.

The plate isn't nearly as important with a properly functioning and well adjusted AFC, since the fuel won't just get dumped in there without the boost to move the AFC out of the way.

I'll say again, I would not take the timing too high with 3.55's and towing with a 12v. I have done it, it's not fun, and the rattle from the timing is not good for the engine.


Food for thought...the engines we use in our farm tractors fire the injectors 3 times at normal working loads, at 1800-2100RPM under load...the pre-injection is at 6* advanced, the main is at TDC, and the post is at 6* retarded. You can bet that if it made a drastic difference in fuel economy to run them at 20-25* advanced, and they would still pull as well for the application, then the company would build them that way. Our fuel efficiency is already 15-20% better than some of our competition.

How is that application much different than a towing application?

Chris
 
Vincejax said:
If you are towing heavy with a 12v you shouldn't be camping out at 1500rpm. If you are you're just lugging it anyway. Good for making noise and smoke but not any good for pulling a hill or accelerating a load. The factory rated hp is @2600-3200rpm for the 6bt engines depending on specific configuration... You say "12v's don't breathe" but you want to keep yours at 1500rpm :nail: Rpm's move air...
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I never said it needs to stay at 1500RPM...but what is the point of taking power from the bottom to get it to the top? The bottom works fine.

70mph with 3.55's is 2000RPM. So why would I recommend tuning the thing to run at 2500RPM? If most of the operation will be from 1700-2500RPM, why would I tell the guy to tune it for only the top of that range?

And if you don't think the trucks I have tuned could pull 40K lbs smoke free at 1500RPM, then that is your opinion, I know what I have done with a 12v almost 20 years ago now, back before all this amazing turbo technology and an abundance of good camshafts were available. It would be a lot easier now.

Chris
 
Signature600 said:
I never said it needs to stay at 1500RPM...but what is the point of taking power from the bottom to get it to the top? The bottom works fine.

70mph with 3.55's is 2000RPM. So why would I recommend tuning the thing to run at 2500RPM? If most of the operation will be from 1700-2500RPM, why would I tell the guy to tune it for only the top of that range?

And if you don't think the trucks I have tuned could pull 40K lbs smoke free at 1500RPM, then that is your opinion, I know what I have done with a 12v almost 20 years ago now, back before all this amazing turbo technology and an abundance of good camshafts were available. It would be a lot easier now.

Chris
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OP didn't state his tire size, you have no idea what his engine RPM is at 70mph.

Cool experience bro, there are other experienced guys on this thread also recommending he run higher timing.

I have owned and ran 3 12v's over the last 15 years and have a 4th DD in the works. From stock/mild to pretty wild. From daily driving to race only. Jasonc has also daily driven a 12v for years and has a few 9sec passes in a 12v to his credit also.
Also since I have an adjustable pump gear I have experimented with many timing settings while observing the results with time slips and a 20 channel data logger. The timing advance being suggested would give a big improvement in responsiveness, economy, and power, but would not make a significant difference in his low end torque. His low end torque will be strong because he has small compounds and a mild camshaft as well as stock valves.
 
Vincejax said:
I've gotten a good laugh out of your spooky tall tales and how we should heed your obscure warnings because you are the ultimate 12v towing mileage KING! :bs:
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Now you’ve reached the point where you’re just annoying. You’ve given plenty of specifics for your side of the discussion. So, FO already.
 
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