Turbo/Injector balance for towing/EGT control

[Hutch24v]

Brand new tires so I’m going to have to deal with the ratio for now. EGT is controllable. Thanks for all the replies. 

[Hutch24v]

Warming up this thread again...looking at new injectors on the DAP website while I make plans to replace my existing 50hp DDPs. 

Moparman et al - what are your recommendations - Re-man Bosch bodies or new? VCO vs SAC?  I'm likely going with 7x10 or 9 sizes. 

 

Thanks...

[Silverwolf2691]

7x010s with a hybrid and a quad is really good. 7x011s with a 63mm? Turbo might be a bit better. I think a cheetah is a 63mm turbo. VCO vs SAC, its a difference of not much.. VCO flows more on the high hp end and is slightly quieter. In the mid HP level the SAC nozzles are a bit better. They are a bit dirtier but micro blind has made things much cleaner. I prefer new bodies personally..

[Hutch24v]

Yeah the Cheetah is a 63/65. I'm planning on swapping it for a faster spool ATS 3000 58/73 to tow with. 

Edited June 8, 2022 by Hutch24v

[Hutch24v]

Another question on this topic for those with autos/47re's and bigger injectors. If my newly built 47re is rated up to 450 HP at the crank should I be wary of going anything bigger than my current 50hp injectors or maybe stretch to 7x009s?  7x010s may be pushing the envelope even with running CAN bus fuel settings on the Quad and no wire tap. Thoughts form the sages out there on this?

[Me78569]

run 7 x .010's without wiretap.    the 7 x .009's just aren't big enough in my opinion.

[Threadzy]

When I bought my bone stock truck I was told the transmission had just been rebuilt. That’s all I knew about it at the time. Once I got home I pulled the inspection cover to find a billet converter. Brand idk. The only thing I’ve  done to it is a Dynamic valvebody.  And a lockup switch. With all my mods it’s held up fine for several years now. My pump

isn’t tapped because it was under warranty. At this point not really interested in it. I don’t want to have to replace a head gasket or drivetrain components anytime soon. The only real towing it does is our travel trailer that dry weighs 6,000 lbs a few times a year.   I’ve towed up grades any where from 7%-11% doing 55 mph. 

[Hutch24v]

I've heard/read from at least a dozen 2nd gen owners now that 7x010s are the right size now. Not everyone though had a 47re.  

 

And yeah i don't want to service my trans ever again so being light on the pedal and quad power is what I'll plan to do. 

 

Just want a comfortable tow rig mostly but not so constrained on power that it can't turn a few heads once in a while. 

 

 

[Threadzy]

Mine is no slouch just running canbus fueling. 

[Mopar1973Man]

12 hours ago, Hutch24v said:

I've heard/read from at least a dozen 2nd gen owners now that 7x010s are the right size now. Not everyone though had a 47re.  

 

And yeah i don't want to service my trans ever again so being light on the pedal and quad power is what I'll plan to do. 

 

Just want a comfortable tow rig mostly but not so constrained on power that it can't turn a few heads once in a while. 

 

 

 

7 x0.010 injectors from DAP custom pop pressure at 320 bar. Then running stock HX35W turbo.

 

Might look at my economy tune, it designed around the MPG so it not producing serious power till 20 PSI of boost. This is pretty mild on the bottom end. Even if you run 245/75 R16 tires it takes a lot of stress of the transmission and driveline being the final ratio is 3.69:1. 

 

One of the biggest killers for 47RE transmission is oversize tires. Oversized tires might look cool but but bad final ratios put huge amount of stress on the transmission. Example: 37 inch tires on 3.55 gears will produce a final ratio of 3.00:1. For sure a transmission killer. Keep in mind I've managed to snap the main shaft on NV4500 with Edge Comp and +75 HP injectors.

 

Just remember I went to Cally hauling my 31 foot RV and still running my stock HX35W turbo. No EGT issues hauling 17,500 pounds. Went with @IBMobile and @JAG1.

 

 

Then just went to Everett WA with @Honey Badger and pulled 300 miles across Washington state and barely burn a quarter tank. (Seattle,WA to Idaho state line)

 

Edited June 16, 2022 by Mopar1973Man

[Doubletrouble]

 That's pretty impressive mpg's on that 300 mile stretch! Wow

[Mopar1973Man]

Another tidbit cold air intakes actually don't help. Warm air promotes easier ignition of fuel. Optimal intake temp is 100 to 140°F. Colder air tends to retard ignition timing. Even towing with 100 to 140 intake temps has no impact on EGTs. Below 80°F the ECM stacks on additional 3 to 4 degrees timing advancement which fouls the timing as too advanced (without Quad). This way I'm running BHAF vs any cold air intake. Like my youtube of 55 MPH on flat ground I'm only like 450°F EGTs.

 

 

Just using my truck as a good design example here not trying to hijack.

Edited June 16, 2022 by Mopar1973Man

[Hutch24v]

Related question on tire size. My current tires are 285/75/16s and the build sheet for my truck lists 265/75/16s so really not much difference. However, the driver-side door sticker lists 245s. Curious on what my speedo is set to. Anyone else have this issue?

[Mopar1973Man]

Huge difference in stress on the transmission. You forget your 4th gear is 0.68:1 compared to my 5 speed of 0.75:1. Plus the final to the ground on 3.42:1 so yeah EGTs and transmission issues are going to happen.

 

Optimal is close to 3.73:1 to the ground. You have two things pushing the gear ratio lower. Hence the starting problem of EGTs. Next will be transmission issues.

 

65 MPH should be very close to 2,000 RPM optimally which I know your way down near 1,600 RPM which is way too low adding stress to both engine (EGTs) and transmission (failure).

 

Very common issue I see every day. But people just like the cool factor, but don't understand just 1 size up (31 to 32 inch) make such a huge difference. Just like I'm just one size down (31 to 30 inch) and way different results. Just only 1 inch can make or break it... seriously!

 

My was purchased new with 265's but opted for the 245's for final ratio improvements. Yes my door sticker is the same 245/75 R16.

Edited June 16, 2022 by Mopar1973Man

[LorenS]

To achieve the same final over-drive ratio as the 5-speed trucks, we 47RE guys would need to run a 3.92 rear end.

3.55*(.75/.68) ~3.92

If running a tire that is 7.8% larger in diameter, that means we need even higher gearing:

1.078*3.92 = 4.22

 

I run 265/65/17 tires, and they are only 0.3% bigger diameter than Mike's tires.

But my final "ratio" is:

3.55*(.68/.75) = 3.22

I'd have to run a 27.6" tire to get back to the same RPM at the same road speed, while in overdrive.

Edited June 17, 2022 by LorenS

[SVALIN]

My door lists the 245s as well. Current tires are 275/70R18 about 33s, (they rub at locked steering…) Calculating off that say I have a final 3.26 with my 3.55s? Not so great. I did like the larger ‘look’. But Im agreeing more and more, easiest way to gain acceleration or HP numbers is to drop a size.

 

My current tire is stock for the later gens that run the 3.73 gears. Anyone had success with that setup, or a size down from that? Thoughts? Besides a lot of work than just changing tires…

For air intake temps, I see around a fairly steady 120F* with my S&B, sea level mild temps. Measured by quad. I haven’t tested it against stock or anything. Probably negligible? I wouldn’t delete my intercooler or anything looking for warmer temps though! I think the 140 sounds reasonable. Certainly good data on cold or freezing temps!

 

I swapped back to the RV275s to try more for fuel milage tuning right now. I can stand on the throttle up grades and barley hit 1300 EGTs. Sort of an oxymoron there I know, go for fuel milage, then stand on the skinny pedal 

 

[Mopar1973Man]

Finally I got you all looking past the Cool Factor into the design factor and getting your truck set up for proper gearing ratio then you notice power gain and efficiency improvements. On other member @Sycostang67 took my advise and now also change because cool factor was the source of EGT problem changed tires down and gain back the performance.

Edited June 17, 2022 by Mopar1973Man

[LorenS]

Despite what I wrote above, I will likely be putting 265/70/17s on my truck the next time.  The facts are that 265/65/17 is a fairly rare truck tire size, so if I need one while far from home it wouldn't be optimal.  Second, tire manufacturer data I read at the time of purchase of 265/65 indicates I can't go to a narrower tire with the 3rd Gen aluminum wheels (like a 245/70/17).  I don't remember the width offhand, but they are apparently too wide.  If this is NOT the case, and that size is readily available (and I'm fairly certain it is) then I'd go the skinnier/shorter route.

 

I have the 3rd Gen brakes, so spending money on 16" wheels and yet another set of brake discs doesn't currently appeal to me.

 

In a perfect world I'd find a cheap Gear Vendors (etc.) not for double over drive, but for "3rd over", if you will, with the 0.78 overdrive they provide.
3.55*(.78/.75) = 3.69, it's exactly 4% so would compensate for my "large stock size" tires.

[Hutch24v]

Yeah the numbers don’t lie. But man those 245s tires sure look puny! For now I’m going to optimize everything else in & around the truck before I size down. Great dialogue though. Thanks 

[LorenS]

5 minutes ago, Hutch24v said:

But man those 245s tires sure look puny!

Yeah, there's a lot of unused real estate in the wheel wells!  4:11s and taller tires sure sounds good to me until you factor is rotational mass, drag from being taller, etc.  And lifting stuff into the bed.  I do like that about my 1995 4WD K2500, the tailgate is still at a reasonable height.