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Mother Cummins already uses a similar system on 4Bta's bigger siblings. It is called Low Temperature Aftercooling (LTA) & it is in current use on the following engines QSK-19L & 23L big inline sixes, QSK-30L, 38L & 45L V12's, QSK-50L & 60L -V16's, QSK-78L V18. The LTA system has its own coolant pump, plumbing, thermostats and radiator. The reason it is used is for big power gains with predictable results. The trick here is to be able to regulate the air fuel ratio @ about 14:1 by weight(stoich) in the factory set up for effeciency and no smoke. This is the reason for the LTA thermostats; to regulate the LTA system @ about 130*F-160*F gives predictable air density at very different ambient temps and altitudes & actually heating the intake charge @ low boost/low ambient temps. The major importance here is to prevent a lean A/F mixture ratio and the resulting engine damage from a very cool (ie:dense) intake charge. This is likely no problem in Texas but here in Canada Brrrr. So Toolmans solution using ice @ the track is predictable and consistant and can be tuned. But some of the other unregulated system suggestions could be a bit expensive on a very cool winter morning!
I think you are incorrectly applying air fuel ratio figures and principles for gas engines to diesel engines.

AFAIK diesels don't run near 14:1 (stoich), and under light load are very happy to run much, much leaner.

But I don't know those bigger siblings, or the LTA system, and if there has been a big change to traditional diesel air fuel ratios bought about by new technology, then I want to be educated about it.
 

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No dyno pulls, Maybe a tad more power on the hills but could be my imagination. Most definitely helped the EGT's. And that is where I needed some help. Checking mileage figures now. If anything good happens Ill post it.
Carl
 

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Mother Cummins already uses a similar system on 4Bta's bigger siblings. It is called Low Temperature Aftercooling (LTA) & it is in current use on the following engines QSK-19L & 23L big inline sixes, QSK-30L, 38L & 45L V12's, QSK-50L & 60L -V16's, QSK-78L V18. The LTA system has its own coolant pump, plumbing, thermostats and radiator. The reason it is used is for big power gains with predictable results. The trick here is to be able to regulate the air fuel ratio @ about 14:1 by weight(stoich) in the factory set up for effeciency and no smoke. This is the reason for the LTA thermostats; to regulate the LTA system @ about 130*F-160*F gives predictable air density at very different ambient temps and altitudes & actually heating the intake charge @ low boost/low ambient temps. The major importance here is to prevent a lean A/F mixture ratio and the resulting engine damage from a very cool (ie:dense) intake charge. This is likely no problem in Texas but here in Canada Brrrr. So Toolmans solution using ice @ the track is predictable and consistant and can be tuned. But some of the other unregulated system suggestions could be a bit expensive on a very cool winter morning!
Your average diesel will start blowing smoke at an AFR of 18:1. At 14:1 you'll be pretty much smoke propelled and pissing off everyone around you.

I highly suspect your information is from cummins propane engines, not their diesel ones.
 

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Cool air

I talked to a guy with a 4BT bronco (the really nice orange one) and he has a setup kinda like you want, uses a small radiator with an electric fan on it. He says that he loves it, and claims he is making 350+ hp with it. I think it is a great idea even though I run air-to-air.
 

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I have a couple of the mercedes type coolant pumps available, if anyone wants to do this mod.

they are electric- draw under 2 amps

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For comparison
4bta with 190hp injectors and a HY35/9 mild pump adjustments

The stock air/water aftercooler with 2" inlet created more back pressure than a dodge 1st gen air to air cooler. The temperature drop between the two was close on the air/water aftercooler with 2" intake pipe, exterior air temp of 78* and relitive humidity of 41% was at turbo inlet was 238* F @ 29 PSI and 194* in the intake. Same setup no adjustments to pump or injectors between the change. 3" pipe to intercooler and 3" pipe from intercooler to intake horn with redution couplers Exterior temp 81* humidity 34% at the turbo inlet it was 223* F manifold pressure @ 25 PSI and it was 174* @ intake.

The hp variation on the Dyno at the time of that run increased by 21hp/ 37 ft/lbs between the two setups. Later we were able to increase the fueling from the pump due to lower EGT's fromthe Air to air setup vs the stock Water/ air. My assumption in reference to the gains was that the Volume of air moved through the air to air cooler was higher than what can be pushed through the Air/water cooler
 

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would one get too much pressure loss if they used both air-air and a oem air-water setup??

or would it not be worth it unless you had lots of feul/ boost?
 

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would one get too much pressure loss if they used both air-air and a oem air-water setup??

or would it not be worth it unless you had lots of feul/ boost?
Likely too much restriction and, unless you did the separate cooler for the JWAC, to no point.

The way the JWAC mounts pretty much means it's last in line on the chain going into the intake (unless you wanna fab a box / outlet for it..), so normally the air would be at a cooler temperature coming out of the CAC than what the water in the JWAC will be.
 

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Discussion Starter · #49 ·
would one get too much pressure loss if they used both air-air and a oem air-water setup??

or would it not be worth it unless you had lots of feul/ boost?
The one situation where I could see a benefit to this setup would be with a compound turbocharged engine. You could place the air-to-air cooler between the first and second stage turbos, and then run the OEM air-to-water setup.
 

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The one situation where I could see a benefit to this setup would be with a compound turbocharged engine. You could place the air-to-air cooler between the first and second stage turbos, and then run the OEM air-to-water setup.
That would be a waste with a compound setup on a 4bt! The JWAC unit would restrict the airflow too much. You're talking 2" inlet to the JWAC! You'd need at least 3" intake tubing, or larger for a good sized compound setup. Now if you used a custom air/water cooler, that would be a different story. It would best be placed between the two turbos though.
Bob B.
 

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I think we are still debating the best overall setup, air/air or air/water. However, the stock jwac air/water aftercooler is best with its own isolated separate circuit.
Carl
 

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The question I have is this:

Has anyone with a JWAC bothered to connect a boost gauge to the intake box AND to the intake of the JWAC just to see if it is all that bad of a restriction? What kind of pressure loss does it really represent?

And I'd like to see the same measurements on CAC equipped units, too.
 

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Cooler

You just have to love those Salt Flat guys........why not !
those guys have done it all.....keep in mind you are the only one you need to make happy..what works for you might not for others.....I'm surprised someone hasn't tried using freon.....and the A/C....
 

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The question I have is this:

Has anyone with a JWAC bothered to connect a boost gauge to the intake box AND to the intake of the JWAC just to see if it is all that bad of a restriction? What kind of pressure loss does it really represent?

And I'd like to see the same measurements on CAC equipped units, too.
I don't think that it is just measuring the PSI. The problem I see with the JWAC would be the volume of air it can flow. For example my JWAC came with a 2" intake pipe and when I did my turbo upgrade it went to a 2.5" pipe which means that my turbo can flow a higher volume of air plus more PSI. I modified the intake pipe to accept a 2.5" pipe but I think that the JWAC is a restriction with that increase in Volume. On one side it it better than nothing but I am interested in higher volume. I still have very high EGT's with the JWAC but they don't climb as fast with it. I am getting a CAC from the 4bta engine modified right now as soon as it is finished and mounted I will post my results on the EGT, PSI and the performance of my engine.
 

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I don't think that it is just measuring the PSI. The problem I see with the JWAC would be the volume of air it can flow. For example my JWAC came with a 2" intake pipe and when I did my turbo upgrade it went to a 2.5" pipe which means that my turbo can flow a higher volume of air plus more PSI. I modified the intake pipe to accept a 2.5" pipe but I think that the JWAC is a restriction with that increase in Volume.
If your aftercooler (or tubing, or about anything in the path between turbo and intake manifold) is causing a restriction, that restriction will show up as excessive pressure drop across the device.

A better device to use than the 2 gauges is an actual pressure drop gauge, which has two connections and directly reads the pressure drop across the thing. I believe anything over about 4-5 PSI drop is indicative of needing a higher flow rate aftercooler.
 

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MY observations

I decided to hook up my regular boost guage on the pre air to water side to see if cooler was restricting I was surprised. On my truck with the hx35 on it I can get 30 psi to the intake if I push it hard. When hooked up before the cooler I can get 38 psi that tells me that the cooler is pretty restrictive, Keep in mind this is with a larger 2 1/2 pipe to the cooler. I have seen some pretty nice air to water coolers on ebay brand new for 80$. There advertisement says it will kool up air for up to 1000 horse, I am sure thats a crock but it looks like an inprovement over the stock set up and comes with 3" inlet and outlet, I think this will be my next move.
 

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I decided to hook up my regular boost guage on the pre air to water side to see if cooler was restricting I was surprised. On my truck with the hx35 on it I can get 30 psi to the intake if I push it hard. When hooked up before the cooler I can get 38 psi that tells me that the cooler is pretty restrictive, Keep in mind this is with a larger 2 1/2 pipe to the cooler. I have seen some pretty nice air to water coolers on ebay brand new for 80$. There advertisement says it will kool up air for up to 1000 horse, I am sure thats a crock but it looks like an inprovement over the stock set up and comes with 3" inlet and outlet, I think this will be my next move.
do you have any pictures of your setup? what did you use for the outlet of the HX35? I have some ideas how to do mine, but i wouldn't mind seeing what yours is like.

Have you taken your JWAC apart ot see if it's coroded/clogged/etc?
 
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