the purpose of a intercooler isnt to reduce egts but to reduce iats. but there really only good if your running more than 12 psi of boost.

 

check out the diesel conversions thread its in there

exactly. you will notice lower egts as well though. but like you said more than 12psi of boost, which most 6.5ls dont do

 

I just bought a WH1C and a cummins intercooler for 150 bucks. Cant wait to do the swap. To fit the intercooler you need to remove the ac stuff up there. Mine doesnt work, so its gone.

 

Ya I think my A/C is hotter than my heat!!!!!!!!

 

Im running 15psi boost on my 93 without intercooler. My radiator is still the original and its all rusted out but not leaking and no overheating issues to speak of. Though i am considering intercooling it when i up the boost.

 

If you were running a electronic truck you would be defueling 15psi boost probably at +285F IAT on a hot day where high IAT defuels the electronic IP for good reason the temp curve above 12psi on a hot Outside Air Temp day is almost a srtaight line up no curve to it as you drive boost higher, remember compressed air is what we use in a Diesel to ingite the fuel in n/a mode add in boost and you really start upping the ante, for power you need cool dense air ergo the need for a turbo that is bettwe matched to the performance you seek, an IC or WMI.

At 15 psi running empty you should be ok so long as you don't sustain your boost @ 15, towing big I suspect (no change that to I know) you would be getting hot from a charge air temperature perspective and the GM-X turbos are really inefficient at that high of boost.

When you say no overheating issues what temp are you running on coolant the GM redline of 260F on the dash is wrong, anything above 210F coolant temp on the 6.5 is hot.

With age of your truck and leaking radiator I would be very cautious running above 15 psi boost, especially with a GM turbo at 15psi boost you are running 45-50 psi backpressure in the engine/turbo to get that much boost, backpressure is high EGT territory what is your EGT temp do you have EGT gage on your rig.

High EGT with High IAT, high fuel flow and high transmission cooling demand assuming you have an auto trans, higher oil temps is recipie for high coolant temp, blown head gaskets and things to generally go boom when you don't want them to.

Also if your coolant level is low from leaks the coolant sensor isn't reading water temp because it is not immersed in water, it may possibly be reading some splash water and engine metal temperature but ECT sensor needs to be immersed to read coolant temp.

As for the question about IC effectiveness mine was an under bumper mount 24" x 6" x 12", it was a Turbonetics one set for the 6.5 that John Kennedy used to sell as a kit, I don't think he sells them but you can visit the Spearco/Turbonetics site and find it still i think, I also have pictures of it on thetruckstop.us site there is a IDIOT runs a website A-1 customs affectionatly known as "steaksauce" to the 6.5 community after a table condiment derived from his sites name, do what you will buy his brand of tripe or not; he is wholly misinformed about 6.5s not matter how many times he says his stuff in bold colors he is wrong.

A quality under bumper IC is not a t risk unless you are hardfcore into mudding/rockcrawling, if that is the case maybe WMI is better choice (NOT A A-1 KIT you have been warned) or you just add armor to it like you add to protect the trans-differentials-driveshaft when crawling. I and most 6.5ers that know their stuff don't recommentd a in grille IC simply because the "cooling stack" for the 6.5 is already marginal, add an IC to the oil-tran-ac & radiator air flow and you really start to push the sytem to it's limits. Cummins-Strokes-DMAX do it because they were designed ground up from day one to use a grille mounted IC, the 6.5 IDI never had it so it is challenged when adding one, think fan clutch-water pump-#of & material fan baldes made from all part of the DI engines design for the ones with in grille ICs.

Before swapping to the ATT high flow turbo from my GM-8 I ran an IC the standard delta on the IC sized for the 6.5 was worst case on hottest of days 105F OAT the IAT was maybe 30F higher than the OAT even up to 20 psi boost running 121mph. Since going ATT I eliminated the IC as no longer being necessary I'm capable of 100mph with just 9-10 psi boost now which keeps IAT in 150-190 F range Bill Heath said in conversation once the Ricardo Comet Engineering folks which is the pre-cup system the 6.2/6.5 has say best economy should happen around 150F IAT, not best power best economy, so removing IC especially in winter when I've seen IAT as low as 50F, I think has helped my mpg.

Where some 6.5 guys mess up is when start adding power adders they forget from a systems perspective to also address things like added heat that has to be managed-extra air from a turbo that was only designed for 185hp at flywheel, and extra fuel delivery needs, it takes time & thought to do it right.

 

Im runnin around 25 psi and i got a big 4 inch think itercooler under the front of the truck, ill try to get some pics to show you if i can

 

I started to chime in 25 psi is on high side for the 6.5 but I see that you are running lowered 18:1 CR, even at that I'm not a big fan of in grille ICs, what IAT you seeing and what is your coolant temp on hot days. Also running Holset turbo which is a whole different animal than GM-X series turbos.

 

The IC is actually located under the bumber were the skid plate would go on the front of the truck
https://www.dieselbombers.com/attach...pril-3-010.jpg

 

I went from 300+ degrees IAT's towing the toy hauler on a 100 degree day to 150-170 with the intercooler and GM8. I now have an ATT and intercooler but haven't checked IAT's yet towing on a 100 degree day.