Kc S300 63/68 or 63/73

jeremiahmercier · Apr 4, 2021

Well, she made her maiden voyage...

100,000,000 X better... Towing their 8,000lb TT to the campsite it never even got into the yellow on the egt Guage. With the 38r, unless you kept your speed and rpms up, it was laggy and hot. Now it did great, even if you got caught behind a slow poke. Turbo responded much better down low, and accelerated the load with ease. Pretty much can ignore the egt guage now.

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dsrace · Apr 5, 2021

jeremiahmercier great to hear. the 38r was a great turbo in it's day. i don't worry about egt's with my sxe s366 either.

dsrace · Apr 5, 2021

Garbage_Mechanic said:
If your coolant temps stabilize under heavy load at 230* you are ok. Have you tried the 6.0 fan? It helps. Also remember the thermostat BEGINS to open at the rated temp.

i never gave them a chance to stabilze. as soon as i saw 230* climbing that 5 mile long pass, i dropped a gear and slowed down. it never went over 230* and thats on a auto meter gauge. so i have read a few posts on the 6.0 fan but never read if it was a large step up or not.

i should probably mention that the trips where i hit 230* were before i replaced the cooling system. i had noticed for a couple of years ( remember i only use the truck to tow the toyhauler so 7k miles a year) that the temps were slightly higher than normal. this is the 3rd powerstroke i have owned over the years clear back to 1992. i have seen where the center of the radiator has developed build up and blocks some heat to the fan clutch. my thermostat housing was rusting again anyway so time to change it. i bought a billet housing and a stock thermostat. i decided to purchase a new radiator from ford as well as a water pump, gasket and fan clutch. i replaced the radiator, fan clutch, water pump , thermostat and housing. the water pump never leaked and had been replaced at 60 miles, i have the receipt from prev owner. when i pulled the pump the bearing had just enough slop that there is a 1/4 circle scuffed into the block face. not deep and you could see that the edges of the blade had touched. no sharp edges and just surface scuffing so i installed the new pump. def why i was running 10 to 15* warmer than normal imo. so now, while towing 11k lbs on a 85 - 95* ambient temp day, i run at 205* pretty solid according to the autometer gauge. i don't drive it empty much but empty it hangs run right where it did at 80k miles which is about 195*. this is why didn't put that 203* thermostat in that i have read about. i primarily tow with it and wasn't sure how that would work on hot days. i could be wrong and maybe it would run at the same temp. my fan clutch does lock up and unlock on hot days loaded , i set the cruise at 75 mph towing 11k lbs btw. i wonder how much more flow the 6.0 fan produces?

jeremiahmercier · Apr 5, 2021

dsrace said:
i never gave them a chance to stabilze. as soon as i saw 230* climbing that 5 mile long pass, i dropped a gear and slowed down. it never went over 230* and thats on a auto meter gauge. so i have read a few posts on the 6.0 fan but never read if it was a large step up or not.

i should probably mention that the trips where i hit 230* were before i replaced the cooling system. i had noticed for a couple of years ( remember i only use the truck to tow the toyhauler so 7k miles a year) that the temps were slightly higher than normal. this is the 3rd powerstroke i have owned over the years clear back to 1992. i have seen where the center of the radiator has developed build up and blocks some heat to the fan clutch. my thermostat housing was rusting again anyway so time to change it. i bought a billet housing and a stock thermostat. i decided to purchase a new radiator from ford as well as a water pump, gasket and fan clutch. i replaced the radiator, fan clutch, water pump , thermostat and housing. the water pump never leaked and had been replaced at 60 miles, i have the receipt from prev owner. when i pulled the pump the bearing had just enough slop that there is a 1/4 circle scuffed into the block face. not deep and you could see that the edges of the blade had touched. no sharp edges and just surface scuffing so i installed the new pump. def why i was running 10 to 15* warmer than normal imo. so now, while towing 11k lbs on a 85 - 95* ambient temp day, i run at 205* pretty solid according to the autometer gauge. i don't drive it empty much but empty it hangs run right where it did at 80k miles which is about 195*. this is why didn't put that 203* thermostat in that i have read about. i primarily tow with it and wasn't sure how that would work on hot days. i could be wrong and maybe it would run at the same temp. my fan clutch does lock up and unlock on hot days loaded , i set the cruise at 75 mph towing 11k lbs btw. i wonder how much more flow the 6.0 fan produces?

I wanna say 6.0 fan is 13k cfm, I think stock 7.3 I around 8-9k. Made a huge difference when I had my 96 7.3

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dsrace · Apr 7, 2021

jeremiahmercier i do not doubt what your saying but my e99 is an sd. based on what i found/read there wasn't much if any diff between the 6.0 and the sd 7.3 fan in the form of cfm. is that true or not? i do know the obs 7.3 greatly benefits as that fan wasn't designed to draw through an innercooler.

jeremiahmercier · Apr 7, 2021

dsrace said:
jeremiahmercier i do not doubt what your saying but my e99 is an sd. based on what i found/read there wasn't much if any diff between the 6.0 and the sd 7.3 fan in the form of cfm. is that true or not? i do know the obs 7.3 greatly benefits as that fan wasn't designed to draw through an innercooler.

Yes sir, I agree. I cannot vouch for what it's worth on a SD 7.3l

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JCart · Apr 12, 2021

Excellent info here Fellas, thanks for sharing.
I have a couple OBS trucks and in particular one has FFD 205/30s (stock HPOP, with a T500 on the shelf) in it with Jelibuilt tunes and supporting mods including retrofitted IC, 6.0 fan, e-fuel, DP etc. Currently has a stock frame turbo with KC’s Sx300 exhaust wheel and a RiffRaff billet intake wheel, KC’s 360 bearing kit and a .91 A/R exhaust housing on it. This truck is a 97 ECLB with Dana 60 front end conversion with 4:10s, ZF-5 running 37” Toyos on it. At issue is I’m thinking of T4 and am not completely sure of the specific turbo to run. Can say I’m not completely happy with the current set up as it’s not crisp enough off idle to 2000 rpm. Generally a little too laggy for my needs. Given 4:10s, 37’s I want as much reliable power off idle to 2500 rpm as I can reasonably obtain. This truck is being used as a DD, with ability to tow 8,000-10,000lbs.
Thanks again for sharing info.
Any suggestions welcome.
j

mcnance865 · Apr 14, 2021

JCart said:
Excellent info here Fellas, thanks for sharing.
I have a couple OBS trucks and in particular one has FFD 205/30s (stock HPOP, with a T500 on the shelf) in it with Jelibuilt tunes and supporting mods including retrofitted IC, 6.0 fan, e-fuel, DP etc. Currently has a stock frame turbo with KC’s Sx300 exhaust wheel and a RiffRaff billet intake wheel, KC’s 360 bearing kit and a .91 A/R exhaust housing on it. This truck is a 97 ECLB with Dana 60 front end conversion with 4:10s, ZF-5 running 37” Toyos on it. At issue is I’m thinking of T4 and am not completely sure of the specific turbo to run. Can say I’m not completely happy with the current set up as it’s not crisp enough off idle to 2000 rpm. Generally a little too laggy for my needs. Given 4:10s, 37’s I want as much reliable power off idle to 2500 rpm as I can reasonably obtain. This truck is being used as a DD, with ability to tow 8,000-10,000lbs.
Thanks again for sharing info.
Any suggestions welcome.
j

Sounds like you need an S364.5sxe/73/.91

jeremiahmercier · Apr 20, 2021

Thought I'd reiterate how much of an improvement this kcs300 is, DRASTIC improvement over the 38R, and the 38R was a massive improvement over the stock turbo! Spools QUICK! And virtually never have to look at the EGT Guage. WELL WORTH THE MONEY!

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ja_cain · Apr 21, 2021

jeremiahmercier said:
Thought I'd reiterate how much of an improvement this kcs300 is, DRASTIC improvement over the 38R, and the 38R was a massive improvement over the stock turbo! Spools QUICK! And virtually never have to look at the EGT Guage. WELL WORTH THE MONEY!

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Good thread. What are you towing/grossing? I just purchased a 39 foot fifth wheel and finally going to address some nagging issues and make a few upgrades my truck. Good to hear this turbo is significantly better than the 38r. My truck has the zf6, what ar housing did you go with? Thanks!

Tiha · Apr 21, 2021

Not sure I want to read this whole thread. Nervous enough already. I just ordered the KC300x. 63/70 Mine is going in a 95. With 180 CC.

Everyone online said get the 1.0 housing and I respect why, but KC turbos page said below 3000 rpm get the .84 housing instead. Above 3000 rpm get the 1.0 housing.

I don't tow or drive anywhere near 3000rpm or above.

I talked to KC turbos and they again said with my setup I will be happiest with .84 housing.

We will know soon. I have e4od, 4.10 and a gear vender so I cruise at 1800-2200 rpm

If nothing else I would imagine that .84 housing will be awesome driving around town. the little info I could find online guys were talking about it spooling quick and at such low rpms.

jeremiahmercier · Apr 23, 2021

ja_cain said:
Good thread. What are you towing/grossing? I just purchased a 39 foot fifth wheel and finally going to address some nagging issues and make a few upgrades my truck. Good to hear this turbo is significantly better than the 38r. My truck has the zf6, what ar housing did you go with? Thanks!

This truck only tows a 31ft TT, just over 8k lbs. We use my 06 6.0psd for our 40ft fifth wheel, a little over 13k. Crazy part is the 6.0 will walk away from the ole 7.3l when we are both towing our campers, even though it's almost double the weight. And I went with the 68mm turbine and .84 housing on the kcs300

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Addicted4 · Apr 24, 2021

6.0 makes more power and has a better trans so it would explain why it pulls harder. Good info on the turbo.

ja_cain · Apr 26, 2021

jeremiahmercier said:
This truck only tows a 31ft TT, just over 8k lbs. We use my 06 6.0psd for our 40ft fifth wheel, a little over 13k. Crazy part is the 6.0 will walk away from the ole 7.3l when we are both towing our campers, even though it's almost double the weight. And I went with the 68mm turbine and .84 housing on the kcs300

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10-4. I bet the 5R and vgt are game changers on that 6.0 too.

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ja_cain · Apr 26, 2021

Addicted4 said:
6.0 makes more power and has a better trans so it would explain why it pulls harder. Good info on the turbo.

Has vgt too, which will have a significant impact on early boost development. I agree though, that 5r is also significant unless, it's still walking away in overdrive, with the the converters locked.

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jeremiahmercier · May 1, 2021

Definitely a combination of things help the 6.0, but I bet a modded 6.0 TC on the 4r100 would help the ole 7.3l too, always hated those loose feeling TC's

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Tiha · May 13, 2021

Finally got to test drive my KC300X stage 1 with .84 housing.

I run 180/0, intercooler. (also in a 1995)

Pretty impressed. first off I get no turbo whistle at all, you don't even know the turbo is on there or working. Just watch the boost needle move.

On 1000 rpm high idle there is a whistle out the exhaust somewhat similar to the 6.0 sound. I didn't try the 1500 rpm yet. I also have a big truck muffler under there.

With 4.10 gears, e4DO and a gear vendor I cruise 70-75 in the 1800-2000 rpm range.
using TW tow tune it is quite responsive. no smoke just works, holds speeds on hills.
I have other tunes to try but so far none of the others hold speed, or barely holds with no pedal left.

EGTs not even close to maxing out even with the hot tunes I have.

Driving around town it will start building boost at 1200-1300 rpm.

My boost gauge only goes to 25 and it has no problem boosting well past that. I need a bigger gauge.

Stock fuel, I have no idea what my fuel pressure is and I probably don't want to know.
Stock HPOP too.

I wish we could have the 5R100 but this late in life I probably won't undertake that fun project.

I know this is maybe the wrong section, and not a direct comparison but when I searched for real world information on this turbo I could not find any so hopefully this helps someone.