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BCB

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I am running a Phat Shaft 62/12 over a S400 that needs to be replaced. i'm not really happy with how well this set up cools. the truck is a 97 12 valve 913 pump with 4gsk TST 4 plate laser cut DV's and 435 injectors. I'd like to make around 650 or better on just motor and keep it nice and cool EGT wise for towing. I'm not real familiar with bottom turbos but i did a couple searches and a lot of reading and i'm leaning towards a K31. Am i on the right track?
 
A 62/75 is a decent setup for towing. The K31 is a 71mm turbo, and will likely light faster than the 75 would, but if you are shooting for 650, I would suggest the 75.

You also may want to consider something other than laser cuts for towing.
 
Ditch the laser cut delivery valves and put in something with a shoulder like .022's, .024's, or 191's.

What size s400 do you have now?

Last, you want to tow w/ 650hp w/ a 12v. :hehe: You going to be towing a lawn mower, I hope.
 
SHughes said:
what is a good power range for towing with a 12v?? 400? 450? 500?
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400hp is cake with a good charger, and a manual...above that, it's either twins only, or RPM! 12v's don't like much over a 62mm for towing with 3.55's in OD...likes to bark the charger.

At least in my opinion...I've towed LOTS of miles with 450hp with a HX40/B2 setup on my 95...I've also tried to tow with my 550hp 98, with the auto and a 71mm VGT...yeah, not so good!

Chris
 
GOLDDUSTERS5703 said:
get rid of the full cuts u should be near 650 as for towing with that much its doable just not fun. a valet switch would help
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Valet switch actually makes little difference...it's all about spoolup. The valet will just keep you from being stupid and flat footing it ;)

Again, just my opinion towing up to about 40K gross!
Chris
 
BCB said:
I am running a Phat Shaft 62/12 over a S400 that needs to be replaced. i'm not really happy with how well this set up cools. the truck is a 97 12 valve 913 pump with 4gsk TST 4 plate laser cut DV's and 435 injectors. I'd like to make around 650 or better on just motor and keep it nice and cool EGT wise for towing. I'm not real familiar with bottom turbos but i did a couple searches and a lot of reading and i'm leaning towards a K31. Am i on the right track?
Click to expand...

You guys dont think the 65mm turbine wheel, and 12cm housing may be the reason for his heat issues? If your running a 62 over a 71 s400 now that should be plaenty for a set of 5x.014 injectors. Maybe im way off though?
 
stick with a S475.

I ran an Hx40/S475 with 5x.014s and tried a lot of different DV's, it ran the best with full cuts at the track (didn't clean up the smoke - hazed down the track), but I would not recommend them for towing.

Stick with 181's for towing.
 
towing about 20k to 28k gross most often 20k gross

the truck currently has a 5 speed with 4.10's it will pull the neck off a trailer the way it sits it just gets hotter and faster then what i want. Spool up is great 1600~1700 and its pretty well lit.
 
I would tend to agree with everyone else that the lazer cuts are the culprit... some 191's would probably work better for you.
 
BCB said:
How much power am i going to lose by going to 191's?
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You might not lose any... I know a few guys that made more power with them since they were using all the fuel instead of just downing the cylinder with it.
 
It seems to me that spool is the main concern while towing... At 422/903 my truck tows 20k gross like it isn't even back there and that's with 3.73s and 33" tires. But then again, I chalk that one up to my VGT. I plan to throw an HT60 (76mm) under it sometime in the future with a goal of around 700hp and still tow. Personally I think it's possible; my set up as right now with a single 60/60/VGT I am hard pressed to push the pyro past 1250* with 39psi of boost and 60psi of drive.

x2 on ditching the full cuts, they don't provide a good clean break in the injection event and allow the injector to dribble fuel in late in the cycle and it makes things hot. Any of the above mentioned DVs should do, and as mentioned there are mixed results, but generally fuel only numbers increase with any of the DVs that have a shoulder left.

I am no expert by any means, but that's my $.02
 
I was thinking they do have a small shoulder left. to be honest its been so long since i put them in a can't remember.Bare with me here but I thought full cuts and laser cuts where two different animals?
 
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