Not running "Right"...

That is insane. I can't believe that those turbos were still putting out that much boost. That was a huge leak! Glad you got it sorted out
 
Yes, on mild"ish" turbo setups using 68mm or smaller turbine wheel setups, I've always gone faster shifting at 3k rpm. Even with the 73mm turbine on the Junker with the big HT80 89mm atmosphere, I still only shift at 3500 rpm or so. I'd say the sweet spot on that setup is 2700 to 3600 RPM.
 
Big Blue24 said:
Yes, on mild"ish" turbo setups using 68mm or smaller turbine wheel setups, I've always gone faster shifting at 3k rpm. Even with the 73mm turbine on the Junker with the big HT80 89mm atmosphere, I still only shift at 3500 rpm or so. I'd say the sweet spot on that setup is 2700 to 3600 RPM.
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Noted. Thanks! Looks like there isn't any races for a few weeks. But I will definitely play around with lowering the shift points at that time and report back!

Kris
 
So I found another problem point the other day where I am losing air; the whimpy stock intake plenum plate has had trouble keeping the gasket from blowing out. So I lasered out a 3/8" solid aluminum plate and at the same time rebuilt my intercooler tanks from scratch to make sure I had good welds and no chance of blowing out again.

Truck has been GREAT, until this morning where I blew the headgasket. 90psi of boost up a grade, 90% throttle, 110psi of drive. Probably at somewhere around 2500rpm if I had to guess. Oil puking out of the radiator oilflow.

I have 625 ARPs torqued to 145ft/lbs with diligent retorques though the last retorque was probably 6 months ago. Running an OEM Cummins gasket, and have stainless orings with .010" crush. What can I do to keep this headgasket intact? Defuel it until a higher RPM?

Thanks,
Kris
 
95cummins5.9 said:
I dont think your asking too much. Purple power works good in the coolant system for cleaning the mess
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So then would you suggest to maybe run 18* or so for DDing and then retime it every time I want to race? Or maybe I just simply waited too long between retorques....?
 
jasonc said:
Don't lug it down so low in the rpm range.
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Yea, I was trying to do some visual logging of drive pressure vs boost vs egt to see how everything was running. Keeping an eye on everything up a steep grade tends to be the easiest to do since you can control vehicle speed under load a lot easier. I guess overdrive up a 10% or more grade with that much boost at that low of rpm is a no-no. lol
 
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ARP recommends 150 ft lbs with those studs (625's), most go a touch over the recommended torque spec, so I'd say you're a little light on the stud torque at 145 ft lbs. With cheaper ARP 2000 studs, I was never able to keep the headgasket alive with orings until I torqued them to 155 ft lbs cold, warm retorque , warm retorque after a couple hard runs, warm retorque again untill they quite moving during the retorques.
 
Big Blue24 said:
ARP recommends 150 ft lbs with those studs (625's), most go a touch over the recommended torque spec, so I'd say you're a little light on the stud torque at 145 ft lbs. With cheaper ARP 2000 studs, I was never able to keep the headgasket alive with orings until I torqued them to 155 ft lbs cold, warm retorque , warm retorque after a couple hard runs, warm retorque again untill they quite moving during the retorques.
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Shoot shoot. Good catch Will. I don’t have the 625s i have the cheaper 2000s. But ok, it sounds like i should take them to 155ftlbs next time.
 
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