650+ is not obtainable with a 62mm compressor. Another, huge factor in spoolup is the exhaust side. One of the biggest reasons turbo lag exists is the weight of the rotating assembly and the power it takes to make it accelerate quickly.

From a stop, a 62/71/13 will out spool a Phat Shaft 62/71/14 or a silver bullet 62/74/14.

Getting back to the rotating mass discussion, the compressor is a lightweight aluminum alloy... titanium in some applications. Going from 62-64 is not a big difference in spool. There is, however, a big difference in surge potential.

Going from a 71 to 74mm exhaust steel allow heavy wheel is a big difference in spool. The reason the 64/65/13 spools the same as 62/71/13 is the weight of the exhaust wheel.

After turbo is spinning and making a little boost, spool up characteristics change quite a bit. Once the turbo is making boost, the draw back of a bigger exhaust turbine wheel now becomes a benefit due to it's "kite" affect. A larger kite catches more wind. A larger turbine wheel catches more exhaust energy and thus can spool faster, even though it is heavier and takes more energy to accelerate to faster speed. In a race from 15 to 50 psi, the silver bullet will win every time.

You cannot have great towing, fast spoolup, and enough air to keep 650 HP of fuel cool enough with a single turbo. If 650 is the goal, you need to learn to deal with turbo lag, or buy smaller than you need now and plan on twin turbos for your 650 HP goal. Many many guys will post this or that but it really comes down to simple physics: a big enough compressor wheel to flow the required air cannot be made light enough in weight to spool up like your stock turbo. You can add all of the fuel you want, spoolup is still limited by the amount of exhaust flow your 5.9 liter engine can produce without being force fed by a turbo. Your truck's spoolup is essentially limited by the naturally aspirated ability of your truck. The smaller the turbo, the faster it gets into "the game" so exhaust flow can increase.

Yes you can add more and more fuel, thus increasing the mass and temperature of exhaust flow, but you start to lose the egt game really quickly and if you are towing, you will max egt's at take off before your turbo gets going. If your empty, you can get away with overfueling to spoolup the turbo, if you're towing you can't.

 

I think Im gonna stick with my original plan and go with the 62/71/13....yall think that is a good compromise? I may not hit 650hp with it, but I may be able to be close or around 600hp with it right?

 

You should be able to push 575hp effeciently with the 62.

 

Guess I was lucky...... Lmills did me right and made sure I stayed on track with Dave Goerend. Even talked with him to make sure I would be happy with both turbo and tranny. Customer service, got to love it.....

 

Thats awesome...I think James Northum is doing that for me as well! Hope it turns out good. Im dropping off my truck this afternoon for the long awaited Goerend trans!!....possibly Turbo!..or hopefully!

 

James Northrum does really good work, have had a couple of friends go through him. One has over 80,000 miles on one of his built trannys.

 

Well Im hoping to get a ton of miles out of mine, so that is all good news!


On a side note....your in Tx, we both have 08 700FI Rhino's with 27"s (but mines ducks unlimited) and have bombed trucks. I'll meet you somewhere and well race them all!

 

Well a ton = 2,000, so I think you'll be good for that and many more miles than that LOL! If it makes you feel better, my bud hauls cattle all day everyday but Sunday, 300+ miles a day. Its holding strong.

 

I wouldn't say 650+ is not obtainable with a 62.....as I was running 670+ for over a year with one....just dont expect it too last very long is all I was saying.