64.7mm vs 67.8mm Turbo ?'s

White Stallion · Feb 12, 2015

Okay guys I can't find anything about this. My trucks an 05 250 6" lift with 37s. It's a street queen and I don't tow. My goals are to have a very streetable fast truck. Looking for 550-600 hp.

I currently have a stage 2 64.7mm turbo (not installed yet) am about to get a twisted stage 3 tranny and am looking to purchase some 190/75s in the next couple of months. Full fuel system will be completed with the injectors.

Now for the questions. Is there that much of a difference between the 64.7 and 67.8 turbo? Will my current stage 2 and other supporting mods get me to my hp goal? Selling my current turbo will still require 1000-1400 to move up to a 68 is it worth it?

MrOneEyedBoh · Feb 12, 2015

From what Ive gathered, the 64.7 has way less lag and feels faster on the street. It flows more earlier, but tops out sooner versus the 67.8. Look in my thread there is a little bit that was touched on by Kcturbos. A local guy had a 67.8 and went to a 64.7 and liked it better. He's going non-vgt now though lol.

Im sure Charlie will pop in and give his builders side of why it does what it does.

White Stallion · Feb 12, 2015

Cool thanks

MrOneEyedBoh · Feb 12, 2015

I think you went the right way with the 64 since your tires are pretty big. Are you going to regear ever?

White Stallion · Feb 12, 2015

Eventually just trying to get the engine and tranny done.

MrOneEyedBoh · Feb 12, 2015

I understand. Well if you do regear then sell that 64 and go to 68.

White Stallion · Feb 12, 2015

Okay thanks

White Stallion · Feb 12, 2015

Just found this thread you started and he pretty much answers my question. http://powerstrokearmy.com/forums/showthread.php?t=60510

KCTurbos · Feb 12, 2015

Well looks like I am a little late to the game. Let me know if you have any more questions.

Your big tires are really going to hurt your performance. The truck will run hotter, smokier, and make less power. Just something to think about. If you don't have gears then they would be a great investment.

You might think about 190/30s and a stage 2 64mm turbo. If you had stock tires then that would get you into the 550-600hp range... but run MUCH cleaner and cooler (something you are going to want with bigger tires)

White Stallion · Feb 12, 2015

Okay I'm open to change plans. Most of you guys have been there and done it. I don't wanna do it twice just because I didn't listen to someone with experience. Sounds like I'm going to keep my 64 and regear for the bigger tires. The more I read the 190/30 will be a better setup. Thanks for the input.