replacement turbo? - Page 2

FARM69 · #16 (**permalink**) 06-27-2008, 11:10 PM

TJ, you'd suggest that the D66 would run 40 pounds? I don't know. If I'm correct the drive pressure for the stocker are around 2:1? Thats a lot when your talking 35+.

Secondary, it sounds like the D66 is right up your alley.

tjbeggs · #17 (**permalink**) 06-28-2008, 09:50 AM

Bean's says the max PSI for the D66 is 40 psi. The D66 has more even drive pressures so thats why it can survive with more fuel.

FARM69 · #18 (**permalink**) 06-28-2008, 10:00 AM

So it's higher than 2:1?

tjbeggs · #19 (**permalink**) 06-28-2008, 10:04 AM

No the D66 is closer to 1:1. Even drive pressures would put no/little pressure on the thrust bearing. But in reality the D66 is not 1:1 So there is still a limit.

FARM69 · #20 (**permalink**) 06-28-2008, 10:06 AM

I still don't understand this drive pressure. A BB is like 1.75:2 right? The stocker is 2:1, how can the D66 be 1:1?

tjbeggs · #21 (**permalink**) 06-28-2008, 10:13 AM

I don't know the exact ration but I just mean that the pressures are more equal than the stocker. One a stock turbo with a 2:1 ration it will require 30 psi exhuast drive pressure to create 15 psi boost pressure. The D66 closes that gap. Just number pulled from thin air but if the d66 is 1.5:1 it would take 22 psi exhuast drive pressure to create 15 psi boost pressure. I would guess that the d66 is closer to 1.5:1 than 1:1

FARM69 · #22 (**permalink**) 06-28-2008, 10:16 AM

Interesting. It must be harder to close that gap with bigger turbos. This almost makes me want to put a manifold pressure gauge on and see.

tjbeggs · #23 (**permalink**) 06-28-2008, 10:19 AM

I will try to get some numbers for the stocker today. I am sure this has already been done but I don't want to search around to find them. Now that I think about it Neal might have done the drive pressure work once he got his BP gauge hooked up....

FARM69 · #24 (**permalink**) 06-28-2008, 10:22 AM

I know in our K-Whopper, you can peg the manifold pressure gauge out at 70. It looks pretty cool to see that needle fly to the right when you spool it up.

Neal probably does, I think I remember him talking about it.

Neal 97 250 · #25 (**permalink**) 06-29-2008, 09:37 PM

Hey Hey Hey I am here guys. I did have a BP gauge on and it seems to fill up with carbon quickly so I disconnected it. I got some info first though. I get almost the same BP as I get boost when pouring the gas to it. I have not done the comparison with the new stage II's though. I would think since the #'s are almost the same stock it is 1:1. Am I thinking right. I am learning with this thread though. It seems odd that BP and boost are almost the same.

Sorry if I got excited but I am on vacation at the beach on the front porch drink in hand and enjoying life as it should be.

secondarychaos · #26 (**permalink**) 06-30-2008, 02:43 PM

Quote:

Originally Posted by www.dieselsite.com

Exhaust backpressures or "drive pressures" as they are called in the turbocharger business plays a huge role in how much boost an engine can produce before stress on engine components fail. Drive pressure is the amount of pressure required to "drive" a certain amount of boost with a particular turbo. These numbers can usually be derived into a mathematical equation. For instance, a stock 7.3L turbo has a drive pressure approximately of a 2/1 ratio. This means for every 1 lb of boost, it takes 2 lbs of drive pressure to produce this. So, a stock turbo producing 35 lbs of boost can easily produce 70 lbs of drive pressure. The ballbearing turbos on the market estimate about a 1.75/1 ratio. That same truck with 35 lbs of boost will generate about 61.25 lbs of drive pressure.

Taken from their explanation of the h2e kit.
so what if you were trying to incorporate a second turbo later? would the d66 fail with a second turbo downstream?

Quote:

Originally Posted by www.dieselsite.com

Now, this turbo kit has a drive pressure close to 1/1. That means the same boost levels of 35lbs only produce approximately 35lbs of drive pressure. Your head gaskets and rods are greatly relieved of excess pressure. So, for high boost levels and high HP applications, this turbo is a must for long life of engine components

so if you can make the volume for the h2e, it'll make huge boost...

FARM69 · #27 (**permalink**) 06-30-2008, 10:00 PM

Lol. I knew I my numbers came from somewhere. Nice find SecondaryC.

mklemin · #28 (**permalink**) 07-01-2008, 01:17 AM

My question is the d66 reliable enough if i was wanting to make a semi high horsepower engine over time.all i read on here is bad mouthing it because of the thrust bearing. you think it will hold up. say i wanted to pull a sled with it sometime?

FARM69 · #29 (**permalink**) 07-01-2008, 07:20 AM

It says its rated for up to 40lbs boost. I would assume it would be able to handle it? I'm not sure if they upgrade those bearings or not.

tjbeggs · #30 (**permalink**) 07-01-2008, 08:01 AM

Quote:

Originally Posted by mklemin

My question is the d66 reliable enough if i was wanting to make a semi high horsepower engine over time.all i read on here is bad mouthing it because of the thrust bearing. you think it will hold up. say i wanted to pull a sled with it sometime?

If your not planning on over 400 hp/stage 2 injectors then the D66 should work well. I have been one of the largest naysayers at least on this forum of the D66 due to the stock thrust bearing (no mods done to those) mainly because I have shredded my stock turbo but the more I looking it failure I think it had more to do with the 10W30 oil I was running and the poor rebuild when it was put on with the previous owner.l

The D66 has been proven thus far to do what it is advertised to do. There are a few guys running it with stage 3 injectors and it still holding up as well. I will be using a different turbo mainly based on I can build a H2E/HX50 kit cheaper than I can buy a D66.