Getting set to start upgrading my ‘01, including 100hp injectors, head studs, turbo, FASS, clutch, exhaust, exhaust brake, Quad, and gauges.   At what point should I consider upgrading to heavier valve springs?   I’m targeting around 450-475 whp with the changes I’m making, but at what point should the stock valve springs be updated?

 

Hope everyone had a very Merry Christmas!

Stock valve spring I'm at 500 HP already. It about Boost pressure and drive pressure when your drive pressures are reaching over 60 PSI you start to blow open the valves. So current the stock springs are good for 60 pounds of force. Just remember exhaust brake takes full advantage of the drive pressure and the 60 PSI spring and pull the truck down to crawl. So when you reach the 50 to 60 PSI boost range it will be time to upgrade. I currently max out boost at 47 to 49 PSI. Currently my last trip to Lewiston Quad on Level 2 it possible to light up the tires without CANBus fuel or Wiretap. 

 

• ~500 HP to the ground.
• 150 HP DAP Injectors (7 x 0.010 @ 320 bar)
• HX35/40 Hybrid (60/60/12)
• Quadzilla Adrenaline

Edited December 27, 20204 yr by Mopar1973Man

Is there a direct correlation between boost and drive pressures?   Can one infer a certain drive pressure from the amount of boost seen?   Or is the amount of drive pressure not accurately predictable from boost?   If not, then it’s probably a good idea to throw a drive pressure gauge on at least temporarily to see what my pressures are running?  Or would you say it should be monitored continuously (permanent installation)?   Is the exhaust manifold the best place to measure drive pressure, or is there a better location to put the sensor?

 

For an exhaust manifold pressure gauge installation, I’ve read where soot/carbon can cause problems for this pressure reading, and that some install a filter canister to capture this debris.   I would guess that adding a filter would be preferable to a clogged line and gauge.  

 

Thanks for the advice Mike!

@Mopar1973Man do you have a drive pressure gauge? Have you dyno’d that rig? 500 to the ground is a HOT tune with that turbo, curious how much your making with it set WFO 

 

 

Most efficient turbos run 1.3-1.5:1 drive:boost, meaning 45 psi of boost is going to be pushing 60 psi drive on most efficient turbos. Some less efficient turbos, like the HE351CW will run 2:1 or more. Rpms also play a big role, 45 psi at 2200 rpms will have a lot lower drive pressure than at 3000 rpms. 
 

I ran a Garrett BB turbo on my 05 that was 1:1 or less most the time, and the highest I think I ever saw it was ~1.2:1, but that’s BB and a large exhaust housing. Journal bearing turbos generally run tighter housings and more drive pressure.

 

So, without a drive pressure gauge I would say that unless your exceeding 45 psi or stock rpms then you’re probably fine. 
 

I ran 103# springs on my 05 but never needed them for boost or drive pressure, but the cam/exhaust brake combo needed them

and would run ~75 psi while slowing. 
 

 

 

Edited December 28, 20204 yr by AH64ID

@AH64ID Not to hijack, but I have heard that the BB stuff is rather short lived compared to the 200k+ you get from a journal, as well as the difference at pressure, both oil and boost, was negligible. 

 

Care to provide a bit of personal experience?

7 hours ago, That Guy said:

@AH64ID Not to hijack, but I have heard that the BB stuff is rather short lived compared to the 200k+ you get from a journal, as well as the difference at pressure, both oil and boost, was negligible. 

 

Care to provide a bit of personal experience?

I haven’t heard that too much, and not a lot of guys I know run them to get an idea. Most the guys I know running them don’t have 100K on them. 
 

I’m sure the one I had has over 100K on it now, and haven’t heard of any issues. 
 

It did make a small bump in warm oil pressure, and nothing cold since the oil pressure relive valve is open. 
 

Spooled great, thou I wouldn’t have shy’d away from a slightly smaller turbine housing for a little better low rpm spoon at elevation.
 

It lowered my overall boost, but made more power at lower EGT’s. Basically, it moved air thru the motor more efficiently and didn’t have the restriction on the intake from the exhaust, so more airflow are lower boost. Lower boost means less heat for the intercooler to remove. 
 

The biggest benefit was the water cooled center section thou, as they have several benefits for turbo longevity. 

There are several new journals options available today that weren’t out yet when I bought the Garret so I’m not sure I’d go that route again, but it’s possibly. I liked that turbo. The 18 is keeping the stock turbo thou.