I installed a Westach dual gauge today with boost and egts. I took the truck for a drive emoty to see what readings I would get. Nothing too exciting so I hooked to to a LOAD, guestimated at 15k lbs. I took it over Dallas Divide which climbs from about 6500ft to about 10k feet with some 5-6% grades.
I went with a 1/4" probe installed in the Jake elbow, post turbo. I thought this would be the easy way to do it, just unscrew the plug and screw in the probe. That was until the plug wouldn't come out and I eventually twisted the head off, which led to Jake removal, drilling, tapping etc. If that probe didn't require a 7/16" hole I would have put it in the manifold. Oh well, its in there now.
Anyway, on the pull the truck never went above about 975 post turbo. I could get a steady 30 psi of boost until about 2400rpm. From there to redline it was iffy, wiggling needle dropping to 25 psi as it ran towards 3000 rpm. I am assuming this is the wastegate bleeding off a little early. I found the egt pretty responsive, almost connected directly to what my right foot was doing. If a manifold mount is more responsive, that needle must snap to attention
I can definately see where I would run hotter in a manual trans truck, if I wasn't watching a gauge. The auto downshifts and keeps rpms up and temps down. I know I could pull it in the next gear but I could also watch the egts climb just before the downshift.
So, about this boost drop off, anybody else see this? Is something like the Banks Big Head actuator the answer to keeping the wastegate closed on the top end? At a steady 2200 rpm the gauge would sit right at 30 psi. I assume there would be advantages to keeping it there until 3000 rpm correct? Or, is it pointless because the turbo is out of its range?
I went with a 1/4" probe installed in the Jake elbow, post turbo. I thought this would be the easy way to do it, just unscrew the plug and screw in the probe. That was until the plug wouldn't come out and I eventually twisted the head off, which led to Jake removal, drilling, tapping etc. If that probe didn't require a 7/16" hole I would have put it in the manifold. Oh well, its in there now.
Anyway, on the pull the truck never went above about 975 post turbo. I could get a steady 30 psi of boost until about 2400rpm. From there to redline it was iffy, wiggling needle dropping to 25 psi as it ran towards 3000 rpm. I am assuming this is the wastegate bleeding off a little early. I found the egt pretty responsive, almost connected directly to what my right foot was doing. If a manifold mount is more responsive, that needle must snap to attention

So, about this boost drop off, anybody else see this? Is something like the Banks Big Head actuator the answer to keeping the wastegate closed on the top end? At a steady 2200 rpm the gauge would sit right at 30 psi. I assume there would be advantages to keeping it there until 3000 rpm correct? Or, is it pointless because the turbo is out of its range?