Attention: TDR Forum Junkies Wow... just wow!
This is a continuation of this thread
Background:
I explained the 66 surging issue I had to Brady and Shane as well as the fact that I wanted something that would suit my driving style better - a turbo that was not for all out horsepower, drag racing, or sled pulling, but yet allowed me to have fun in town and towing as well as random acts of "pouring-the-coals-to-her". Subsequently, I enquired if I could just keep my SPS turbo, but change just the compressor wheel and housing since I had a very stout turbo platform that has already been paid for.
They did express some concern though that the custom 14 cm2 exhaust side of the SPS 66 would "overdrive" the 62 mm wheel as well as the fact they haven't tried this configuration on any of their own personal trucks yet and were reluctant to have me be the guineau pig 250 miles away.
Another idea was to just swap my SPS 66 for a regular PS 62 with a more "laid-back" 14 cm2 exhaust, but we soon realized that I had a different exhaust flange (flared HTB2 style), as opposed to their normally sold turbos, that was machined onto my SPS 66 specifically for my downpipe. After some more discussion, I volunteered that I keep my wastegate set at 40 psi anyway so that it would do what it is supposed to do while retaining some factor of safety for overshooting the wastegate. After this was said, it became a "no-brainer" and we agreed to go this route! We would never know until we tried...
Turbo Re-work:
My SPS 66 was completely torn apart, cleaned, and inspected. Nothing wrong was found. After wheel balancing checks, a brand new 62 mm extended tip compressor wheel and matching housing were installed onto my already stout SPS platform.
Results versus SPS 66:
-my low end grunt is back with no surging or barking!
-empty cruise boost increased by 1-2 psi overall
-empty cruise EGT decreased by 100-150*
-off-idle smoke as well as low boost smoke duration significantly decreased and cleans up quickly
-hot-rodding around town and the interstates show boost versus drive pressure is essentially 1:1 up to when my wastegate opened at 40 psi. From 10 psi to 40 psi, the boost is on average 1 psi greater than drive pressure. Right after 40-42 psi, drive pressure dropped to ~10 psi after the wastegate opened.
-In terms of "spool-up feel", the top end slam-you-back-in-the-seat is slightly reduced, BUT this feeling is occuring about 150-200 rpm lower than the SPS 66. This SPS 62 turbo also hits 10 psi sooner than the SPS 66 so current owners of the SPS 66 can only imagine what this feels like!
-The "spool-up feel" is not touchy either. I rolled into the throttle at all speeds on some big hills for a load and in no way did the boost rise get out of hand. It was very much controllable.
-highest top end EGT I hit so far was 1300* with the TST twins on 3x2, MP8 on 40%, 100 HP injectors. As soon as 40 psi was hit, the wastegate opened and the EGT dropped 200-300* and I held this until redline @ 108 mph. Once I get some more miles on it, I'll turn up the TST some more. Note the most I've turned the TST up to is 4x4 in my configuration because it is so violent that it freaks me out sometimes...
Closing Thoughts:
Although I admit it was a bit frustrating trying to get a hold of Shane and Brady earlier this week due to their extremely busy schedules and everyone wanting everything from them RIGHT NOW, the early frustration has totally paid off in me having a turbo configuration that more suits my needs because they LISTENED to what MY NEEDS were. The final test is towing of course, but judging from my empty experience so far I believe I will not be disappointed.
Judging by comments after taking Brady and Shane for a ride, this turbo will probably not be a "prototype" anymore soon... :-laf
(they said they still need to test it in their own personal trucks that don't have cams, injectors, manual versus auto, etc... )
I hope to get some dyno time in January as well as some tow time. I'll just post the results of these events on this thread. I'm expecting less HP due to less air from the smaller 62 wheel, but I also expect torque to slightly increase due to the turbo spooling earlier/quicker.
This is a continuation of this thread
Background:
I explained the 66 surging issue I had to Brady and Shane as well as the fact that I wanted something that would suit my driving style better - a turbo that was not for all out horsepower, drag racing, or sled pulling, but yet allowed me to have fun in town and towing as well as random acts of "pouring-the-coals-to-her". Subsequently, I enquired if I could just keep my SPS turbo, but change just the compressor wheel and housing since I had a very stout turbo platform that has already been paid for.
They did express some concern though that the custom 14 cm2 exhaust side of the SPS 66 would "overdrive" the 62 mm wheel as well as the fact they haven't tried this configuration on any of their own personal trucks yet and were reluctant to have me be the guineau pig 250 miles away.
Another idea was to just swap my SPS 66 for a regular PS 62 with a more "laid-back" 14 cm2 exhaust, but we soon realized that I had a different exhaust flange (flared HTB2 style), as opposed to their normally sold turbos, that was machined onto my SPS 66 specifically for my downpipe. After some more discussion, I volunteered that I keep my wastegate set at 40 psi anyway so that it would do what it is supposed to do while retaining some factor of safety for overshooting the wastegate. After this was said, it became a "no-brainer" and we agreed to go this route! We would never know until we tried...
Turbo Re-work:
My SPS 66 was completely torn apart, cleaned, and inspected. Nothing wrong was found. After wheel balancing checks, a brand new 62 mm extended tip compressor wheel and matching housing were installed onto my already stout SPS platform.
Results versus SPS 66:
-my low end grunt is back with no surging or barking!
-empty cruise boost increased by 1-2 psi overall
-empty cruise EGT decreased by 100-150*
-off-idle smoke as well as low boost smoke duration significantly decreased and cleans up quickly
-hot-rodding around town and the interstates show boost versus drive pressure is essentially 1:1 up to when my wastegate opened at 40 psi. From 10 psi to 40 psi, the boost is on average 1 psi greater than drive pressure. Right after 40-42 psi, drive pressure dropped to ~10 psi after the wastegate opened.
-In terms of "spool-up feel", the top end slam-you-back-in-the-seat is slightly reduced, BUT this feeling is occuring about 150-200 rpm lower than the SPS 66. This SPS 62 turbo also hits 10 psi sooner than the SPS 66 so current owners of the SPS 66 can only imagine what this feels like!
-The "spool-up feel" is not touchy either. I rolled into the throttle at all speeds on some big hills for a load and in no way did the boost rise get out of hand. It was very much controllable.
-highest top end EGT I hit so far was 1300* with the TST twins on 3x2, MP8 on 40%, 100 HP injectors. As soon as 40 psi was hit, the wastegate opened and the EGT dropped 200-300* and I held this until redline @ 108 mph. Once I get some more miles on it, I'll turn up the TST some more. Note the most I've turned the TST up to is 4x4 in my configuration because it is so violent that it freaks me out sometimes...
Closing Thoughts:
Although I admit it was a bit frustrating trying to get a hold of Shane and Brady earlier this week due to their extremely busy schedules and everyone wanting everything from them RIGHT NOW, the early frustration has totally paid off in me having a turbo configuration that more suits my needs because they LISTENED to what MY NEEDS were. The final test is towing of course, but judging from my empty experience so far I believe I will not be disappointed.
Judging by comments after taking Brady and Shane for a ride, this turbo will probably not be a "prototype" anymore soon... :-laf
(they said they still need to test it in their own personal trucks that don't have cams, injectors, manual versus auto, etc... )I hope to get some dyno time in January as well as some tow time. I'll just post the results of these events on this thread. I'm expecting less HP due to less air from the smaller 62 wheel, but I also expect torque to slightly increase due to the turbo spooling earlier/quicker.
:-laf
