Laggy Turbo
#16
10-14-2018, 09:42 PM
My injectors are in my sig and, relatively speaking, are sized very similar to yours; 160/30
I'm not saying drive around in 4th (5th - whatever) gear, but you have to downshift it if you want to accelerate hard. My 160/30s accelerate just fine from 65 MPH in top gear unless I hammer the throttle. Then I get lots of smoke, feel like I am waiting on boost, etc... Gotta get the RPMs up if you want fast boost with no smoke.
I'm not saying drive around in 4th (5th - whatever) gear, but you have to downshift it if you want to accelerate hard. My 160/30s accelerate just fine from 65 MPH in top gear unless I hammer the throttle. Then I get lots of smoke, feel like I am waiting on boost, etc... Gotta get the RPMs up if you want fast boost with no smoke.
What gearing do you have? What tires?
Also a GT38r and KC38R aren’t the same.
If you have 3.73s and stock tire size I suggest you look for leaks somewhere in your pre turbo exhaust or for boost leaks. No way you should have lag until 1900rpm. That’s basically where I’m at.
#17
10-14-2018, 09:58 PM
Can’t see signatures,
What gearing do you have? What tires?
Also a GT38r and KC38R aren’t the same.
If you have 3.73s and stock tire size I suggest you look for leaks somewhere in your pre turbo exhaust or for boost leaks. No way you should have lag until 1900rpm. That’s basically where I’m at.
3.73s on 285/75/16, up-pipes were replaced along with all intake boots and seals. I suspect no leaks, hits 28-30 PSI no problem on a race tune.
Not saying the turbos are the same but man I can't imagine that big of a difference. I'd hate to see you waste money on another turbo...
#18
10-14-2018, 10:01 PM
3.73s on 285/75/16, up-pipes were replaced along with all intake boots and seals. I suspect no leaks, hits 28-30 PSI no problem on a race tune.
Not saying the turbos are the same but man I can't imagine that big of a difference. I'd hate to see you waste money on another turbo...
Not saying the turbos are the same but man I can't imagine that big of a difference. I'd hate to see you waste money on another turbo...
Do you have a boost leak tester? If not I suggest you buy one. When I had a boost leak it was my map sensor and boots.
#19
10-14-2018, 10:12 PM
#20
10-14-2018, 11:10 PM
#21
10-14-2018, 11:34 PM
Not exactly apples to apples, but here is a PHP dyno comparison of different 38R setups on the same truck, all around ~550 WHP... none hit over 34 PSI. I'm no airflow engineer but I recall in my initial research a year ago that 38R flows like 30%+ more air than the stock turbo, so it takes way less pressure to make the same (or more) power.
Garrett 38R 1.0 vs 1.15 dyno test - PowerStrokeArmy
I didn't mean to hijack... I still think you need to downshift if you want power. 2200-2500 RPMs is where it starts to feel fast.
Garrett 38R 1.0 vs 1.15 dyno test - PowerStrokeArmy
I didn't mean to hijack... I still think you need to downshift if you want power. 2200-2500 RPMs is where it starts to feel fast.
#22
10-15-2018, 07:42 AM
A stock turbo should hit well over 30, but not a 38R unless you stick big injectors in, even then probably not much more. I'm only on 160/30s which are a hair bigger than stock. 30 PSI is probably on the high end for my setup. I live at elevation so that also plays a factor.
#23
10-15-2018, 08:18 AM
#24
10-15-2018, 09:20 AM
Fleet Owner
I learned a while back that equating boost pressure to HP is not the right way I wanted to go about planning how a truck should end up. If I can make the same HP with 15 lbs of boost with an SXE vs. 30 lbs of boost with a 38R, then the SXE is where my money will go. This is just an example.
Boost pressure is not always a good thing, especially when you start to get over ~35 lbs without upgrading valve springs and plenums. Yet, another reason why I went with the SXE because they are very free flowing, offer lower the EGT's and provide more than enough power while keeping the boost pressures down to a reasonable level.
Seems like you really need to figure out what it is you are looking for out of the truck before sending your money off somewhere. Only you can answer the questions of what you are looking for and what your goals are for the truck.
Good luck with your choices.
#25
10-15-2018, 12:39 PM
but that’s my max.
But like Sous said,
boost doesn’t equate to hp or torque.
That’s why I want to get rid of this turbo for a better one, which means I gotta make some phone calls.
#26
10-15-2018, 12:40 PM
Every truck is different. Even if the two trucks had the same turbo, injectors and tune, they would perform a bit differently.
I learned a while back that equating boost pressure to HP is not the right way I wanted to go about planning how a truck should end up. If I can make the same HP with 15 lbs of boost with an SXE vs. 30 lbs of boost with a 38R, then the SXE is where my money will go. This is just an example.
Boost pressure is not always a good thing, especially when you start to get over ~35 lbs without upgrading valve springs and plenums. Yet, another reason why I went with the SXE because they are very free flowing, offer lower the EGT's and provide more than enough power while keeping the boost pressures down to a reasonable level.
Seems like you really need to figure out what it is you are looking for out of the truck before sending your money off somewhere. Only you can answer the questions of what you are looking for and what your goals are for the truck.
Good luck with your choices.
I learned a while back that equating boost pressure to HP is not the right way I wanted to go about planning how a truck should end up. If I can make the same HP with 15 lbs of boost with an SXE vs. 30 lbs of boost with a 38R, then the SXE is where my money will go. This is just an example.
Boost pressure is not always a good thing, especially when you start to get over ~35 lbs without upgrading valve springs and plenums. Yet, another reason why I went with the SXE because they are very free flowing, offer lower the EGT's and provide more than enough power while keeping the boost pressures down to a reasonable level.
Seems like you really need to figure out what it is you are looking for out of the truck before sending your money off somewhere. Only you can answer the questions of what you are looking for and what your goals are for the truck.
Good luck with your choices.
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