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Should I upgrade my current GTP38 or just go ahead any buy a GTP38R or an Applied Performace 802 etc etc. I'm not looking to make a 700hp coal roller but the turbo lag and surge is definitely annoying and yes i will be upgrading injectors slightly as well. Just looking for some input from personal experiences.
It's an 02 F250 100% Stock except a 75hp chip. 4r100 tranny 235000 miles.
One option would be to rebuild you current one and install a billet compressor wheel until you spring for new injectors. When you do decide you need a different turbo, check out KC turbos. They have a ball bearing turbo that is rebuildable and it supposedly out performs the 38R.
You should not have any lag. Need to figure out what is causing that. Check for leaks from the turbo to the engine. You can do this "boost leak test" with a 3" pvc plumbing cap and an air compressor regulated to 30psi. Pressurize and fix any obvious leaks then get out the soapy water to find the little ones. Also inspect the exhaust from the engine to the turbo for leaks. Soot = leak.
A wicked wheel 2 style machined compressor wheel from many reputable companies will get rid of the surge. Rebuild the turbo with a kit with the 360 bearing.
Another cause of lag can be losing exhaust backpressure due to leaky up pipes, as Brandon touched on. If they are OE they are probably leaking. The joint where the uppies go into the collector on back of the turbo is a hoky design, basically a slip joint. Over time the repeated slippage due to heat expansion of the pipes wears the mating surface with the brass seal in there. You may see soot marks on the pipes or on the firewall. If pressure is lost there it is not being applied to the turbo, resulting in low boost and lag. All above suggestions are great, but don't forget the exhaust side of the turbo. Best fix is bellowed uppies but you can get down the road by replacing the donuts with Felpro 8194 donuts.
A billet compressor wheel is a great upgrade to an otherwise stock truck. That's where I'm at with stock sticks. If substantially bigger injectors are in the future the 38R will get more out of them and be less likely to smoke. Tunes are a giant influence on that tho. Beyond that is a T4 setup with a wide variety of turbo options but that's a higher HP scenario.
Hard to make suggestions without more specific goals and budget.
...Beyond that is a T4 setup with a wide variety of turbo options but that's a higher HP scenario.
Hard to make suggestions without more specific goals and budget.
A T4 setup doesn’t have to be a higher HP scenario! With stock injectors, a 364.5sxe will outperform any drop in turbo whether daily driving, towing or racing, albeit at an additional $1k price tag.
