Okay, so this might not be a “performance” truck, but it’s my ‘99 Toyota 4Runner that I’m currently in the process of turbocharging, and would like recommendations on turbo sizing. It comes from the factory with the venerable Toyota 5VZ-FE 3.4L V6 which is known to easily surpass 500k miles. It also comes with a whopping 190hp/220tq which, unsurprisingly, struggles to tow just about anything.

While this is my camping and trail riding rig, it is also my boat hauler in the summertime. And there in lies the problem, because my boat + trailer + fuel + gear weighs somewhere around 4,000lbs, and I live on a small mountain where I pull a 6% grade for 3 miles to get home. This truck hates that.

My goal is to turbo at 7psi with peak air flow somewhere around ~30lbs/min. I’m thinking this should put me in the ~280hp neighborhood. The few people that have turbo’d these trucks seem to have good results with the GT3071R and GT3076R. I’m thinking probably the 3071 might be a better fit for me? If going with either of those turbos, which a/r for the exhaust side? .82? Larger? Want to make sure it’s appropriately sized so as to not generate excessive heat while towing under boost. But at the same time still have decent spool when traveling at higher elevations through the mountains while unloaded.

Before anyone starts with BuT wHy NoT jUsT gEt A dIfFeReNt tOw vEhIcLe …

I already have my rig built the way I want it. Bigger Tundra brakes, suspension, external transmission cooler, backup camera, projector headlight retrofit, bigger fuel injectors, piggyback controller, etc. I’m not looking to rebuild another camping rig, but rather improve upon what I’ve already got.

Appreciate any input you guys have.

 

Before I even read your thread, my suggestion was going to be the 3071R

I built a gen3 3SGTE with a 3071R on it, it made its way into a Celica GT4 and its making 440whp on 18lbs with e85. Its a good turbo, lights off quick

Edit-RE: hot side size- might be a trial and error thing for you to determine what is best. This is going to be dependent on a number of factors, like altitude, load, what RPM you want to spool at and what RPM you're ok with it choking at, if it's going to choke. Personally I'd pick the largest size available and downsize from there if necessary

Raises a question for me however- how are you tuning the truck? Not with a 7th injector, right? Because that is a recipe for disaster

 

I currently have 315cc 7MGE Supra injectors installed, which replaced my factory 245cc. I have both the URD MAF/T calibrator and the URD AFR Sensor calibrator. I’m thinking the AFR sensor calibrator will be the most useful as it’ll allow me to adjust closed loop fueling.