vteckiller2000

I'm basing it on the 370-380 rwhp I am seeing from these tune/exhaust trucks. 25-26% drivetrain loss seems excessive.

That said, the 600+ lb/ft engine torque probably helps get that big truck to that 100+ mph trap. I just don't see 500 hp there with those tiny turbos.

engineermike

According to Full Race, the stock F150 EB turbo's are good for a combined 47 lb/min at choke. That should be good for 500 hp.

And just FYI, I used the basic hp calculation using weight and mph. Keep in mind that the conditions were very good when the 103 mph pass was made.

byoungblood

They don't happen to have compressor maps, do they?

Centexguy

500hp/1000ftlbs of torque will propel a 7-8000lb diesel into the high 12s/low 13s. So to make 6000lbs do that wouldn't take THAT much power.

Centexguy

I find that what works on paper rarely translates to real life. If the engine was a 100% efficient in using all of that air and fuel then I could see the turbos working but it's not.

engineermike

According to Full Race, there is some sort of agreement that the compressor maps not be published. For now, at least.

engineermike

I've been turbocharging engines for quite a while and they all start on paper, but later translate to real life. On one of my combo's, the turbo was rated at 90 lb/min at choke but made 940 hp on the dyno. And this was using old school tech, likely not as efficient as the 4-valve vvt DI engine.

If what FR is saying about 47 lb/min at choke is right, then 470 hp would be a conservative estimate. A rule of thumb is actually that 1 lb/min = 10 rwhp, but that generally applies to manual transmission cars with less drivetrain losses.

mtxpert

If you have a set of turbos off a car, how hard is it to get compressor maps made up? I'm googling it but must be looking for something wrong.

engineermike

Not very easy. You need to be able to hold it at a constant, known shaft speed and measure flow rate, inlet temp, discharge temp, inlet pressure, and discharge pressure. The most difficult part on these would be holding it at a constant, known speed, as they likely spin well over 100,000 rpm.

Centexguy

Has anyone looked into VGT turbos for these? They've been using them for years on the diesels.