Running twins like that allows the use of a cam with a tighter LSA. The drop in back pressure from having the second turbo there reduces the potential for flow reversion by a LOT.

The fact that the cam they chose kicked some *** isn't even debatable

 

You know theres some smug engineerings over at GM after reading this
rightfully so

I dont understand how 75s took them that far, seems like they would need injectors twice as big...unless they are running 300psi fuel pressure.

 

That's what I was thinking! Aside from the sheer amazement at the power and the boost they threw at it. I'm at 88% IDC with my 75#'ers on E85 and a 3.0" pulley and don't go above 6600.

 

That whole magazine rinks of BS, 75lbers wont even support that power level, need somewhere around 85-100lb injectors. If the 450 horse naturally aspirated is from the 4.8 and not some other engine, then the whole article goes down the drain, so yeah i dont think so.

 

The injectors can be bandaided somewhat with high fuel pressure like mentioned, and the lesser load of a engine dyno might contribute to the smaller injectors being acceptable some.. I see the mentioned bigger fuel rails, any mention of the rest of the fuel setup? Does make it a little hard to swallow seeing just the 75s mentioned.

Now the n/a argument, 450n/a on an engine dyno would probably be around 370ish thru a 60e auto. So that means could a 4.8 with 7/8 headers, fast intake, good heads, and no accessories at all be able to peak @7k rpm with that cam and make 370rwhp. Imo yes it could be done..

I think everybody is overlooking what i would call a pretty impressive top end with that intake and heads. Everything ive seen with a fast and boost has shown really good numbers and performs really well, this is no different..
Do this on a completely stock 4.8 with no upgrades and i think they barely break the 1k mark..?

 

I'm skeptical. The injectors are too small and it's an engine dyno. I read a lot of these engine dyno writeups and they always seem liberal with the numbers. At any rate, it's a very impressive project.

 

You don't think a heads, big cam, Fast intake, large primary headers, no accessories, electric water pump, 4.8 can put down 450? Take 20% away for drivetrain losses and you would see ~360 rwhp in a vehicle. Seems legit to me...

As for the injectors, I don't know...

Edit: skolman beat me to it, lol

 

^^^ LMAO Boats & Hoes

 

The fuel injectors come down to fuel pressure. Those 75lb's quickly become 100lb+. I run my 80's at 94 and would go higher if I had a stronger pump setup to support it. I would say they have more then enough pump suppling pressure/volume at the test stand.

As to the power, here's another one, stock crank and rods. It does have pistons though, ended up making 1342HP/928TQ at 7500rpms.

http://www.youtube.com/watch?v=1r4kC...ature=youtu.be

This is a 4.8L rod on the left, 5.3 mid, lq9 on end. Sure hell doesn't look like a 1300HP rod. I would want to be wrapped in armor if I pushed my truck to those levels for a 1/4 pass.

109615jpg_000000054522.jpg?t=1260125938

 

Hmmm small displacement has proven good turbo hp, you also have to consider they are running 118 octane which should in turn lower duty cycle from needing less gas and having a cooler combustion, someone please correct me on this if im wrong....But im blown away myself on them achieving that on those injectors id myself like to know how much fuel pressure they were running