Fastest 8.1 Thread...
Jan 21, 2011 | 09:41 AM
#11
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Joined: Nov 2004
Posts: 1,051
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From: ODESSA, TX
I built a 2006 2500 hd 4x4 8.1 using raylar Heads, Intake , Diamond pistons , Manley Rods , SW long tubes , Custom 4 inch Rear mount turbo BW S480 on 10 psi , fuel system , Meth , ATS Ally , 4:10's ... Dynos 800hp 800tq to the wheels on our mustang dyno ... Went to the track using ats five disc stall for a duramax 500rpm tighter then stock [I guess they didn't here me that i was building a GAS 8.1 ] ... The truck wouldn't make boost till the 330 mark ... Still went mid 12's @ 117-119 mph ... Now with new Vig stall 2800 5 disc with turbo stator [ Leaves at 3-5 psi on foot brake ] I would guess mid 11's ... Track is still closed ... Oh FYI 60ft 2.5 LOL
Mar 30, 2011 | 11:19 PM
#13
Teching In
Joined: Apr 2006
Posts: 48
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From: San Antonio Area
Went 13.6 @104 last year and 13.80 @103 this year at LS1 shootout. 4x2 3:73 gears 13psi boost on twins pump gas and 7k lbs. 60' 2.3. Will prob add Caltracs when I can, like to throw is some 105 Octane and up the boost but worried bout strenght of stock pistons...
Oct 24, 2011 | 10:57 AM
#19
he said it was dropping at 5000 88 kpa, intake is a known restriction on these motors. He said once i put my custom intake proper sized injectors and open up the intake before the tb and bigger tb i should defintely see a change. I was 122 percent duty cycle on stock injectors at 67 pounds of fuel pressure
Oct 27, 2011 | 10:41 AM
#20
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Joined: Oct 2005
Posts: 1,379
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From: Woodstock Ontario Canada
Definitley sounds like there is some induction restriction there. Swap out from the stock 75mm tbody and grab some marine 8.1 42 lbrs or better.
I remember the 525hp HP3 8.1 used the same fuel map as the 420hp HP2 but used a different regulator to up the fuel pressure to support the 525hp. The 420hp HP2 used the 300kpa(43.5-3BAR) FPR and the HP3 use the same injectors but 400kpa(58psi-4BAR).
They used the stock 8.1 marine injectors and port matched intake.
peace
Hog
I remember the 525hp HP3 8.1 used the same fuel map as the 420hp HP2 but used a different regulator to up the fuel pressure to support the 525hp. The 420hp HP2 used the 300kpa(43.5-3BAR) FPR and the HP3 use the same injectors but 400kpa(58psi-4BAR).
They used the stock 8.1 marine injectors and port matched intake.
peace
Hog
