Disappointing HP numbers
#1
Staging Lane
Thread Starter
Disappointing HP numbers
I went for a final street tune and using HP Tuners hp calculations, it only pulled 390 hp. Seems absurdly low to me.
I started with a brand new GM LQ9 long block. I pulled the rectangle port heads and installed a set of 243 heads with a fresh 5 angle valve job. Added a BTR stage II low lift truck cam, springs and correct pushrods and topped it off with a TBSS intake with flex fuel injectors and shorty headers running thru a Gibson cat back 3.5 single pipe. I also have a built 4l65E transmission with a TBSS I6 converter which is stalling in the 2600 to 2800 rpm range. It runs really strong but I am still disappointed.
Is the HP tuners number reasonable?
Tim
I started with a brand new GM LQ9 long block. I pulled the rectangle port heads and installed a set of 243 heads with a fresh 5 angle valve job. Added a BTR stage II low lift truck cam, springs and correct pushrods and topped it off with a TBSS intake with flex fuel injectors and shorty headers running thru a Gibson cat back 3.5 single pipe. I also have a built 4l65E transmission with a TBSS I6 converter which is stalling in the 2600 to 2800 rpm range. It runs really strong but I am still disappointed.
Is the HP tuners number reasonable?
Tim
#2
TECH Veteran
iTrader: (5)
I'd put it on a dyno before losing any sleep. Even if it made 390 at the wheels, thats a good chunk of power. I have a cam'd and bolted 5.3 running thru your exact drivetrain and it makes 302 at the wheels NA. So you're +90 (calculated) on that number. I'd say thats pretty good! What were you expecting?
#3
Staging Lane
Thread Starter
I'd put it on a dyno before losing any sleep. Even if it made 390 at the wheels, thats a good chunk of power. I have a cam'd and bolted 5.3 running thru your exact drivetrain and it makes 302 at the wheels NA. So you're +90 (calculated) on that number. I'd say thats pretty good! What were you expecting?
Tim
#4
TECH Veteran
iTrader: (5)
There is no NA 6.0 on this planet that will burn 91 and make 500 thru 35" tires and a big ole 9.5" ring gear
So to clarify, are you talking calculated crank hp or are you talking calculated wheel horsepower?
You need to get that thing on a dyno to maximize the power. Keep adding timing until it starts losing power then back off 2-4 degrees. Were you tuning with a wideband? what does fueling look like at WOT? Maybe some power on the table there too
So to clarify, are you talking calculated crank hp or are you talking calculated wheel horsepower?
You need to get that thing on a dyno to maximize the power. Keep adding timing until it starts losing power then back off 2-4 degrees. Were you tuning with a wideband? what does fueling look like at WOT? Maybe some power on the table there too
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#9
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