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Anyone Put The 8.1 On A Dyno

DamGio

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DamGio Enthusiast

DamGio

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I was just wondering what the BIG BLOCK puts down. My truck is a suburban LT 2500 and every week the scale at the dump consistently tells me the truck weighs about 7300 lbs. empty with about a 1/2 tank of gas. This is my first experience with a V8 and i thought the big block would be the shit but am very disappointed. I know the weight might be the issue but i can't Even break the rear tires loose. I thought the monster torque would do something other than when it's raining or wet outside. Am i really getting 455 ft. lbs from the factory? I read somewhere idling it makes 220 ft. lbs. is that true? Will a custom tune really make a difference? I think i want to go back to my turbo 4 in the EVO. At least i can pin my daughters to the seat and hold them there in 4 of the 5 gears.

KMGZ400 Senior Enthusiast

KMGZ400

Posted
Posted

you have a big ass truck it will not be fast!... its never gonna be anything like an evo ... its meant for pulling really heavy shit. you should try and mod it with an exhaust, filter and tune and you might be happier.

 

i think a trailblazer ss might be up your alley.

GasHog369 Senior Enthusiast

GasHog369

Posted
Posted

agreed... Make it breath better first with a full intake , then get that air out with duals, and utilize it all with a tune. Then you will be happier..

 

 

If not, hook up a chain between the evo and your truck and that will make you happy :thumbs:

stlavsa Senior Enthusiast

stlavsa

Posted
Posted
agreed... Make it breath better first with a full intake , then get that air out with duals, and utilize it all with a tune. Then you will be happier..

 

 

If not, hook up a chain between the evo and your truck and that will make you happy :thumbs:

 

 

lol you dont need duals but and personally i think its not the way to go. A tune will give you more power, and make the truck much nicer to drive. Not saying that freeing up the airflow with some sort of intake and exahaust is a bad idea, BUT the tune will be much more effective. Theoretically all three would be your best bet, just have the truck tuned for the intake/exhaust combo.

 

It will make the truck much more enjoyable to drive all around thats for sure. Do you really need to be "pinning your daughters to the back of the seat in 4 of the 5 gears?" Maybe one or two gears but driving your daughters aroudn at 120mph? lol i duno.

DamGio Enthusiast

DamGio

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  • Author
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agreed... Make it breath better first with a full intake , then get that air out with duals, and utilize it all with a tune. Then you will be happier..

 

 

If not, hook up a chain between the evo and your truck and that will make you happy :thumbs:

 

 

I don't want to go fast did you see what it weighs Even though i think it has really good brakes i wouldn't get the speed governor removed when or if i get a custom tune. If I want to go fast I'll take EVO and leave the kids home. I just want to piss the wife off with some tire smoke every now and then and light em up on demand for my daughter. Bottom line i just want to play with my truck and i do use it to tow heavy shit every time i break the EVO it rides back to the shop on the back of the truck and when i need to deliver and install custom cabinets the truck pays for itself (I really bought the truck for the cabinets) I looked for that truck for over 8 months it's my dream truck but it would be a wet dream if i could play around with it

DamGio Enthusiast

DamGio

Posted
  • Author
Posted
agreed... Make it breath better first with a full intake , then get that air out with duals, and utilize it all with a tune. Then you will be happier..

 

 

If not, hook up a chain between the evo and your truck and that will make you happy :thumbs:

 

 

lol you dont need duals but and personally i think its not the way to go. A tune will give you more power, and make the truck much nicer to drive. Not saying that freeing up the airflow with some sort of intake and exahaust is a bad idea, BUT the tune will be much more effective. Theoretically all three would be your best bet, just have the truck tuned for the intake/exhaust combo.

 

It will make the truck much more enjoyable to drive all around thats for sure. Do you really need to be "pinning your daughters to the back of the seat in 4 of the 5 gears?" Maybe one or two gears but driving your daughters aroudn at 120mph? lol i duno.

 

 

 

120-? in 4th i'm about 155 heading fast to the top speed of 177 (want to go for a ride)

stlavsa Senior Enthusiast

stlavsa

Posted
Posted
agreed... Make it breath better first with a full intake , then get that air out with duals, and utilize it all with a tune. Then you will be happier..

 

 

If not, hook up a chain between the evo and your truck and that will make you happy :thumbs:

 

 

lol you dont need duals but and personally i think its not the way to go. A tune will give you more power, and make the truck much nicer to drive. Not saying that freeing up the airflow with some sort of intake and exahaust is a bad idea, BUT the tune will be much more effective. Theoretically all three would be your best bet, just have the truck tuned for the intake/exhaust combo.

 

It will make the truck much more enjoyable to drive all around thats for sure. Do you really need to be "pinning your daughters to the back of the seat in 4 of the 5 gears?" Maybe one or two gears but driving your daughters aroudn at 120mph? lol i duno.

 

 

 

120-? in 4th i'm about 155 heading fast to the top speed of 177 (want to go for a ride)

 

 

 

I have been in plenty of fast cars ones that i actually feel safe at 170+ !!

 

I didnt realize that evos were geared so tall. I dont believe that i have rode in one now that i think about it, but i was comparing it o STIs i dont think they will do 155 in 4th gear. More like a top speed of about 160ish.

 

 

I just did a quick google search and its that posted topspeeds for lancers are 150-157?? I guess that must be electronically limited not by gearing? So your saying that if you car had a the stock speed govenor that you woulda been able to hit it in 4th gear?

 

 

EDIT: i just did a quick search seems there are plenty of guys going thru the traps @ rev limiter (raised) in 4th gear hitting 120-125 MPH which was pretty much my guess.

Mike@Diablosport Enthusiast

Mike@Diablosport

Posted
Posted
I was just wondering what the BIG BLOCK puts down. My truck is a suburban LT 2500 and every week the scale at the dump consistently tells me the truck weighs about 7300 lbs. empty with about a 1/2 tank of gas. This is my first experience with a V8 and i thought the big block would be the shit but am very disappointed. I know the weight might be the issue but i can't Even break the rear tires loose. I thought the monster torque would do something other than when it's raining or wet outside. Am i really getting 455 ft. lbs from the factory? I read somewhere idling it makes 220 ft. lbs. is that true? Will a custom tune really make a difference? I think i want to go back to my turbo 4 in the EVO. At least i can pin my daughters to the seat and hold them there in 4 of the 5 gears.
Here is a dyno sheet from an 03 8.1 tuned here on our dyno. This is the same 87 octane tune available to anyone who purchases a Predator for their truck.

 

03_81L_josh_87octane.jpg

 

Pretty stout gains!

stlavsa Senior Enthusiast

stlavsa

Posted
Posted

Mike help me understand the dynograph. Which A:F line is the tune and which is the stock? How can one possibly be that flat?

 

 

 

I was just wondering what the BIG BLOCK puts down. My truck is a suburban LT 2500 and every week the scale at the dump consistently tells me the truck weighs about 7300 lbs. empty with about a 1/2 tank of gas. This is my first experience with a V8 and i thought the big block would be the shit but am very disappointed. I know the weight might be the issue but i can't Even break the rear tires loose. I thought the monster torque would do something other than when it's raining or wet outside. Am i really getting 455 ft. lbs from the factory? I read somewhere idling it makes 220 ft. lbs. is that true? Will a custom tune really make a difference? I think i want to go back to my turbo 4 in the EVO. At least i can pin my daughters to the seat and hold them there in 4 of the 5 gears.
Here is a dyno sheet from an 03 8.1 tuned here on our dyno. This is the same 87 octane tune available to anyone who purchases a Predator for their truck.

 

03_81L_josh_87octane.jpg

 

Pretty stout gains!

 

Mike@Diablosport Enthusiast

Mike@Diablosport

Posted
Posted
Mike help me understand the dynograph. Which A:F line is the tune and which is the stock? How can one possibly be that flat?

 

 

 

I was just wondering what the BIG BLOCK puts down. My truck is a suburban LT 2500 and every week the scale at the dump consistently tells me the truck weighs about 7300 lbs. empty with about a 1/2 tank of gas. This is my first experience with a V8 and i thought the big block would be the shit but am very disappointed. I know the weight might be the issue but i can't Even break the rear tires loose. I thought the monster torque would do something other than when it's raining or wet outside. Am i really getting 455 ft. lbs from the factory? I read somewhere idling it makes 220 ft. lbs. is that true? Will a custom tune really make a difference? I think i want to go back to my turbo 4 in the EVO. At least i can pin my daughters to the seat and hold them there in 4 of the 5 gears.
Here is a dyno sheet from an 03 8.1 tuned here on our dyno. This is the same 87 octane tune available to anyone who purchases a Predator for their truck.

 

03_81L_josh_87octane.jpg

 

Pretty stout gains!

 

 

Great question.

 

The stock 8.1 cal does not let it go into PE for 30 full seconds, meaning you have to stay WOT for 30 seconds before it will add power enrichment (fueling) to make power. It stays at 14.7:1 even at WOT, thus the HUGE torque gains (40+ ft/lbs) you see across the board.

 

The 8.1 is begging for a good tune.

stlavsa Senior Enthusiast

stlavsa

Posted
Posted

Ok so let me see if i got this straight, because I have never tuned any of these trucks or any GM only different makes.

 

 

By the graph, your saying that it needs more fuel to make more power, and you find that it makes the best power somewhere in the 12.x:1 range (i cant see the graph right now while im replying). So you make this power by #1 eliminating the 30second delay on the power enrichment, and then richen up the fuel cells, and most likely do some work with the timing as well.

 

Of the thing to run 14.7:1 full throttle it must really be a pretty detuned motor, like low compression, conservative timing settings? (if you cant tell i dont even know the specs of these monsters). But now I can see why they can make tremendous power naturally aspirated with some headwork, cams and high compression pistons.

Mike@Diablosport Enthusiast

Mike@Diablosport

Posted
Posted

Yes, you've got it figured out.

Ok so let me see if i got this straight, because I have never tuned any of these trucks or any GM only different makes.

 

 

By the graph, your saying that it needs more fuel to make more power, and you find that it makes the best power somewhere in the 12.x:1 range (i cant see the graph right now while im replying). So you make this power by #1 eliminating the 30second delay on the power enrichment, and then richen up the fuel cells, and most likely do some work with the timing as well.

 

Of the thing to run 14.7:1 full throttle it must really be a pretty detuned motor, like low compression, conservative timing settings? (if you cant tell i dont even know the specs of these monsters). But now I can see why they can make tremendous power naturally aspirated with some headwork, cams and high compression pistons.

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