Thorley Header Project Update
I was just about to guess something like this. I was actually going to ask what the real need for a tune was. I'm not disagreeing with you, but one of my friends said I needed to get a tune after the headers. The reason I was gonna ask was because my friend has been known to be wrong.
Was that 224hp rating an actual baseline, meaning no mods, for the car? Or was it with one or two mods already in place?
I don't know how much hp we lose getting from the engine to the tires, but I did some calculation. If your 224hp was a baseline, with no mods, that is 73.9% (I'll round to 74%) of the factory 303 hp rating. Assuming you lost the same percentage of power with the 276 hp rating, I calculated 372.98 hp (round to 373). How close am I?
Also, what do you suggest for those of us who don't live near a shop that can dyno tune stuff?
Was that 224hp rating an actual baseline, meaning no mods, for the car? Or was it with one or two mods already in place?
I don't know how much hp we lose getting from the engine to the tires, but I did some calculation. If your 224hp was a baseline, with no mods, that is 73.9% (I'll round to 74%) of the factory 303 hp rating. Assuming you lost the same percentage of power with the 276 hp rating, I calculated 372.98 hp (round to 373). How close am I?
Also, what do you suggest for those of us who don't live near a shop that can dyno tune stuff?
The 224 was with an old tune on the current mods. You REALLY need a tune after any mojor modifications. I was able to hold far more timing and we had to pull a ton of fuel out of it. If you don't live near a shop, drive to one. Mail order tunes aren't going to do you anywhere near the good a real tune will.
Staging Lane
Joined: Nov 2009
Posts: 72
Likes: 0
The 224 was with an old tune on the current mods. You REALLY need a tune after any mojor modifications. I was able to hold far more timing and we had to pull a ton of fuel out of it. If you don't live near a shop, drive to one. Mail order tunes aren't going to do you anywhere near the good a real tune will.
Also, how much did getting the tune cost you?
Last edited by westtexastiger; Apr 1, 2010 at 03:46 PM.
Staging Lane
Joined: Mar 2008
Posts: 88
Likes: 0
From: Fairport, NY
Thanks for the info AB.
My headers are getting installed next week. I installed the intake, DP and exhaust and then had it tuned. Once I have the headers on I will try and go in and have it dyno tuned again.
My headers are getting installed next week. I installed the intake, DP and exhaust and then had it tuned. Once I have the headers on I will try and go in and have it dyno tuned again.
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The 224 was with an old tune on the current mods. You REALLY need a tune after any mojor modifications. I was able to hold far more timing and we had to pull a ton of fuel out of it. If you don't live near a shop, drive to one. Mail order tunes aren't going to do you anywhere near the good a real tune will.
TECH Regular
Joined: Dec 2005
Posts: 432
Likes: 0
From: Huntington WV
Awesome! Looks like I'll wait to talk to my tuner and make sure he can pencil me in at the time I install my headers, I was gonna do it this weekend, but it can wait.
On a side note, DTH refunded the deposit money back in my account today, so I'm going to put that towards the tune, rock on.
On a side note, DTH refunded the deposit money back in my account today, so I'm going to put that towards the tune, rock on.
AlabamaGuy,
It's unfortunate that you ended up dyno-ing so low. Didn't you put down 267hp with a catback and rockers before? I was hoping you'd be at 290hp. I would have to say that my car is pulling like crazy! I took my buddy for a ride, who has a 91 5.0 and a 89 super coupe and he was amazed! He weighs about 250 so I was amazed too! I know, I need a tune, and I'm sure I'm leaning out. I was tuned before, with just a downpipe and I was super lean. I'm really hoping for 280-285hp but it seems like know mater what we do, we are all stuck at 275ish N/A. Sittingmongoose was stuck for awhile and finally got it right after paying big bucks! I'll get tuned as soon as I get my intake on.
Not trying to be a dick or anything, I was just hoping for a lot more. Your trap blows mine away. On my dyno you'd be about 265-270 with that mph. I was at 238 runing 99.8mph. With your headers and new tune your new trap should be around 103.6.
Keep us posted, and we race cars not dynos right?
It's unfortunate that you ended up dyno-ing so low. Didn't you put down 267hp with a catback and rockers before? I was hoping you'd be at 290hp. I would have to say that my car is pulling like crazy! I took my buddy for a ride, who has a 91 5.0 and a 89 super coupe and he was amazed! He weighs about 250 so I was amazed too! I know, I need a tune, and I'm sure I'm leaning out. I was tuned before, with just a downpipe and I was super lean. I'm really hoping for 280-285hp but it seems like know mater what we do, we are all stuck at 275ish N/A. Sittingmongoose was stuck for awhile and finally got it right after paying big bucks! I'll get tuned as soon as I get my intake on.
Not trying to be a dick or anything, I was just hoping for a lot more. Your trap blows mine away. On my dyno you'd be about 265-270 with that mph. I was at 238 runing 99.8mph. With your headers and new tune your new trap should be around 103.6.
Keep us posted, and we race cars not dynos right?
AlabamaGuy,
It's unfortunate that you ended up dyno-ing so low. Didn't you put down 267hp with a catback and rockers before? I was hoping you'd be at 290hp. I would have to say that my car is pulling like crazy! I took my buddy for a ride, who has a 91 5.0 and a 89 super coupe and he was amazed! He weighs about 250 so I was amazed too! I know, I need a tune, and I'm sure I'm leaning out. I was tuned before, with just a downpipe and I was super lean. I'm really hoping for 280-285hp but it seems like know mater what we do, we are all stuck at 275ish N/A. Sittingmongoose was stuck for awhile and finally got it right after paying big bucks! I'll get tuned as soon as I get my intake on.
Not trying to be a dick or anything, I was just hoping for a lot more. Your trap blows mine away. On my dyno you'd be about 265-270 with that mph. I was at 238 runing 99.8mph. With your headers and new tune your new trap should be around 103.6.
Keep us posted, and we race cars not dynos right?
It's unfortunate that you ended up dyno-ing so low. Didn't you put down 267hp with a catback and rockers before? I was hoping you'd be at 290hp. I would have to say that my car is pulling like crazy! I took my buddy for a ride, who has a 91 5.0 and a 89 super coupe and he was amazed! He weighs about 250 so I was amazed too! I know, I need a tune, and I'm sure I'm leaning out. I was tuned before, with just a downpipe and I was super lean. I'm really hoping for 280-285hp but it seems like know mater what we do, we are all stuck at 275ish N/A. Sittingmongoose was stuck for awhile and finally got it right after paying big bucks! I'll get tuned as soon as I get my intake on.
Not trying to be a dick or anything, I was just hoping for a lot more. Your trap blows mine away. On my dyno you'd be about 265-270 with that mph. I was at 238 runing 99.8mph. With your headers and new tune your new trap should be around 103.6.
Keep us posted, and we race cars not dynos right?
Last edited by AlabamaGuy; Jul 25, 2010 at 11:41 PM.
Thought you had rockers too?
Here's what I went with and what a frickin difference!
http://www.maxchevy.com/tech/2007/ii_7-rocker-1.html
Here's what I went with and what a frickin difference!
http://www.maxchevy.com/tech/2007/ii_7-rocker-1.html
Thought you had rockers too?
Here's what I went with and what a frickin difference!
http://www.maxchevy.com/tech/2007/ii_7-rocker-1.html
Here's what I went with and what a frickin difference!
http://www.maxchevy.com/tech/2007/ii_7-rocker-1.html
TECH Enthusiast
Joined: Jun 2008
Posts: 621
Likes: 1
From: Zeeland, MI
A new intake should wake these header cars up a lot.
You all now have a much freer flowing exhaust, an Intake, a good Cam, and some new Rockers is where the rest of the power is hiding....
Does anyone have a dyno sheet from their headers??
You all now have a much freer flowing exhaust, an Intake, a good Cam, and some new Rockers is where the rest of the power is hiding....
Does anyone have a dyno sheet from their headers??
TECH Fanatic
Joined: Jan 2007
Posts: 1,029
Likes: 0
From: LITH, IL.
I was very disappointed. I dyno'd ***/*** with Catless DP and a cutout. The thing is, I gained a **** ton of power and torque under the curve. I gain traction in 1st then break loose again around 40 mph...we'll see how the time slips go but it is so much quicker now I'm amazed. I think something might have been up with the dyno. He said it'd been worked on since the last time I'd been on it so who knows. I do know Henson Performance can put one hell of a tune on a car!
Last edited by AlabamaGuy; Jul 25, 2010 at 11:43 PM.
Launching!
Joined: Oct 2009
Posts: 291
Likes: 1
From: Toronto, Canada
Thought you had rockers too?
Here's what I went with and what a frickin difference!
http://www.maxchevy.com/tech/2007/ii_7-rocker-1.html
Here's what I went with and what a frickin difference!
http://www.maxchevy.com/tech/2007/ii_7-rocker-1.html
I read the article , sounds great. Do you happen to have the part number for those rockers?