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importance of and improving power curve

General engine tech -- Drag Racing to Circle Track

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77cruiser
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Re: importance of and improving power curve

Post by 77cruiser » Mon Sep 03, 2018 11:47 am

randy331 wrote:
Mon Sep 03, 2018 11:16 am
77cruiser wrote:
Mon Sep 03, 2018 10:16 am
I'd be curious to see how much the 1 5/8 step headers were hurting you.
It may not be as much as we think.
I may be disappointed when I buy/build a nice straight 1 3/4 x 1 7/8 step header and gain 7 HP but loose 5 Lbs tq. But you never know,.. could be 25 HP.

Randy
How about 4-2-1 headers?
Jim

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Re: importance of and improving power curve

Post by randy331 » Mon Sep 03, 2018 12:02 pm

77cruiser wrote:
Mon Sep 03, 2018 11:47 am

How about 4-2-1 headers?
You see them some on pulling trucks. Pro stock trucks is where I've seen them so far.

A 4-2-1 header may be easier to fit in the chassis. There ain't much room on the drivers side to fit them. Driveshaft and driveshaft loops a differential etc.

A 4-2-1 may help the power curve and the power curve seems important in pulling trucks for sure.


Randy

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Re: importance of and improving power curve

Post by 77cruiser » Mon Sep 03, 2018 12:19 pm

randy331 wrote:
Mon Sep 03, 2018 12:02 pm
77cruiser wrote:
Mon Sep 03, 2018 11:47 am

How about 4-2-1 headers?
You see them some on pulling trucks. Pro stock trucks is where I've seen them so far.

A 4-2-1 header may be easier to fit in the chassis. There ain't much room on the drivers side to fit them. Driveshaft and driveshaft loops a differential etc.

A 4-2-1 may help the power curve and the power curve seems important in pulling trucks for sure.


Randy
When I built my 4-2-1's they weren't too bad to build, a lot easier than 4-1. Calvin Elston told me way easier & less tubing plus easier fit. First time I ever tried anything like that.
http://www.speedtalk.com/forum/viewtopic.php?t=41836
Jim

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Re: importance of and improving power curve

Post by randy331 » Sat Sep 08, 2018 10:24 am

77cruiser wrote:
Mon Sep 03, 2018 12:19 pm
When I built my 4-2-1's they weren't too bad to build, a lot easier than 4-1. Calvin Elston told me way easier & less tubing plus easier fit. First time I ever tried anything like that.
http://www.speedtalk.com/forum/viewtopic.php?t=41836
Could you spec me a try Y ? I want more TQ at peak TQ more HP at peak HP and more power above peak HP.
In other words I want more power from 5000 rpm up to 9800 rpm.

Can you spec me that header ?? LOL

Randy

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Re: importance of and improving power curve

Post by 77cruiser » Sat Sep 08, 2018 11:09 am

randy331 wrote:
Sat Sep 08, 2018 10:24 am
77cruiser wrote:
Mon Sep 03, 2018 12:19 pm
When I built my 4-2-1's they weren't too bad to build, a lot easier than 4-1. Calvin Elston told me way easier & less tubing plus easier fit. First time I ever tried anything like that.
http://www.speedtalk.com/forum/viewtopic.php?t=41836
Could you spec me a try Y ? I want more TQ at peak TQ more HP at peak HP and more power above peak HP.
In other words I want more power from 5000 rpm up to 9800 rpm.

Can you spec me that header ?? LOL

Randy
No I'm a old rookie, I bet you have an idea of what you need. Pipemax would be a start.
Jim

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Re: importance of and improving power curve

Post by Frankshaft » Sat Sep 08, 2018 11:18 am

randy331 wrote:
Sat Sep 08, 2018 10:24 am
77cruiser wrote:
Mon Sep 03, 2018 12:19 pm
loo
When I built my 4-2-1's they weren't too bad to build, a lot easier than 4-1. Calvin Elston told me way easier & less tubing plus easier fit. First time I ever tried anything like that.
http://www.speedtalk.com/forum/viewtopic.php?t=41836
Could you spec me a try Y ? I want more TQ at peak TQ more HP at peak HP and more power above peak HP.
In other words I want more power from 5000 rpm up to 9800 rpm.

Can you spec me that header ?? LOL

Randy
I would try and move the peaks up. If it runs up there, I would try and get the peak closer to where it runs. Pulling isn't my thing, but I still build a fair number of engines or do heads for them, and evertiime we moved the peaks up, it pulled better.

user-30257

Re: importance of and improving power curve

Post by user-30257 » Sat Sep 08, 2018 2:52 pm

randy331 wrote:
Sat Sep 08, 2018 10:24 am
77cruiser wrote:
Mon Sep 03, 2018 12:19 pm
When I built my 4-2-1's they weren't too bad to build, a lot easier than 4-1. Calvin Elston told me way easier & less tubing plus easier fit. First time I ever tried anything like that.
http://www.speedtalk.com/forum/viewtopic.php?t=41836
Could you spec me a try Y ? I want more TQ at peak TQ more HP at peak HP and more power above peak HP.
In other words I want more power from 5000 rpm up to 9800 rpm.

Can you spec me that header ?? LOL

Randy
Dyno, and change primary lengths, collector lengths and merge type. Slip style headers are great for tuning the curve.

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Re: importance of and improving power curve

Post by randy331 » Sun Sep 09, 2018 4:19 pm

Frankshaft wrote:
Sat Sep 08, 2018 11:18 am
randy331 wrote:
Sat Sep 08, 2018 10:24 am
77cruiser wrote:
Mon Sep 03, 2018 12:19 pm
loo
When I built my 4-2-1's they weren't too bad to build, a lot easier than 4-1. Calvin Elston told me way easier & less tubing plus easier fit. First time I ever tried anything like that.
http://www.speedtalk.com/forum/viewtopic.php?t=41836
Could you spec me a try Y ? I want more TQ at peak TQ more HP at peak HP and more power above peak HP.
In other words I want more power from 5000 rpm up to 9800 rpm.

Can you spec me that header ?? LOL

Randy
I would try and move the peaks up. If it runs up there, I would try and get the peak closer to where it runs. Pulling isn't my thing, but I still build a fair number of engines or do heads for them, and evertiime we moved the peaks up, it pulled better.
I'd like to raise the peaks some, but I've seen the engine as high as 9600 and as low as 5200 during full throttle pulling.
If you can keep the truck hooked up at the end of the pull, TQ around peak TQ seems to help too.
With the ones I have info on, seems once they get below peak TQ rpm, it's lights out in a hurry.
I have a few things I'm planning on doing to try and raise the peaks.
Be nice to have it better everywhere.

Randy

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Re: importance of and improving power curve

Post by CGT » Mon Sep 10, 2018 8:56 am

randy331 wrote:
Sun Sep 09, 2018 4:19 pm
Frankshaft wrote:
Sat Sep 08, 2018 11:18 am
randy331 wrote:
Sat Sep 08, 2018 10:24 am


Could you spec me a try Y ? I want more TQ at peak TQ more HP at peak HP and more power above peak HP.
In other words I want more power from 5000 rpm up to 9800 rpm.

Can you spec me that header ?? LOL

Randy
I would try and move the peaks up. If it runs up there, I would try and get the peak closer to where it runs. Pulling isn't my thing, but I still build a fair number of engines or do heads for them, and evertiime we moved the peaks up, it pulled better.
I'd like to raise the peaks some, but I've seen the engine as high as 9600 and as low as 5200 during full throttle pulling.
If you can keep the truck hooked up at the end of the pull, TQ around peak TQ seems to help too.
With the ones I have info on, seems once they get below peak TQ rpm, it's lights out in a hurry.
I have a few things I'm planning on doing to try and raise the peaks.
Be nice to have it better everywhere.

Randy
What do you think about trying more lift? That could possibly be better everywhere in that rpm range....
"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

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Re: importance of and improving power curve

Post by steve316 » Tue Sep 11, 2018 9:20 am

Increasing intake track cross sectional area will aid in moving peak HP up in the rpm range. If you have room to take max cross section taper to 4.5 in to 5 in at plenum should increase spread from peak TQ to peak HP. Every time I increased taper in intake manifold it helped. Just something to consider.

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Re: importance of and improving power curve

Post by randy331 » Wed Oct 17, 2018 10:19 pm

Pulling trucks,.... :D again.

I know you guys are tired of pulling truck talk. :D

Well,.... looks we're in tear down mode for some winter up dates.

Wanted to see a big carb on the 421 for a test hook, so I got a 1.92 venturi x 2.250 throttle bore carb from Mark to try, but the track wasn't good,.... so not sure. Wanted it to be hooked up hard and see the 421 brought back down to 5000 rpm or so, but didn't happen. No traction. Spun out at part throttle. Wanted to see if it'd stay on line like the Braswell we been running, but.....not a good test.


So,.... how do you size a carb for a pulling truck?

Got some other pulling truck engines to do/up grade over the winter, and 2 more besides us need carbs.


Guess I could start a new thread on them.

3 big blocks and our 421 small block are up for some work.


Randy

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Re: importance of and improving power curve

Post by randy331 » Wed Oct 17, 2018 10:22 pm

CGT wrote:
Mon Sep 10, 2018 8:56 am
What do you think about trying more lift? That could possibly be better everywhere in that rpm range....
This,... from the guy who said not to change things in the valve trian cause it seems happy now ??? :lol:
Lift is on the table for change for next year. :D

Randy

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Re: importance of and improving power curve

Post by CGT » Thu Oct 18, 2018 11:20 am

.
"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

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Re: importance of and improving power curve

Post by Frankshaft » Thu Oct 18, 2018 12:20 pm

randy331 wrote:
Wed Oct 17, 2018 10:22 pm
CGT wrote:
Mon Sep 10, 2018 8:56 am
What do you think about trying more lift? That could possibly be better everywhere in that rpm range....
This,... from the guy who said not to change things in the valve trian cause it seems happy now ??? :lol:
Lift is on the table for change for next year. :D

Randy
How about a 30 degree radius intake seat? For big low lift flowz. And some major port bias? I think that would crank the port energy thru the roof.

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Re: importance of and improving power curve

Post by CGT » Thu Oct 18, 2018 12:23 pm

randy331 wrote:
Wed Oct 17, 2018 10:22 pm
CGT wrote:
Mon Sep 10, 2018 8:56 am
What do you think about trying more lift? That could possibly be better everywhere in that rpm range....
This,... from the guy who said not to change things in the valve trian cause it seems happy now ??? :lol:
Lift is on the table for change for next year. :D

Randy
Lift could possibly calm the valvetrain even more.....depending on how you go about getting it..
"Never let your hobby ride you. Work while you work and play while you play"

"Hobbies are a contradiction; they take work and turn it into leisure, and take leisure and turn it into work."

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