|
Re: How much are my small headers killing my performance
[Re: cudaman1969]
#2150735
09/08/16 11:28 PM
09/08/16 11:28 PM
|
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
Plymouth340
OP
mopar
|
OP
mopar
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
|
I'll throw this out there, not sure if it means much. Read about a test some engine builder did on a small block Chevy, on the dyno, with the results of dinging headers, if it lost power. They went so far as to almost flatten them completely and saw no power loss, maybe 4 or 5 hp tops, they where dumbfounded? You might see a change in a poorly designed set over a top of the line set, but not the gains you're looking for, IMO That could be true. But what was the horsepower level of that motor? I would think this 900 horsepower motor turning 8,700 rpm it would make a bit of difference. I would be skeptical of it being 900 hp unless I was there when they dynoed it. Did he say what mph the other car was going? The header banging was a u-tube video. I dought they could fake it. 153 mph @ 3280lbs this motor is legit it has the best of everything on it
|
|
|
Re: How much are my small headers killing my performance
[Re: slantzilla]
#2150801
09/09/16 01:06 AM
09/09/16 01:06 AM
|
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
Plymouth340
OP
mopar
|
OP
mopar
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
|
Are you runing the same converter, trans gearing, and rear gear he did? no,no,no all I'm wondering is if these 1 7/8 headers I'm using are killing my performance and if it would be worth the work to make the larger step headers work !!!
|
|
|
Re: How much are my small headers killing my performance
[Re: Plymouth340]
#2150868
09/09/16 08:51 AM
09/09/16 08:51 AM
|
Joined: Jan 2005
Posts: 4,243
Charlotte, North Carolina
sgcuda
master
|
master
Joined: Jan 2005
Posts: 4,243
Charlotte, North Carolina
|
It would, at least be worth the effort to try them. That much power, with the rpm needed, might be cause for concern with a 1 7/8" tube. The longer the tube, the more the restriction. Works just like resistance in wiring. Smaller tubes, in general, give more torque. Bigger tubes are for mid to high rpm use. You have to watch your fuel curve through mid range with big tubes.
[image][/image]
|
|
|
Re: How much are my small headers killing my performance
[Re: Plymouth340]
#2150966
09/09/16 12:38 PM
09/09/16 12:38 PM
|
Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,491
So. Burlington, Vt.
|
153 mph @ 3280lbs this motor is legit it has the best of everything on it The moroso chart shows that to be pretty much right on 900hp.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
|
|
|
Re: How much are my small headers killing my performance
[Re: sgcuda]
#2151083
09/09/16 03:01 PM
09/09/16 03:01 PM
|
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
Plymouth340
OP
mopar
|
OP
mopar
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
|
It would, at least be worth the effort to try them. That much power, with the rpm needed, might be cause for concern with a 1 7/8" tube. The longer the tube, the more the restriction. Works just like resistance in wiring. Smaller tubes, in general, give more torque. Bigger tubes are for mid to high rpm use. You have to watch your fuel curve through mid range with big tubes. Yes I think it will be worth the effort. I've never built headers before but to make these fit shouldn't be that bad I have a tube chassis car there's lots of room. And my time is free
|
|
|
Re: How much are my small headers killing my performance
[Re: fast68plymouth]
#2151086
09/09/16 03:03 PM
09/09/16 03:03 PM
|
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
Plymouth340
OP
mopar
|
OP
mopar
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
|
153 mph @ 3280lbs this motor is legit it has the best of everything on it The moroso chart shows that to be pretty much right on 900hp. Yes the power is there. Just seems like something's holding this motor back. I've tried a lot of things and nothing really seems to make much difference so this is my next step
|
|
|
Re: How much are my small headers killing my performance
[Re: Plymouth340]
#2151216
09/09/16 06:54 PM
09/09/16 06:54 PM
|
Joined: Jan 2003
Posts: 20,158
Park Forest, IL
slantzilla
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 20,158
Park Forest, IL
|
It will be interesting to see if your headers are killing 150 horse.
"Everybody funny, now you funny too."
|
|
|
Re: How much are my small headers killing my performance
[Re: Alchemi]
#2151799
09/10/16 08:10 PM
09/10/16 08:10 PM
|
Joined: Jan 2003
Posts: 4,395
The Pale Blue Dot
Skeptic
master
|
master
Joined: Jan 2003
Posts: 4,395
The Pale Blue Dot
|
All that header beat up test did was prove that the wrong headers were on the motor to start with.... You need to watch the follow up video. TL/DR answer, no they were the best size.
|
|
|
Re: How much are my small headers killing my performance
[Re: fast68plymouth]
#2151875
09/10/16 10:07 PM
09/10/16 10:07 PM
|
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
Taking time off to work on my car
|
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
At seasons end...... Might be worth a trip to the dyno and see just how much difference in power there is between the headers......before going through the effort of fitting them to the car. x2 Not only would you find out what the other headers are worth, it could provide more data to help with converter setup.
|
|
|
Re: How much are my small headers killing my performance
[Re: Plymouth340]
#2152381
09/11/16 02:56 PM
09/11/16 02:56 PM
|
Joined: Jan 2003
Posts: 30,989
Oregon
AndyF
I Win
|
I Win
Joined: Jan 2003
Posts: 30,989
Oregon
|
I did a header test on my 470 engine between 2" dyno headers and 1 3/4 stepped to 1 7/8 dyno headers. At 6800 rpm the 2" headers were 10 ft-lbs better.
Last edited by AndyF; 09/11/16 03:05 PM.
|
|
|
Re: How much are my small headers killing my performance
[Re: Plymouth340]
#2152422
09/11/16 04:05 PM
09/11/16 04:05 PM
|
Joined: Feb 2011
Posts: 4,302
Nebraska
72Swinger
master
|
master
Joined: Feb 2011
Posts: 4,302
Nebraska
|
Damn, I'm not so upset with having 1.75 TTI's on my 420 G3 anymore.
Mopar to the bone!!!
|
|
|
Re: How much are my small headers killing my performance
[Re: pittsburghracer]
#2542525
08/28/18 02:58 PM
08/28/18 02:58 PM
|
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
Plymouth340
OP
mopar
|
OP
mopar
Joined: Feb 2006
Posts: 501
CEDAR RAPIDS
|
From everything I've read and heard about this engine combo I would lean towards the converter not being the right stall. That seems to be the biggest issues Well I finally put in a 7 inch converter and it picked up all most 2 tenths..9.07 @ 149 in 4000 da air..that was the ticket and I haven't tried leaving at higher rpm yet or a little more jet
|
|
|
Re: How much are my small headers killing my performance
[Re: justinp61]
#2542663
08/28/18 07:05 PM
08/28/18 07:05 PM
|
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
|
Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
|
Your not gonna see a 100hp difference from the set you have on the car to the ones that were on it.. I was running a W-9 with step headers (1 7/8-2-2 1/8.. if your conv stalls at 7000 it is real close I stalled at 5600 and it was a bit low.. I shifted at 8200 rpm.. it didnt make any more power when shifted at higher rpms.. I went up to 9400 and dint do a damn thing 
|
|
|
Re: How much are my small headers killing my performance
[Re: Plymouth340]
#2542989
08/29/18 01:03 PM
08/29/18 01:03 PM
|
Joined: Jul 2004
Posts: 19,317
State of confusion
Thumperdart
I Live Here
|
I Live Here
Joined: Jul 2004
Posts: 19,317
State of confusion
|
From everything I've read and heard about this engine combo I would lean towards the converter not being the right stall. That seems to be the biggest issues Well I finally put in a 7 inch converter and it picked up all most 2 tenths..9.07 @ 149 in 4000 da air..that was the ticket and I haven't tried leaving at higher rpm yet or a little more jet What carb(s) are you running............
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
|
|
|
Re: How much are my small headers killing my performance
[Re: Plymouth340]
#2543006
08/29/18 01:41 PM
08/29/18 01:41 PM
|
Joined: Jan 2003
Posts: 19,355
Las Vegas
Al_Alguire
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 19,355
Las Vegas
|
FWIW the smallblock in the heads up car made over 1000 with a set of 1 7/8" 20 long primary headers on the dyno. Headers on the car are 1 7/8 to 2 to 2 /18". Car ran 8.0's last year at 2800.
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
|
|
|
|
|
