1 3/4 vs 1 7/8 header dyno RESULTS!!!
03-26-2005, 03:05 PM
#1
10 Second Club
Thread Starter
iTrader: (14)
Join Date: Mar 2002
Location: Kansas City, KS
Posts: 2,893
Likes: 0
Received 0 Likes
on
0 Posts
1 3/4 vs 1 7/8 header dyno RESULTS!!! this is on my 408, old headers were 1 3/4 dynatechs with open headers, 3" collectors, no extension at all. now it has Thunder 1 7/8 with high velocity 2.75" merge collectors and 17" extensions.
overall I'm suprised by the results. thought it would gain a little more hp up top. my shift points are definatly going to have to be 3-400 rpm higher now.
here's the graph.
overall I'm suprised by the results. thought it would gain a little more hp up top. my shift points are definatly going to have to be 3-400 rpm higher now.
here's the graph.
Last edited by 383ss; 03-26-2005 at 03:28 PM.
03-26-2005, 03:16 PM
#2
Wow, interesting results. Certainly not the big kick in the mid-range I was expecting. You may want to experiment with shorter extensions (like 10"). An 8" change in length can have a dramatic impact on peak torque and hp. I think there's tq. to be gained with either longer or shorter (my bet) extensions.
Thank you for reporting the results. We've been anxiously awaiting!
Thank you for reporting the results. We've been anxiously awaiting!
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
03-26-2005, 08:26 PM
#3
Staging Lane
Join Date: Nov 2004
Location: Ashburnham, MA
Posts: 86
Likes: 0
Received 0 Likes
on
0 Posts
Looks like you just traded close to the same amount of torque for a similar gain in hp up top. Being a truck owner with the plan to drop an LS1 and T56 into it I deffinately would be looking for all the torque possible. Looking forward to any changes you might make for improvements. Thanks for being the ginea pig
-Mike
-Mike
03-27-2005, 01:12 AM
#6
12 Second Club
iTrader: (2)
Join Date: Jan 2004
Location: Palos Hills, IL
Posts: 3,321
Likes: 0
Received 0 Likes
on
0 Posts
Not bad, as said before looks like a fair trade off. Excellent information and graph for comparison. I prefer the torque however, maybe you can try a different cam or something thatll up the torque a bit?
Trending Topics
03-27-2005, 06:24 AM
#8
TECH Regular
iTrader: (2)
Join Date: Dec 2001
Location: Iowa
Posts: 459
Likes: 0
Received 0 Likes
on
0 Posts
Interesting.. Did you change anything else? Was the tune tweaked any at all? Was the weather different at all from the initial dyno? Heat, Humidity?
I'd keep the 1 7/8" on there.. Those are some mighty impressive numbers..
I'd keep the 1 7/8" on there.. Those are some mighty impressive numbers..
03-27-2005, 09:06 AM
#9
10 Second Club
Thread Starter
iTrader: (14)
Join Date: Mar 2002
Location: Kansas City, KS
Posts: 2,893
Likes: 0
Received 0 Likes
on
0 Posts
damn, I completely forgot. I added a TNT power ring also. I meant to take it off before the dyno, but it slipped my mind 
not sure if that would have made any difference ???
by the way, this is a 99% track car, so the gains are valid and worth it to me. well, maybe not worth the $400 I spent to upgrade to these, but at least I got something out of it, although it hasn't shown at the track yet. I've been there twice with this setup now and have not run any better. ALTHOUGH I was using the same shift points as the 1 3/4 setup, so I'm hoping that is the difference. will get track results friday.
tune was not tweaked and I did not get A/F. the meter wasn't working at the dyno weather conditions were very similar between dyno's.
not sure if that would have made any difference ??? by the way, this is a 99% track car, so the gains are valid and worth it to me. well, maybe not worth the $400 I spent to upgrade to these, but at least I got something out of it, although it hasn't shown at the track yet. I've been there twice with this setup now and have not run any better. ALTHOUGH I was using the same shift points as the 1 3/4 setup, so I'm hoping that is the difference. will get track results friday.
tune was not tweaked and I did not get A/F. the meter wasn't working at the dyno
weather conditions were very similar between dyno's.
03-27-2005, 09:10 AM
#10
10 Second Club
Thread Starter
iTrader: (14)
Join Date: Mar 2002
Location: Kansas City, KS
Posts: 2,893
Likes: 0
Received 0 Likes
on
0 Posts
damn, I completely forgot. I added a TNT power ring also. I meant to take it off before the dyno, but it slipped my mind not sure if that would have made any difference ???
by the way, this is a 99% track car, so the gains are valid and worth it to me. well, maybe not worth the $400 I spent to upgrade to these, but at least I got something out of it, although it hasn't shown at the track yet. I've been there twice with this setup now and have not run any better. ALTHOUGH I was using the same shift points as the 1 3/4 setup, so I'm hoping that is the difference. will get track results friday.
tune was not tweaked and I did not get A/F. the meter wasn't working at the dyno weather conditions were very similar between dyno's.
not sure if that would have made any difference ??? by the way, this is a 99% track car, so the gains are valid and worth it to me. well, maybe not worth the $400 I spent to upgrade to these, but at least I got something out of it, although it hasn't shown at the track yet. I've been there twice with this setup now and have not run any better. ALTHOUGH I was using the same shift points as the 1 3/4 setup, so I'm hoping that is the difference. will get track results friday.
tune was not tweaked and I did not get A/F. the meter wasn't working at the dyno weather conditions were very similar between dyno's.
03-27-2005, 09:16 AM
#11
10 Second Club
Thread Starter
iTrader: (14)
Join Date: Mar 2002
Location: Kansas City, KS
Posts: 2,893
Likes: 0
Received 0 Likes
on
0 Posts
also look at the gains from 6000+ it goes from about a 5hp gain there to 30+ hp from 6500 up. if you are really spinning your setup, these would definatly be the way to go.
03-27-2005, 01:01 PM
#12
Banned
iTrader: (10)
Join Date: Aug 2002
Location: Phoenix
Posts: 3,721
Likes: 0
Received 0 Likes
on
0 Posts
You probably would have made more power with macs. 
Just kidding. Vince had similar results with his 408 in his vette.
What determines primary tube size anyways? Engine displacement or hp?
Just kidding. Vince had similar results with his 408 in his vette.
What determines primary tube size anyways? Engine displacement or hp?
03-27-2005, 04:01 PM
#14
12 Second Club
iTrader: (2)
Join Date: Jan 2004
Location: Palos Hills, IL
Posts: 3,321
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by dug
You probably would have made more power with macs.
Just kidding. Vince had similar results with his 408 in his vette.
What determines primary tube size anyways? Engine displacement or hp?
Just kidding. Vince had similar results with his 408 in his vette.
What determines primary tube size anyways? Engine displacement or hp?
How much taht puppy needs to BREATH, so in most cases displacment but cam specs come in there as well
03-28-2005, 06:17 PM
#17
That's surprising to me. I recently had HPE swap my FLP 1 3/4 headers to the Kooks
1 7/8 headers and through a single 3 inch cut-out in the same conditions and same dyno. I went from 446 rwhp to 459 rwhp and I had them install a new Mosier 12 bolt rearend with 3.73 gears at the same time the Kooks were installed. I figure I lost 10-15 rwhp from the 12 bolt over my previous 10 bolt 3.23s. I was tuned in for each set though and no bottle on the wifes' car so a N2O ring wasn't an issue. Every car is different. I am running an HPE 383 Stroker for comparison purposes. I'd check that A/F tune. There just might be a bit more hidden in there. Good luck!!!
1 7/8 headers and through a single 3 inch cut-out in the same conditions and same dyno. I went from 446 rwhp to 459 rwhp and I had them install a new Mosier 12 bolt rearend with 3.73 gears at the same time the Kooks were installed. I figure I lost 10-15 rwhp from the 12 bolt over my previous 10 bolt 3.23s. I was tuned in for each set though and no bottle on the wifes' car so a N2O ring wasn't an issue. Every car is different. I am running an HPE 383 Stroker for comparison purposes. I'd check that A/F tune. There just might be a bit more hidden in there. Good luck!!!
03-28-2005, 06:54 PM
#19
12 Second Club
iTrader: (2)
Join Date: Jan 2004
Location: Palos Hills, IL
Posts: 3,321
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by gator's 99TA
john its going to make a big differnce on the spray. believe me.
Why is that? freer flowing exhausts seem to take well to spray vs. freer flowing intake
