408 put down 475/475
03-24-2013, 07:04 PM
#21
Heres more details on my build:
408
11:1'ish Compression
PRC LS3 Ported/Polished Heads
LS3 Intake
235/242 .635/615" 112+2 LSA
Pacesetter 1 3/4" Longtubes
3" ORY
Flowmaster Muffler
LS7 Lifters
Like i said, their was 100% humidity out due to the rain so i'm assuming I lost some power their but not sure how much to gain if it were 0%....
I thought about running dumps but my tuner said i'd lose a lot of backpressure and it might do more harm than good....
I'll eventually get a FAST setup and 1 7/8" headers as well. Any insight/info you can give me would be great!!!
408
11:1'ish Compression
PRC LS3 Ported/Polished Heads
LS3 Intake
235/242 .635/615" 112+2 LSA
Pacesetter 1 3/4" Longtubes
3" ORY
Flowmaster Muffler
LS7 Lifters
Like i said, their was 100% humidity out due to the rain so i'm assuming I lost some power their but not sure how much to gain if it were 0%....
I thought about running dumps but my tuner said i'd lose a lot of backpressure and it might do more harm than good....
I'll eventually get a FAST setup and 1 7/8" headers as well. Any insight/info you can give me would be great!!!
03-24-2013, 07:14 PM
#22
I agree! Just google search flowmaster muffler vs electric cutout
Not true, I have proof:
This car has a flowmaster cat-back on it.
[
Red = cut-outs closed,
Blue = obviously cut-outs open
Before I explain, I'll tell you that I'm not a flowmaster hater, quite the oppositre infact I am a flowmaster fan. I have a flowmaster y-collector and muffler on my own car (3.5 mufflex, single out) and I love it.
But stating facts only, I will tell you that these # are from an iron block 402 with ported 317 castings in my friends '00 TA. The dyno is Ed Wrights dyno in Tulsa, OK. Just in case anyone wants to call BS, call up Ed Wright and ask him. And I was there to witness this, these pics were taken with my phone.
And also, this car had dual electric cut-outs in the y-pipe. I assure you that if this car would have had a single cut-out in the usual location just infron of the rear axle, there wouldn't have been 25hp difference between open and closed.
This car has a flowmaster cat-back on it.
[Red = cut-outs closed,
Blue = obviously cut-outs open
Before I explain, I'll tell you that I'm not a flowmaster hater, quite the oppositre infact I am a flowmaster fan. I have a flowmaster y-collector and muffler on my own car (3.5 mufflex, single out) and I love it.
But stating facts only, I will tell you that these # are from an iron block 402 with ported 317 castings in my friends '00 TA. The dyno is Ed Wrights dyno in Tulsa, OK. Just in case anyone wants to call BS, call up Ed Wright and ask him. And I was there to witness this, these pics were taken with my phone.
And also, this car had dual electric cut-outs in the y-pipe. I assure you that if this car would have had a single cut-out in the usual location just infron of the rear axle, there wouldn't have been 25hp difference between open and closed.
03-26-2013, 11:07 PM
#24
TECH Enthusiast
iTrader: (13)
Join Date: Sep 2007
Location: SC
Posts: 666
Likes: 0
Received 0 Likes
on
0 Posts
Heres more details on my build:
408
11:1'ish Compression
PRC LS3 Ported/Polished Heads
LS3 Intake
235/242 .635/615" 112+2 LSA
Pacesetter 1 3/4" Longtubes
3" ORY
Flowmaster Muffler
LS7 Lifters
Like i said, their was 100% humidity out due to the rain so i'm assuming I lost some power their but not sure how much to gain if it were 0%....
I thought about running dumps but my tuner said i'd lose a lot of backpressure and it might do more harm than good....
I'll eventually get a FAST setup and 1 7/8" headers as well. Any insight/info you can give me would be great!!!
408
11:1'ish Compression
PRC LS3 Ported/Polished Heads
LS3 Intake
235/242 .635/615" 112+2 LSA
Pacesetter 1 3/4" Longtubes
3" ORY
Flowmaster Muffler
LS7 Lifters
Like i said, their was 100% humidity out due to the rain so i'm assuming I lost some power their but not sure how much to gain if it were 0%....
I thought about running dumps but my tuner said i'd lose a lot of backpressure and it might do more harm than good....
I'll eventually get a FAST setup and 1 7/8" headers as well. Any insight/info you can give me would be great!!!
03-27-2013, 09:21 AM
#25
TECH Apprentice
iTrader: (9)
Join Date: Sep 2005
Location: Etowah
Posts: 351
Likes: 0
Received 0 Likes
on
0 Posts
Your entire exhaust set up is not even close to ideal so those numbers are very strong. Id say with big tube headers and duals youd be at or over 500. Ive never seen back pressure make power on a LS motor, especially to the extend that you have. I picked up 22/14 just going from spiral flows to xr-1s on my 408s dual set up
03-28-2013, 12:33 AM
#26
TECH Apprentice
iTrader: (1)
Join Date: Jan 2010
Location: Arlington, TX
Posts: 350
Likes: 0
Received 0 Likes
on
0 Posts
Dont worry about back preasure. Ls engines like to breath. A fast and better exhaust would get you nice gains. I personally dont like the sound of cutouts but that is just my opinion.
03-28-2013, 07:52 AM
#30
TECH Regular
Join Date: Dec 2003
Location: Cherry Hill, New Jersey State
Posts: 486
Received 0 Likes
on
0 Posts
You have a real high and wide TQ range for this combination, this is the idel engine for road crossing race. With TQ you will be replacing the rear tires frequently.
This combination is wounderfull
This combination is wounderfull
03-28-2013, 08:22 AM
#31
No offense, but we normally make 500rwhp+ with stock bottom end, stock cubic inch LS3's with CNC Ported heads and our Stage 2 camshaft which is smaller than yours. You really need a better exhaust set-up. Go as big as you can possibly fit as it will not hurt a thing.
LS3's need a little more help in the exhaust flow department and having a great flowing exhaust set-up is key to making big power with them. Scavenging starts in the exhaust system and if the exhaust system is not up to snuff then the numbers will fall big time. With cylinder heads that flow as much air as the LS3 heads do, you have to have a great flowing exhaust set-up to fully un-cork the flow potential of these cylinder heads.
Also, if your dyno numbers are corrected then it doesn't matter what the weather is like outside. Correction factors correct for weather conditions to what is known as "SAE correction" or "STD correction". This takes the current weather conditions out of the equation and converts the numbers to set of "ideal conditions". If your dyno numbers are not corrected then yes different weather will affect your power numbers.
LS3's need a little more help in the exhaust flow department and having a great flowing exhaust set-up is key to making big power with them. Scavenging starts in the exhaust system and if the exhaust system is not up to snuff then the numbers will fall big time. With cylinder heads that flow as much air as the LS3 heads do, you have to have a great flowing exhaust set-up to fully un-cork the flow potential of these cylinder heads.
Also, if your dyno numbers are corrected then it doesn't matter what the weather is like outside. Correction factors correct for weather conditions to what is known as "SAE correction" or "STD correction". This takes the current weather conditions out of the equation and converts the numbers to set of "ideal conditions". If your dyno numbers are not corrected then yes different weather will affect your power numbers.
03-28-2013, 11:37 AM
#32
Maverick - I ran a 92mm from Alper Motorsports (about 1/3 the price of a NW or FAST)
Martin - No offense taking. I'm really loving the contructive criticism so I can improve my build as I do feel like this motor has a lot more potential. I know bigger isn't always better but would Kooks 2" headers be overkill, or should I stick with the 1 7/8" and a true dual setup? Same goes for my intake. What would a benefit from more, FAST 92 or 102? Thanks for all of your information!
Martin - No offense taking. I'm really loving the contructive criticism so I can improve my build as I do feel like this motor has a lot more potential. I know bigger isn't always better but would Kooks 2" headers be overkill, or should I stick with the 1 7/8" and a true dual setup? Same goes for my intake. What would a benefit from more, FAST 92 or 102? Thanks for all of your information!
03-28-2013, 04:32 PM
#34
I would certainly not discard a 2" primary header on a stroker engine and I think it would really un-cork a lot of power from your set-up. That along with a 3" true dual set-up would be worth at least 25-30rwhp in my eyes and possibly even more in this situation.
03-28-2013, 04:39 PM
#35
Heres the link for the 2" kooks i found.
https://ls1tech.com/forums/parts-cla...-10-1-4-a.html
Found some for even cheaper with a flowmaster y merge setup included for $750.
https://ls1tech.com/forums/parts-cla...d-6-speed.html
https://ls1tech.com/forums/parts-cla...-10-1-4-a.html
Found some for even cheaper with a flowmaster y merge setup included for $750.
https://ls1tech.com/forums/parts-cla...d-6-speed.html
