can you guys post up your 408 results/setups here?
Originally Posted by str8evl
I agree whole heartedly with this post. I blew my motor up the beginning of last season and am now ready to go bigger, but these #'s are all over the place. On that same note though, If I laid down 100hp/tq but ran 10's then I would be more than happy. Having a track only car i could care less about streetability. SDPC seems to producing a great product with a warrenty, but the way that these (the 402/408's), for the most part similar motors are all over in the power range it makes one weary about whats going on. Is it in the tune? Is it the builder? As a racer what I really want to know is what kind of times are this things throwing out? I know it all depends on setup and what not, but any track #'s are better then HP #'s to me. what I am looking to do is a 402 or 408 with a 90/90, et 245's, powerglide to a 9". Everything is set in stone other than the heart (the motor). So that being said, is 6 cubes worth the weight on the nose? I have so many questions on these motors that have yet to be fully answered in any of forums I visit. This being the tech site, of course the info i get here is the most informational. keep this thread alive and you guys that are already running these motors keep the info rolling because there is alot of us doing a balancing act on the eternal question what motor? 
The 408 vs 402 debacle - Don't buy a 408 for extra cubes. Buy a 408 for block strength and piece of mind; no sleeving, know what I'm saying - sleeves can have issues. Also, if you want to spray, go 408. Iron > aluminum when it comes to handling the funny stuff
As far as power goes, it is determined by many things. All of these #'s you're seeing are #'s to the wheels; not at the crank. These numbers will vary greatly depending on drivetrain and mods. If you want the best power, get the best parts.
For my setup, I ran proven heads from TEA, one of the best head companies known. I wanted the engine to be able to breathe and exhaust. The heads can do both, but are limited by upstream and downstream mods. I have Kooks 1-7/8" headers; again a proven power maker. My intake is slightly restricitve still, but that is being remedied tomorrow night and I will only get this thing to churn out more brute power.
For the skeptics, power can be made. But, in your favor, lackluster power can be made as well. If you are going to do this setup, buy a shortblock from a reputable builder. Buy your heads from a non-budget cylinder head company. Budget means inferior - period. You want superior, non-budget heads for a multi-thousand dollar setup, so don't skimp. Look for area under the curve, not peak flow numbers
It's all in the parts combination. Good headers are useless with crappy heads and/or intake. Good heads are useless with a crappy set of headers and/or intake. A good intake is useless with a crappy set of heads and/or headers. Make it breathe, make it exhaust, make it a beast. Get the best of the best, and your results will be the best
Don't fear low numbers - fear a low budget
Teching In
Joined: Oct 2005
Posts: 45
Likes: 0
From: central IL
I've got a 408 built by Texas Speed... AFR 205 heads... 244/248 .612/.615 115lsa cam.. 1 3/4 pacesetter LTs, ASP underdrive pulley, LS6 intake, 3" ORY, Hooker catback... along with the Racetronix PnP kit & 42# injectors.. and a SLP maf... stock TB. It's an Auto with 3.23 rear gears & 3800 stall converter. It was trailered to & tuned by Speed Inc in Schaumburg IL when we were finished putting it together. It put down 450hp/425tq with zero miles on the motor.... running a 'low' 10.2:1 compression ratio... on 93 octane.
I'm hoping with a FAST 90 / NW 90 setup... it should pick up a couple more ponies. It falls off some at the top... think it's running out of breath.
I'm hoping with a FAST 90 / NW 90 setup... it should pick up a couple more ponies. It falls off some at the top... think it's running out of breath.
Humm....
well im gonna go with the TSP 408 with about 12.5:1 and there texas giant, my AFR 205s that are being ported and an asp pulley, 1 3/4 LTs and ory to a magnaflow cat back, 42 lbsers, gonna keep the LS6 intake for now and hope for 500hp and 480TQ.
I hoper ill get there i know there more with a 90-90 swap but thats another G i dont have.
im gonna drop a post somewhere else and see what everyone things of my plans.
well im gonna go with the TSP 408 with about 12.5:1 and there texas giant, my AFR 205s that are being ported and an asp pulley, 1 3/4 LTs and ory to a magnaflow cat back, 42 lbsers, gonna keep the LS6 intake for now and hope for 500hp and 480TQ.
I hoper ill get there i know there more with a 90-90 swap but thats another G i dont have.
im gonna drop a post somewhere else and see what everyone things of my plans.
Originally Posted by camarokid94
Humm....
well im gonna go with the TSP 408 with about 12.5:1 and there texas giant, my AFR 205s that are being ported and an asp pulley, 1 3/4 LTs and ory to a magnaflow cat back, 42 lbsers, gonna keep the LS6 intake for now and hope for 500hp and 480TQ.
I hoper ill get there i know there more with a 90-90 swap but thats another G i dont have.
im gonna drop a post somewhere else and see what everyone things of my plans.
well im gonna go with the TSP 408 with about 12.5:1 and there texas giant, my AFR 205s that are being ported and an asp pulley, 1 3/4 LTs and ory to a magnaflow cat back, 42 lbsers, gonna keep the LS6 intake for now and hope for 500hp and 480TQ.
I hoper ill get there i know there more with a 90-90 swap but thats another G i dont have.
im gonna drop a post somewhere else and see what everyone things of my plans.
hope you like race gas for your 12.5 CR.... and why the AFR 205's? your spending alot of money for a head that doesnt flow well up top...
i'd shoot for the stage III or II Darts.
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Originally Posted by ty_ty13
hope you like race gas for your 12.5 CR.... and why the AFR 205's? your spending alot of money for a head that doesnt flow well up top...
i'd shoot for the stage III or II Darts.
i'd shoot for the stage III or II Darts.
__________________
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
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
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
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
Originally Posted by ty_ty13
hope you like race gas for your 12.5 CR.... and why the AFR 205's? your spending alot of money for a head that doesnt flow well up top...
i'd shoot for the stage III or II Darts.
i'd shoot for the stage III or II Darts.
Here's mine. can't believe I hadn't posted it already :lol
iron 408
M6, 4.10 gears, dyno with 28" slicks
12.8:1 comression
CHS ported 5.7L heads flowed 293@600
FMS 246/250 .632
1 7/8 QTP headers
all the bolt-ons
Fast 90/90
stock Rockers
Melling lifters
550rwhp 515rwtq
It dyno'd 545rwhp and 535rwtq with 1 3/4 headers
I just swapped over to a Vic JR intake and will dyno it saturday. hoping for ~570rwhp. will be at the track sunday, hoping for 10.0's @ 135. I never quite had everything worked out with the old setup, but I'm sure it would have gone 10.3's.
iron 408
M6, 4.10 gears, dyno with 28" slicks
12.8:1 comression
CHS ported 5.7L heads flowed 293@600
FMS 246/250 .632
1 7/8 QTP headers
all the bolt-ons
Fast 90/90
stock Rockers
Melling lifters
550rwhp 515rwtq
It dyno'd 545rwhp and 535rwtq with 1 3/4 headers
I just swapped over to a Vic JR intake and will dyno it saturday. hoping for ~570rwhp. will be at the track sunday, hoping for 10.0's @ 135. I never quite had everything worked out with the old setup, but I'm sure it would have gone 10.3's.
Last edited by 383ss; Mar 2, 2006 at 02:22 PM.
yep, it did. you can see it helped quite a bit up top though. it only gained 5rwhp peak, but brought my peak out another 500rpm and added up to 35rwhp
[IMG]http://mofbody.com/john/1%207-8%20vs%201%203-4.jpg[/IMG]
[IMG]http://mofbody.com/john/1%207-8%20vs%201%203-4.jpg[/IMG]
Check out this stock 241 head, ls6 intake, and 408ci. https://ls1tech.com/forums/dynamometer-results-comparisons/462218-stock-headed-408-468-460-w-ls6-pacesetters.html
I bet some 205 heads will really wake it up.
I bet some 205 heads will really wake it up.
Originally Posted by camarokid94
Humm....
well im gonna go with the TSP 408 with about 12.5:1
well im gonna go with the TSP 408 with about 12.5:1
what springs, lifters, and rockers you running?
that vic will really let those headers breath!
that vic will really let those headers breath!
Originally Posted by 383ss
Here's mine. can't believe I hadn't posted it already :lol
iron 408
M6, 4.10 gears, dyno with 28" slicks
12.8:1 comression
CHS ported 5.7L heads flowed 293@600
FMS 246/250 .632
1 7/8 QTP headers
all the bolt-ons
Fast 90/90
550rwhp 515rwtq
It dyno'd 545rwhp and 535rwtq with 1 3/4 headers
I just swapped over to a Vic JR intake and will dyno it saturday. hoping for ~570rwhp. will be at the track sunday, hoping for 10.0's @ 135. I never quite had everything worked out with the old setup, but I'm sure it would have gone 10.3's.
iron 408
M6, 4.10 gears, dyno with 28" slicks
12.8:1 comression
CHS ported 5.7L heads flowed 293@600
FMS 246/250 .632
1 7/8 QTP headers
all the bolt-ons
Fast 90/90
550rwhp 515rwtq
It dyno'd 545rwhp and 535rwtq with 1 3/4 headers
I just swapped over to a Vic JR intake and will dyno it saturday. hoping for ~570rwhp. will be at the track sunday, hoping for 10.0's @ 135. I never quite had everything worked out with the old setup, but I'm sure it would have gone 10.3's.
Originally Posted by ty_ty13
what springs, lifters, and rockers you running?
that vic will really let those headers breath!
that vic will really let those headers breath!
Originally Posted by Z'mnypit
Im about to raise mine to around 12.1:1 Maybe 12.5:1 If I knew then what I know now I would have done that from the start. Screw this 10.7:1 even though it really shined on the bottle. Over 100hp pick up on a 75 shot.
my 12.8:1 picked up 130rwhp on a 100TNT shot. I thought that was fing insane.
Originally Posted by 383ss
my 12.8:1 picked up 130rwhp on a 100TNT shot. I thought that was fing insane.