seriously.... what intake manifold for my 408?
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seriously.... what intake manifold for my 408?
I have been researching this do death, and trying to decide the best intake manifold for my built 408ci.
here is some info on my set up currently, and would like some input in what direction to go in...
Motor is a tsp 408ci 9.5:1, prc stg 2.5 ls6 heads, cam is 232/240, .595/.609, 115LSA, 112ICL. 4l60e and 3500 stall
I originally intended on boosting my car, however, funds are too limited, and plan switched to N20 at least for a season or so.
Car is speed density tuned, and running an ls6 intake manifold, and stock tb, a combo I was going to keep with forced induction.
I want the most out of my motor n/a, will likely be switching do a more n/a oriented cam, and need some real world suggestions. I have found gobbs of info about manifold and tb choices for forced induction, but no clear cut opinions on the best n/a suited manifold would be for my 408.
here is some info on my set up currently, and would like some input in what direction to go in...
Motor is a tsp 408ci 9.5:1, prc stg 2.5 ls6 heads, cam is 232/240, .595/.609, 115LSA, 112ICL. 4l60e and 3500 stall
I originally intended on boosting my car, however, funds are too limited, and plan switched to N20 at least for a season or so.
Car is speed density tuned, and running an ls6 intake manifold, and stock tb, a combo I was going to keep with forced induction.
I want the most out of my motor n/a, will likely be switching do a more n/a oriented cam, and need some real world suggestions. I have found gobbs of info about manifold and tb choices for forced induction, but no clear cut opinions on the best n/a suited manifold would be for my 408.
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The motor runs very well even n/a right now. it is a true street car, and will see the track regularly, however, it is driven to work every day.
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Just keep the LS6 intake. Wow you might gain 5rwhp from the fast 102 and TB. $1300 for 5rwhp does not sound like anything I would waste my money on. LS6 intake is one of the best factory intakes.
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#9
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Op I agree though I would maximize your cam choice for good tq even if it costs you a little power up top. If possible I would rip off the heads and try to raise compression a bit by using a thinner gasket or decking the heads if you have the room.
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Show me 2 Dyno graphs with a street 408ci stroker engine with a factory stock FAST 102LSXr intake and 102TB that picked up 15-20rwhp. I will be waiting. Now if it is a mamofied FAST 102 then I can see 15-20rwhp.
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http://www.camaroz28.com/forums/ls1-based-engine-tech-19/dyno-comparison-ls6-intake-ported-tb-vs-fast-90-90-ported-668811/
https://m.facebook.com/SpeedIncUSA/posts/493346047343080
https://ls1tech.com/forums/dynamometer-results-comparisons/1091587-professional-products-vs-fast-vs-ls6-intake-numbers.html
http://www.ls1gto.com/forums/showthread.php?t=137522
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My mistake. For some reason I kept thinking this was an LS3 head and intake setup and was comparing the gains from stock LS3 intakes to stock FAST 102 intakes. Yes for a cathedral port 408 stroker setup I would have to agree. But I still think that I would put my cash towards the rest of the build and get the best of the best and if I had to run the LS6 intake for a bit until I got more cash for the FAST intake then that's what I would do. You will absolutely not notice the difference between 20rwhp more or less in the seat of the pants feel. Plus an intake is super easy to swap out. A lot easier than swapping out the totally wrong 317 heads he was planning on using. A good compromise would be running the Texas speed stage 2.5 cnc ported heads and then with the money saved on that compared to going with a set of aftermarket heads that cost twice as much then you would have plenty of cash left over to get the fast 102 and have it ported as well. And with that setup and the right cam there is no reason why you shouldn't be well over 500rwhp and still have lots of torque. Of course as long as you have all the supporting mods and make sure everything is matched up correctly and don't believe the hype that bigger is better like most do and make crap power.
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Read my thread and youll understand why NOT to use a ls6 on a 408...
https://ls1tech.com/forums/dynamometer-results-comparisons/1772986-408-build-please-critique-numbers-433hp-390tq.html
https://ls1tech.com/forums/dynamometer-results-comparisons/1772986-408-build-please-critique-numbers-433hp-390tq.html
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I managed to squeak 450whp out of her only after going speed density and removing the maf, lid and air filter. My combo chokes out after 5700rpm really bad. Starts pulling a vacuum in the intake manifold.
#20
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Read my thread and youll understand why NOT to use a ls6 on a 408...
https://ls1tech.com/forums/dynamomet...3hp-390tq.html
https://ls1tech.com/forums/dynamomet...3hp-390tq.html
You made ok numbers for your altitude and rear but you never even tried a fast int hat thread... you're still leaving atleast 20hp on the table.
Last edited by redbird555; 07-11-2015 at 08:24 PM.