will the steath ram flow enough air to make max power"
09-15-2002, 05:10 PM
#1
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Thread Starter
will the steath ram flow enough air to make max power"
I was asked?"will the steath ram flow enough air to make max power"
well lets do the math,
the steath ram is designed for the sbc engine, the largest normally built sbc displacement is the 434cid engine. the 434 engine spinning 7000rpm (thats well over the normall rpm for that engine even in race form) can use about 880cfm at 100% efficiency. the steath ram is cut to fit a 58-60mm twin throttle body bore size. that bore size flows about 1000cfm, well above the level thats necessary to feed even that larger than normal displacement.
now holley says that the ports in the steath ram flow about 300cfm
and several people have flowed the intake and thats true, but keep in mind that flow benches measure steady state flow, also keep in mind that the 4 cycle engine has a total of 720 degs in the total repetitive cycle and only about 250 (THE CAMS INTAKE DURRATION) of those 720 degrees are used to flow air into the cylinders on the intake stroke and if you carefully take the time to measure youll find that about 85% of that 250 degrees is flowing a usefull amount of airflow for a total of about 259cfm at a time per cycle trying to move into a single cylinder. now since the cylinder on a 434 spinning 7000rpm only needs 110 cfm even at a steady state flow into the cylinder and the cylinder can only hold that aproximate 110cfm the intake (steath ram) flows more than enough air to make max power , and more than enough air to to feed the largest flowing heads that normally fit the steathrams intake ports (like the 195cc AFR cnc heads)now as Ive said before an engines power depends a great deal on how much air/fuel mix you can stuff into, burn effectively and get out of the cylinders per second, now without power adders like nitrous or a supercharger your going to be limited to about 1.25-1.35 hp per cubic inch of displacement and the small block engine is phyisically limited in size to about 440 cid without very expensive parts. since the potential power potential can be approximately be figured with the formula (.257 x cylinderhead flow x 8=hp potential) and the best heads and intakes combined flow about 310cfm or about 625hp max potentially, the steath rams airflow falls right in at the max flow/horse power potential. most other intake systems like the TPI,super ram, performer RPM, etc. now available lack this high level of air flow when matched and flowed with the heads now available thus limiting the rate at which fuel/air mix can be drawn in, burned and expelled fron the sbc cylinders. short answer, the steath ram ,matched to a great set of cylinder heads, good roller cam and headers, makes a great combo that can come near to the max potential hp. most other intakes lower the total airflow into the engine, the steath ram being a modifyed tunnel ram intake does not and as such has the potential to make max hp in the 575-625hp range for a non-assisted sbc useing the older style 23 degree cylinderheads
yes that still leaves the problem that the steath ram is 1" too tall to fit under the stock C-4 hood unless a hood scoop is used or mods are done to the plenum on the steath ram but its still a great option compared to that worthless TPI intake system that limits you to a max of about 400hp even when ported
the manifold is exactly the correct size! remember that each runner is a column of air and that air has volume, weight and energy. now its true that the cylinder can only take 110cfm BUT remember that during of all the time the engine is running is in a 720 degree repetitive cycle? and the air can only flow into the cylinder durring the 250 degrees or so that the valve is held open by the cam? well that means that the air flow needed is 720 degs/250 degrees x 110=316cfm or just about what the intake port on the stealth ram can flow at max volume. or put another way youll need to push 316cfm down the port because its only open durring 34.7% of the time available to fill that cylinder
[Modified by grumpyvette, 1:44 PM 9/16/2002]
well lets do the math,
the steath ram is designed for the sbc engine, the largest normally built sbc displacement is the 434cid engine. the 434 engine spinning 7000rpm (thats well over the normall rpm for that engine even in race form) can use about 880cfm at 100% efficiency. the steath ram is cut to fit a 58-60mm twin throttle body bore size. that bore size flows about 1000cfm, well above the level thats necessary to feed even that larger than normal displacement.
now holley says that the ports in the steath ram flow about 300cfm
and several people have flowed the intake and thats true, but keep in mind that flow benches measure steady state flow, also keep in mind that the 4 cycle engine has a total of 720 degs in the total repetitive cycle and only about 250 (THE CAMS INTAKE DURRATION) of those 720 degrees are used to flow air into the cylinders on the intake stroke and if you carefully take the time to measure youll find that about 85% of that 250 degrees is flowing a usefull amount of airflow for a total of about 259cfm at a time per cycle trying to move into a single cylinder. now since the cylinder on a 434 spinning 7000rpm only needs 110 cfm even at a steady state flow into the cylinder and the cylinder can only hold that aproximate 110cfm the intake (steath ram) flows more than enough air to make max power , and more than enough air to to feed the largest flowing heads that normally fit the steathrams intake ports (like the 195cc AFR cnc heads)now as Ive said before an engines power depends a great deal on how much air/fuel mix you can stuff into, burn effectively and get out of the cylinders per second, now without power adders like nitrous or a supercharger your going to be limited to about 1.25-1.35 hp per cubic inch of displacement and the small block engine is phyisically limited in size to about 440 cid without very expensive parts. since the potential power potential can be approximately be figured with the formula (.257 x cylinderhead flow x 8=hp potential) and the best heads and intakes combined flow about 310cfm or about 625hp max potentially, the steath rams airflow falls right in at the max flow/horse power potential. most other intake systems like the TPI,super ram, performer RPM, etc. now available lack this high level of air flow when matched and flowed with the heads now available thus limiting the rate at which fuel/air mix can be drawn in, burned and expelled fron the sbc cylinders. short answer, the steath ram ,matched to a great set of cylinder heads, good roller cam and headers, makes a great combo that can come near to the max potential hp. most other intakes lower the total airflow into the engine, the steath ram being a modifyed tunnel ram intake does not and as such has the potential to make max hp in the 575-625hp range for a non-assisted sbc useing the older style 23 degree cylinderheads
yes that still leaves the problem that the steath ram is 1" too tall to fit under the stock C-4 hood unless a hood scoop is used or mods are done to the plenum on the steath ram but its still a great option compared to that worthless TPI intake system that limits you to a max of about 400hp even when ported
the manifold is exactly the correct size! remember that each runner is a column of air and that air has volume, weight and energy. now its true that the cylinder can only take 110cfm BUT remember that during of all the time the engine is running is in a 720 degree repetitive cycle? and the air can only flow into the cylinder durring the 250 degrees or so that the valve is held open by the cam? well that means that the air flow needed is 720 degs/250 degrees x 110=316cfm or just about what the intake port on the stealth ram can flow at max volume. or put another way youll need to push 316cfm down the port because its only open durring 34.7% of the time available to fill that cylinder
[Modified by grumpyvette, 1:44 PM 9/16/2002]
09-16-2002, 01:18 AM
#2
Re: will the steath ram flow enough air to make max power" (grumpyvette)
Planning on installing one on my car soon.
At this time I am trying to figure out, what's the best way (chipest) to buy it and from who. I know that Summit sels them and Jegs.
If purchased as unit it's only $279 + $200 for fuel rails, but as complete unit w/comander 950 fuel managment system, TB, etc.. it's over 2k. Still, good deal.
Ziggy
At this time I am trying to figure out, what's the best way (chipest) to buy it and from who. I know that Summit sels them and Jegs.
If purchased as unit it's only $279 + $200 for fuel rails, but as complete unit w/comander 950 fuel managment system, TB, etc.. it's over 2k. Still, good deal.
Ziggy
09-16-2002, 01:48 AM
#3
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Re: will the steath ram flow enough air to make max power" (grumpyvette)
[QUOTE]
well lets do the math,
now without power adders like nitrous or a supercharger your going to be limited to about 1.25-1.35 hp per cubic inch of displacement
I'm curious(not flaming you), as to how this computes? I've got a 379ci. small block, 23* cyl heads, producing 670+hp (1.76hp/ci) at flywheel, a 331ci small block 525hp(1.58hp/ci). at flywheel, and have done carburation on many 420+ ci small blocks that have dyno'd 700+ hp. I'm not a USER, I personally think power adders are for ...... I'll stop there I don't want to make enemies with anyone here! :D Also how about nascar? 2+ hp/ci when they were useing 23* heads?I'm not trying to offend you or anyone, just curious as to how this formula works? What is it based on? As for the stealth ram making power? Major potential! I'm currently building my own version,(holley beat me to the draw :mad ) using one of my old drag race tunnel rams and a home made air box(plenum), and I'm also considering my own throttle body(1400-1500cfm!) for this contraption! :D I'm building it for a 406, hoping for 700+hp, and 8200 rpm capability! :cool: :cheers:
well lets do the math,
now without power adders like nitrous or a supercharger your going to be limited to about 1.25-1.35 hp per cubic inch of displacement
I'm curious(not flaming you), as to how this computes? I've got a 379ci. small block, 23* cyl heads, producing 670+hp (1.76hp/ci) at flywheel, a 331ci small block 525hp(1.58hp/ci). at flywheel, and have done carburation on many 420+ ci small blocks that have dyno'd 700+ hp. I'm not a USER, I personally think power adders are for ...... I'll stop there I don't want to make enemies with anyone here! :D Also how about nascar? 2+ hp/ci when they were useing 23* heads?I'm not trying to offend you or anyone, just curious as to how this formula works? What is it based on? As for the stealth ram making power? Major potential! I'm currently building my own version,(holley beat me to the draw :mad ) using one of my old drag race tunnel rams and a home made air box(plenum), and I'm also considering my own throttle body(1400-1500cfm!) for this contraption! :D I'm building it for a 406, hoping for 700+hp, and 8200 rpm capability! :cool: :cheers:
09-16-2002, 09:51 AM
#4
Pro
Thread Starter
Re: will the steath ram flow enough air to make max power" (sinistervette)
sinistervette
the 1.25-1.35hp per cubic inch and .257 x flow x8=potential hp formulas are based on the average results seen on thousands of engines that were dynoed after being hotrodded / modifyed for better than stock performance ,resulting it what normal results show for an average high performance engine. like any average theres always a few of any group that fall at the extreme edges of the data that are not average!
the 1.25-1.35hp per cubic inch and .257 x flow x8=potential hp formulas are based on the average results seen on thousands of engines that were dynoed after being hotrodded / modifyed for better than stock performance ,resulting it what normal results show for an average high performance engine. like any average theres always a few of any group that fall at the extreme edges of the data that are not average!
09-16-2002, 10:37 AM
#5
Re: will the steath ram flow enough air to make max power" (grumpyvette)
I just purchased the stealth ram intake and fuel rails from summit racing. The heads I have are AFR 195's, is there any advantage to port matching the intake to the fel-pro 1205 gasket? The cam I am using is a comp cams 282S, .050 dur 236/236 net lift .506.
09-16-2002, 10:56 AM
#6
Pro
Thread Starter
Re: will the steath ram flow enough air to make max power" (350camaro)
I port match the runners on the intake and heads and blend the changes in size in the ports on some intake head combos but truefully Ive seen only minor improvements by doing so. I bet you can just install the intake after a mild port match to clean up any casting flash and youll be just fine! don,t get to crazy just get it fairly close. btw let us know how it works out! Im useing a slightly milder cam ,
http://dab7.cranecams.com/SpecCard/D...1=Display+Card
(and its obviously just a little too small for max hp, and just a little to large to be a great daily driver cam, but it seems to work well with the 383 and 11:1 cpr and 30# injectors I have but its obvious that a better cpu would help at this point on my car
http://dab7.cranecams.com/SpecCard/D...1=Display+Card
(and its obviously just a little too small for max hp, and just a little to large to be a great daily driver cam, but it seems to work well with the 383 and 11:1 cpr and 30# injectors I have but its obvious that a better cpu would help at this point on my car
