Too much intake

[shootme5150]

To recap, when my engine is complete, I'm going to be running a 347 with TW ported heads (flowing close to 300CFM), haven't picked a cam, and I'm looking to hit 400RWHP. Is a Victor 5.0 intake too much intake for that setup? Would I be better off with the RPM II? Ported Cobra / GT40?

Thanks for the input

edit: this will be a street / strip car... I'll be using it as my second driver.

 

[ty-rone]

I think it would depend on what you want to do with it. If you are not going to be revving the extra rpm's the vic affords you then there is no point in using it. Doesn't the vic rob a little low end grunt?

 

[N8Miller]

Ok, there are lots of alternatives here. you could use a 1" spacer and lower your RPM power band. will the vic be too much, no. RPM2 is the LEAST i would use.

talk to grn92lx, hes building a very similar 347 as we speak.

 

[shootme5150]

the one I'm looking at comes with a spacer, however I thought that would up the power band. Ah well. Just like ty asked, I'm primarily concerned that it will kill me down low.

 

[NKau]

the one I'm looking at comes with a spacer, however I thought that would up the power band. Ah well. Just like ty asked, I'm primarily concerned that it will kill me down low.

What's the main intended purpose of the car? If it's going to be 90% street, I'd personally put on an RPMII or TF Track Heat. If it's going to be primarily a track car, then the Vic would make more sense.

 

[TC93]

What gears are you running,, 5-speed or auto,, NA or power adder??? Depends on the combo and what you're looking to do. I run a box stock E-brock RPM on my blown 331 with good results.

If you match the cam and gears with it, and like mentioned above, plus use the extra RPMs out of it then the intake should work well.

Have 2 friends running that intake; one has it on a blown 347 in a 93 vert. Oh his set-up it works great, especially with 14#'s of boost. Not too much worried about low end.

2nd one runs it on a DSS 306 with about 10:1 compression and a higher RPM cam, with a 5-speed and 4.10 gears. The only thing holding him back, is he still has the stock rev limit. His car will pull all the way up to the 6250 mark. If he could spin it another 500 RPM then he should see some good results. With his cam he needs to be shifting around 6400 or 6500.

 

[N8Miller]

well, the 1" spacer will lower your rpm range about 400 rpms. your larger displacement will ALSO lower the rpm range about 300-400. that would put your power from 3100-7000 or so.

my advice, the TFS R is a perfect inbetween for a stroker motor and it has a better RPM range.

 

[Grn92LX]

Use a trickflow R or a victor efi (if you dont mind the BS of not having egr and having to rig up pcv) You will need to port match the TW head to run a victor. The rpm ranges mean NOTHING. cam timing and bigger cubes drop those "ratings" down a LOT. To make big power with a small head you need MORE intake. An rpm II or holley will work great but IMO the TFS R is the hot ticket giving you the best of both worlds.

I'm building a 6500rpm 347 now with unported TW heads and i'm shooting for low 11/high 10 second power.

See this thread if you think a victor won't make any low end torque- http://www.corral.net/forums/showthread.php?t=194797&highlight=victor+intake

Build the engine to make POWER and stop worring about excessive low end torque. That will NOT help you WIN races!!

 

[shootme5150]

thanks, grn. The heads I have are supposedly heavily ported (they'll be here Monday), wouldn't I have to port either intake? How often do you see used TFS R intakes around? Currently, the Victor is on ebay for 275, ending tomorrow. I'll keep watching, but I was going to grab it if it went for 375 or less. Seems like a deal.

Also, as I said, I'm going to be streeting this car more often than not, so I want to ensure I've got enough torque to move the damn thing off the line...

 

[Grn92LX]

Who ported them? Where did you buy them from? What cam are you gonna use?

I recommend the trickflow R manifold. The rpm II or holley would work great as well, I just like taking it a step above the norm

List me your entire combo/plans and i'll help you go fast

 

[shootme5150]

Who ported them? Where did you buy them from? What cam are you gonna use?

I recommend the trickflow R manifold. The rpm II or holley would work great as well, I just like taking it a step above the norm

List me your entire combo/plans and i'll help you go fast

I bought them off ebay, supposedly they were ported by Total Engine Airflow. TEA claimed a flow of 305CFM, the person I bought them from had them flow tested locally with these numbers:

Intake at .200~158, .300~203, .400~245, .500~275, .600~285, .700~293 CFM. at 28" Exhaust at .200~120, .300~165, .400~188, .500~203, .600~212, .700~222 CFM. at 28"

Trick flow twisted wedge small block ford cylinder heads. Fully ported by Total Engine Airflow. 2.02 intake and 1.60 exhaust valves ,Ferrea 6000 series stainless steel valves. Double valve springs set up for hyd. or hyd. roller to .575 lift. 55cc chambers, bronze guides, guide plates, Arp rocker studs, New valve job and seals. Heads have just been clean up milled.Also included are six 1.72 roller rockers, and a set of Arp head bolts. Heads have just been assembled and are ready to bolt on.

Basically fresh from the machine shop with a valve job and everything was checked. From the limited research I've done, I'm thinking of a TFS Stage 2 cam, but haven't locked anything down. That was really my next point of research.

As of now, I've got the heads, I'll be going with a 347 Stroker kit, I'm figuring a 75MM TB / MAF with 30# injectors (maybe ~40s?), and the ignition upgrades to ensure I have spark, fuel pump and regulator, etc (the usual). Rocker choice will likely depend on my cam choice and clearance.

I'm only a few weeks into the planning, really. The entire package won't go together until this winter, though, when I have the time and money for the machining of the block.

Thanks for you help.

 

[N8Miller]

thanks to grn92, i got a R intake for $400 shipped (thanks, Nate McVey ). they are much more hard to find than other intakes, but you just have to be patient. i also saw one on ebay 3 weeks ago with the "buy it now" option of $400.

 

[shootme5150]

I've got plenty of time... if that's the route to go, I'll wait. Prefer that to mismatching

 

[tmoss]

Pick the best intake (or try without a cam spec'd)

TFS street intakes have 15",first generation TFS tracks have 14",later ones have 13".
cobra = 15"
performer rpm efi 13.25, 1.90" cross sections, 8 sq in at the tb exit
Performer EFI, same base as rpm, smaller upper cross section, 1.25" longer = 14.5" total length
RPMII 13.25, 2.58" cross sections, 8 sq in at the tb exit expand to 12 sq in at the plenum
Victor 5.0 Runners are 11.5" long and 50% larger in area than Performer 5.0 #3821 runners.

 

[shootme5150]

am I looking at this backwards? Should I spec my cam first and match the intake up to that?

 

[Grn92LX]

Cam gets picked last. Or talk to a custom cam designer about your combo and goals and they can set you up. Like I said, i'm building a similar combo but with unported TW heads. I'm gonna be using the trickflow R manifold. I just sent Ed curtis the cam payment today. According to him, the cam's gonna be pretty aggressive to get big power from a small head

 

[detroitmuscle99]

just put together a well matched combination, dont put a crazy manifold on a motor thats never gonna see high-rpms, if you look at most manufacturers of heads, cams, and intakes, they list the operation range of the part, its not b.s., go by that, and select parts that compliment the rpm range youre motor will see, by doing that you'll make good peak power everytime, but more than anything a well matched combo will have a very broad torque band (means it makes peak torque for a long rpm range), and that car will always go consistantly quick and be a good street car.

Do you know what will happen if you mismatch parts of different operating ranges? yeah, you'll make good peak torque and power, but it'll drop off fast, and the guy making 20 less peak h.p. with matched components is gonna pass you because he's making his peak power across a broader, more useable, rpm range.

anyhow, call Comp Cams and talk to Tony, he'll recommend you a good cam to run, or use there catalog, its easy to reference a cam for your motor from them. Edelbrock makes a EFI intake for every RPM range, and there catalog is also easy to reference yourself the right manifold.

 

[tmoss]

just put together a well matched combination, dont put a crazy manifold on a motor thats never gonna see high-rpms, if you look at most manufacturers of heads, cams, and intakes, they list the operation range of the part, its not b.s., go by that, and select parts that compliment the rpm range youre motor will see, by doing that you'll make good peak power everytime, but more than anything a well matched combo will have a very broad torque band (means it makes peak torque for a long rpm range), and that car will always go consistantly quick and be a good street car.

Do you know what will happen if you mismatch parts of different operating ranges? yeah, you'll make good peak torque and power, but it'll drop off fast, and the guy making 20 less peak h.p. with matched components is gonna pass you because he's making his peak power across a broader, more useable, rpm range.

Good advice. You don't choose an intake and then a cam you consider all the parts at once. Yes, choosing a cam is an integral part of choosing an intake. Duration plays heavily into what cross section will work best with the cam. A simplified explanation is - you can get by with less cross section if you have more duration and you can use a larger cross section if you have less duration and more uasable lift.

Don't listem to anyone who tells you just put the biggest stuff you can find on the engine. I've got dyno comparisons that show that is not a correct approach. MATCH THE COMBO.

 

[Michael Yount]

....and folks like Buddy Rawls or Ed Curtis will help you match the combo - in addition to spec'ing the cam, they'll help you match up the other bits.

While there's helpful info here, it's rarely a substitute for getting the pros involved. We can only help you guess...

 

[shootme5150]

....and folks like Buddy Rawls or Ed Curtis will help you match the combo - in addition to spec'ing the cam, they'll help you match up the other bits.

While there's helpful info here, it's rarely a substitute for getting the pros involved. We can only help you guess...

Where's the fun in that? The IC engine isn't a 'monster living in the hillside'... There has to be a way to figure this stuff out without the basic trial and error method. I want to LEARN this stuff, not run to the nearest 'pro' and ask him to do it for me. Surely many of the people here have locked down WHY this stuff works together... What combinations DON'T work together (with regards to flow, duration, RPM, back pressure, etc - not referring to brand names).

Should i merely go by spec'd RPM numbers? Seems like the easy way out, but if that's what I should do, that's what I'll do.

I'm looking for things along the lines of what tmoss wrote... "you can get by with less cross section if you have a longer duration"... "on't listem to anyone who tells you just put the biggest stuff you can find on the engine. I've got dyno comparisons that show that is not a correct approach. MATCH THE COMBO."

Again, is it as simple as RPM ranges? If this has all been covered, I'll try searching again, but trying to decide what to search ON to get good results...