Intake TB combo for high revving 347
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From: Estero, FL
Intake TB combo for high revving 347 I am having some trouble trying to figure out which is going to be the best route to go down for my new motor.
Motor specs:
Forged 347ci
14.0:1
BIG duration cam (sorry cant give out specifics on the cam just yet)
MTI Stage 2R LS6 heads
With the cam it should turn 8000-8500 without any issues.
I will be running 114 leaded fuel and going over to speed density tuning. So no 02 or knock sensors.
I run in Open Road Races. These cover 90-130 miles at extended high RPMS. Usually anywhere from 30-40 minutes and sometimes a bit longer. I have thought about going with the Fast 90/90 combo but have also been eyeing the single plane edelbrock Victor Jrs. The Fast would be an easy swap and even make life easier to tune. But I dont quite know what the limitations RPM wise are with it. And if it can give the motor air past 7500 it really isnt of any use to me.
My old school experience and considering NASCAR runs a single plane intake says I need to start looking that direction to feed the motor air at high RPM. But I dont wiute know the best way to tune for that style of intake.
If I went the single plane intake and ran a megasquirt to control fuel and the stock ecu for ignition would it be plausible that the Victor would make more power?
Any input would be greatly appreciated on this one. I am pretty much stuck trying to figure this one out.
Motor specs:
Forged 347ci
14.0:1
BIG duration cam (sorry cant give out specifics on the cam just yet)
MTI Stage 2R LS6 heads
With the cam it should turn 8000-8500 without any issues.
I will be running 114 leaded fuel and going over to speed density tuning. So no 02 or knock sensors.
I run in Open Road Races. These cover 90-130 miles at extended high RPMS. Usually anywhere from 30-40 minutes and sometimes a bit longer. I have thought about going with the Fast 90/90 combo but have also been eyeing the single plane edelbrock Victor Jrs. The Fast would be an easy swap and even make life easier to tune. But I dont quite know what the limitations RPM wise are with it. And if it can give the motor air past 7500 it really isnt of any use to me.
My old school experience and considering NASCAR runs a single plane intake says I need to start looking that direction to feed the motor air at high RPM. But I dont wiute know the best way to tune for that style of intake.
If I went the single plane intake and ran a megasquirt to control fuel and the stock ecu for ignition would it be plausible that the Victor would make more power?
Any input would be greatly appreciated on this one. I am pretty much stuck trying to figure this one out.
It's all theory until you try it.
The intake doesn't form a true limit, but only deminishing returns.
As pressure drops in the intake at WOT your power output drops.
Now again in theory you would look at where the stock style intake manifold makes its peak power. To adjust peak power to a higher RPM it's generally accepted that a shorter runner is needed. It doesn't mean that you can't peak power at 4800 RPM and still make some power at 8000 RPM. It just means that your peak power is far away from your operating range.
To be most effective you want to have the heads, cam, intake, and exhaust all tuned for the RPM range where you need your power.
Tuning any one of these for that range will not be very effective without matching the others as well.
There are simulators out there to help you pick runner lengths and valve timing, but simulators only go so far and more can be learned by experimenting.
Sorry this post isn't all that helpful. I was just rehashing the theory.
The intake doesn't form a true limit, but only deminishing returns.
As pressure drops in the intake at WOT your power output drops.
Now again in theory you would look at where the stock style intake manifold makes its peak power. To adjust peak power to a higher RPM it's generally accepted that a shorter runner is needed. It doesn't mean that you can't peak power at 4800 RPM and still make some power at 8000 RPM. It just means that your peak power is far away from your operating range.
To be most effective you want to have the heads, cam, intake, and exhaust all tuned for the RPM range where you need your power.
Tuning any one of these for that range will not be very effective without matching the others as well.
There are simulators out there to help you pick runner lengths and valve timing, but simulators only go so far and more can be learned by experimenting.
Sorry this post isn't all that helpful. I was just rehashing the theory.
with what your looking to do, i'd suggest the Harrop itb intake. its a little pricey but wont loose flow up top or effect your low end tq. if this is out of your budget then the victor jr. is your best bet above 7500+ rpms.
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From: Estero, FL
Originally Posted by Nasty N8
Hey we are working on a new intake with longer runners than the last one. Give me a call I want you to test it. Is your motor ready for dyno soon?
Nate
Nate
I'll try to get ahold of you today.
First off I assume this is a dry sump motor, or atleast certainly hope it is, especially with endurance racing.
Second, you can use your ls1 pcm (if you have one) with a single plain intake no problem. There are many doing it here and I'll be doing it as well with my sb2.2 nascar intake for my 434. I absolutely posatively would not run a fast 90 on something spinning that high. They cut air flow on 320 cfm heads by around 15-20% at higher lift ranges if my memory serves me correct and the runners are going to be a little long for any kind of tuning to occur at those high rpms. Is a sheet metal intake out of the equation for you or one of these harrops? There are good single plain setups ready to bolt on out there but, atleast in the gmpp, the runners are very very short on them but that may serve you well with your high rpm intentions. Good luck!!!
Second, you can use your ls1 pcm (if you have one) with a single plain intake no problem. There are many doing it here and I'll be doing it as well with my sb2.2 nascar intake for my 434. I absolutely posatively would not run a fast 90 on something spinning that high. They cut air flow on 320 cfm heads by around 15-20% at higher lift ranges if my memory serves me correct and the runners are going to be a little long for any kind of tuning to occur at those high rpms. Is a sheet metal intake out of the equation for you or one of these harrops? There are good single plain setups ready to bolt on out there but, atleast in the gmpp, the runners are very very short on them but that may serve you well with your high rpm intentions. Good luck!!!
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From: Estero, FL
Would a 4150 be better than a FAST 90? I have been looking at some of the TB's and single runners that Kinsler makes. Thier single runner intakes are about 500 cheaper than the harrop aussie intakes and have more options available. The downside to those is that tuning is a bitch and the expense to get in the door is a killer.
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Verdad Gallardo In my opinion the 4150 intake/throttle body is far superior for a motor that will turn as high as you stated.
Not superior to the individual runner intakes your talking about though.
Not superior to the individual runner intakes your talking about though.
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From: Laguna Niguel, CA
I am very curious about the specs on this motor! I would love to know what parts you are using to build this monster.
A high-revving small block has always been my dream motor and this looks like a killer combo
A high-revving small block has always been my dream motor and this looks like a killer combo
6600 rpm clutch dump of death Administrator
Joined: Dec 2001
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From: Texas
The short runner has been tested vs a FAST. Below 4500 you loose about 20+ HP ,and torque. Around 4500rpm the grpahs meet. Over that the delta begins the other way, and by 7000 or so you are 20-30HP up. So, in a high rpm application I'd say a short runner is fine.
But, the Harrop manifold is really cool if you want to tune runner length. I'd look at it over a Kinsler based on one criteria. The Kinsler is straight up and down, and the Harrop lays on its side. So, you stand a better chance of clearing the hood. But ona Camaro cowl, I think there would some cutting involved with the Harrop. On the Kinsler I don't see it fitting.
But, the Harrop manifold is really cool if you want to tune runner length. I'd look at it over a Kinsler based on one criteria. The Kinsler is straight up and down, and the Harrop lays on its side. So, you stand a better chance of clearing the hood. But ona Camaro cowl, I think there would some cutting involved with the Harrop. On the Kinsler I don't see it fitting.
Originally Posted by NataSS Inc
Would a 4150 be better than a FAST 90? I have been looking at some of the TB's and single runners that Kinsler makes. Thier single runner intakes are about 500 cheaper than the harrop aussie intakes and have more options available. The downside to those is that tuning is a bitch and the expense to get in the door is a killer.
On The Tree
Joined: Dec 2003
Posts: 179
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From: Bloomington, MN
Check out TPIS, they have just what you are looking for,they make the intake,throttlebody,and fuel rail coil pack combo,check out their website [tpis.com] look under new stuff and there is a bunch of dyno comparisons to look at.
Originally Posted by triumphman
Check out TPIS, they have just what you are looking for,they make the intake,throttlebody,and fuel rail coil pack combo,check out their website [tpis.com] look under new stuff and there is a bunch of dyno comparisons to look at.
Staging Lane
Joined: May 2005
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From: Vevay,IN
If its any consolation, I know of a ford 302 purestreet car that turns 8000 with the holley efi intake and a 250/260 @ .050 on a 106 center, this is a hydraulic roller with lots of spring pressure and without honda rods, and a 75 mm throttlebody
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From: Nottingham, Notts, England, UK
Originally Posted by J-Rod
The short runner has been tested vs a FAST. Below 4500 you loose about 20+ HP ,and torque. Around 4500rpm the grpahs meet. Over that the delta begins the other way, and by 7000 or so you are 20-30HP up. So, in a high rpm application I'd say a short runner is fine.
.
.
Hi J-Rod, That's one of mine and Steve's flow test was encouraging
Thing is, it's simple enough to shorten the carbon trumpets and play around with plenum volumes and throttles. So, when Steve's got some free time I've asked him to shorten the trumpets and do another test. He could also flow test without the trumpets.Boosted.
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Posts: 881
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Are there any rules? If not, what is your cost constraint? In 2006, a ported LS6 head is not state of the art, in either ports or combustion chamber.
With these motors, why run 8000 for an extended period if not required by the rules. F1, NASCAR, revs are there to deal with the rules. Otherwise, why run those revs and not more displacement?
If you are running 8000+ for a sustained period, saying 'forged' doesn't qualify a bottom end, nor does ported LS6 head qualify. This is the land of $1000+ shaft rockers, $700 solid lifters, $500 valve springs, $2500 cranks, $2000 rods, and $4000 heads. Nascar cup cars go through these things like water. Even restricted cars, like Hooter's Cup cars limited in both valve lift and rpm, eat the valve springs.
If your rules are flexible enough to allow the ITB of your choice, there appear to be many more Harrop installations than Kinsler, or Kinsler is more likely to be on a professional racing car, like the C5R/C6R Corvettes.
However, a review of the rules and budget is probably the first thing to consider.
With these motors, why run 8000 for an extended period if not required by the rules. F1, NASCAR, revs are there to deal with the rules. Otherwise, why run those revs and not more displacement?
If you are running 8000+ for a sustained period, saying 'forged' doesn't qualify a bottom end, nor does ported LS6 head qualify. This is the land of $1000+ shaft rockers, $700 solid lifters, $500 valve springs, $2500 cranks, $2000 rods, and $4000 heads. Nascar cup cars go through these things like water. Even restricted cars, like Hooter's Cup cars limited in both valve lift and rpm, eat the valve springs.
If your rules are flexible enough to allow the ITB of your choice, there appear to be many more Harrop installations than Kinsler, or Kinsler is more likely to be on a professional racing car, like the C5R/C6R Corvettes.
However, a review of the rules and budget is probably the first thing to consider.
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Joined: Dec 2004
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If there are no engine rules, why are you building an 8500rpm 347???
You could probably match it with a warmed over LS7 doing less than 7000 rpm, or a larger engine going even slower. Now a more vanilla bottom end will live. And the top end will be significantly kinder to springs and valves.
Or why not add a supercharger? Or add a supercharger to a 427, or a 441, or a 457. Then you could have more power, more flexibilty, and just overall drivability at less cost. And be much more likely to be around at the finish. With big displacement and FI, this could nearly be an emissions-legal motor.
You were building a maybe 700hp motor using special fuel that wouldn't run smoothly below say 2500. Here you build 800hp that would pull smoothly from 1500-1800 on pump gas. Even NA, you could match the 700hp or so, although it would probably want to be over 2000 rpm. FI also eliminates, or at least reduces, the intake issues.
You could probably match it with a warmed over LS7 doing less than 7000 rpm, or a larger engine going even slower. Now a more vanilla bottom end will live. And the top end will be significantly kinder to springs and valves.
Or why not add a supercharger? Or add a supercharger to a 427, or a 441, or a 457. Then you could have more power, more flexibilty, and just overall drivability at less cost. And be much more likely to be around at the finish. With big displacement and FI, this could nearly be an emissions-legal motor.
You were building a maybe 700hp motor using special fuel that wouldn't run smoothly below say 2500. Here you build 800hp that would pull smoothly from 1500-1800 on pump gas. Even NA, you could match the 700hp or so, although it would probably want to be over 2000 rpm. FI also eliminates, or at least reduces, the intake issues.