LS7 / C6R Velocity Stack Induction/Injection
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From: Ft. Lauderdale, FL, USA
Originally Posted by TUF383
Nup ... The Harrop Hurricane bolts straight on to an LS1/LS2. 
It will also feed a 427ci, but not with C5R heads (yet). We are planning on a C5R/LS7/L76 version, but it is a little way off.
It will also feed a 427ci, but not with C5R heads (yet). We are planning on a C5R/LS7/L76 version, but it is a little way off.
Originally Posted by Quickin
Will the Butterfly intake bolt up to the "ET Performance" LS1 265 heads?
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From: Ft. Lauderdale, FL, USA
Originally Posted by Beast96Z
The 265's use a conventional LS1/6/2 bolt pattern, so I'd venture to say yes, it would.
Harrop or the Hogan intake
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From: Texas
Originally Posted by Quickin
Which should flow better on a 427 or 436 stroker:
Harrop or the Hogan intake
Harrop or the Hogan intake
My understanding from those who have used them is the short runner sheetmetal intake (like the Hogan) work ok on say F/I applications.
On a N/A motor you see a big jump in peak power (say as much as 50HP), but the toll to the area under the curve makes it too big a tradeoff.
I know SW saw this on his 427 SR C5, and others I've spoken with have seen the same even on big inch motors.
The nice thing about the ITB intakes is you can tune runner length, and with the Harrop (and similar intakes) with the runners laid over, you can tune enough length in to not kill bottom end, still make nice power, and keep drivability up over a shared plenum intake.
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From: Fat Chance Hotel
It's like the old days when we used to pick dual/single plane over tunnel ram. Plenum volume and runner length play such a dramatic role in power production that you need to pick a design based on how you'll be driving i.e. street, drag, road, etc. A good comparison is TPI vs. LT1. The TPI's long runners built torque quick but fell on its face early vs. the LT1's short runner design which lost some down low relatively, but picked up more up top. Both had a similar size plenum.
Without a decent plenum volume you lose velocity in the runner at lower rpms due to a lack of "momentum." That's why tunnel rams or sheet metal intakes will lose low end power. But the hurricane intake kind of fit the best of both worlds since there is a "box" that becomes the plenum.
The older M5's (~1990) had a very similar intake. 3.5 litre I-6, 6 individual TB's attached to a plenum box. Each throttle had a vacuum port to adjust the balance between TB's.
Without a decent plenum volume you lose velocity in the runner at lower rpms due to a lack of "momentum." That's why tunnel rams or sheet metal intakes will lose low end power. But the hurricane intake kind of fit the best of both worlds since there is a "box" that becomes the plenum.
The older M5's (~1990) had a very similar intake. 3.5 litre I-6, 6 individual TB's attached to a plenum box. Each throttle had a vacuum port to adjust the balance between TB's.
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Verdad Gallardo 6600 rpm clutch dump of death Administrator
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From: Texas
Originally Posted by technical
It's like the old days when we used to pick dual/single plane over tunnel ram. Plenum volume and runner length play such a dramatic role in power production that you need to pick a design based on how you'll be driving i.e. street, drag, road, etc. A good comparison is TPI vs. LT1. The TPI's long runners built torque quick but fell on its face early vs. the LT1's short runner design which lost some down low relatively, but picked up more up top. Both had a similar size plenum.
Without a decent plenum volume you lose velocity in the runner at lower rpms due to a lack of "momentum." That's why tunnel rams or sheet metal intakes will lose low end power. But the hurricane intake kind of fit the best of both worlds since there is a "box" that becomes the plenum.
The older M5's (~1990) had a very similar intake. 3.5 litre I-6, 6 individual TB's attached to a plenum box. Each throttle had a vacuum port to adjust the balance between TB's.
Without a decent plenum volume you lose velocity in the runner at lower rpms due to a lack of "momentum." That's why tunnel rams or sheet metal intakes will lose low end power. But the hurricane intake kind of fit the best of both worlds since there is a "box" that becomes the plenum.
The older M5's (~1990) had a very similar intake. 3.5 litre I-6, 6 individual TB's attached to a plenum box. Each throttle had a vacuum port to adjust the balance between TB's.
Originally Posted by J-Rod
Very true, but keep in mind on an ITB intake, that the "world" is your plenum, so there is never a loss of pressure in your intake (unless you suddenly get jetisoned into space). Ok, htere might be some if you have enough camshaft duration (but it would take alot).
Now, the real question...who will have sent me one of these beauties and have it sitting on my doorstep so I can do some f-body test fitting? Hmmmm?
I even have HPTuners, a wideband, and 1-bar SD enhanced...you know you want to...
Originally Posted by J-Rod
Very true, but keep in mind on an ITB intake, that the "world" is your plenum, so there is never a loss of pressure in your intake (unless you suddenly get jetisoned into space)
I like it!
I could see Harrop makin gsome money of that intake if they would find a trusted sponsor that would be willing to test fit it. I'd surley be interested if I knew it would fit, but I couldn't see forking over $3k for a maybe.
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From: Ft. Lauderdale, FL, USA
Originally Posted by TUF383
You are correct ...
We do have a C5R manifold but it is not the Hurricane as initially shown.
The C5R manifold is not a mass-produced item, each one is hand-built and port matched .. typically for race applications.
Here's some images ...
I love my job ...
We do have a C5R manifold but it is not the Hurricane as initially shown.
The C5R manifold is not a mass-produced item, each one is hand-built and port matched .. typically for race applications.
Here's some images ...
I love my job ...
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From: Fat Chance Hotel
Originally Posted by J-Rod
Very true, but keep in mind on an ITB intake, that the "world" is your plenum, so there is never a loss of pressure in your intake (unless you suddenly get jetisoned into space). Ok, htere might be some if you have enough camshaft duration (but it would take alot).
I guess that's why the race cars that use those intakes use an air box attached to an air duct in the body. That fixes everything.
Originally Posted by Beast96Z
I could see Harrop makin gsome money of that intake if they would find a trusted sponsor that would be willing to test fit it. I'd surley be interested if I knew it would fit, but I couldn't see forking over $3k for a maybe.
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From: Texas
Originally Posted by technical
But the world doesn't scavenge... I guess that's why the race cars that use those intakes use an air box attached to an air duct in the body. That fixes everything.
I guess that's why the race cars that use those intakes use an air box attached to an air duct in the body. That fixes everything. https://ls1tech.com/forums/showp...9&postcount=293
The independent runner stuff with the small independent throttles before each port with the constantly pressurized near 100 kpa "mega plenum of the world" above those same little throttle bodies are just less affected by the exhaust reversion that affects a plenum car worse since the whole intake system on these setups is at very low pressure and the exhaust is at such a higher pressure. The exhaust reversion can and does fill up the whole plenum behind the central TB or carb and the whole runner of each cylinder with exhaust diluted air that causes the repeated and erratic misfiring that we hear as the cool loping sound some people love so much.
With enough overlap the IR systems will also lope too and turn black under those cute little throttle bodies from idling with all the same vacuum under them when they are closed and idling but they have less of the total runner to become as contaminated since the higher pressure is close at hand right above them and in the rest of the runner. You will sometimes, with really big cams in these systems see the exhaust and regular reversion in the form of standoff above the runners with some of them at lower engine speeds.
Also when you crack the throttle instead of an entire manifold plenum having to pressurize up slowly instead, now the port sees full atmosheric pressure and density basically almost instantaneously so the throttle response is WAY better. In fact some people need a progressive linkage or it's too jerky for them! Also just realize that Australians ARE crazy and they all drive cars with blowers and NOS and have mohawks. They also like cubic inches in a lot of their racing and RWD but that's finally coming back to the USA too as people here have had their fill of the FWD crap.
The independent runner stuff with the small independent throttles before each port with the constantly pressurized near 100 kpa "mega plenum of the world" above those same little throttle bodies are just less affected by the exhaust reversion that affects a plenum car worse since the whole intake system on these setups is at very low pressure and the exhaust is at such a higher pressure. The exhaust reversion can and does fill up the whole plenum behind the central TB or carb and the whole runner of each cylinder with exhaust diluted air that causes the repeated and erratic misfiring that we hear as the cool loping sound some people love so much.
With enough overlap the IR systems will also lope too and turn black under those cute little throttle bodies from idling with all the same vacuum under them when they are closed and idling but they have less of the total runner to become as contaminated since the higher pressure is close at hand right above them and in the rest of the runner. You will sometimes, with really big cams in these systems see the exhaust and regular reversion in the form of standoff above the runners with some of them at lower engine speeds.
Also when you crack the throttle instead of an entire manifold plenum having to pressurize up slowly instead, now the port sees full atmosheric pressure and density basically almost instantaneously so the throttle response is WAY better. In fact some people need a progressive linkage or it's too jerky for them! Also just realize that Australians ARE crazy and they all drive cars with blowers and NOS and have mohawks. They also like cubic inches in a lot of their racing and RWD but that's finally coming back to the USA too as people here have had their fill of the FWD crap.
6600 rpm clutch dump of death Administrator
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From: Texas
Originally Posted by technical
But the world doesn't scavenge... I guess that's why the race cars that use those intakes use an air box attached to an air duct in the body. That fixes everything.
I guess that's why the race cars that use those intakes use an air box attached to an air duct in the body. That fixes everything. https://ls1tech.com/forums/showp...9&postcount=293
The independent runner stuff with the small independent throttles before each port with the constantly pressurized near 100 kpa "mega plenum of the world" above those same little throttle bodies are just less affected by the exhaust reversion that affects a plenum car worse since the whole intake system on these setups is at very low pressure and the exhaust is at such a higher pressure. The exhaust reversion can and does fill up the whole plenum behind the central TB or carb and the whole runner of each cylinder with exhaust diluted air that causes the repeated and erratic misfiring that we hear as the cool loping sound some people love so much.
With enough overlap the IR systems will also lope too and turn black under those cute little throttle bodies from idling with all the same vacuum under them when they are closed and idling but they have less of the total runner to become as contaminated since the higher pressure is close at hand right above them and in the rest of the runner. You will sometimes, with really big cams in these systems see the exhaust and regular reversion in the form of standoff above the runners with some of them at lower engine speeds.
Also when you crack the throttle instead of an entire manifold plenum having to pressurize up slowly instead, now the port sees full atmosheric pressure and density basically almost instantaneously so the throttle response is WAY better. In fact some people need a progressive linkage or it's too jerky for them! Also just realize that Australians ARE crazy and they all drive cars with blowers and NOS and have mohawks. They also like cubic inches in a lot of their racing and RWD but that's finally coming back to the USA too as people here have had their fill of the FWD crap.
The independent runner stuff with the small independent throttles before each port with the constantly pressurized near 100 kpa "mega plenum of the world" above those same little throttle bodies are just less affected by the exhaust reversion that affects a plenum car worse since the whole intake system on these setups is at very low pressure and the exhaust is at such a higher pressure. The exhaust reversion can and does fill up the whole plenum behind the central TB or carb and the whole runner of each cylinder with exhaust diluted air that causes the repeated and erratic misfiring that we hear as the cool loping sound some people love so much.
With enough overlap the IR systems will also lope too and turn black under those cute little throttle bodies from idling with all the same vacuum under them when they are closed and idling but they have less of the total runner to become as contaminated since the higher pressure is close at hand right above them and in the rest of the runner. You will sometimes, with really big cams in these systems see the exhaust and regular reversion in the form of standoff above the runners with some of them at lower engine speeds.
Also when you crack the throttle instead of an entire manifold plenum having to pressurize up slowly instead, now the port sees full atmosheric pressure and density basically almost instantaneously so the throttle response is WAY better. In fact some people need a progressive linkage or it's too jerky for them! Also just realize that Australians ARE crazy and they all drive cars with blowers and NOS and have mohawks. They also like cubic inches in a lot of their racing and RWD but that's finally coming back to the USA too as people here have had their fill of the FWD crap.
Originally Posted by J-Rod
Anyhow, many times a box is used to filter and direct air, along with holding a restrictor for some class racing. The IR stuff in many cases will make more HP without an airbox and being exposed to outside air with no box. I have some dyno graphs that illustrate this if you'd like to see them.
Originally Posted by MeentSS02
Yeah, I really wouldn't want to fork over $3K for a maybe either, but I have their technical drawings with all of their dimensions sitting in front of me, so I'll see what can be done. It's just that little part where the metal cowling dips down on the F-body that has me concerned, because I'm pretty sure it will clear the plastic part above it without an issue. It will just be that one little section.