Would replacing the Y air intake pipe with a pipe that doesnt have ribs all around it improve the speed of precious airflow that enters the engine.



With all those ribs the air flow is contantly agitated inside and while the ribs provide a much needed flex for engine movement , could this be overkill.

Surely some smaller ribs at strategic flexing points on the pipe would mean that you get the flex needed but more importantly where you needed it. Maybe somthing a little like this or with silicone pipes:



Maybe you could totally redesign the intake pipe so the 2 pipes instead of merging could be channeled into a larger pipe that tapers off into the correct fitting into the engine. This could improve the 'ram air' effect possibly since you have more molecules of air pushing into the engine as opposed the restrictive Y pipe?

I have heard of up to 20% better airflow using smoother intakes. With some decent air filters must be worth several bhp and some much needed torques???

 

the throttle body presents much more of a bottleneck than the intake hose. but you could easily put together new intake ducting with silicone pieces.

internally, the intake manifold itself seems like a pretty solid design, too.


i really think the biggest benefits we can get from the 4.3L will come from a larger throttle body or dual throttle bodies (which would require a new manifold.

 

Intake hose I believe is smooth in the inside and is only ribbed on the outside for structural rigidity.

90% of the potential gains on the vantage on the exhaust & software side. Intake does little to nothing and should always be done last on these cars.

 

yup, because intake mods deal with bottlenecks. Vergis is looking at addressing potential bottlenecks.

 

This
The air hose is smooth on the inside
AM tested the S with twin throttles but they never made it to launch (I suspect they will at some point)
At WOT the throttle and the air path to the rear most cylinders are the limiting factors

 

Am I correct in assuming that this is because the limited airflow is being consumed by the forward cylinders?

 

Anyone have the actual diameter of the stock throttle plate in mm? Also, diameter for opening for the intake manifold in mm? Both these would greatly help determine how much more airflow could be obtained.

Given the powerband shape on my old 4.3L with ECU and catback RPI, it was blatantly obvious the throttle both was not a bottleneck in airflow at 425-430 crank HP (and that was still on stock cats and stock headers).

I am guessing the stock throttle plate will really only become a true bottleneck above 470HP so as of right now it's not even close to necessary as most of the airflow restriction is on the exhaust side. ONCE you do all of the exhaust side, THEN it makes sense to start addressing the throttle body restriction.

As with all bottleneck theory, you always start by upgrading the most restrictive bottleneck first, then working your way down to the least restrictive. Upgrading the throttle body with stock headers and cats on the car is a complete waste of time/money IMO, you are better off focusing elsewhere. Also remember, upgrading throttle bodies will require an all new custom tune to compensate for all the additional volume of air coming in (which no such tune exists yet), so you are much better off doing the other stuff first.

Hope that helps,
007

 

https://www.6speedonline.com/forums/...ml#post3892786

 

This is what we really need





For camparison:


It re-engineers the whole intake system. Dual throttle bodies with an inlet for each side of the engine, giving much better distribution of intake air (no more choking out the rear-most cylinders). The fuel rails are now inside the intake manifold; I'm willing to bet this was done for packaging purposes since the manifold now dominates the space where the fuel rails normally are.

I think a more feasible solution, would be to adapt the OEM intake manifold. Cut the front of the manifold off at the taper, fabricate a new front that tapers to a dual TB setup (much less taper due to wider TB housing).

Here's my wicked sweet, highly-technical design.


The EGR (yellow circle) needs to be relocated or, better yet, eliminated -if possible. The red squares up front are the new dual TBs. The blue arrows are airflow. The horizontal thick red line on the strut brace is a wall inside the intake manifold, which you can see here:



The above pic is looking through the TB opening. Airflow runs directly into a wall, which the air must then redirect and flow around to get to the intake runners.

By having a dual TB setup, airflow will be coming into the manifold on the sides of the wall, rather than pointing directly at it. I'm guessing this could improve throttle response quite a bit. Ford Racing makes a couple dual-TB setups that might be suitable. One is 2x63.5mm and the other is 2x65mm. Assuming the pivot bar is the same size, the 2x65mm TB should have a similar opening. However, the TB will open faster with a dual-plate setup than single, so more air will come through quicker at the same throttle position (all else being the same). That should mean better response - so long as the tune for the new setup takes it into account and the throttle doesn't become too touchy. (For reference: http://www.summitracing.com/parts/fms-m-9926-cj65)

Of course, the intake hoses would need to be changed out to accommodate the new TBs, but that should be relatively simple compared to modifying the intake manifold. Or, if you want to adapt the stock main air hose but adapt it for the new dual-flap TB, just lop off a few inches closest the the TB and stick this in there: http://www.jegs.com/i/Spectre/865/9791/10002/-1

Most of us have already done exhaust, air filters, and tune.

 

Telum great write up.

Cant believe the wall exists inside there. Seems to be the whole intake manifold and design was done to retard the vantage performance so it would not pip the DB9.

Would it be beyond the realms of possibility to open the hole out a bit???

Or maybe redesigning the manifold, or milling existing one to increase volume? But I dont know how it looks underneath..

 

The TB is smaller than the inlet in the intake manifold, so opening the inlet to the manifold won't do anything. The wall is there because the intake runners open to the sides - so as soon as air enters the manifold, it hits the side of the first runner. Can't do anything about that without a complete redesign (like the GT4 manifold). That's why I'm thinking adapting the front of the OEM manifold to use a dual-TB will help without costing an arm and a leg (just an arm in this case, I think). Being wider, the dual-TB will allow airflow to approach the runners from further out, giving a better angle of approach compared to the OEM single-TB.

 

Ahh I see now. Yes that would be an interesting project that make sense. Do you think with all the exhaust mods done you could get the V8 4.3 to 450 bhp with such an air induction mod thrown in as well??? Now that would be very exciting !!!!!

 

I honestly don't know what the numbers would look like, and I don't even want to speculate haha. What I'd like to do is improve the factory setup (which was designed to a price point). Things to keep in mind: the intake runners give the engine much of its power characteristics. In general: shorter intake runners give higher HP but less TQ, while longer intake runners give higher TQ but less HP. Modifying the front of the intake manifold shouldn't change those characteristics. Rather, it should simply improve airflow to the cylinders. I'd like to think a dual-TB setup will give the engine a little more power (more airflow) and a little more response (better airflow routing).

I think to get much more out of it, you'd have to get into the engine itself. Port out the cylinder heads and put in better internals (higher quality and better balanced crank, rods, pistons). Or... bump up the displacement.

 

Yeah true. But to bump up my 4.3 to a 4.7 would probably cost the same as a used 4.7 lump that I could just drop into the car.

 

Intake mods in general are a complete waste until you do all the necessary exhaustm& software upgrade. I genuinely believe you an hit that 470hp mark with full exhaust (headers, cats, muffle) and custom tune to match all 3. At that point a larger throttle body would help above 6000rpm, but below that gains would be minimal, only better throttle response below that point. The 4.7L needs the throttle body more than the 4.3L with all the mods (obvious given its larger displacement).