New 928 Intake plan based on Aston Martin v8 Intake Manifold
#76
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Mark --
Find some pictures of Louie Ott's inlet ducting over the radiator. His is ITB but his pre-plenum ducting should give you some ideas. You'll have throttles in that section, along with your airflow/MAF or MAP sensor setup depending on which engine management system you are going to use.
Find some pictures of Louie Ott's inlet ducting over the radiator. His is ITB but his pre-plenum ducting should give you some ideas. You'll have throttles in that section, along with your airflow/MAF or MAP sensor setup depending on which engine management system you are going to use.
that was my first idea, but then if you look at the layout, that oil filler wont have a spot to be extended too, and it cant be left in the stock place as the intake "rear" would be in that space. thats my first choice... ............But, the aston martin intake from the last port, is about 10" rearward or forward (if pointed forward) so its much larger than i thought. PLUS, i need to add the MAF and a filter to it. so, now ill leaning toward the front facing set up, and the extension of the oil filler to the rear.
#77
Properly tuning that engine that is sitting the chassis that you just discovered needed rack bushings would gain much more than any manifold you will come up with on your own.
#78
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so did fan.
mine made 335rwhp with no tuning as a 5 liter, and now 375 with a bunch more displacment and a restrictive intake.
so, i would bet that the intake will provide about 40HP with no other changes.. how many could you think you could tune it up too?
#79
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https://rennlist.com/forums/928-foru...l#post13877729
The manifold you are trying to build is not really a challenge fabricated the right way. All you need to make it happen is pony up the cash.
The manifold you are trying to build is not really a challenge fabricated the right way. All you need to make it happen is pony up the cash.
#80
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https://rennlist.com/forums/928-foru...l#post13877729
The manifold you are trying to build is not really a challenge fabricated the right way. All you need to make it happen is pony up the cash.
The manifold you are trying to build is not really a challenge fabricated the right way. All you need to make it happen is pony up the cash.
I do think you might be discounting the value of the properly designed intake. ill agree, that the runners are the most important part, and the encapsulation is important, but not as critical. however, we all saw how painstaking it was to make the bell mouth inlets to each runner by hand on a lathe. ive seen some intakes, none of them, so far but a few , look like they would be better than the AM intake, and the ONLY challenge (that i could be discounting, i agree) is to adapt the plennum,runner packakage to your lower manifolds on a jig to have an intake.......... the rest is challenging too. (less with your oil filler adaptation)
#82
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If you fail to plan...........you plan to fail.. we are still in planning stage.
have tig welder (a master) and the intake.. now, need to get the lower manifolds made and then put it together... THEN, ill worry about moving things around to fit.
#83
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Dreaming without any basic factual information like the actual dimensions is hardly "planning". And " PLANNING " to worry about moving things around later really is planning to fail.
You really need a mock up block with heads etc. for you to have any chance of success.
Otherwise the Salisbury Plenum might be your best option.
You really need a mock up block with heads etc. for you to have any chance of success.
Otherwise the Salisbury Plenum might be your best option.
#84
Chronic Tool Dropper
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Mark, if you haven't already done so, get in touch with Hans and Greg to see where they are in making their intake flange plates for the heads. Hans was having those CNC'd in small runs, and has a very good idea of what might need to be changed to make the nozzle fittings taller for you, perhaps including some of the angle you'll need. From your descriptions so far, I'm not exactly clear on how you plan to transition from the ram tubes through a compound bend and another straight section all above the heads. You can't have a bend immediately above the head -- you MUST straighten the flow before the head, so the manifold flow is perpendicular and on axis with each port on the head. Turbulent flow in that area will cancel out any benefits you might see from the runner length; at that you'd do as well with a big plenum box and virtually no tubes at all, ala Threshie.
#85
Rainman
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at that point there would be no chance of resonant tuning (since the whole runner length from "valve to plenum" would be in the head, about 85mm) but it'd have a really big chamber to suck air from.
#86
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There have been some interesting hints on the effects of proper runner lengths vs horsepower. I think Cheburetor in Europe noted that they saw a big improvement almost accidentally during a dyno tuning session on a modified engine, when they swapped in some longer BMW pipes. Would we see a reduction by the same amount if the ram tubes were completely eliminated? There's lots of work already around just the shape of the bell mouth and proximity to other adjacent flows; to the point where just a flat-floor intake even with the supercharger would not be good at all. The Threshie intake actually has a couple large plenums with fabricated runners to each port, so my analogy was poor. On supercharged engines, the air density change might support proportionally shorter runners, still much better than the pizza box "manifold" that many DIY setups seem to use due to space limitations. Think along the lines of better flow with less intake pressure, so less drive HP needed and less heat-of-compression to have to deal with. Separate discussion from Mark's project though.
#88
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it'd be REAL interesting to see what happens on a dyno if you bolted one of the supercharger "pizza box" manifolds onto a stock S4 engine and rigged up a throttle body and "adapter" to go in place of the supercharger.
at that point there would be no chance of resonant tuning (since the whole runner length from "valve to plenum" would be in the head, about 85mm) but it'd have a really big chamber to suck air from.
at that point there would be no chance of resonant tuning (since the whole runner length from "valve to plenum" would be in the head, about 85mm) but it'd have a really big chamber to suck air from.
Mark, if you haven't already done so, get in touch with Hans and Greg to see where they are in making their intake flange plates for the heads. Hans was having those CNC'd in small runs, and has a very good idea of what might need to be changed to make the nozzle fittings taller for you, perhaps including some of the angle you'll need. From your descriptions so far, I'm not exactly clear on how you plan to transition from the ram tubes through a compound bend and another straight section all above the heads. You can't have a bend immediately above the head -- you MUST straighten the flow before the head, so the manifold flow is perpendicular and on axis with each port on the head. Turbulent flow in that area will cancel out any benefits you might see from the runner length; at that you'd do as well with a big plenum box and virtually no tubes at all, ala Threshie.
#89
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Thread Starter
Dreaming without any basic factual information like the actual dimensions is hardly "planning". And " PLANNING " to worry about moving things around later really is planning to fail.
You really need a mock up block with heads etc. for you to have any chance of success.
Otherwise the Salisbury Plenum might be your best option.
You really need a mock up block with heads etc. for you to have any chance of success.
Otherwise the Salisbury Plenum might be your best option.
for example, if the intake was too tall, it would probably make me just walk away. but because it is the same size , it is encouraging as alll i see is the legs to attach to the lower maifold adapter as a minor challenge. after that, its the intake inlets... the ISV and vacuum attachements are minor in my opinon. again, we have seen the intake installation of mark and Joe. this is not much differnent, and much more simple (one throttle body, etc)
#90
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so how long are the A M runners below the plenum ?? how many inches to the head surface on the A M manifold ? In other words how much space do you have to make a 1 inch offset to get to both cylinders 1 and 4 . That determines how crooked / angled the runners to those two would have to be.