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New 928 Intake plan based on Aston Martin v8 Intake Manifold

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Old 07-10-2017, 08:48 PM
  #16
V2Rocket
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i'd like to see you do it, but i am certain that DIYing will still be more cost effective than trying to modify one.

port spacing...IIRC the AM engine is derived from the Jaguar V8, right?
so it's got ~96mm bore spacing vs the 928's 122mm...

you can buy/borrow an AM intake and measure runner length and taper, you say the ports are about the same at the head.

at that point it's making 8 identical bent tubes and fitting them in a box that fits under the 928's ample hood room.
Jim Bailey might have one of those Salisbury plenums for sale...

Greg and Jerry are taking a long time because they want to be very careful and make their work PERFECT, whether for themselves or potential customers. but if you just want a go-fast part for your race car and your own curiosity, "how hard can it be"?



Originally Posted by mark kibort View Post
as a guide? have you seen the details of the AM intake? you have seen how many HOURS greg and others have spent on making these things with tubular welding, etc. . its a TON of work. the AM intake is tuned, correct, and perfect, all but for one issue........ the intake port spacing.. however, its only an inch over all 4 cylinders.. so, we only need to angle the runners to the feet, by 1" over 13" , or each foot centerline , needs to move about .25". i think its doable. and they are not $1000 parts... there are several for less than 500bucks... ask greg which is harder, makng one or adapting one.
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Old 07-11-2017, 01:20 AM
  #17
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Most one-off efforts run into stumbles that turn into face-plants. If a factory manifold can be modified without having hard turns in the last few inches to the flanges, and all the other stuff can be made to work, then kudos to you for taking this on.

That said, some pretty savvy fabricators have been working at this for a while, and find that the time needed to get all the things to fit is pretty significant even after the design is done.

The dr bob prediction is that the effort should be spent on a design that can be 3D printed. Mustang and Corvette manifolds are plastic and seem to survive OK. If I wanted to do some modifying, I'd be looking hard at 'murican pieces in plastic as a starting point, so that glue can be used for fit-up rather than welding as your metal AM piece will require. I'm guessing you haven't done any TIG welding on cast aluminum parts before; it's not something you casually learn on at home or pick up from watching yeau-toob shorts. Tell me if my assumptions are wrong.
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Old 07-11-2017, 03:42 AM
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If you can figure out runner length you can probably fab your own sheet metal intake faster than figuring out bore spacing.
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Old 07-11-2017, 10:11 AM
  #19
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Personally I love it. You've been talking about this for awhile Mark. I say do it. Good luck with it. BTW, I've dealt with Pacific Motors (One of the first intake pics) and was pleased with the deal. Great price, fast shipping, good part.
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Old 07-11-2017, 12:29 PM
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Single-plane cross-runner intake manifold will work on an 87+ car with the stock hood with either a front mounted, or bottom mount throttle body. Here is an early proof of concept that shows it all fits using my old flanges. Its also easy to make this into a twin plenum with dual forward facing throttles.

Making a 928 intake is not that hard.... making one that fits everyone is. Good luck with the Aston mods. It will be interesting to see how it comes together.






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Old 07-11-2017, 12:48 PM
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Originally Posted by mark kibort View Post
In pusute of more power out of he 928 stroker, or probably out of the 5 liter engines as well, and all the success we have seen with a myriad of custom intake manfolds, (from 50 to 100hp without much tuning or changes) i planning to build up a Aston Martin based intake manifold for the 928S4.

In simple terms, im taking the Aston Martin intake, and cutting off its legs, and adapting it to the 928 manifold adapters. (with welding or hard rubber mounts)
the entire length of the foot print of the AM intake is 12" vs the 928 S4 intake being around 13". i think that 1" shared by each runner, is doable to adapt to the custom manifold adapters made by a few on this list. I almost bought the last adapter, but wasn't committed as i am now to try and make this project a reality.

based on the success of this style of manifold on the 5liter, 4.6liter mustang and the 4.3 and 4.7 Vantage V8s, i think the gains should be substantial. these motors , easily make near 400-500hp with similar cam profiles, valve sizes and displacements to our 928S4s

the plan is to make it all as stock as possible, with little or no changes to the fuel lines and only a re-position of the intake to be rear mounted with a custom airbox, or front mounted with a single throttle body, using the stock throttle cable system (sans the lower pulley)

I think its a beautifully designed intake and if the mating to the custom manifold adapter is possible (and i think it looks that way) it will be a HECK of a lot easier than the effort made to make these from scratch. PLUS, this is proven technology. albeit for another engine, but with similar flow characteristics.

thoughts?
+1

(And you really must stop posting all that engine ****. :-) ).
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Old 07-11-2017, 01:27 PM
  #22
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Originally Posted by V2Rocket View Post
i'd like to see you do it, but i am certain that DIYing will still be more cost effective than trying to modify one.

port spacing...IIRC the AM engine is derived from the Jaguar V8, right?
so it's got ~96mm bore spacing vs the 928's 122mm...

you can buy/borrow an AM intake and measure runner length and taper, you say the ports are about the same at the head.

at that point it's making 8 identical bent tubes and fitting them in a box that fits under the 928's ample hood room.
Jim Bailey might have one of those Salisbury plenums for sale...

Greg and Jerry are taking a long time because they want to be very careful and make their work PERFECT, whether for themselves or potential customers. but if you just want a go-fast part for your race car and your own curiosity, "how hard can it be"?
I just measured the intake. the port spacing across from one another is near the same.. about 11" . the height , is almost exactly the same , 7", so it will clear the hood as the 928 intake does.
i would think worst case on the spacing between the ports, you could lap off the runners at the plennum base if you needed to ,and angle them down to the 928 head. i know things like this look easy at first when it comes to spacing like this, but it surely looks doable. certainly if that is the only challege, it would be MUCH easier than building an another one from scratch.
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Old 07-11-2017, 01:50 PM
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It is definitely adaptable if you can hack it off at the plenum where the runners start, then angle from there. Have you sourced your pipes yet?
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Old 07-11-2017, 02:41 PM
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Slightly off-topic
After looking at all of these intake threads, I have come to the conclusion that once a product is offered, price point is key. In an era of polymer intakes on cars now, production would be less expensive going this route. However, initial costs for tooling would drive overhead up in the short term. Demand is key to keeping price reasonable.
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Old 07-11-2017, 02:54 PM
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Originally Posted by Mongo View Post
Slightly off-topic
After looking at all of these intake threads, I have come to the conclusion that once a product is offered, price point is key. In an era of polymer intakes on cars now, production would be less expensive going this route. However, initial costs for tooling would drive overhead up in the short term. Demand is key to keeping price reasonable.
Um, that's in chapter one of Econ 101 for every product ever produced. This isn't a big mystery.

I thought you were in finance? Wasn't this covered?


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Old 07-11-2017, 03:19 PM
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Yes but someone needs to explain it in lay-man's terms around here.

And finance is different than economics in that it involves funds management and risk. Technically I am an accountant.
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Old 07-11-2017, 03:32 PM
  #27
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In laymans terms, the tooling for a low production nylon intake will be approximately $65,000. NylonMoldUSA is one of the only companies in the states with the technology to do this. They actually have a graph showing the difference in cost for a simple 4-cyl intake manifold.



So (and these are old prices, so are more now), the 20 manifolds you may be able to sell over a couple year period are going to cost $65,000 up front, to clarify $65,000/20pieces=$3,250/manifold just in the tooling alone... excluding all engineering and design of course the actual.

So, unless you are willing to front the $65K to get the project started.... fab it from aluminum or keep dreaming.
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Old 07-11-2017, 03:46 PM
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Well that's the end of plastics.
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Old 07-11-2017, 04:31 PM
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Originally Posted by Mongo View Post
Well that's the end of plastics.
You work for a bank.

Start up a corp called: "Mongo's Plastic Intakes" - get a line of credit for $70,000 and get this going!!

You live close to Mark, have him co-sign.

See how "easy" this stuff is?
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Old 07-11-2017, 04:34 PM
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i like the economics of what im suggesting. a well designed aluminum intake that is a work of art. (HUGE money and time to try and replicate) the AM intake.. lap off the runners and just have straight tubes mounted to the Hans manifold adapter.seems like an easy mod that will have substantial gains.. substantial gains for the cost of such a project seems to be worth investigating and, as i look closer, building. the AM intake is on the way.

the philosophy and logic is the same that Tesla used in their first gen car. why re'invent the wheel? convert the lotus to use their power plant... brilliant.

so, what are the challenges?

1. welding tubes at the right angles to Hans manifold adapters on a jig
2. mounting the ISV, brake booster
3. selecting the correct size TB to mount to the intake. (AMV8 TB is electronic, so no go there)
4. mount MAF and air box
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