Mongo

This I have to see. Fingers crossed Mark and I hope you are successful!

mark kibort

im excited about it... the intake is on the way.. worst case, its wall art!
its a work of art internally. no match for a bunch of tubes... if the only challenge is putting on its "feet" i think it will be quite straight forward. this gets away from the dual throttle body, synchronizing and cabling them...... my goal is to make it as much of a bolt on as possible , once the "feet" are in position.

Is there anyone that has the stock S4 foot print on Cad or a drawing? I dont want to have to find a salvage one to do my mock up.

thanks

Mark

James Bailey

Good news is you will have half the ingredients to make thermite.....which might come in handy

Mongo

In California yes

mark kibort

the intereting thing about the design, as it has upside even on the AMV8 when they went to a 4.7 liter from a 4.3 liter AND, they had a larger diameter TB/plennum version that gave 20hp to the 4.3 version! so, a 4.3L V8 that puts out 400hp vs the 5 liter 928 putting out 330rwhp in GT form, with nothing more than the intake and 20% less displacement. the 4.7L puts out 430hp.. a full 100hp more than our 928GT

the interesting thing about the engines, is that the AM vantage 4.7 V8 is a 3.6" x 3.6" bore and stroke. (91mm x 91mm)... same as the stroker, and 1/2" less piston diameter.
picture the Stroker( 92mm stroke) 6.4 Liter , dumbing it down to a 4.7 liter and making near the same HP as mine makes today. 370rwhp is common for AM 4.7V8. the same motor in race form (ecu tweeks, etc) puts out 500hp. (near 430-440rwhp) same as the mustang Boss 302 (5 liter) with the same stockish tweeks

the cams are near the same lift as the GT
the duration is near the same
the S4 has slightly larger valves
compression is only slightly higher in the vantage. 10.3 vs 11:3
vantage has only variable valve timing on the intake alone which helps midrange power. (interesting they didnt do variable intake plennums , like the porsche does.....which is the reason the efficiency is bad on the aston vs the porsche . Ulrich Bez, who designed much of the 993, was the chief enginner /designer of the Am V8)
redlne is 7300rpm with peak power at 7000rpm

on paper, the intake is the majority of the HP output difference.

dr bob

A lot of assumptions there. So except for the variable valve timing, at least 10% higher compression ratio, "near" the same lift on the cams, different heads with siamesed rectangular ports, a different exhaust and different engine management, and oversquare geometry, it's pretty much identical. On paper. The intake manifold is what makes all the extra horsepower? Impressive.


A Thought: Do a little measuring to see how much room there would be above that AM manifold as it is now if it were sitting on the 928 heads and still clear the hood. That's how much room you have to fit an adapter plate between the AM manifold and the 928 heads. Now decide how much you can modify the AM manifold's ports with grinder to do some of that "matching" in the manifold. Then the rest in the adapter plate. Get that design nailed, and have it done in a CAD that can be translated for a CNC to do the actual work. Or get the pieces laser cut and you do the final "blending" with the plates assembled on the manifold. Hans has the head and port layout done already so you know what the bottom needs to look like.

dr bob

You don't need a salvage intake as much as you need the block and heads with all the water, fuel and vapor plumbing in place. You'll probably dream of having fuel available above some injectors at some point so the engine will run. Throttle bodies and air filter, linkages, ducting, etc. will prove handy at some point. Better to do all of that stuff on an engine on a stand. You'll likely want to test run and dyno the engine before it goes into your car too.

To get to a point where it's an easy "user bolt on", you have a little engineering and fabricating work in front of you, plus testing, before it's ready for Prime Time.

mark kibort

Thats what im doing. yes, the intake is the exact height of the current intake,which gives a little room for errors and the .25" spacer/gasket.
when i get the intake and the jig, ill start thinking and planning on the approach. but in the mean time, ill get the space above the intake limits. currently, it doesnt look to be much of an issue. near the same height as stock

as far as your comments on the engine, those are rounding errors. we all know what the net gains of 1 point of compression would be . its not much. same lift on the cams as what i have currently. the port shape to the heads is different, but i dont think we are talking a 100hp for the redesign of those to match. if we match the design, we match the HP.... the only difference is engine management. sure, there are some differences there. my fuel mixtures are near dead spot on to 12:1 , near optimal. sure, i dont have fancy valve timing, but ive optimize with timing for a narrow operational range. its not an "oversquare geoemtry".. actaully its under square. OUR geometry is oversquare, so its better and easier on the block/bearings.

anyway you look at it, most of the gains come from the intake. more examples would be found on the mustang 302 engine. 450rwhp out of a 5 liter.. again, nothing too radical on valves, intake ports, cams, or even compression. most is in the intake. something that should be obvouis, due to the fact that we all saw what the threshie intake did by just slapping it on. and trust me, it was slapped on. home depo 4 " pipe for the MAF with the hot wire siting on one side, home depot plumbing tubes, crazy bends and cross talk tubes.... bolt on , 100hp... so, lets be honest, the intake is responsible for most of the gains, where most of the things tried by Mark Anderson, didnt do much.. larger TB, extrude hone intake, all did next to nothing. maybe all that allowed the intake to work better. who knows. the point is, if i was a betting man. which i am, im confident that the AM intake will provide good gains and cost effective ones too!

thanks for the comments.

Mk

bureau13

I hope you're right, because that would be awesome, however I think you're vastly over-estimating how much of those horsepower gains come from the intake, and how much comes from the engine management. Look at pretty much all modern cars now....they run cleaner, more efficiently and with significantly more power than their 30-year-old counterparts, whether you're talking about high-end performance cars or econoboxes, etc. Why is that? Computers! Not intakes.

But, like I said...I would be tickled to death for you to prove me wrong.

Mongo

It's all about air and how much you can get in it.

The engine is a giant vacuum pump if you think about it really.

Do it Mark! The more manifolds the better!

mark kibort

You are confusing efficiency with power. yes, most modern cars have much more efficient drive electronics, individual port injection, Vanos, etc. but not any of that really effects the HP all that much. want an example? how many of these "tuned" 928S4s make anywhere near as much as my S4 with a simple set of upgraded GT cams with 1mm more lift? i dont think any. (330rwhp). mixture is correct there is not much you can do for a narrow operating range, AND, valve timing was played with for optimizing in the higher RPM ranges. spark, only can do so much, even with race gas. there is no 100hp lurking there, but if you remember, Joe Fan and Mark anderson just bolted on an intake and got near 100hp overnight! no tuning all stock ECU . even when Mark tried to optimize "tuning" he didnt see any more gains .. dont underestimate the power of a "good" intake. there are enough similarities to the mustang and AMV8 to make me believe , at least 50hp is lurking there and maybe less for a stock S4, but still worth doing.

so yes, i dont think its much of a challenge to prove you wrong there. there is nothing that stands out that wouldnt be better with this intake, especially seeing the HUGE gains of other (near home made intakes) that gained near 100hp with no other mods.

i know it wont be easy but im up for the challenge and already have the intake on the way. with a little help from the list, this project might become a reality and help others too! certainly i wont be able to do it alone.

yep.. thats the truth right there. Reduce the loses and the mass flow goes up, along with the power, near proportionately.

Rick Carter

Subscribed

hacker-pschorr

Ok everyone, let's not get ahead of ourselves here.

He's doing this for an all out race car, a setup which will be in the upper 85% of the RPM range for the vast majority of its life. This is a whole different mindset than building a streetcar, most of which are automatics.
Frankly on that note the runners are too long for my taste, but the bare minimum goal of improving on the S4 intake is equal length runners. Especially if sticking with the stock computers.
Turbo Todd proved beyond any doubt how good the stock intake can be if you setup and tune 8 individual maps (with his red supercharged car). Such a setup is outside the scope for 99% of 928 projects. Even then, you still have the flow limitations of the intake restricting you.

The collective "we" have nothing to gain or accomplish by questioning his hypothesis for going forward with this modification.
So please, Mark is doing his part (as he and I discussed) to keep himself on track, so do the same and don't de-rail his thread.

Okey Dokey????

AO

That's like telling me to stop looking at naked women... You're no fun!

mark kibort

thats the beauty of this mod. im not changing any of the fuel lines or water lines. its all going on top of the engine, using the stock fuel and water configurations. leaving the oil filler in place too. the entire idea is to make something that is bolt on (relatively speaking) the throttle body is the challenge, but once i have it on the car ill have to rig up the pulley system for it. air filter could be the contrapton with the inline filters, or a big cone filter. thats the challenge

dyno testing before? did fan or mark A. dyno test on a stand? no.....
Still , the largest bolt on HP we have ever seen in N/A 928-land. Why do you think we need to tune? The MAF and ECU do an incredible job of regulating air and fuel. The MAF doesnt know what is on the other side of it. flow rates are all over the map in a stock /or modifiied configuration. (no pun intended) part throttle, 5 liter , 6.4 liter, WOT throttle big valves , little valles, threshie intake, stock intake, it doesnt matter what flows will be metered and produce good Fuel air ratios, unless we run out of fuel.........and i dont think with my goals this will be an issue. again, mark and joe had great fuel air ratios with no tuning and just a RRFR.
i dont expect to get 520rwhp... but 420 to 440rwhp might be a reasonable goal and safe too. currently at 375rwhp and with the 30lb injectors way turned down to under 40psi. (ideally , i should have gone with the 85 injectors). if you remember, i got 330rwhp with the stock 19lb injectors turned up to 70psi. always in the safe fuel /air mixture range overall, top RPM to bottom.

Im trying to reduce the variables to a scant few. bolt on the intake, stock fuel rails, and a throttle body , probably the 86S version if the bolt pattern is the same. adapt a port for the ISV and connect the breathers in the same general area as they are stock, and that will be it.

the height of the intake is the same as the S4. i have to spread out the runners, which seems geometrically possible but is the largest challenge.
Once this intake is on the jig and assembled, the rest is pretty straight forward.

the intake should be here in a week or so.