ptuomov

What engine design software are the fellow enthusiasts using? What are the strong points and weak points of the products you have used?

RyanPerrella

nothing applies to the 928 so i dont know why it would be of any relevance

there arent exactly a bunch of intake manifolds out there either or heads from edelbrock or anything.....not sure what your looking for here.

ptuomov

say engine analyzer pro

RyanPerrella

isnt that for figuring out carb and intake and cam setups for chevy's and fords?

if so then there is no such thing for 928's. Are no off the shelf arts that would make such changes available. Everything that has been done is usually a one off custom or a 3 off custom.

namasgt

Ricardo wave
this software can be used to optimize exhaust, cams, intake, and a lot more.
it will give you HP curves within 5 % of the dyno runs if you set your model right.
I used it to optimize stepped exhaust for a CBR engine. I was going to do it for the 928 engine but I don’t have the stock cam values. If someone here can help me out with what I need I can make the model in a day or two and post it here.
I will post a picture of the model I made for the Honda engine later today.
here is a link so you know what this software can do
http://www.ricardo.com/engineeringse...aspx?page=wave

namasgt

here I put the picture in word file. I can do the same for the 928 or any engine if I have the information I need.

ptuomov

What model year for the cam angles? For example, '87 and '88 S4 are documented as follows:

Timing ( 1 mm lift,
zero play)

Intake opens 11 degrees after TDC
Intake closes 36 degrees after BDC
Exhaust opens 17 degrees before BDC
Exhaust closes 2 degrees before TDC

namasgt

can you get me the maximum lift of the valves and their diameters. also I will need the rod lenght, port diamete and depth( for intake and exhaust), engine operating temperature.
this is the information I have so far, see if their right:
4957 cc engine
78.9 mm stroke
100 mm bore
10.0 : 1 compression ratio
13726548 firing order
90 degree V8
I will also need exhaust lenght and outter diameter, and the trottle bore size.
I was hoping that maybe somone here has actually measured the stock valve lift against crank angle.
the values you gave me for the cams will give me 205 degree duration for intake and 195 degree duration for exhaust with a 13 degree overlap. but these are at 1 mm lift right ?

what Im trying to do is to get as much information as I can to generate stock HP and torque similar to real life.

ptuomov

This is what I got from the workshop manual:

Bore mm/in. 100/3.94
Stroke mm/in. 78.9/3.11
Displacement (actual) cc/cid 49571/302.5
Compression ratio as low as 9.4:1 for s4 to as high as 10.0:1 for gt
Max. power kW/HP 235/316 at engine speed 6000
Max. torque Nm/lbft 430/316.9 at engine speed rpm 3000
Max. specific power, DIN 70020 kW/L/HP/L 47.4164.6 44.6/60.5
Fuel cut-off to limit engine speed at rpm 6600
Cross plane 90-degree V8 with 1 3 7 2 6 5 4 8 firing order


The following is from memory based on other people posting here (caveat emptor cubed):

Rod length 150mm
Piston compression height 42.6mm
Deck height 0.08 mm
Head gasket 1 mm

1987 928 S4 approximate combustion chamber volume at TDC:
Head 41 cc (+/- 1cc)
Piston 25 cc
Gasket 8 cc
Total 74 cc

The S4 intake manifold acts as a Helmsholtz resonator when the flappy
is closed and as an open pipe when the flappy is open and the pulses
offset each others in the plenum. For low rpm, the flappy is closed,
for medium rpm the flappy is open, and for high rpm the flappy is
closed again. Whether flappy is closed or not at high rpm makes no difference to torque or power.

Intake manifold runner lengths, excluding the port length:

1: 19 cm
2: 27 cm
3: 28 cm
4: 23 cm
5: 20 cm
6: 32 cm
7: 28 mm
8: 23 mm

Manifold runner entries are 46.5 mm id round. The manifold runner exits (to ports/head) are kidney shaped, and about 49.5mm by from 40.3 mm to 37.0 mm.

Intake valve diameter 37 mm
Exhaust valve 33 mm
Tulip shape
Valve stem diameter 7 mm minus the tolerance

Carl Fausett's stock 88/89 s4 master cam profile:
Intake lift/duration .354” / 200 deg
Exhaust lift/duration .313” / 190 deg

The throttle body butterfly diameter 74mm.

I don't know about the exhaust manifold. The runners are not exactly equal length.

Credit due to people who posted these originally, I remain responsible for the errors and omissions, of course. If the info turns about to be wrong, I will issue a full refund for how much you just paid for it.

Best,
ptuomov

namasgt

Ive been working on this software for 5 months now and its owned by school not me, we use it to optimize our intake and exhaust configuration for our race car.its been used for the past 4 years by othere people in our group with good results thats why were still using it. I've heard the software is very expensive but it doesnt cost me anything just a little time. the results are sensitive to correct cam values, engine temperature, correct intake design, and exhaust if I were to make a stock model. but If for example there is an example out there that uses a certain size ITBs and exhaust with known values for their cams and they know their HP from Dyno . then it will all be easier I can just try to dublicate their engine to see if the software gives me a close enough value to real life. then I will know that I have a working model. and we can go from there in optimizing the engine. Im not looking into making money this is just for my own experiment and ofcourse I will put the results on the forum.

GregBBRD

I personally use my brain, my flow bench, and my dyno. Not in any particular order.....

ptuomov

;-) I can't afford a flow bench or a dyno, and since I've lived the life "to its fullest," computer software is the only option left for me...

But seriously, do you think that the optimal amount of computer software use is the corner solution at zero?

GregBBRD

You're going to have to translate that for me. I'm too old to know what you are asking.

namasgt

We do dyno our cars but we don’t have a flow bench. we optimize the intake using fluent or Star CCM +, then we use wave to see what HP gains we get for that particular intake. using the software appropriately also takes brain.
if we were to make a bunch of different exhaust configurations and test them on the dyno it would take a long time and it would be costly. but since we have this software for free, we use it. its alot faster and easier to change configurations and see what the tradeoffs are. when I was showing the software to some engine guys they got very interested and were suprised of the softwares capability. they wanted to test their engines to see what they get.
Im not trying to prove any thing here. I just wanted to personaly test the engines capability on the software, how much HP I can get from it ? I was hesitant to ask the forum for help to make the model but since the question came up I though it would be a good time to bring up the subject .
so far it seems like not many people are interested.
I wander if Sterling would be interested.

Dennis K

I'm interested.