Hello from the UK

[BenR]

i use EA pro 3.3, PFA pro and the entire Performance trends package......very expensive to hold all the licences.

And also LES.

However, fiddling with simuation software is one thing, and it is a great tool, but the time it takes to model an engine accurately you could of built one..........and in which case you would of done anyway.

I still prefer to design engine specs mentally, those who can tend to be better off as there are things you cant model in engines software.

I dont run 20v 4age's, i dont find then that good to work with and their performance is limited, horrible design flaws between black and silver tops.

A carbon airbox to surround the ITB's?
As for runner lengths in these applications, i find that you typically cannot get enough at all due to space limitations, everytime i start my basis with going for as long as i can in the space, then twiddle it on the dyno, trial and error for tuned lengths is better than calculating them IMO.

[Richie]

BenR Wrote:I dont run 20v 4age's, i dont find then that good to work with and their performance is limited, horrible design flaws between black and silver tops.

So, you would prefer the 16v over the 20v (blacktop or silvertop) as a base engine to work with?

[BenR]

yes, the 20v configurations are poor.

You have one with an ok port design, but it has a crap combustion chamber design with zero quench. Then you have one with an ok chamber design with a little quench, but crap ports.

Either way, they arent great, the bottom end parts are, but the top end is rubbish.

[Richie]

BenR Wrote:yes, the 20v configurations are poor.

You have one with an ok port design, but it has a crap combustion chamber design with zero quench. Then you have one with an ok chamber design with a little quench, but crap ports.

Either way, they arent great, the bottom end parts are, but the top end is rubbish.

Ben, so what would the best spec engine be, combining all the best parts?

[BenR]

best spec 4age?

Smallport 16v head, massive port work and oversize valves, welded chambers with matching custom forged 1.5mm 4032 slipper pistons with reduced comp height, as long a rod as possible in titainium, billet crank wth narrowed journals, 12.5mm lift 310 deg cams, custom plenham intake system, a rather fancy exhaust manifold and system with anti-reversal flanges.

There is so much more to list, but in general, 240-260bhp is what you should be looking at.

[Richie]

BenR Wrote:best spec 4age?

Smallport 16v head, massive port work and oversize valves, welded chambers with matching custom forged 1.5mm 4032 slipper pistons with reduced comp height, as long a rod as possible in titainium, billet crank wth narrowed journals, 12.5mm lift 310 deg cams, custom plenham intake system, a rather fancy exhaust manifold and system with anti-reversal flanges.

There is so much more to list, but in general, 240-260bhp is what you should be looking at.

Sounds awesome!!!!
Need to get me a project car soon.

Thanks for answering my questions

[BenR]

no probs

[NoHachi]

Hi,

Modeling an engine usually doesn't take me more then an afternoon or so. That gets me close enough to make some ball park estimations (which usually the best you can expect. Further tuning gets you the rest of the way).

Would like to run an airbox for the added hp and better MAP signal. Also makes proper filtering (paper filters) easier. Still looking for an affordable EMS that can run MAP/TPS blend algorithms...basically waiting until one of the megasquirt guys comes out with an update. Untill then, open trumpets is not an option for me.

Callin the port/chamberdesign of the 20V rubbish is a bit over the top. They were designed using better software then u and I are using, and certainly by much better qualified engineers. As a stock engine they are just fine, though I agree that they're not an ideal base for extreme NA tuning.

[BenR]

I'm sorry, that is where we will have to disagree.
The 4age story is one where the designers (who in terms of qualifications) are probably light years ahead of you or me, but got the whole mod considerably wrong the whole way along.

First they design an engine that geometrically is good, resembles the BDA in its geometry. However, the bigport is just plain crap, i have no idea what they were thinking, port sizing capable of feeding your average yank v8 but stiffled with tiny valves. Chamber is quite good, but factory machining made it so horrible and det sensitive that CR had to be kept so low. They make TVIS to try and cure some of the initial design flaws, but it just doesnt work.

Then they make the smallport, the best 4age around. A port shape that is actually decent, the 16v chamber which has an acceptable level of quench.

Then come the 20v's.........in std trim they come with wilder cams and ITB's and more complex management, so its no wonder they hit 100bhp/ltr. But it isnt because they are better designed. The ITB;s they run are poor, the port designs are horrible and generate poor flow quality, the chambers have no quench at all, and without quench your fighting a battle against end gasses, auto ignition, stupid amounts of ignition timing and a piston crown design that just doesnt benefit anything in anyway.

If quench wasnt important, then all of us top tuners dont spend all our time trying to increase it and use it effectively.

Modelling and engine takes me more than a day, i have to design and input every factor. This is more than your geometry and bearing clearances and friction factors, but weighs of every component, cam profile per 0.5degree, top end geometry data and valve train assebly data, then i have to port and flow a head and add that data, input every part of the ports dimentions/geometry/volumes/seat configurations etc etc. Induction methods, exhaust parameters, fueling and ignition factors...the list is endless and takes a fair amount of time to input all the correct data. And at the end of that, the results are only aids, most of the time about 5% accurate, but either way, you still have to build the engine and will net the same result if you modelled it or not. Not many customers have the budget to design and redesign and engine.

Dont bother with megasquirt, if you want a cheap and good ecu, run a VEMS unit or an omex. I personally arent one for over complicating ECU's, i find it a waste of time.......good tuning makes up for any fancy systems people are running. Most of my ITB setups run tps vs rpm with the MAP used for baro correction, running MAP on ITB's is over complicating and you dont gain anything.

A good foam filter has the capacity and filtration quality which is fine for tarmac use, i would only bother considering paper if the user was not going to look after the filter and was competing in very dusty conditions.

With your carbon airbox are you talking of just surrounding the ITB entries? If so, MAP values wont be affected unless the throttle is placed upsteam, if the plenham is before the butterflies then you will still recive map variations at idle with any decent cams. But on many ecu's you can just run tps vs rpm at low range and swap to MAP for load at higher rpm once the value settles.

Oh, and just to bring the point home....20v's are rubbish. In an attempt to increase valve area they destroy burn conditions, and you cant add too much quench or you just shroud the valves, making all that area pointless in the first place. And the ports are just plain bad........although the audi 20v ports are worse.

[Richie]

So much info in this thread, awesome!!!