can an A/F engine management part make this much difference?

[SS8_Gohan]

just looking around for who invented the turbo charger, seems BMW had the first passenger car with one, the 2002 in 1973 but the renault ad says they "created" it? :confused: i dunno..

anyways, just came across this, and i'm like cool. Skyline gets a mention

"Turbo looses steam

Multiple valves and double-overhead camshaft designs developed reasonable performance without the complication of turbo-charging, and these methods were politically correct too since they consumed less fuel. Consequently today there are only a few petrol-powered road cars that still use turbo-chargers for enhanced performance.

Computers soon started playing an even bigger role in cars. Engine management systems linked to fuel-injection systems meant getting more out of the engine was even easier. For example, one can buy chips that can boost power by 100 bhp for some Japanese cars, such as the Nissan Skyline. Moreover, on-road speeds were being restricted all over the world. Though most of the sports cars today are capable of doing more, they are restricted electronically not to exceed 250 kmph even in autobahn-blessed Germany"

100bhp from a chip or PowerFC or whatever, is that a bit of a strecth or realistic?

[NO_RSPECT]

not sure cos I dont have management,

but please bear in mind with most advertising like renault, you have to listen carefully,

i am sure it says our designers created the turbocharge, now it doesnt say Renault created the turbocharge, hell their designers could have worked for BMW...get my drift.

stupid advertising too misleading

[Warpspeed]

The turbo was invented by a Swiss guy called Alfred Buchi around 1910. If you do not believe this, do a Google search and see. The turbo has been around almost as long as the internal combustion engine, it is nothing new.

Towards the end of the first world war, a few of the wood and canvas biplanes with ancient radial engines were turbocharged.

The reason modern engines have DOHC four valve heads is that this allows very good power while also maintaining economy and emissions.

The thinking behind this is that you can have good top end airflow (power) and also use very restrictive valve timing (emissions and economy) together.

With four very small light valves, and direct cam actuation the valves can open and close much faster. The valve springs can be lighter, and the valve lift does not need to be so great. All of this is of great benefit to a racing engine, but it also means you can run very restricted valve timing with little or no overlap, and still get good top end airflow.

Power is the result of how much air (oxygen) can flow through the engine, then adding enough fuel to burn the available air. There are four ways to get a lot of oxygen into the engine.

You can just build a big engine. Your big engine will be powerful because it is big.

Or you can make a small engine turn at high speed, and also be efficient at that higher speed.

You can supercharge the engine so it works in denser air.

Or you can add oxygen directly by combining nitromethane or nitrous oxide to the fuel as an oxygen booster.

The power is limited by available oxygen to burn, increasing the fuel further beyond this will not increase power.

I doubt if adjusting air fuel ratios are going to improve power, unless the original air fuel setting is very lean.

The majic carburettor, or fuel injection chip that doubles your power is BS.

More power needs more air, and extra fuel to burn that extra available oxygen. It is as simple as that.

The old two valve heads can be made to breathe reasonably well, but you need a very lumpy cam to do it.

[SLY33]

Originally posted by Warpspeed

I doubt if adjusting air fuel ratios are going to improve power, unless the original air fuel setting is very lean.

Dont you mean unless the original a/f setting is rich? As is the case of std R33 management yeah? And by leaning them out with a custom ecu brings the extra power?

Im no tuner, but thats my understanding!

[Warpspeed]

You could be right, but as far as I know correctly functioning EFI systems are never set so rich that you lose large amounts of power. What would be the point in that ?

Sometimes if a system detects a fault it may deliberately go super rich to save the engine, for instance a runaway overboost condition, or massive overheating.

If a system is hugely over fueled, the extra fuel takes up space that the oxygen would normally occupy, and power decreases.

There are really two CORRECT air fuel ratios.

Best economy is when all the fuel molecules are burned, every last one of them. There is always some excess oxygen in the exhaust at best economy setting.

Best power setting is where all the available oxygen is consumed. There will always be some slight unburned fuel in the exhaust at the best power setting.

There is never any economy gain from going excessively weak, or power gain from going excessively rich.

That is my understanding of it anyway. If all Skylines are set deliberately rich from the factory to use more fuel and lose power, you have to ask yourself why would they do that ?

[Nacho Vidal]

SLY33 you are spot on.

Warpspeed, Nissan set the std management to run rich to stave off detonation (this has been covered in many an HPI mag). This is not too evident when the cars are stock, but add an exhaust and FMIC, and rich they run. When a programmable ECU is tuned, the extra power is made by leaning out the mixtures, which brings the detonation threshold closer, which is why its up to the tuner be conservative enough so that detonation wont occur, whilst getting the most "safe" power.

Power gained typically from a 33 with the usual mods and 12poundish boost, is around 25-30kw at the wheels.

And there you have it, NACHO.

[Warpspeed]

Again you are probably right.

But if its true, why have the Nissan engineers not lowered either the boost or compression ratio and run correct mixtures ?

I suspect that a properly tuned stock engine running on the higher octane fuel available in Japan does not run rich at all.

Here in Oz, and after you have modified your engine, the EFI computer detects that something is not quite right, and runs rich.

So fair enough, you lean it off, and it goes better.

But I also would like to bet that the Australian delivered Skylines (R31, and R32 GTR) do not run rich in standard tune. Anyone know ?

[whatsisname]

In the case of the R33 GTS25t my best guess is that the Nissan engineers set the RB25DET engine up to run conservatively rich? That way they ensure maximum engineering tolerance & protect the cars warranty. Why not run a lower comp ratio & boost level instead? The RB25DET is designed to have good off boost response & decent top end power (above that of the RB20DET), something that both the aforementioned changes would've hurt.

Further to the above - Now add lower octane Aussie fuels & modifications such as large FMIC, & the ECU does it's best to run rich as hell!

More relevant to the thread topic - My car had just on a 50rwkw gain after fitting a Unichip. Before/after, same dyno, all within a few hrs. This gain was from the combination of modifications I'd performed, but until I had some control over the ECU it just got richer & richer (in the 9:1 range!). So yes, in some case a 100hp gain from just a 'chip' is possible (not on it's own though).

[SS8_Gohan]

wow... there some detailed responses!! i actually wanted to write A/M is in after market, but for some reason had 'A/F' which after all the discussion could be air/fuel which still sorta fits..... oh well, u guys got the jist

i'll definitely remember this thread come time to re-chip/ECU the car.... HEAPS of good info, thanks guys!

[EnricoPalazzo]

In reply to the Renault trick on words, BMW also do it with their new BMW X5 diesel engine which took the chequered flag at nuburing. It doesnt mean it won the race, just that it finished.

Most people dont understand that.

[T0nyGTSt]

Hmm... if you put it that way...

If your car had shite load of mods (fmic, cams, exhaust, new turbo etc. etc.) but a standard ECU with bad tune AND you just dropped in a PowerFC AND you got say a full dyno tune you could feasibly get 100rwkW extra...

It's not a common scenario but is it?

Aftermarket engine management is a forgone conclusion if you want to modify the car and the original ECU is full of flaws...

T.

[Warpspeed]

I think TOny has summed it all up rather well.

[Greg]

"100bhp from a chip or PowerFC or whatever, is that a bit of a strecth or realistic?"

http://www.powerchipgroup.com/interact/dat...asp?pid=Nis0058

Your Nissan Skyline R33 2.5 Turbo uses a turbocharger to maximize power of its engine, however your car does not use sufficent boost to produce good power. There are 2 modifications which we perform on your car. Firstly we provide a Powerchip Board which plugs into a connector on your ECU to alter the fuelling and timing to suit an increase in boost. Secondly, we increase the boost output of the turbo charger. Fitting takes about 2 hours and must be perfomed by a specialist. We have authorized fitters in most areas. Please enquire at the time of order for your nearest fitting station.

In standard form, the Skyline R33 2.5 Turbo produces 187 kW and 295 Nm.

Powerchip has a range of chips to suit your car, which can increase it's power to between 209 kW and 215 kW, and it's torque to between 321 Nm and 330 Nm.

The price of the Powerchip is AUD $990.

[Guest INASNT]

Originally posted by Greg

"100bhp from a chip or PowerFC or whatever, is that a bit of a strecth or realistic?"

http://www.powerchipgroup.com/interact/dat...asp?pid=Nis0058

Your Nissan Skyline R33 2.5 Turbo uses a turbocharger to maximize power of its engine, however your car does not use sufficent boost to produce good power. There are 2 modifications which we perform on your car. Firstly we provide a Powerchip Board which plugs into a connector on your ECU to alter the fuelling and timing to suit an increase in boost. Secondly, we increase the boost output of the turbo charger. Fitting takes about 2 hours and must be perfomed by a specialist. We have authorized fitters in most areas. Please enquire at the time of order for your nearest fitting station.

In standard form, the Skyline R33 2.5 Turbo produces 187 kW and 295 Nm.

Powerchip has a range of chips to suit your car, which can increase it's power to between 209 kW and 215 kW, and it's torque to between 321 Nm and 330 Nm.

The price of the Powerchip is AUD $990.

are u advertising for powerchip are u?

any aftermarket management can do all that and more.

[T0nyGTSt]

$990???

An S-AFC II would be a much better investment.

$990 is 2/3 or 3/4 of the way to a full ECU like an FC, EMS, etc.

T.

[Warpspeed]

Have to agree. A proper dyno tune with a programmable ECU is always going to be better than a one size fits all "chip".

[Greg]

"are u advertising for powerchip are u?"

lol. hell no, just someone said "100bhp from a chip or PowerFC or whatever, is that a bit of a strecth or realistic?" so i thought i'd post some info of what a chip can do for you. but yeah a powerfc is definitely better.

one of my friends gained about 20 hp on his 318i by fitting a $250 chip (now runs on 98 ron fuel), so in some cases they are good.

[Xeron]

Heres a lil bit of info, its generally accepted that an engine produces most power in rl conditions at an afr of 13.8. Then think of how much more rich u guys run. But yer, u need run rich or ull detonate. Oh and another one, guess when DOHC engines were first invented, i cant remember off the top of my head, but its also around 1912 or something. So much for them being new technology

[Warpspeed]

Yeah, its really interesting. Some of those early cars with DOHC engines, had wheels made from wood, and only had tiny little drum brakes on the rear wheels only.

If you could see the skinny round section tyres they put on those wooden wheels you would just freak out.

The early cars may only have been capable of 80Kmh flat out, but on a rutted and potholed dirt road, you would still need balls of steel to drive at that speed I would think.