Chiptuning

[Mark Verboom]

Just thought it might be useful to share my experiences with chiptuning.

Although it wasn't on an Aygo but on a C1, but it doesn't make a difference

engine wise.

To be sure I could make an objective conclusion on the improvements, I did

my own before and after testing. I had the car tuned by Ziptuning in the

Netherlands, the results can be seen below in the graph.

If you want more background, I got a more detailed story online on my own

website:

http://www.verboom.net/projects/c1/20091121/index.html

Mark

[jjj_aygo]

Just thought it might be useful to share my experiences with chiptuning.

Although it wasn't on an Aygo but on a C1, but it doesn't make a difference

engine wise.

To be sure I could make an objective conclusion on the improvements, I did

my own before and after testing. I had the car tuned by Ziptuning in the

Netherlands, the results can be seen below in the graph.

If you want more background, I got a more detailed story online on my own

website:

http://www.verboom.net/projects/c1/20091121/index.html

Mark

Sorry to hear u lost so much time and money on this mod! I can't believe they can get away with !Removed! u over so badly!

[geezbeez]

I thought it looked too good to be true, then I realized Green was before and Red after. not one colour for torque and one for bhp.

You have clearly took a very scientific aproach.

I see, from your article that the system on Aygo/C1 is not what I would call true variable valve timing but what I would call variable valve advance.

I had a '96 Alfa 155 with a similar (primitive) valve timing advance, on the Alfa the ECU only advanced the timing momentarily (and I believe enritchened the mixture) when the accelerator was depressed, this was done to improve throttle response. I understand on the Alfa the inlet timing could only be in one of 2 positions. Advanced or not advanced.

I dont know if this is possible but to get more power on the Aygo/C1 would it be possible or desirable to bore out the throttle body and fit a slightly larger butterfly. Get more air in and (within limits) ECU should sort the mixture acordingly?

[Raistlin]

That is really depressing, Thanks the the heads up

[daveyjp]

It only proves what most already know - simple remaps are only any good if you have a turbo engined vehicle.

[Mark Verboom]

I dont know if this is possible but to get more power on the Aygo/C1 would it be possible or desirable to bore out the throttle body and fit a slightly larger butterfly. Get more air in and (within limits) ECU should sort the mixture acordingly?

I've looked at the throttlebody just for fun. Don't know if it is a limiting factor in getting air in. But modifying it might be costly if it goes wrong. If you need to get a new one they are OVER 1500 euro's (new)!!

It only proves what most already know - simple remaps are only any good if you have a turbo engined vehicle.

I know that it is easier on a turbo, and I know that it is useless on an NA engine without any modifications. But the vvti had a serious chance of getting more air into an NA engine.

Still, from what I understand they run these engines over 85bhp in the race series with, from what I understand, a diferent air intake, exhaustmanifold and exhaust and a remap. So there seems to be some potential somewhere :)

Mark

[geezbeez]

Yes, 1500 euros is a lot! Surprized that expensive!

Is the throttle body plastic and in one part with the inlet manifold?

Shape of inlet manifold does look quite good but have not taken apart to see if theres a restriction anywhere.

[Projectzip]

Ouch!!!

I got in touch with a tuner and went to see him and after a few brief emails between him and some bod in germany they cocnluded nothing could be gained from a remap with this engine!

I wish I had seen this sooner it may have saved you a few bucks.

Best thing you can do is a full exhaust and a nice air filter.

or if youve got the dosh a Rotrex Supercharger

[geezbeez]

The supercharger conversion includes a remap. I dont know the finer details but think it includes a 4th injector and a piggy back device so the original ECU is not altered. Think piggy back controls 4th injector and amends info to the ecu controling other 3 ?

Initially these piggy back devices sound naff but I understand that they are getting better and this is becoming more the norm, means you dont get your ECU messed and have to pay for new ecu or remap to original after a poor remap,

When initially fitted they are loaded with zeros and do nothing but when tuned they store + and - values to ater the readings the ecu recieves acordingly.

e.g alter the air reading passed to the ECU so it thinks its getting more and adds more fuel.

However as you say seems no point in remapping on this engine unless your forcing induction.

It's true there are some wild claims about remaps and that even when a garage know they can do nothing to your car but make it worse they may easily be seduced by your easy money rather than be honest and say dont bother. Another daft claim is that you will only be using more fuel if you take advantage of the extra power available. If you accelerate at same speed you wont use more fuel. Well what about cruising at 70mph? If the mixtures richer at 3000 rpm you will get worse ecconomy.

Its probably testament to modern ECUs on NA cars that you can't make them better.

Im guessing the ECU must be more than just a simple fixed look up tables saying this much air = inject this much fuel otherwise you could remap and get a few more bhp and better economy, based on rolling road that would map taking into account small differences between suposedly identical engines, albeit mainly based on amount of wear in the engine.

Dont know all the things Modern ECUs measure but believe they take readings of Mass of Air entering engine, Lambda sensors (usually 2), engine rpm through TDC and BDC sensors, accelerator depression and are able to dynamically alter for small diferences in your engine as it wears or differences in fuel grade (plobably based on the lambda sensor readings). 15 years ago ECUs were fitted with a little transistor (or something of that sort) telling them what fuel grade to expect. Modern ECUs just seem to know and adjust timing of engine acordingly? Id be interested to know how they do that?