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Discussion Starter · #1 ·
When I first got my car with the original alfa air filter I tried shell optimax. It did not seem to change the performance and after a short while I stopped using it. Some time after I fitted a K.N air filter which improved performance and induction sound but seemed to create a rough tick over. Last week the local petrol station had run out of normal unleaded and therefore filled the car with optimax. The rough tick over has disapeared and the performance has improved even more. :)
 

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<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:<hr /><font size="1" face="Verdana, Helvetica, sans-serif">Originally posted by Justin Fox:
<strong>Um, what's a tick over?</strong><hr /></blockquote><font size="1" face="Verdana, Helvetica, sans-serif">idle
 
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Discussion Starter · #5 ·
Thanks Paul
I will try Optimax in my new motah hopefully all being well when I pick it up Saturday.Nice long drive home so will need to fill up. :)
 

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Some tech talk about ECU's boys.

The Alfa's use Bosch ECUs. There seems to be a great deal of hype around resetting the ECU for Optimax for more performance. The Bosch ECU adopts a self learning for only two parameters and these regard the fuel timing. The ECU learns the correct mixtures for tick over, that's why you may have noticed a difference when starting to run optimax.

The other self learning option is the injector duty cycle. Under light load (less than 25% throttle) conditions the lambda value is measure and the fuel trimmed to reach lambda 1. This is to aid fuel efficiency, so under these conditions the tank of optimax should give better fuel consumption.

Under all other conditions the ECU refers back to the standard maps. Which depends on engine speed,throttle position and air mass. The timing is not altered depending on type of fuel in any way. A engine remap would need to be carried out to achive this. I'm not saying no performance increase from optimax is expected but it is unlikely to make a huge difference unless the car is mapped for it.

So what your saying about smoother tick over only backs up one of the self learning features on the Bosch units.

Mr T
 
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Discussion Starter · #8 ·
There is also the closed loop system will also play a part in the air to fuel ratio. A standard car pre cat and early models cars with seperate injection and ignition e.c.u's had to refer to a fixed set or adaptive maps for the overall fuel system management. With the need for later cars with cats, the exhaust gases pre cat had to be perfect, ie a perfect burn unless the cat would be distroyed. The lamda senser at the pre cat stage ensures this by feeding back information to the combined fuel and ignition ecu to either make the fuel mixture lean or rich dependant on the information recieved which is the result of the injector open time. The increase in the optimax combustion output will result in the lamda ensuring what ever is burnt in the engine it is still at the most effiecent burn it can be. The lamda senser will infact see a lower fuel octane rating and more air as its friend but at the expense of smooth engine performanc until such time as the mixture becomes too weak and causes stalling. As said the e.c.u also has set idle programs and full load enrichment settings which are contained which the engine mapped memory for differant conditions but they all have to be governed by the lamda ratio at all times.
 
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Discussion Starter · #9 ·
After all this info, I am still none the wiser (probably because I am no techno-wizard!). But is it possible to get the engine re-mapped (by Official alfa dealer?) for the fuel with higher octaine rating, and if so, what is considered the best Air Filter to further improve performance? Also, aftermarket engine re-maps by tuning houses.....what chip have you boys/girls found worked best (was there a discernable difference?)?

My personaly experienc, is that after using 97 (changing from previous 95) is that the idle/tickover is rougher, but that fuel consumption has improved by +-10%. I now average about 10.8 - 11.2 (l/100k). Wheras previously with 95, I would average 12.8l/100k (and sometimes even 13l/100k!). I have spoken to my alfa dealership, and he stated that they could not set the ECU for the increased octane rating. But they'r useless, so if anyone has found different pls let me know!
 

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The problem with getting the car mapped to the higher octane fuel is you won't be able to revert back to lower octane fuel. I haven't heard of any Alfa main dealers remaping cars. If the service over hear is anything to go by then I wouldn't trust them.

If you are thinking of getting the car chipped then there are a couple of options. Jano has come up with a good generic map that sorts out a lot of the problems with the existing Alfa maps. This will give you a performance increase and still allow you to run on 95. Squadra's chip is mapped on 97 so you will only be allowed to run 97.

The other alternative is Unichip which is South African, you can get the car mapped to your requirements and even set up two programs for 95 and 97 RON. This system should take advantage of all MODS. The drawback is it's a piggyback computer, so I know here in the UK you would find it very difficult to hide from the insurance company.

Mr T
 
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Discussion Starter · #11 ·
I think Jano has quite a few 147 maps in his drawer now.He has mapped mine for 98 Ron,so i use Optimax and Millers OP.Lambda sensors blew though,and the Engine Mgt failure light is permanently on,but apart from that,its fine :)
 
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Discussion Starter · #12 ·
Will investigate those mapping options.

Probably try thr unichip, cos its easily available in SA. Is Janos a company or a member on AlfaOwner forum? Also, those who have fitted a chip, what sort of improvements (fuel consumption, 1-100km/h, etc)can be expected (if used with higher fuel)?
 

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I've had mine chipped by Monza Sport, but can still use 95RON. The power increase is claimed to be around 7% to 10%.
I have nothing to measure the performance with but it noticably pulls better across the rev range.
Fuel economy will be worse as the injectors are working harder.
 

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Sorry Shaheed, Jano is the director of Autodelta, Autodelta products can be ordered from the Alfaowner shop. The Autodelta system is a remap so it would require you sending off the ECU, maybe not an option if you use the car everyday. If you e-mail AO sales then they can get a list of remaps from Jano if he has different remaps for 97RON.

I've been forwarded a Dyno plot for Unichip on a 156 2 TS which has given it a gain of 15bhp. I don't know the in's and out's of what type of fuel was used. The biggest improvements with these remaps is not so much top end but between 2000 and 4000 rpm.

Mr T
 
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Discussion Starter · #15 ·
"The biggest improvements with these remaps is not so much top end but between 2000 and 4000 rpm. "

agreed,although it feels more like 3000-5000.Makes a big difference not having to h+t and slam second.
 

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Good to have the feedback Dave, just getting data from the graphs. Haven't got the car chipped YET so I could command on how it feel though I'm sure you'll be right.

Should have some dyno plots soon boys. So the plan is a cat run and decat run. New carbon fibre air intake run then full remap run. So hopefully you guys will get an idea as to the performance gain however vague they may be on a RR.
 
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