Ok I brought my 04 STi down to my local tuning guys yesterday to see if they could ecu-tek it.

Theyplugged the computer in to see if they could access the ecu but couldnt so it must have been mapped previously?

I didnt think it had been.

So we put it on the rollers.

Now my car has a cat back exhaust (centre section and second cat removed) but standard up pipe. It also has an HKS panel filter, a Walbro 255 fuel pump.

Both runs gave pretty much spot on the book figure of 265bhp with 233 Ib ft

I questioned this with the guy and said I thought that was low considering its probably been mapped and with the basic mods I was expecting closer to 300bhp.

He scratched his head and did a boost pressure test.

It was maxing at 1.2 bar boost.

I then told him I am running my car on standard 95 unleaded and have been pretty much since I got it.

Bingo...

He told me that assuming the car has been mapped for super unleaded, running standard unleaded is causing the engine to knock ie petrol is igniting in the block before it should?

So when car hits boost the boost is holding but the ecu is putting the standard base map to avoid detonation and hence cutting power.

265 bhp on base map...makes sense

They said you could be loosing 20-30bhp on standard unleaded.

So they said put a few tanks of super through it with maybe a bottle of millers octane boost and come back next week and I should see the true figures.

Is this correct?

I was told that I need to go to a Ecu-tek dealer to get unlock codes to map it further? But how do I know it was actually Ecu-tek'd. I dont think it had the pro drive map as surely it would have had the other mods as well like the prodrive up pipe etc.

Thanks

 

mate you should not run a scooby on anything else other than super unleaded, v power ect (99 ron)

 

A main dealer or independant mapper will soon tell you if it's been mapped previously.
If it hasn't you'll be required to pay the EcuTek license fee (£150) on top of the mapping fee, or alternatively you can go to one of the mappers who use Open Source software with no licence fee.
Stay away from that 95 ron, it's just nasty

 

My 05 STi Ecu Tek mapped at Scoobyworld to 97ron Total Excellium-giving 314.8bhp.I know can get higher on V Power etc,but car runs great and i'm happy with it at this time.

 

OMG... You run your car on 95ron???

 

I had a 04sti done 275 at the Powerstation ,standard back box change only 98 ron

 

Tim, im not sure where you took the car as there are no decent mappers in NI!

I realise 97 ron is hard to get over here but if you shop around you will find it no problem.

If you want your car checked properly by a full blown Ecutek dealer and mapper i have JGM coming over next month to map several cars. He is regarded as the best by many including myself hence nobody else will touch my car in my ownership.

Pm for details if you are interested, NI Tuners are a gamble when it comes to Subarus as many have found out. Going by what you have written above i think i know where you took your car.

I can also Deltadash your car if you wish to run some logs. Wouldnt we just love V-Power!!!

 

If the car was mapped on higher octane fuel and you've been running it on 95 Ron chances are it's been detecting detonation through the range and knocking your advance multiplier down from 16 to 8, and therefore retarding ignition timing to save itself.

My advice would be to run it easy on the remainder of the 95 then fill on on VPower and find someone local to reset ecru and delta dash log it ( or similar)

Bottom line is the cars hate 95ron and deserve better!

Hope this helps

Neil

**Edited due to commercial content**

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71/200 - I pm'd you...cheers!

Scoobyworld - thats what I was told by my tuner who rolling roaded it and it only gave 263bhp on the second run and he scratched his head and then I told him I had been running it since March on 95 RON. He said exactly pretty much the same as what you just have so its nice to have the info seconded!

How can 2 RON octane make such a difference?

What is the advance multiplier and ignition timing? How does this relate to power/boost/torque?

Is detonation the result of under fueling? Why would a lower RON fuel cause detonation? What the heck is detonation?

Sorry complete noob I know but I love learning stuff like this!

So do you think my car is actually making more than 265bhp - it should be!?

 

No problem - Some good info on wikipedia on RON ratings and effects of, quick search should pull a few examples up.

Ignition timing - in short at what point btdc (before top dead centre - the highest point the piston reaches) the spark is fired - too high a number and the rising piston meets the flame front then fights it, too low a number and the flame front is chasing after the piston on the downwards stroke and not making maximum potential power. Getting ignition correct throughout rev range and load sites is essential for safe maximum power.

On the 01-05 Impreza there are basically 2 ignition tables - base ignition map and ignition advance map - then there's the ignition advance multiplier. On a reset ecu this starts off at 8 (out of a maximum of 16 on a 2004 2 litre car). This means the ecu will use all of the value in the base ignition map and half that of the ignition advance map. If it detects no knock, it raises the advance multiplier to 10, then 12, 14 and 16. It can also drop it back if it detects knock. At 16 it's then adding the full value in the ignition advance map to the ignition base map to work out the final ignition value at a given load / rpm. If your car's mapped on 99 Ron fuel and you fill it with 95, chances are the ecu will detect knock and reduce the adv down to 8 or even lower, end result no knock, but obviously less power.

Changing boost levels has an affect on ignition timing. So correct mapping of a car is a constant job of making small corrections to the map whilst monitoring boost, fuelling and listening for knock, amongst other things. Correct fuelling is also absolutely essential for safe running and longevity of the engine.

Sorry for rambling, think that answers your questions though without going into too much depth


Neil

 

Could have been mapped on 95 and is perfectly safe on it.

Mapped to 535bhp on 95 ron - just depends on the map (and the mapper)

If it has been mapped before then 'some' non ecutek mappers can remap it regardless

 

Could have been mapped on 95 and is perfectly safe on it.

Mapped to 535bhp on 95 ron - just depends on the map (and the mapper)

If it has been mapped before then 'some' non ecutek mappers can remap it regardless