[Guy Humpage]

A cheapskate writes:

Can any of the popular ecu upgrades (for a 9-5 2.3 lpt) be run using 95-octane unleaded? None of my usual petrol haunts sell Super-UL and the local Shell charges a fortune for Optimax (and indeed, all their fuel, the Shell over by St Albans on the M25/M1 jubction sells their Optimax for less than the local 95 retails for).

I believe the Trionic is clever enough to stop any pinking but would that negate the power gains.

Editted to add: Perhaps I should have posted this in 'performance'...

 

[murphwiz]

Every upgrade I've seen has recommended using a premuim super unleaded

 

[PHudson]

Originally posted by Leon [9-5 stg2]:
[qb] Every upgrade I've seen has recommended using a premuim super unleaded [/qb][/b]

Abbott said mine would be OK on normal. Better performance on super unleaded, but normal is fine.

 

[maxter]

Pre and post ECU upgrade (SP Stg1, 9-5 2.0lpt) I ran on Optimax and initially noticed quite a difference, even more so with a shot of the new BP firewater! However, for the 1st time after 5 months of new ECU I filled up with the local supermarkets U/L'd and so far I haven't notice any fall off of performance or engine response etc. Maybe the ECU upgrade was more than enough for my

needs?
M

 

[burre]

From what I know, you should use super plus, or premium, whatever they call it. The Trionic will drive ok with lower grades but sometimes, based on how bad the fuel is, performance can suffer. I was stuck filling up on plain unleaded in Paris one visit, and the boost wouldn't even get to the stock max boost pressure let alone the pressure that the Hirsch ECU shoots for.

 

[john]

All tuners recommend higher grades of fuel in order to maximise performance. Trionic will cope with 95RON unleaded just fine - even on upgraded ECUs but you will not see the full potential of the upgrade.

Saab recommend 98RON for my 9-3 Sport in STANDARD 200bhp form for the same reason as the tuning companies, but use of lower grades was fine.

 

[Guy Humpage]

Thanks for the replies. That's just what I wanted to hear.

Question 2:

Given the scenario of using 95-octane for pottering around town but filling up with 97/98 when going somewhere special, How long would it take the ecu to 'learn' to use the high boost levels available? Would it just be a case of doing a single adaptation run as you'd do when the new ecu was first installed?

 

[mikeloadsasaabs]

I always use cooking supermarket unleaded in my 2.0 9-5 with the Saab perf upgradde, to be honest I never thought of using super unleaded.....

. However, due to the relatively cheap price, I filled up with Optimax on my way back from Austria last year and couldn't spot the difference. I did nothing in particular for my ECU to relearn (well, you don't mess around with removing fuses & special runs with a wife, child, and a bootful of luggage do you? ). Whether it would have been different if I had, who can tell. I was driving quite fast afterwards.....

 

[zeke]

How long would it take the ecu to 'learn' to use the high boost levels available?

Not sure on T7 vehicles, but on my T5 there's three different adaptations: boost, fuel, and knock. According to Dr. Boost, boost adaptation is best done in the highest gear starting at a very low (15k) rpm. Fuel adaptation occurs at low speeds and takes a very long time. Knock adaption occurs at steady load for 10 min. @ 80 kmh, very tricky.

 

[Vigge]

Originally posted by robert lavergne:
[qb]Not sure on T7 vehicles, but on my T5 there's three different adaptations: boost, fuel, and knock.   [/qb][/b]

You probably mean boost, fuel and timing?

Trionic 7 is a very adaptable unit and it will adjust itself if knocking occurs.

And remember knock control on moders engines is is not a safety funktion but a normal funktion. It is not a fault if the knock control operates during normal running.

But you should also remember that the above might not be true with your upgrade ECU. I know for fact that Maptun and Nordic have not tampered the knocking sensitivity, but SP/BSR is an another story, at least the Viggen software was.

If you want some information about knocking you can do the following. You dont need to have instruments connected to the car while you are driving but you'll need access to TECH II.
Here is what you need to do:

Go to a place where they have TECH and ask them to look up cylinder specific knocking counter values. Write these up and go out some hard accelerations from 2000- rev limiter.
Go back to tech and check the numbers again. So you'll see numbers on the counter but fair ammount is only acceptable and the distribution between cylinders is supposed to be about even.