I know it depends on mods, fuel etc but lets say you have a MY95 UK car with a full decat, filter, and optimax and a MY99 car with the same mods etc. Is the older car more likely to exhibit symptoms, due to wear and tear, different ecu, turbo, intercooler angle etc

Mikey :cool:

Dont think it has to much to do with age. I mean look at the STI's from 96> alot of these suffer from possible det and big end failure...

How can wear and tear result in det, especially as the MAF sensors on the older cars are alot more reliable then the newer impreza's.

I think it has alot to do with the ECU and fuel. I.e if its a jap import or if its a uk car with mods.

Dan:D

I wasn't saying wear and tear causes det, just floating the idea. I don't know, maybe injectors wear or become clogged, maybe the older designs are more prone to something which contributes to det, maybe the widget thingy in the older cars was made of plastic but the newer cars have a metal one. Just wondered.
Also surely you are not saying that UK cars don't suffer from det? Do you mean that they are less likely due to the mapping?

Mikey :cool:

Standard uk scoob :confused: what's one of them? ;)

Mikey :cool:

I think Pete Lewis owns it ;)

Ah yes that one! It's worth £5k more than mine don't you know :D

Reckon i've had more than £5k's worth of fun outta mine though :D:D

Mikey :cool: <MY00 with a few bits done to it, de valued, probably detting a bit, tracking needs sorting, done 57,500miles in 2.5 years and loved every one of them, apart from the odd ABS in the snow sliding down a hill moment ;) >

What sort of rpm induces det?

Eh? Your question doesn't make sense. There's no specific rev range that is more prone to detonation, although it goes without saying that if a car is prone to det, it's more likely at high boost/revs than cruising...

4000-5000rpm range is most likely to det due to best volumetric efficiency at that point. A standard MY99/00 will det on 95 RON fuel when hot, know it cos I've seen it.

As for Jap imports - not a clue :D

Cheers

Simon

No, I had Det on my Sti7 with PPP. I believe that the reason was that a fuel garage had put 95 Octain in the Super pump as it hasn't happened again.

Not really. Can see what you are trying to say but there's no generalised "rule" that can be applied here.

While the AE800/801 (and a few 802's towards the run-out) ECU's used on the MY99 cars probably fuel a bit richer than the older cars, the MY99's are probably statistically more likely to suffer MAF sensor failures, which can themselves lead to det/damage etc.

Thus, each car really has to be considered on an individual basis - there are too many exceptions to form any sort of rule...

Its no real surprise this is true, UK cars are mapped for UK fuel and thus have less chance of detonation compared to a JAP import car which is mapped for JAP 100+RON fuel, running on UK 97-98.9RON fuel...

On a standard UK car you will probably see hardly any det.

Dan:D


[Edited by dhorwich - 9/12/2003 12:35:11 PM]