The art of Chip Tuning.

[cookie]

just stumbled on this thread on VPC

page 3 shows what can go wrong, although as justin says

There are no safety features with pre fly by wire cars >99

I know this because i had my first T5 (S70) chipped by them and before i had got the car home (21 miles) due to the ecu sending all the wrong signals i had a hole burnt in the top of my piston the size of a 5p piece. They paid for the replacement piston and ancillaries as it was thier fault and also removed the "Not so super chip of thiers"

so garage took responsibility and sorted his car out.

[foggyjames]

I suggest anyone with a modified turbo car runs a wideband AFR meter (i.e. which gives a true air-fuel ratio read-out, not just a load of pretty lights connected to a narrowband which means next to nothing), and possibly an exhaust gas temp setup as well.

Strictly speaking, assuming you're not on the threshold of detonation otherwise, you *can* run really quite lean in boost...buuuuuut....it adds a LOT of heat....take it too far, and you get melted pistons. I'd say up to a few psi you can stay at 14.7 right to redline...and I'm quite sure a few OEMs do exactly that to save fuel and curb emissions. This is where extensive testing allows OEMs to work out the safe limits.

On full load, anything less than mid 13s (x:1 AFR) is really asking for trouble!

cheers

James

[Nuisance]

So what about running 14.7:1 @ 18-20 PSI? up to 4000 rpm?

It's gotta be getting hot in there.

[pyaap]

Originally Posted by Nuisance

So what about running 14.7:1 @ 18-20 PSI? up to 4000 rpm?

It's gotta be getting hot in there.

But then again, isn't that just as it was intended, so isn't this 'perfectly safe'???

I'd have thought the red dotted line was a bit of a give-away, especially if the data acquisition software has it incorporated there in the first place?

[pyaap]

Originally Posted by Nuisance

So what about running 14.7:1 @ 18-20 PSI? up to 4000 rpm?

It's gotta be getting hot in there.

Actually, thinking about it, you have to count yourself very lucky because you have an ME7 equipped car. I've seen datalogs of how quick the ME7 system responds to different situations and as much as I hate to say it, that could very well be the reason why your engine is still in one piece, and the other, from the similarly tuned Motronic equipped car gave up the ghost soon after its owner picked it up and melted a piston.

Originally Posted by cookie

just stumbled on this thread on VPC

page 3 shows what can go wrong, although as justin says



so garage took responsibility and sorted his car out.

Indeed, I wonder what he would have had felt / said / done if Superchips were to tell him where to go since they had already had his money!

[Nuisance]

The result was very quick, but something just didn't feel right from the start. The car felt as if it wanted to do more, and occasionally hinted at what it could do.
When it was cold it was blindingly fast, but sort of weakened off when it warmed up.

I do wonder about this engine now, and will probably get it changed. It feels OK, but without seeing inside it I can't tell what damage may have occured.

The ME7 is indeed a very good bit of kit. When I got this car it had it's wastegate stuck shut, but the ECU managed to protect it.

There is much controversy and confusion over what map Chris had and the tuner seems to be keeping it that way. VT have insisted that they mapped Chris's to 12:1 but cannot deny that mine was in excess of 14.7:1 I can't call it, other than to say why do two virtually identical setups, one at 12:1 and another at 14.7:1 I smell a rat!

The diference with the MTE map is blinding. the car is spot on. There are other things that need sorting now, I'm just glad all that is behind me. I've lost a few grand in the process, but theres no point crying over spilt milk.

[Nuisance]

I guess this proves the car was running lean.

This was averaged over a journey of 300 miles.

And on the VT map I was constantly throwing codes, {Main system catylist efficiency below threshold}

[don kalmar union]

There are further developements on www.t5d5.org

I have to say that the point has been aired there that some well established forums have been very, very reticent to host any posts whatsoever on this subject and therefore really letting down the Volvo community.

Regards, Don.

[PNuT]

i find it slightly ironic what mikest5r has to say about the vpcuk forum

[Engineer]

While accepting the ME7 control system is superior (mainly due to MAP sensors and the ECU’s ability to control throttle opening) when operating correctly to the older Bosch 4.4, it’s a bit unfair to condemn the 4.4 to the dustbin just because certain engines have failed as mine has done an excellent job quite a few times when having to contend with s—t petrol and extreme ambient temps before and after it was mapped modified etc.

Cheers