Worth remapping the ECU after new exhaust & decat?

[St. Anger]

Afternoon folks,

As some of you may have read in the past, I switched from a standard exhaust in my MK1 to an IL Motorsports dual exit system. Pleased as punch with it so far - so much so that in my quest for more noise, I've just bought a second hand cat replacement pipe from a bloke on Nutz.

Is it worth remapping the ECU to tell the engine management about these changes? The car is running sweet as a nut at the moment and don't really want to waste that!

Thanks in advanced,
Nikos.

[MX-5 Lazza]

You can't remap a Mk1 ecu. It can be worth having the AFM & timing professionally tuned but that wouldn't be cheap for minimal gains. Better to make sure it's well serviced and all the sensors are in good willing condition.

[St. Anger]

Ahh, thanks Lazza, I didn't know that!

I'm going to give it a big proper service in March (new pads all round and do the gearlever boots etc), would perhaps be an idea to check these sensors as well - any pointers where to start looking?

[Richyvrlimited]

MX-5 Lazza said:

You can't remap a Mk1 ecu.

Yeah you can, but it's a relatively recent thing in the west at any rate, (they've been re-programming for years in Japan).

I'm not aware of a UK based company, but in the USA Dynotronics will hapilly re-map your ECU. (They'll accept an ECU you post to them, but obviously you're just going to get a 'better' tune rather than an optimized one for your car).

[MX-5 Lazza]

I didn't know that Richy. Does the retune make much of an improvement?

[Richyvrlimited]

MX-5 Lazza said:

I didn't know that Richy. Does the retune make much of an improvement?

Not a clue.

I imagine it'd be the exact same results as fitting and tuning a standalone ECU to an otherwise stock car.

[MX-5 Lazza]

Richyvrlimited said:

Not a clue.

I imagine it'd be the exact same results as fitting and tuning a standalone ECU to an otherwise stock car.

I thought the maps on the Mk1 ecu was very course though so I doubt it would be as effective as a decent standalone ecu or even a piggy-pack.

[Richyvrlimited]

MX-5 Lazza said:

I thought the maps on the Mk1 ecu was very course though so I doubt it would be as effective as a decent standalone ecu or even a piggy-pack.

That's the point though, you're re-mapping the stock ECU and fine tuning it from it's 'cover the world's fuel/environment types' to a car specific tune. It'll be just as effective as a standalone, and a lot better than a piggyback, (IMO).

If you're implying the stock MK1 ECU has poor resolution that's not true, it has a fuel and ignition table larger than most aftermarket ECU's.

The stock ECU is widely derided as rubbish, but I think that's unfair, it'll work in any country at any elevation at any temperature (within reason), driven like a granny or beaten on repeatedly on a track, so there is a large buffer in it's tuning to be able to cope. Unfortunately that translates into a minor loss of performance, something that via fine tuning you can claw back, (at the expense of running more on the ragged edge).

When I last read about it Dynotronics claimed they would soon be able to remove the stock AFM or MAF and to also be able to cope with FI with the stock ECU.

[skinny]

and, it nails idle a lot better than most aftermarket ecu's do

the only downside with the stock ecu is that it's a bit conservative - in terms of resolution and capability tho it's not too bad.