Removing Throttle Delay - chipping experiences

Removing Throttle Delay - chipping experiences

Author
Discussion

RobM77

Original Poster:

35,349 posts

239 months

Friday 13th May 2005
quotequote all
I have an X plate BMW 330ci just bought it and am really pleased - in fact I'd go so far to say as it is my perfect road car (I prefer to get my fun on the track y'see so drive quite slowly on the road).

However...

As with the vast majority of modern cars, there is a delay between pressing the throttle and the engine responding. This makes the car frustrating round town - unsatisfying on the twisties and downright dangerous to drive fast.

BMW won't change it, so I've been advised down the chipping and tuning route. I've never done this to a road car before, let alone one worth this much. Does anyone have any advice or reccomendations? Are there any possible negative side effects?

AMD seem to provide the best solution, though it comes at a price. All mods will increase my power, which hikes my insurance up sadly.

Any feedback gratefully recieved! - thanks.

andytk

1,553 posts

271 months

Friday 3rd June 2005
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Absoloutly no help whatsoever, but I've noticed the same thing on my skoda fabia.

The throttle response is so retarded that I swear it thinks its a turbo motor with more lag than a boiler.

I didn't know that chipping it improved things though. Not that I'll be chipping the skoda

Andy

pdV6

16,442 posts

266 months

Friday 3rd June 2005
quotequote all
andytk said:

I didn't know that chipping it improved things though.

If its a "fly by wire" throttle, then throttle resonse is controlled by the ECU & therefore modifiable.

Marquis_Rex

7,377 posts

244 months

Thursday 9th June 2005
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Throttle response is not ONLY a corrolary of the EMS system but in fact more to do with the geometrics/mechanics of the engine. Such as (briefly)- throttled volume VCT mapping, rotational inertia of the crank, flywheel etc etc.

If it is an E46 I suspect it may have a TORQUE based EMS system rather than a airflow based system. (infact I'm almost sure of this because I can't see how you would easily map a dual VANOS system properly with an old style airflow based system) BMW/Bosch pioneered the torque based EMS system. If it IS a torque based system there is almost no way that an aftermarket place such as AMD will be able to remap it properly. A Torque based engine management system works on TORQUE demand from the driver and then a delivered torque- by varying all sorts of things on the system- such as intake VCT, exhaust VCT, spark, EGR, fueling parameters. It will vary these things optmising for things such as emissions and fuel economy, but everything is in the memory in terms of look up tables. These look up tables have come from rigourous R and D work. Unlike some of the older systems a Torque based EMS system may delay transient throttle openings (fly by wire) in the interests of getting the emissions and fueling spot on- but not by much, may be 70 ms. Hardly perceptible.

As more and more cars go to Torque based EMS I am pleased to say that the roll of some of these lying "chip tuning" companies racking in the cash will be broken. Aftermarket may have to be forced to go to whole brand new aftermarket EMS systems such as Motec , MBE etc etc to replace the existing Motronic system. ££Ker-ching$$$!