I am looking to improve the smoothness of the idle and improve the power applcation through the normal driving rev range. I am not neccessarily seeking increased bhp as I intend to keep the air in and exhaust standard on my C4 cab. Which replacement for the standard Motronic chip in the DME control unit would you recommend? Greatly value your experience and comments.

 

Hi Ian,

i have in my ´91 C4 a http://www.911chips.com/ from Steve Wong installed and very happy!

Take a look at his website and get in contact with him.

Greetings from Hamburg

Christian

 

This has been discussed at length and would be def also worth a search.

Chips for 964 have a mixed rep in my experience of Rennlist, and I remain unconvinced over all. This guy's website looks promising, but don't they all? The majority of his feedback is from 3.2 owners. I'm glad to see that you can specify stock rev limiter level - but although I am tempted I would need more reassurance! Monkeying with Ferdinands magic formula all too often seems to be a bad idea, from what I can tell. My car is stock with just 2ry bypass, and just goes so damn well and so reliably I'd hate to ruin it.

The other option that will be mentioned is a live remap, which is what I am considering over a mail order chip.

EDIT: 1000th post!

 

I don't believe the chip I had did anything (JZ Machtec) - and I don't really believe many of them do (at least not noticeably). I also doubt any will improve response through the rev range - they usually aim for top end improvements.

If you need to improve the smoothness of your idle, you have some other problem which is unlikely to be fixed by a replacement chip. My idle is absolutely rock steady.

 

I have a superchip in mine, but it came with it installed. I still have the stock chip, but to be honest, the car drives really well, so will leave as is.

 

I think Dave is right on - clean your intake system including the ISV, then get your injectors cleaned and you'll have the smoothest idle possible. A chip will likely do little in this regard. And for a street car I don't think it's worth it. For $100 you can get your injectors serviced which will probably give you better performance than a chip, AND cost less, AND improve your idle!

 

Johnny - great comment!!

 

My other thought about changing the power curve would be changing the character of the car.
That howling post 4k rush is hard to beat, especially as the intake flap thingy opens - if I'm driving very quickly or trying not to be embarassed by a big turbodiesel, I just keep the revs up!

 

All aftermarket performance chips do the same thing only to different levels. So the trick is to find an eprom that advances ignition timing during WOT as close as possible to the point of mean best torque without causing borderline detonation. How far away are you from AMD? They have the equipment to perform live dyno-remapping, everything else is a crap shoot.

 

FWIW.......IMHO chips on 3.2 engines do make a difference you can feel....especially in the low end and very high end. For some reasons though on the 964's I have driven over the years that have been chipped, I didn't quite get the same perception.

 

Ian, there is a place down in halifax that has a 4 wheel dyno, mostly used by the rice burning crew, but I'm sure it would be interesting to see how both our cars compare.
What do you think, anyone else in the North of the UK fancy a look see ?
http://www.theracingline.co.uk/welcome.php

 

Jason,
AmD have gone through major changes , location, owners etc so may not be
an ideal choice.
I wonder if Daves DME lack of chip sparkle is due to the wrong set of maps being recalibrated. This used to be such a common problem from retail tuners .
Unfortunately there are so few people who have real on hands experience
and have the equipment to be able to do the job properly .

Pretty well any UK 964 running on 98 RON gas has 20 bhp available.
I remapped a lot of 964s , calibrated motors to win national series and won a nice side bet with a country importer who didnt believe in 964 recalibrating.

It all seems amazing that this debate is running close to 20 years old ! If it wasnt sad ,it could be so funny !!

Geoff

 

Try Wayne Schofield at Chip Wizard in Rochdale - he has a four wheel drive rolling road and a live remap is about £500. No affiliation, I've been in a couple of 911's he's mapped, rough idle with lighweight flywheel cured and feel a lot smoother to drive. I'm not even going to mention any power increases as I'm not wearing flame-proof underwear..

 

"So the trick is to find an eprom that advances ignition timing during WOT as close as possible to the point of mean best torque without causing borderline detonation."

And that's what Porsche did initially, unless one wants to run race fuel!

"How far away are you from AMD? They have the equipment to perform live dyno-remapping"

On a stock engine, no real benefit results from custom tuning, i.e. since it's the typical "pushed
timing" that provides the "feel" that one gets as the AFRs are bascially right-on. Furthermore,
it's a real ripoff, i.e. beyond the typical waste of a performance chip.

Save your money and buy a carbon fiber shift ****, i.e. cars always "feel"
better after an installation.

 

Well that sucks, I will take a mental note to no longer suggest them.