bogdan

I'm going for a cat delete, X-pipe and RMB and I've been looking for a ECU upgrade here in Europe. The 9tuning.com specialist has a chip for GT ( others only do teh S4 and GTS). Has anyone any experience with these chips?

Skrilla01

Based on my research its all mixed reviews some swear they 'feel" a difference and others say there is none.

LostInSpace

You're unlikely to get an effective tune from this chip, which one assumed will be done on a standard car. The increased breathing from the X-Pipe would subtly change the tune and other factors such as fuel quality will also have an effect.

The only effect solution would be a custom tune with a Sharktuner, which may be difficult to obtain in your part of the world. Could you hire/lease one?

Nicole

LandSharks.de have a cat upgrade that, combined with dyno tuning, provides an additional 30hp. It also makes the sound more "raspy", according to the owners who had the conversion done.

FredR

Bogdan,

Wow a 928 owner in Romania- great stuff!

First of all you do not want to go for an x pipe and an RMB- it will be stupidly noisy. I have an X pipe and a RMB but I cut out the central resonator and fitted a biggish Bullet muffler- of course you need specialist SS fabricator to do this with. Sound is awesome.

For these type of mods you do not really need to make any modifications to the fuelling as it does not make any noticeable impact to the tuning. However all 32V 928's seem to follow the same pattern in that they are a bit lean mid range, a bit rich top end and benefit from more advance mid range [less so top end] and playing around with these settings gives a noticeable improvement.

If you are going to play around in this department go for John's Sharktuner with PEM's or forget it is my advice. The ST opens up a whole new world of ownership experience but you need a laptop and you need a wideband sensor [Innovate or Tech-Edge] to make this a reality. The ST is a must for those blowing or building monster strokers- much less so for stock motors.

Stock chips tend to be a bit conservative because it is a "one size fits all" approach so they have to allow for many variations. An after market chip may well tap into some of the potential small benefits but invariably they get closer to the ragged edge and if you have [for instance] relatively poor fuel in Romania you may find you run into problems. With the ST you can see exactly what is happening with the sharkplotter software that is supplied and can correct in a matter of seconds any weak points on the maps.

Regards

Fred R

AO

The aftermarket chips have little affect on a GT. Maybe a few HP, but probably not worth it IMO.

The X-pipe will wake it up the most.

Also, making sure your knock sensors are working properly and all the other top-end pieces are working properly will yield you the best results.

Murray

Is there an easy way to test the knock sensors without removing them or does this require a special Porsche diagnostic tool?

morganabowen

How much are these chips

Murray

According to their website they are 150 pounds or approx. $240.

John Speake

Ther only practical method is with a diagnostic tool, or a SharkTuner which will read them in real time.

FredR

If one of the knock sensors fails the ignition is de-facto fully retarded by the full range of retardation that can be applied [I think it is 6 degrees but not sure off hand]. If your system is working OK and you undo the knock sensor connectors one at a time, you should feel the car run a bit flatter at top end. If you feel no difference, that would suggest the knock sensor is down.

Other than that, the only practical way to tell is to fit the Bosch hammer or a sharktuner if you can get hold of one.

Regards

Fred

AO

The way you describe it, it sounds like you will be able to tell which one is bad, but you can't. If either or both is bad the timing will be retarded by 6°. Only when they are both working (plus the Hall sensor) will the timing be at its full potential.

FredR

Andrew,

The orginal query was "is there any way to tell". I know I could feel the difference when one of my sensors went but initially I did not know where the problem was or even where to look in those initial 928 ownership days 11 years ago. The point I was trying to allude to was that it might help one understand when your sensors are working correctly as on a good system disconnecting one will induce lower top end performance.

Once you know or suspect one of them is down you take it to someone with a Bosch hammer. I dare say one can frig a test to fool the computers with a jumper of some kind in the event that a sensor has failed or simply connect known good sensors without mounting them.

Either way, once a sensor is down you know the inlet manifold is coming off and you replace both sensors while you are in there. We see more knock sensor failures over here I suspect due to the extreme heat but even so I reckon they are good for about 10 years here.

Fred

Murray

Would a Bosch Hammer diagnostic tool be a common tool for a shop that works on german cars to have? If so, there's a local shop here that I may take the car to and have them run a diagnostic check of the sensors.
The car feels like it is running fine, but I don't have anything to really compare it to. I read a lot of posts about the knock and hall sensors and the effect on performance, so I just want to know if they need replacing. I'd rather not replace them if they don't need to be.

Thanks for the feedback.

John Speake

A Bosch Hammer might still be in use at some specialist garages but only ones who work on pre 95 Porsches.

A PST2 Porsche tester get you up the the era of Bosxster Mk1 and 996, the PIWIS all cars up to the Panamera.

Hammer, PST2 and PIWIS will all test a 928, altrhough many specialists prefer the Hammer for a 928. That's preference as well.