Pp520 vs sprint 520 - Page 4

ToddA1 · May 7th, 2012, 00:23

Has anybody contacted RC, and if so has he gotten back to anyone?

I'm researching nozzles and chips. RC was a company I've considered, but this issue would easily rule him out. Are his tunes that good where people are willing to deal with this?

-Todd

50harleyrider · May 7th, 2012, 03:50

Jeff never answered me back but he is a busy man and I didn't try calling him. My shuddering is hardly noticeable now that the summer blends of fuel are out. I suspected winter blend may have been the culprit. I still highly recommend a tune. RC2 if your only doing nozzles.

Abacus · May 7th, 2012, 04:47

I have a RC2+ and am very happy with it, but still have the shudder despite the non-winter fuel. I just got the PP520's back from Kerma (DBW) and will see if the shudder is still present with them. If so, I'll put a switch inline with the VSS and see if that makes a difference. It is annoying.

ToddA1 · May 7th, 2012, 05:19

That's something else I was wondering.... how many people are doing the hot swap program? Having the injectors matched may help the issue.

Are DBW, LLC and Kerma the same company? 2 different sites with different pricing. DBW claims that his company is the only one with the specialized equipment to properly set the pop pressures on these nozzles.

One site offers the hot swap, but also mentions letting the nozzles run in for 500 miles. I thought this was confusing.

-Todd

50harleyrider · May 7th, 2012, 09:52

Quote:

Originally Posted by ToddA1

That's something else I was wondering.... how many people are doing the hot swap program? Having the injectors matched may help the issue.

Are DBW, LLC and Kerma the same company? 2 different sites with different pricing. DBW claims that his company is the only one with the specialized equipment to properly set the pop pressures on these nozzles.

One site offers the hot swap, but also mentions letting the nozzles run in for 500 miles. I thought this was confusing.

-Todd

I've done two hot swaps with Kerma. No problems. Just make sure you take the bolt and tubing barb fitting off #2 or 3 for the bypass or you won't get it back. Kerma definitely has pop capabilty and gives you the numbers for each injector when he sends them back. If Drivebywire sees this thread, he'll comment. I've found Paul to be very accomodating if there are any issues.

Abacus · May 7th, 2012, 10:34

They sent mine back as I forgot to take them off when I sent them 2 sets for cleaning and calibration.

Kerma uses DBW's calibration setup, so I think they have a partnership if they are not the same company. The address I sent them to using Kerma's forms is DBW.

I have not done the hot swap program since I had a spare set of injectors and a spare B4, so I cannot comment on it, sorry.

Houpty GT · February 1st, 2013, 15:02

Quote:

Originally Posted by Abacus

I have a RC2+ and am very happy with it, but still have the shudder despite the non-winter fuel. I just got the PP520's back from Kerma (DBW) and will see if the shudder is still present with them. If so, I'll put a switch inline with the VSS and see if that makes a difference. It is annoying.

Did the injectors stop your shuttuddering(TM)?

Abacus · February 1st, 2013, 17:20

No, they did not.

I disconnected wire U2/2 (VSS) on the fuse block and that cured it completely. The new injectors made it a lot worse.

IndigoBlueWagon · February 2nd, 2013, 02:35

This issue has been around for years, no known fix for RC tuned cars that I've found. I dealt with it in my '97 A3 and finally gave up and went back to stock tuning. It would always shudder with Bosch .205s and with PP357s, right at 1600 in 4th and 5th. I think it's a simple problem of the combination of a tune and larger nozzles (either alone seems OK) causing some kind of fueling issue and shudder.

The B4 I just bought has a very mild RC2 (fuel economy focused) and stock nozzles. No shudder. And when I had an Aligator tune in my A3 it didn't shudder. However, Jeff showed me the fuel maps in that tune and it added no fuel. My son's A3 has RC2 and stock nozzles, has never shuddered. My last B4 had stock nozzles and an RC tune in the BK ECU, and later RC3 in a GQ. No shudder. My latest B4 has an FA ECU. And my A3 had an ED, later re-flashed to a JB to get rid of the shudder. Didn't work. So I don't think it's ECU dependent, or, said another way, all the early ECUs can cause shudder.

I really don't think there's an answer to this without the electronic mods described here.

Abacus · February 2nd, 2013, 08:41

I like Jeff's tunes and he is a great guy, but this has been a known issue for a long time and he seems to refuse to believe it's due to his tune and not the car. Due to that, I have been thinking of trying a Malone tune for the next one, just so I don't have to deal with it.

Removing the wire is easy enough, and it took longer to remove the lower panel than to remove the wire, but I shouldn't have to. It has happened on the GQ with the RC3+, the FA with the RC2+, and the JB with the GQ RC3+ chips, and is definitely much worse with more fuel. I swappd it into my brother's B4 with stock 190Bar injectors and it was still present, but not as much. I can only conclude it's an issue with the tune and is exacerbated with more fuel. Adjusting the IQ was the first thing I tried and it made no difference.

It's the refusing to acknowledge the issue that is the problem for me. As I said, Jeff is a great guy and I love his tunes otherwise, but the shudder makes driving the cars miserable. I haven't tossed a switch in place yet but will soon because we're headed to Florida in a month and I will want to use the cruise control.

starrd · February 2nd, 2013, 09:07

I have a Malone 4.5 tune on my GQ ECU with PP357's, and K03/04 hybrid and I have the shudder also. I also have a RC3 tune for the GQ ECU that I ran with stock nozzles and stock turbo (18 psi) and it also did this.

I have also played with the IQ and timing but with no success. I have just adjusted my driving style to minimize this by shifting down to 4th earlier than I would with my TD Passat.

Houpty GT · February 2nd, 2013, 10:40

To be fair, the root cause is definitely not the tune. It may be something that makes it worse just as the nozzles can. My shutter has gotten worse through the years and disconnecting the speed sensor is not an option for me since it gives me bucking in 1st and 2nd gear.
I think there is something in particular that wears on the non-ribbed pumps that leads to this problem. Perhaps it is the valves? I purchased an 11mm pump and will install it to see if it goes away. Results to come in 3 weeks.

IndigoBlueWagon · February 2nd, 2013, 14:07

I think you may be on to something. The timing line on my '97 A3 always "floated" indicating fuel was getting past the piston. The red B4 didn't show this. My '97 B4 got a new pump about 50K ago so I'll have to check to see if it's ribbed and if the timing line is steady.

Abacus · February 2nd, 2013, 14:19

With the stock ECU the shudder goes away. This was noticed with swapping the RC3 into my brother's B4 with the stock injectors and swapping a stock BK and then GQ into the wife's B4 and the B4V with upgraded injectors.

The other wagon had no shudder with the stock injectors and the Wett chips.

IndigoBlueWagon · February 2nd, 2013, 14:24

Doesn't mean it's not a pump issue. The lower fuel request from a stock tune may prevent it from occurring. My '97 didn't shudder with the stock ECU and .205s, but did with RC. Didn't with Aligator. But as I mentioned above, Aligator's tune added no fuel.