Upsolute with C N75 installed + other N75 info

[thorin33]

I got the C N75 today from Fifth Ave. They had one C version left as old stock. Northland only carried the F version and South Centre was costing $20 more. I'm not sure if they even had the C version. So for those who are thinking of chipping, it seems it is very hard to get the C version of the N75. There is the new find that the Audi H version is exactly the same as the ECS Race version. However, from the reviews I read, this seems to cause an overboost condition which causes the ECU to go to limp mode. The C is basically the same as the F minus the surging. Anyway back to my review.

As most of you have read from my other post, I was experiencing some surging after getting Upsoluted. I drove it for a week, including a drive to Edmonton, to see if it was just the ECU re-learning. It was not the case unfortunately. On my way home from Edmonton on Sunday, I was still getting the surging. I installed the C N75 tonight. The install is very easy except for getting the one-time clamps off. I went for a very short test drive but voila....surging is gone. I will take it for a more thorough test drive tomorrow when I have the time.

The Upsolute chip is great. It's hard to put into words. All I can say is I'll take you for a ride and you can see for yourself. Let me know if you have any questions.

[thorin33]

Peter asked me to post any new info I found so here it is. Surging seems to only happen on on the later 2001 cars and higher. Let me summarize what different N75 valves there are:

C - older part that cures surging
F - current part that generally surges with
chipped cars
H - consensus is that these are the same as the
ECS race N75. This will cause the turbo to
overboost and possibly put you into limp
mode. Also it seems in most cases it will
only cure surging initially but the surging
comes back and in some cases it is even more
severe.

Peter, the valve that you and I were talking about it the same H that I described above. IMO, I would stay away from the H valve. Rene (Upsolute researcher in Australia) sent Simon an email to recommend the C version to cure my surging. That is why I sourced a C version. It is very diffucult to obtain the C valve as they no longer make them.

Another solution that some people have has success with is replacing the stock DV. This would be a good time to experiment. Since both our cars exhibited the same surging behavior, you could try the HKS BOV (or any other aftermarket DV) and see how it affects your surging over the next couple of weeks. I'll do the same with the C N75 and we can compare notes to see which is the best solution for people who may want to chip in the future. Anyway this is getting too long so I will stop.

[thorin33]

First update with the C N75:

I had the C version in for about 4 days now. At first I thought that is had completely cured my surging woes. Last night, I was experiencing some slight surging. Not as severe as before but still there none the less. This morning the surging was gone. I have some ideas but I will report back when I know more.

[GTIski]

You will always have slight surging when chipped..
the C version should help a bit but don't count on it to completely eliminate the problem..
I surge (just slightly) depending on the weather conditions. I have had various DV valves (currently Hyperboost) with the C version all along. One way to avoid surging is to learn when Your car does it and learn how to shift to avoid it. That is what I have done. Every time I go down to Van my surging is completely gone therefore I have come to the conclusion that it might be the elevation here in Calgary (just a silly theory). My first chip (WETT) was really bad and ever since I put in my APR the symptoms have rarely come back. One thing that I might change is my MAF sensor.

[thorin33]

Thanks for the info. It is nice to hear about how this has affected other people. I think it is temperature/weather dependant as well. What do you think helps more with the surging; replacing the DV or the N75. I think this will help people who are thinking of chipping in the future. Have you known anyone using the ECS or H valve?

[GTIski]

ECS helps some and brakes some.ECS even says it depends on the car and your setup...
I would try "Daves Device" from www.davesdevices.com. It is a cheap mod and most people have really positive results..Some run manual boost controllers on top of the chip as well..
Like I said, I went through 5 different brands of DV and had C N75 all along. You can try my Forge or TT DV if You wish to see if that is the source of it for You.

[thorin33]

From what I can tell, I don't think the DV is the problem but it might be. It wouldn't hurt to try and see if it helps my problem. The reason I say it is probably not the source is that you are still experiencing slight surging, which I am as well. If my DV decides to go on me, I'll take you up on your offer and maybe even buy one off of you.

[GTIski]

I had some surging coming home last night.
Today, tried it around lunch and guess what??? no surging quite puzzling!!!

[thorin33]

I am really starting to think that this is weather related now. It is much warmer this afternoon than it was last night. My 2 cents for what it is worth. From what I have seen, when I surge it has been colder. By colder I mean below zero. Could be unrelated but I think this is the cause. I'm going to just let it be as my surging isn't all that bad. Hopefully my stock DV holds. GTIski, how long did your stock DV last?

[GTIski]

I have surged in the summer before my friend ..
I think it has to do with the humidity more than a temperature..
My stock DV lasted 2-3 weeks after my first (WETT) chip went in but there is no formula for that..I have to tell You that the new Hyperboost performs much much better than any of the previous ones (Forge, AUDI TT, Porsche 944,Stock)..

I am going to get "DavesDevice" and experiment with it .. Perhaps we can come up with the combination to cure everyones surging

[thorin33]

You probably have a better handle on this then I do GTIski. I've only been chipped a couple of weeks now. I have done a lot of research of this however. Did you order the Dawes device yet? You'll have to keep me updated after the install. Heck, give me a call when you do it and I'll come over and help. Like you said, hopefully between the 2 of us, we can get this surging this figured out. Maybe I can try another DV at that time too.

[GTIski]

I will order it in the new year..I would be a suicide to order things from the states at this time. ..
I have been chipped for two years now. I think I am one of the only few to try two different chips and have some sort of practical comparison...I wonder if the two chips have the same symptoms ..Do You surge under partial or full throttle??

[thorin33]

Yeah Christmas time is NOT the best time to do mail order.

I only surge at WOT. I really only see it when I am in 4th gear and from about 3000rpm+, I can see and feel the surge. I can't notice it at any other time.

If you want, we can get together sometime and you can take it for a test spin.

[GTIski]

ya man..I have been meaning to come to a VeeDub meeting for some time...I have talked to Sean before..oh, and GotTurbo when I gave him my Porsche944 DV. /..Other than that, I don't know anyone else from the club./

I will surge under Full throttle on 3rd and 4th between 4-5k...but only sometimes....never in 2nd like most Vortex Members. For a long time I thought it was my MAF sensor cause every time I gave it an alcohol bath it wouldn't surge at all for a few days.. How much are the N75 valves anyway?.. I might just buy one and play around with the settings on it to see if it makes any difference.

[thorin33]

I rarely if ever make it out to the meetings as I play volleyball on Thursday nights. It has been recommended NOT to play around with the settings on the N75. It does fix the surging temporairily but will eventually return and actually lost boost.

I paid $110 for the C N75. How much did you pay for yours? I know they are hard to get. I still have my F version. I have also read that some guys have just replaced their F with another F and it has gotten rid of surging. I am more skeptical of this however.