n75 question please help !!!!! [UPDATE] anyone with wastegate experience please!!

[Geoffafa]

has anyone ever had the n75 go bad on their car? if so what were the symptoms? i have a feeling it might be bad, because the car keeps going into limp, and it keeps getting worse, and i am throwing absolutely no codes on VAGCOM. please any info would be greatly appriciated.


>>>>>>> Today i had my N75 valve replaced, and it didnt help much, it does run a little better, but i still have a little pause at around 10 psi, before it kicks up to the full boost, then i hadthe bright idea to check my MAF, it was dirty as shit, so i cleaned it, made a world of a difference when boost picked up, but i still have the pause at 10 psi... the mystery continues

><><><><><>> i am beginning to think it might be my wastegate, my mechanic took a quick look and said it didnt look normal, maybe it was turned too far out, but the issue there is no one has ever touched my wastegate.
but i have a question, if anyone could count the thread on their untouched wastegate and get back to me, so i can have a refrence to go by to see if mine has been tampered with or not, would be greatly appriciated...

thanks a bunch AZers

[Slo.Mo.Shun.]

Get a new one, they are pretty cheap. Trial and error some times is the best way to figure out this kind of issues.

Already broke one in my car and had to replace it.

[Geoffafa]

Get a new one, they are pretty cheap. Trial and error some times is the best way to figure out this kind of issues.

Already broke one in my car and had to replace it.

thanks asshole, adam is getting me one on friday, but what happened exactly when yours went bad????

[Slo.Mo.Shun.]

I broke it experimenting with the wastegate and boost controllers trying to disable the N75. I had been rerouting lines to the intake manifold and all that crap until one day I pulled too hard and broke one of the plastic nipples.

Those were the crazy days, at one point my car would only boost 8 psi.

[Geoffafa]

I broke it experimenting with the wastegate and boost controllers trying to disable the N75. I had been rerouting lines to the intake manifold and all that crap until one day I pulled too hard and broke one of the plastic nipples.

Those were the crazy days, at one point my car would only boost 8 psi.

damnnn lol thats back in the day lol.... but yeah dude my shit limps like dj laz man. its bad and getting worse

[Auditude2.0T]

is your car ever not in limp mode? lol

[Geoffafa]

is your car ever not in limp mode? lol

lately no... it must be since im trying to reach enzoballin's mustang horsepower :)

[Auditude2.0T]

lately no... it must be since im trying to reach enzoballin's mustang horsepower :)

well your not getting that kind of power without a flux capacitor.

[brownishwater]

it has to be Gintani tuned also

[quattrosaint]

damnnn lol thats back in the day lol.... but yeah dude my shit limps like dj laz man. its bad and getting worse

haaaa he is still around....... I grew up in FTL

[Tru NY Player]

only somebody from miami could understand that dj laz remark..lol

but i read about that n75 problem on another forum..
i think they did the trial and error thing too..
swap it out!

[Nico]

has anyone ever had the n75 go bad on their car? if so what were the symptoms? i have a feeling it might be bad, because the car keeps going into limp, and it keeps getting worse, and i am throwing absolutely no codes on VAGCOM. please any info would be greatly appriciated.

Mine was cracked. But the car didn't go into limp mode. The symptoms were only seen when logging boost actual vs requested and the duty cycle on repeated runs. During the normal duty cycle the valve should close 100% to allow boost to build and then drop down to about 60% at redline so that there isn't too much boost at redline.

A faulty valve in my case meant that my N75 was always 90% closed as I wasn't able to hold boost.



The logs with the fixed valve sorry about the different values used in the 2 graphs. but notice how actual is right on par with requested and the N75 duty cycle drops to about 60%:

[Geoffafa]

Mine was cracked. But the car didn't go into limp mode. The symptoms were only seen when logging boost actual vs requested and the duty cycle on repeated runs. During the normal duty cycle the valve should close 100% to allow boost to build and then drop down to about 60% at redline so that there isn't too much boost at redline.

A faulty valve in my case meant that my N75 was always 90% closed as I wasn't able to hold boost.



The logs with the fixed valve sorry about the different values used in the 2 graphs. but notice how actual is right on par with requested and the N75 duty cycle drops to about 60%:

thanks a lot man, the mystery limp continues i guess

[PNB7]

I dont know if its cheaper but i just saw this on sale on ECS just heads up if you didnt already get a new one

[Nico]

thanks a lot man, the mystery limp continues i guess

Have you logged you boost and duty cycle. In my case I only had a minor boost leak but if in your case the leak is larger and your car is not reaching specified boost and your N75 Duty cycle is off it could be enough to cause limp mode.

What about your cam follower? Log your requested fuel and actual fuel this may also cause limp mode.

Do some logs thats the best way to find the problem!

Goodluck

[Geoffafa]

Have you logged you boost and duty cycle. In my case I only had a minor boost leak but if in your case the leak is larger and your car is not reaching specified boost and your N75 Duty cycle is off it could be enough to cause limp mode.

What about your cam follower? Log your requested fuel and actual fuel this may also cause limp mode.

Do some logs thats the best way to find the problem!

Goodluck

i have logged, and you would swear the logs dont come from my car, they are perhaps the most perfect logs ever seen, but certainly the car doesnt ride reflecting those logs

[Geoffafa]

I dont know if its cheaper but i just saw this on sale on ECS just heads up if you didnt already get a new one

what are you talking about homie? did you post a link im not seeing?

[PNB7]

http://www.ecstuning.com/stage/edpd/...ro&engine=2.0T

This should be it...I was looking at the holliday sale thing and this just popped up good timing. I gotta make it out to the meet with you guys I just got burried with school + I'm waiting on some new mods/i rear ended someone today on US 1 in traffic...fucking hate driving in this city so for sure new bumper i think

[PNB7]

its backordered till the 2nd though it says...dont know if its worth waiting or not

[Sanjman]

well your not getting that kind of power without a flux capacitor.

... and 1.21 "Jigawatts"

[Nico]

i have logged, and you would swear the logs dont come from my car, they are perhaps the most perfect logs ever seen, but certainly the car doesn't ride reflecting those logs

I'm sure you have done this already but if you haven't make sure you have an expert tuner look at your logs for you. I had logs that seemed to look ok but then my engine blew. After wards a very experienced tuner discovered a engine speed sensor intermittent failure from my logs that had caused my engine to fail. Make sure you are logging all the correct parameters. I would assume revo has guidelines for this.

[Geoffafa]

I'm sure you have done this already but if you haven't make sure you have an expert tuner look at your logs for you. I had logs that seemed to look ok but then my engine blew. After wards a very experienced tuner discovered a engine speed sensor intermittent failure from my logs that had caused my engine to fail. Make sure you are logging all the correct parameters. I would assume revo has guidelines for this.

the guys at my shop logged my car, then we actaully sent the logs to chirs@ revo for a second opinion, cant get more "expert" than that IMO

[Geoffafa]

http://www.ecstuning.com/stage/edpd/...ro&engine=2.0T

This should be it...I was looking at the holliday sale thing and this just popped up good timing. I gotta make it out to the meet with you guys I just got burried with school + I'm waiting on some new mods/i rear ended someone today on US 1 in traffic...fucking hate driving in this city so for sure new bumper i think

damn dude sorry to hear about that, hopefully DTM bumper in the works? cars gonna look sick when its done.
and about that n75 valve. the OEM is 11 dollars, i dont want to pay 85 for "trial and error" purposes

[Nico]

the guys at my shop logged my car, then we actaully sent the logs to chirs@ revo for a second opinion, cant get more "expert" than that IMO

Dam! that is a mystery

[Geoffafa]

Dam! that is a mystery

i have no idea as to what it could be, im trying to pick up a pattern but thats no use because there is none, but the only thing i have noticed is that lately after i put gas it goes into limp for a while, and i have no idea because i use the same gas every single time, since i bought the car

[Nico]

i have no idea as to what it could be, im trying to pick up a pattern but thats no use because there is none, but the only thing i have noticed is that lately after i put gas it goes into limp for a while, and i have no idea because i use the same gas every single time, since i bought the car

What about the low pressure fuel pump? I read some where that this pump is in the fuel tank and the sensor can go bad, think they call it the thrust sensor, it is attached to the HPFP and tells the LPFP how much fuel to supply to the HPFP.
If you are hiting linp mode it must be a fuel or timing thing.

[Geoffafa]

What about the low pressure fuel pump? I read some where that this pump is in the fuel tank and the sensor can go bad, think they call it the thrust sensor, it is attached to the HPFP and tells the LPFP how much fuel to supply to the HPFP.
If you are hiting linp mode it must be a fuel or timing thing.

but it should throw a code if the sensor is bad.... i need to check my fuel filter, but im beginning to lean towards being a wastegate issue... who knows

[Slo.Mo.Shun.]

Some one is up late ... ;)

[Geoffafa]

Some one is up late ... ;)

the door swings both ways my friend :)

[Nico]

but it should throw a code if the sensor is bad.... i need to check my fuel filter, but im beginning to lean towards being a wastegate issue... who knows

I wouldn't be so certain. Everyone assumes these things throw codes. I've had a busted DV on my car for months -no code,
intermittently faulty PCV - no code,

I'm no expert but maybe ask your shop whether they think it could be the sensor.

[Geoffafa]

I wouldn't be so certain. Everyone assumes these things throw codes. I've had a busted DV on my car for months -no code,
intermittently faulty PCV - no code,

I'm no expert but maybe ask your shop whether they think it could be the sensor.

i dont think its fuel related, i did some road test and it doesnt matter the rpm,gear, or load, it still has that pause or hiccup at 10 psi