Jump to content
SAU Community

Recommended Posts

Hey

I just got my car back from X Speed

they are reknown tuners for powerfc and ant scali knows his stuff

The car over all runs pretty good and the knock levels are ALWAYS below 20

Except once last night i got cut off by a car and went past him on gate in 4th gear

it rev'd out to 5600rpm and read a knock of 126?

i was concerned and cleared the hold settings , put it in 3rd and reved it out to 6000rpm and it didnt go above 14 (did the same 4-5 times more that night still the same)

Am i worrying for nothing? because basically its cost me a small fortune to upgrade to the 25 after blowing 2 rb20's in my 32 and i really dont want to blow another engine

its tuned very safe - no timing at 14psi with 11.8 afr and lower with a max power of 312hp

Also is it possible for a rock or something making a noise in the engine bay to cause a knock reading?

Im new to the pfc so any information will be appreciated!

Link to comment
https://www.sau.com.au/forums/topic/181369-apexi-pfc-knock-readings/
Share on other sites

HAHA NOW YOUR ALL WORRYING ME!

should i just keep an eye on it and if it happens again then get it sorted

or would you advise not to give it shit at all and contact x speed?

i have been reading the pfc faq but i dont want to play with any settings yet

so basically that knock reading wouldnt of have done any damage?

Did you hit the rev limiter as ive seen high counts on the limiter.

Get Ant to put the Datalogit in your car and drive it on the street and see where the count is as it could be timing wrong/Fuel at one point or just a random noise and try hitting the limiter.The PFC count is a guide but not 100%.

I have seen higher counts on the road than the Dyno.

it is as nib said, a guide

the higher the level, the higher the knocking or detonation

it wont be related to speed but load

more often that not, in most cases;

car is tuned

runs prefect on dyno

jack all knock

car is taken on street

user loads it up

see's knocking

what generall occurs is you load it up on the street and you touch some areas of the map that weren't

tuned or have a bit too much timing. the dnyo is a simluator so it does a pretty good job

but its pretty common to see a car knock a bit differently on the street

if it was me and its my work shop i would tune the cars

then tell the owner to take it for trash and come back with the top score knock figures

then re-adjust based on that, ive seen so many tunes get done, then knock on the street after it

its no ones fault if that make sense, its just load variations and how much you give it curry on the street

not a big problem - easily fixed and sorted

iv seen it happen a bit to mine, got tuned on dyno, the tuner hooked his laptop up i took it for a hammer on the limiter something savage and very hard driving.. come back and 20 - 25 MAX.. at time i get some crap air or anything and knock may go to 60 for a split second.. had it checked over and is perfect.. the tune is perfect.. Also on my brothers 180 it went over 50 and it had a manifold gasket leak.. checked it over on the tune, was perfect, changed gasket.. highest hit was 20..

It could be noises, leaks, rattles that the knock sensor may pick up.

what i thought was a dodgy dump gasket ended out being the 6th cyl mani gasket leaking BAD

i think this may have something to do with it

it only happened once and other than that its NEVER gone into the 20's

the tune was a very very safe tune and had timing taken out of it up top

i havent hit the limiter yet and dont intend to anytime soon

it was night time and cold and i dont have a boost controller on it yet but the dyno reported very smooth boost levels and because of the timing taken out up top it drops the boost down a bit

ive got a blitz ebc on order and when it comes im goin back to x speed for a retune

and fekuar , when a person pulls infront of u when your doin 110 they deserve to be gated

once they copped some of that then i went back to the speed limit

:P

bouncing off the limiter shouldnt effect knock reading to much, mates 400hp 180 drifting on track never see's a knock reading higher than 35 and he bounces off limiter endless times.. a mate of mine used to record a knock reading of 95 when he started his car up on pfc h/c but once cleared and driving never went abover 30 knock, yet 95 on startup... bizzare

As NIB says I recommend you take it back and get some timing taken out of it.

Probably best to note what rpm and conditions occured at the time of knock so they know where to take out the timing.

Its funny you should have the same problem as me.

Got mine tuned at X-speed the first time about a month ago and I have now have the exact same problem.

I have recorded knock as high as 90 although it has spiked up to 70 probably about three times.

20 to 30 is the max I ever use to see on the old tune so it will definately be getting a retune.

I am completely refraining from boosting anything over 0.9 bar at the moment.

I will be taking the car back to have this sorted shortly. My guess is that the standard timing map used by Xspeed is probably a good compromise for general street driving and also gives a good result on the dyno. Usually what most customers want.

A knock of 150 is regarded by the factory Nissan ECU is true detonation so a knock of 120 will need a retune.

I get high knock during heavy acceleration when combined with wheel spin.

Alternatively a high boost setting of 1.2 bar and around 5500 rpm will do it (knock of 50 or so). Was reluctant to repeat to prove conclusively.

Just holding the throttle pinned in second gear and hitting the limiter was not enough to induce any knock over 20.

Because I race at the AHG driving center the engine is encountering these types of conditions for a duration of 1 minute over the short-tight track layout.

I have a Blitz IBC and I have tried all sorts of EBC settings such as gain and manual control which has not on its own (short of reducing boost to 0.9 bar) stopped the occurance of occasional high knock.

I definately wont be competing again until I have had a retune. I am quite happy to sacrifice some top end power however to improve engine longevity if that is what is required. Unfortunately the ignition map has been hidden or I would post up some timing values for comparison.

Basically I think road and track conditions are a lot more arduous than the steady ramping of a dyno roller and hence introduce dynamic transient conditions such a rapid acceleration or throttling on and off at maximum horsepower. The airflow meter probably doesnt react quick enough under these situations.

I dont see this as Xspeeds fault as I did not advise them the car would be used for these types of activities.

They also indicated (when picking up the car) that they would have tuned the car differently if I wanted a tune for "response" as compared to "horsepower". I guess I originally thought the standard map would suit both spirited and casual driving styles alike however may have been an oversight on my behalf.

Advising the tuner of the required vehicle use may have avoided the need for a retune in my case.

However, no harm seems to be done, and a lesson was learnt.

Would be interested to here how you go and whether you get it sorted as this has caused me some concern also.

yeah i got them to tune it as a safe safe tune and hence they took timing out up top and left everything else standard on the timing side of things

ant said if it had timing put into it aswell as ultimate fuel (tuned on vortex) it would make 350 easily on 1 bar

im not after max power

all i want is reliability with a bit of poke

so far im very happy with everything , im just cautious because of the money and stress the car has caused me

the main reason i chose a pfc is because of the knock sensor reading and when i seen a high reading i worry

i just want to enjoy it and drive it from now on without the stress!

It could have been:

Engine noise

Could have hit a really cold patch of air

Something might have rattled

a backfire

Rev Limiter

Bad Fuel

anything

Even if your tune seems "safe" you'll still see a bit of random knock here and there. You can never stop it. There are too many variables. Just make sure that it doesn't happen constantly.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I did end up getting it sorted, as GTSBoy said, there was a corroded connection and wire that needed to be replaced. I ended up taking out the light assembly, giving everything a good clean and re-soldered the old joints, and it came out good.
    • Wow, thanks for your help guys 🙏. I really appreciate it. Thanks @Rezz, if i fail finding any new or used, full or partial set of original Stage carpets i will come back to you for sure 😉 Explenation is right there, i just missed it 🤦‍♂️. Thanks for pointing out. @soviet_merlin in the meantime, I received a reply from nengun, and i quote: "Thanks for your message and interest in Nengun. KG4900 is for the full set of floor mats, while KG4911 is only the Driver's Floor Mat. FR, RH means Front Right Hand Side. All the Full Set options are now discontinued. However, the Driver's Floor Mat options are still available according to the latest information available to us. We do not know what the differences would be, but if you only want the one mat, we can certainly see what we can find out for you". Interesting. It seems they still have some "new old stock" that Duncan mentioned 🤔. I wonder if they can provide any photos......And i also just realized that amayama have G4900 sets. I'm tempted too. 
    • Any update on this one? did you manage to get it fixed?    i'm having the same issue with my r34 and i believe its to do with the smart entry (keyless) control module but cant be sure without forking out to get a replacement  
    • So this being my first contribution to the SAU forums, I'd like to present and show how I had to solve probably one of the most annoying fixes on any car I've owned: replacing a speedometer (or "speedo") sensor on my newly acquired Series 1 Stagea 260RS Autech Version. I'm simply documenting how I went about to fix this issue, and as I understand it is relatively rare to happen to this generation of cars, it is a gigantic PITA so I hope this helps serve as reference to anyone else who may encounter this issue. NOTE: Although I say this is meant for the 260RS, because the gearbox/drivetrain is shared with the R33 GTR with the 5-speed manual, the application should be exactly the same. Background So after driving my new-to-me Stagea for about 1500km, one night while driving home the speedometer and odometer suddenly stopped working. No clunking noise, no indication something was broken, the speedometer would just stop reading anything and the odometer stopped going up. This is a huge worry for me, because my car is relatively low mileage (only 45k km when purchased) so although I plan to own the car for a long time, a mismatched odometer reading would be hugely detrimental to resale should the day come to sell the car. Thankfully this only occurred a mile or two from home so it wasn't extremely significant. Also, the OCD part of me would be extremely irked if the numbers that showed on my dash doesn't match the actual ageing of the car. Diagnosing I had been in communication with the well renown GTR shop in the USA, U.P.garage up near University Point in Washington state. After some back and forth they said it could be one of two things: 1) The speedometer sensor that goes into the transfer case is broken 2) The actual cluster has a component that went kaput. They said this is common in older Nissan gauge clusters and that would indicate a rebuild is necessary. As I tried to figure out if it was problem #1, I resolved problem #2 by sending my cluster over to Relentless Motorsports in Dallas, TX, whom is local to me and does cluster and ECU rebuilds. He is a one man operation who meticulously replaces every chip, resistor, capacitor, and electronic component on the PCB's on a wide variety of classic and modern cars. His specialty is Lexus and Toyota, but he came highly recommended by Erik of U.P.garage since he does the rebuilds for them on GTR clusters.  For those that don't know, on R32 and R33 GTR gearboxes, the speedometer sensor is mounted in the transfer case and is purely an analog mini "generator" (opposite of an alternator essentially). Based on the speed the sensor spins it generates an AC sine wave voltage up to 5V, and sends that via two wires up to the cluster which then interprets it via the speedometer dial. The signal does NOT go to the ECU first, the wiring goes to the cluster first then the ECU after (or so I'm told).  Problems/Roadblocks I first removed the part from the car on the underside of the transfer case (drain your transfer case fluid/ATF first, guess who found out that the hard way?), and noted the transfer case fluid was EXTREMELY black, most likely never changed on my car. When attempting to turn the gears it felt extremely gritty, as if something was binding the shaft from rotating properly. I got absolutely no voltage reading out of the sensor no matter how fast I turned the shaft. After having to reflow the solder on my AFM sensors based on another SAU guide here, I attempted to disassemble the silicone seal on the back of the sensor to see what happened inside the sensor; turns out, it basically disintegrated itself. Wonderful. Not only had the electrical components destroyed themselves, the magnetic portion on what I thought was on the shaft also chipped and was broken. Solution So solution: find a spare part right? Wrong. Nissan has long discontinued the proper sensor part number 32702-21U19, and it is no longer obtainable either through Nissan NSA or Nissan Japan. I was SOL without proper speed or mileage readings unless I figured out a way to replace this sensor. After tons of Googling and searching on SAU, I found that there IS however a sensor that looks almost exactly like the R33/260RS one: a sensor meant for the R33/R34 GTT and GTS-T with the 5 speed manual. The part number was 25010-21U00, and the body, plug, and shaft all looked exactly the same. The gear was different at the end, but knowing the sensor's gear is held on with a circlip, I figured I could just order the part and swap the gears. Cue me ordering a new part from JustJap down in Kirrawee, NSW, then waiting almost 3 weeks for shipping and customs clearing. The part finally arrives and what did I find? The freaking shaft lengths don't match. $&%* I discussed with Erik how to proceed, and figuring that I basically destroyed the sensor trying to get the shaft out of the damaged sensor from my car. we deemed it too dangerous to try and attempt to swap shafts to the correct length. I had to find a local CNC machinist to help me cut and notch down the shaft. After tons of frantic calling on a Friday afternoon, I managed to get hold of someone and he said he'd be able to do it over half a week. I sent him photos and had him take measurements to match not only the correct length and notch fitment, but also a groove to machine out to hold the retentive circlip. And the end result? *chef's kiss* Perfect. Since I didn't have pliers with me when I picked up the items, I tested the old gear and circlip on. Perfect fit. After that it was simply swapping out the plug bracket to the new sensor, mount it on the transfer case, refill with ATF/Nissan Matic Fluid D, then test out function. Thankfully with the rebuilt cluster and the new sensor, both the speedometer and odometer and now working properly!   And there you have it. About 5-6 weeks of headaches wrapped up in a 15 minute photo essay. As I was told it is rare for sensors of this generation to die so dramatically, but you never know what could go wrong with a 25+ year old car. I HOPE that no one else has to go through this problem like I did, so with my take on a solution I hope it helps others who may encounter this issue in the future. For the TL;DR: 1) Sensor breaks. 2) Find a replacement GTT/GTS-T sensor. 3) Find a CNC machinist to have you cut it down to proper specs. 4) Reinstall then pray to the JDM gods.   Hope this guide/story helps anyone else encountering this problem!
    • So this being my first contribution to the SAU forums, I'd like to present and show how I had to solve probably one of the most annoying fixes on any car I've owned: replacing a speedometer (or "speedo") sensor on my newly acquired Series 1 Stagea 260RS Autech Version. I'm simply documenting how I went about to fix this issue, and as I understand it is relatively rare to happen to this generation of cars, it is a gigantic PITA so I hope this helps serve as reference to anyone else who may encounter this issue. NOTE: Although I say this is meant for the 260RS, because the gearbox/drivetrain is shared with the R33 GTR with the 5-speed manual, the application should be exactly the same. Background So after driving my new-to-me Stagea for about 1500km, one night while driving home the speedometer and odometer suddenly stopped working. No clunking noise, no indication something was broken, the speedometer would just stop reading anything and the odometer stopped going up. This is a huge worry for me, because my car is relatively low mileage (only 45k km when purchased) so although I plan to own the car for a long time, a mismatched odometer reading would be hugely detrimental to resale should the day come to sell the car. Thankfully this only occurred a mile or two from home so it wasn't extremely significant. Also, the OCD part of me would be extremely irked if the numbers that showed on my dash doesn't match the actual ageing of the car. Diagnosing I had been in communication with the well renown GTR shop in the USA, U.P.garage up near University Point in Washington state. After some back and forth they said it could be one of two things: 1) The speedometer sensor that goes into the transfer case is broken 2) The actual cluster has a component that went kaput. They said this is common in older Nissan gauge clusters and that would indicate a rebuild is necessary. As I tried to figure out if it was problem #1, I resolved problem #2 by sending my cluster over to Relentless Motorsports in Dallas, TX, whom is local to me and does cluster and ECU rebuilds. He is a one man operation who meticulously replaces every chip, resistor, capacitor, and electronic component on the PCB's on a wide variety of classic and modern cars. His specialty is Lexus and Toyota, but he came highly recommended by Erik of U.P.garage since he does the rebuilds for them on GTR clusters.  For those that don't know, on R32 and R33 GTR gearboxes, the speedometer sensor is mounted in the transfer case and is purely an analog mini "generator" (opposite of an alternator essentially). Based on the speed the sensor spins it generates an AC sine wave voltage up to 5V, and sends that via two wires up to the cluster which then interprets it via the speedometer dial. The signal does NOT go to the ECU first, the wiring goes to the cluster first then the ECU after (or so I'm told).  Problems/Roadblocks I first removed the part from the car on the underside of the transfer case (drain your transfer case fluid/ATF first, guess who found out that the hard way?), and noted the transfer case fluid was EXTREMELY black, most likely never changed on my car. When attempting to turn the gears it felt extremely gritty, as if shttps://imgur.com/6TQCG3xomething was binding the shaft from rotating properly. After having to reflow the solder on my AFM sensors based on another SAU guide here, I attempted to disassemble the silicone seal on the back of the sensor to see what happened inside the sensor; turns out, it basically disintegrated itself. Wonderful. Not only had the electrical components destroyed themselves, the magnetic portion on what I thought was on the shaft also chipped and was broken. Solution So solution: find a spare part right? Wrong. Nissan has long discontinued the proper sensor part number 32702-21U19, and it is no longer obtainable either through Nissan NSA or Nissan Japan. I was SOL without proper speed or mileage readings unless I figured out a way to replace this sensor. After tons of Googling and searching on SAU, I found that there IS however a sensor that looks almost exactly like the R33/260RS one: a sensor meant for the R33/R34 GTT and GTS-T with the 5 speed manual. The part number was 25010-21U00, and the body, plug, and shaft all looked exactly the same. The gear was different at the end, but knowing the sensor's gear is held on with a circlip, I figured I could just order the part and swap the gears. Cue me ordering a new part from JustJap down in Kirrawee, NSW, then waiting almost 3 weeks for shipping and customs clearing. The part finally arrives and what did I find? The freaking shaft lengths don't match. $&%* I discussed with Erik how to proceed, and figuring that I basically destroyed the sensor trying to get the shaft out of the damaged sensor from my car. we deemed it too dangerous to try and attempt to swap shafts to the correct length. I had to find a local CNC machinist to help me cut and notch down the shaft. After tons of frantic calling on a Friday afternoon, I managed to get hold of someone and he said he'd be able to do it over half a week. I sent him photos and had him take measurements to match not only the correct length and notch fitment, but also a groove to machine out to hold the retentive circlip. And the end result? *chef's kiss* Perfect. Since I didn't have pliers with me when I picked up the items, I tested the old gear and circlip on. Perfect fit. After that it was simply swapping out the plug bracket to the new sensor, mount it on the transfer case, refill with ATF/Nissan Matic Fluid D, then test out function. Thankfully with the rebuilt cluster and the new sensor, both the speedometer and odometer and now working properly!   And there you have it. About 5-6 weeks of headaches wrapped up in a 15 minute photo essay. As I was told it is rare for sensors of this generation to die so dramatically, but you never know what could go wrong with a 25+ year old car. I HOPE that no one else has to go through this problem like I did, so with my take on a solution I hope it helps others who may encounter this issue in the future. For the TL;DR: 1) Sensor breaks. 2) Find a replacement GTT/GTS-T sensor. 3) Find a CNC machinist to have you cut it down to proper specs. 4) Reinstall then pray to the JDM gods.   Hope this guide/story helps anyone else encountering this problem!
×
×
  • Create New...