Jump to content
SAU Community

Recommended Posts

i recently had a pfc installed and tuned by hyperdrive on a 33 gtst.

All seems to be well but i have noticed that occasionally the knock seems to jump to excessivley high readings. It would generally jump to a maximum of about 70 and my mechanic told me it is probably because i need to install an aftermarket fuel pump.

The issue im still concerned about is that the other night i gave it a bit of full throttle action in 3rd gear on the freeway and had a knock of 122 (running 13psi)

the values are as fallows:

speed: 107

ign: 43 (maximum value on pfc so i dont know if its the value at time of knock)

airflow: 4690

rpm: 4844

inj: 68.7%

knock: 122

temp: 81

From using the search button ive found it could either be a faulty knock sensor or poor tuning, or is this still in relation to needing to upgrade the fuel pump, even though the inj duty is 68.7%?

any help is appreciated coz i like my engine in one piece!

Link to comment
https://www.sau.com.au/forums/topic/124840-3rd-gear-knock/
Share on other sites

Hmm, If I were you I'd go to a dyno and get some A/F readings.

Could be running lean, which isn't good. Now that might be because of a dud fuel pump, or the tuning (seeing as the inj duty is only at 68.7%).

Can't tell really unless you get some A/F readings, and even then it could be the tune, or not enough fuel pressure.

Link to comment
https://www.sau.com.au/forums/topic/124840-3rd-gear-knock/#findComment-2304585
Share on other sites

if you wanna try and fix it yourself you can give it a shot, its fairly easy, the powerfc faq in my signature tells you how to do this.

also you should have a GTR pump ideally around 180rwkw ish in an r33.

also 13psi is pointless and just adding extra heat, drop it to near 12

Link to comment
https://www.sau.com.au/forums/topic/124840-3rd-gear-knock/#findComment-2304652
Share on other sites

Hey there mate my name is Aaron and i am in the process of opening the doors of my new business In Tune Performance and Engineering which will be located in Oconnor Western Australia and will be opening on approximately the 17th of this month. From my experience a fuel pressure and fuel flow test needs to be carried out and probably a replacement fuel pump upgrade will need to be carried out. I don't believe that there would be a tuning issue such as has been noted. Hyperdrive would not have let the vehicle leave with a knock reading of 122. Something else has happened since the vehicle was tuned there. If the vehicle needs a new fuel pump i would recommend an adjustable fuel pressure regulator be fitted at the same time (not a Malpassi) as the vehicle will need to be re-tuned once these mods have been done. I also agree with one of the other posts recommending that the boost be dropped to approximately 12 psi if you are still using the std intercooler otherwise 13 psi will be ok if you are running an aftermarket front mount. My business will be providing a full dyno tuning service and i specialise in Motec, Haltech, Microtech, Autronics, Power FC, and Xede as well as most other systems on the market. Feel free to call anytime for advice or service on 0414874824.

Good luck with your project.

Link to comment
https://www.sau.com.au/forums/topic/124840-3rd-gear-knock/#findComment-2304763
Share on other sites

thanks for all your suggestions i will look into them

if you wanna try and fix it yourself you can give it a shot, its fairly easy, the powerfc faq in my signature tells you how to do this.

also you should have a GTR pump ideally around 180rwkw ish in an r33.

also 13psi is pointless and just adding extra heat, drop it to near 12

I will have a look over the next few days at trying to fix the problem myself.

I am a little worried that a knock at that level might kill my engine if i get it wrong so ill read through and take it easy :D

Im also looking at buying a bosch 044 pump, would it be worth installing the pump before i go ahead and try to fix any problems?

Link to comment
https://www.sau.com.au/forums/topic/124840-3rd-gear-knock/#findComment-2308085
Share on other sites

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

    • The rain is the best time to push to the edge of the grip limit. Water lubrication reduces the consumption of rubber without reducing the fun. I take pleasure in driving around the outside of numpties in Audis, WRXs, BRZs, etc, because they get all worried in the wet. They warm up faster than the engine oil does.
    • When they're dead cold, and in the wet, they're not very fun. RE003 are alright, they do harden very quickly and turn into literally $50 Pace tyres.
    • Yeah, I thought that Reedy's video was quite good because he compared old and new (as in, well used and quite new) AD09s, with what is generally considered to be the fast Yokohama in this category (ie, sporty road/track tyres) and a tyre that people might be able to use to extend the comparo out into the space of more expensive European tyres, being the Cup 2. No-one would ever agree that the Cup 2 is a poor tyre - many would suggest that it is close to the very top of the category. And, for them all to come out so close to each other, and for the cheaper tyre in the test to do so well against the others, in some cases being even faster, shows that (good, non-linglong) tyres are reaching a plateau in terms of how good they can get, and they're all sitting on that same plateau. Anyway, on the AD08R, AD09, RS4 that I've had on the car in recent years, I've never had a problem in the cold and wet. SA gets down to 0-10°C in winter. Not so often, but it was only 4°C when I got in the car this morning. Once the tyres are warm (ie, after about 2km), you can start to lay into them. I've never aquaplaned or suffered serious off-corner understeer or anything like that in the wet, that I would not have expected to happen with a more normal tyre. I had some RE003s, and they were shit in the dry, shit in the wet, shit everywhere. I would rate the RS4 and AD0x as being more trustworthy in the wet, once the rubber is warm. Bridgestone should be ashamed of the RE003.
    • This is why I gave the disclaimer about how I drive in the wet which I feel is pretty important. I have heard people think RS4's are horrible in the rain, but I have this feeling they must be driving (or attempting to drive) anywhere close to the grip limit. I legitimately drive at the speed limit/below speed the limit 100% of the time in the rain. More than happy to just commute along at 50kmh behind a train of cars in 5th gear etc. I do agree with you with regards to the temp and the 'quality' of the tyre Dose. Most UHP tyres aren't even up to temperature on the road anyway, even when going mad initial D canyon carving. It would be interesting to see a not-up-to-temp UHP tyre compared against a mere... normal...HP tyre at these temperatures. I don't think you're (or me in this case) is actually picking up grip with an RS4/AD09 on the road relative to something like a RE003 because the RS4/AD09 is not up to temp and the RE003 is closer to it's optimal operating window.
    • Either the bearing has been installed backwards OR the gearbox input shaft bearing is loosey goosey.   When in doubt, just put in a Samsonas in.
×
×
  • Create New...