Jump to content
SAU Community

Recommended Posts

Ok guys recently had new turbo put on and tune on 13psi makng 240kw's and loving it, the other day I was just cruising in 4th, then (for whatever circumstance) dropped into 2nd and flattened it. After this looked in my rear view mirror and there was a massive puff of black smoke, and driving seemed to bit flat... long story short, it now doesn't seem to be making much boost. It still spools and I can feel it start to pull but after hitting 4k it kind of just flattens off and has NO top end power.

So, doing a bit of research on this forum some guys have complained of melting metal cats so took that off and had a look and doesn't seem to be 'melted' at all so I'm assuming it's not that. Also had a look at all intercooler pipes and doesn't seem to be any cracks or loose fittings.

Could this be a spark issue? Coilpacks?

I understand black smoke is overfuelling problem, but has only happened that one time and has not been smoking at all since... and having an aftermarkt ecu I would assume the tune would take care of and r n r issues. Also like to add that exhaust note has changed, seems a LOT quieter than previously.

Really starting to upset me, any help appreciated!

Edited by SLEEPR85
Link to comment
https://www.sau.com.au/forums/topic/292968-r34-down-on-power/
Share on other sites

Well it was idling a bit rough last night, not violently shaking or anything just a bit rougher than usual, was enough for me to notice. Driving between idle and 3k seems a bit sluggish also before the boost comes on, then it kinda of spools and doesn't really convert into power....

How does it free rev does it feel normal? If it doesnt take the cat off again and give it a rev to be sure it is a blockage in the exhaust. It will be LOUD. You could drive it up the street but you might get locked up. How much boost is it getting up to and is it blowing any black smoke anymore. What ecu is it and can you check the sensor inputs especially coolant temp incase somthing has gone wrong and its seeing very cold will make it rich.

Revs feel a bit choked, that's why i thought it was the cat.... not blowing black smoke anymore, just that one time. Running emanage ultimate ecu, still boosts to over 10psi but haven't really fully booted it. Where would these sensor inputs be?

Was speaking to a mate of mine who has owned and built a few skylines and he suggested that the front compressor of my 2835gt may had let go, does this seem likely? Still boosts but sounds like its sinning twice as hard to get half the power i was getting....

Took the pipe off from the turbo to the intercooler to see if there was any oil leaking anywhere but didn't feel anything. Apart from taking the front intake off the turbo to get to the front compressor (which is surprisingly hard to get to) is there any easy way to know if the turbs is blown or not?

  • 2 weeks later...

Hows it going? Have you sorted it out yet? Most aftermarket ecu's have some kind of sensor check or data readout. i dont know about emanage though.

other than buckets of grey (oil) smoke coming out the or bad noises the only way to check your compressor wheel is to get your fingers to it and check for play. if they do let go its prob best to check it. You dont want it in your engine.

Let us know what yo find

  • 3 weeks later...

Ok an update for anyone's future reference.

Took it to my mechanic, said really couldn't fault it in many ways, except when he looked at the sparkies they seemed to be white which would mean that my engine is running lean... suggested i put it on the dyno for a more accurate reading of afr's, etc.

Ended up being injectors were set close to 100% duty cycle and was causing them to cut out at high revs, so my tuner said he dropped it and lowered boost by 1psi down to 12psi.... which still made the same kw's as at 13psi....

Now the question i have now is why would they just start doing that all of a sudden? Do they have a default "safe mode" that when they hit 100% they automatically go back to standard? Think its upgraded fpr time!

Ok an update for anyone's future reference.

Took it to my mechanic, said really couldn't fault it in many ways, except when he looked at the sparkies they seemed to be white which would mean that my engine is running lean... suggested i put it on the dyno for a more accurate reading of afr's, etc.

Ended up being injectors were set close to 100% duty cycle and was causing them to cut out at high revs, so my tuner said he dropped it and lowered boost by 1psi down to 12psi.... which still made the same kw's as at 13psi....

Now the question i have now is why would they just start doing that all of a sudden? Do they have a default "safe mode" that when they hit 100% they automatically go back to standard? Think its upgraded fpr time!

more likely boost cut. The emanage does not care whether its in the high or low octane map.

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 296mm rotors are the R33 turbo brakes. The 310mm rotors are the R34 turbo brakes. The calipers are nearly the same, but not. They're the same caliper but the R34 caliper has longer legs so that it sits out far enough to go over the rotor. The pads are the same for both. When you say, "I bough tsome EBC"....did you just mean pads? Or rotors? 310mm rotors fit under 17" wheels. There may be some wheels without enough clearance though. I can't fit my fingers between the barrel of my wheel and the "corners" of my R34 calipers, but there is plenty of room behind the spokes. This is on Enkei RPF1. You can fit 324mm rotors inside a 17" wheel, but I'd be willing to bet that it would be close to impossible with the Nissan/Sumitomo caliper (using an adapter, of course), because the Sumitomo caliper is fatter than the Brembo caliper that is supposed to go on the 324mm rotors.
    • Hi. Can someone tell me what brakes(and mainly WHERE) can i buy brakes on R34 GTT? I bought some EBC which SHOULD go on my car(i have GT but it has GTT brakes) but it does not fit, Brakes are "too" small(296mm) Are 310mm be good or? I have 17 inch wheel so no "big boys" but for me driving i just need one that fits and i can get here in EU/Czech.
    • Since winter isn't that harsh anymore in Poland, i will definetely drive it 365 days a year 😉. But if the snow hits i will try it for sure and let U know. Only swap i am planning to do is of course R34 GTR front 😍.
    • Hey. Very valuable information about pitwork, I will pay attention when buying any consumable parts 🙏 As for the carpets - I got a handful of information from nengun, from which it appears that indeed the carpets for the driver's side are OEM. They are not able to show me any pictures due to the long chain of different sales entities but after I place the order, as soon as the goods arrive at the nengun warehouse from which they will send the shipment to me they can send me photos and if my purchase differs from OEM I can immediately return it / cancel the purchase. I think I will give it a try 😉. Of course i'll let you know what's what as soon as i get them P.s. I know the topic is not relevant to the thread, but both nengun and amayama have these SICK 😍 trunk room lamps available. Do you know anyone who ordered them? I need to have one in my car
    • I've managed to find this: Nissan_Stagea_AutechVersion260RS (1).pdf
×
×
  • Create New...