Jump to content
SAU Community

Recommended Posts

Hi I just bought a GTR34 vspec, and want to make sure everything is safe.

now the car currenly run 380kw on wheel 21psi, boost by t517z*2. the turbo lag is really big, full boost around 6000rpm. and the AFR is look a bit lean, 4000rpm about 12AFR 7000-8000 around 13AFR.(I don't know about GTR, but my evo is allways under 12) the owner told me is very safe, no need retune. and the injector is nismo 600cc. if i don't want tune up the power do i need some bigger injector???the highest injector duty is about 90%+. but i'm sure its not 100%

the car only done 2500kms after engine rebuild. so i may need change to full syn engine oil when its up to 3000kms.

and the car doesn't have power fc hand controller. do i need one???

can you guys give me some suggestion, what should I do next??? retune it?? bigger injector?? etc....

the car running really good, its not like a 10 years car. and many nice mods. easy daily drive. I just don't like the big turbo lag.

please help thanks guys!!!

  • Replies 40
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

My advice is to park it in my shed and give me the keys........................lol

When does you boost begin? If its 3,000 -3500 then thats normal. Your injectors could be beginning to lean out at top revs, 90% duty cycle is close to too much, little head room.

You don't need a hand controller, it can be tuned and driven without one.

take it to a reputable tuning shop and get them to check it out, wont cost much considering how much you have already spent buying it.

If you didnt like the lag why did you buy it, would have been plenty of other good powered options to buy that are more responsive.

if you wanna push it harder, you will need bigger injecors. the tune may be alright, just have less margin for crap fuel etc.

what was your last ride before this? an R34 GTR with 380rwkw would be an absolute weapon, if its a street car, stick with what you got, as your just going to add more lag with gains that probly arent all that great, and you may find that the car is actually *slower* in most typical 'street' situations

if u wanna race it, strip it bare (coz its free) and go run some numbers

if you wanna push it harder, you will need bigger injecors. the tune may be alright, just have less margin for crap fuel etc.

what was your last ride before this? an R34 GTR with 380rwkw would be an absolute weapon, if its a street car, stick with what you got, as your just going to add more lag with gains that probly arent all that great, and you may find that the car is actually *slower* in most typical 'street' situations

if u wanna race it, strip it bare (coz its free) and go run some numbers

yeah thats right, I even can't catch up a DC5-R when the boost not coming up. when the boost come up, the DC5 just like stoped.

My advice is to park it in my shed and give me the keys........................lol

When does you boost begin? If its 3,000 -3500 then thats normal. Your injectors could be beginning to lean out at top revs, 90% duty cycle is close to too much, little head room.

You don't need a hand controller, it can be tuned and driven without one.

yes, the boost start around 3000, full boost on 6000.

take it to a reputable tuning shop and get them to check it out, wont cost much considering how much you have already spent buying it.

If you didnt like the lag why did you buy it, would have been plenty of other good powered options to buy that are more responsive.

I like it, maybe I just not used to it.

if you wanna push it harder, you will need bigger injecors. the tune may be alright, just have less margin for crap fuel etc.

what was your last ride before this? an R34 GTR with 380rwkw would be an absolute weapon, if its a street car, stick with what you got, as your just going to add more lag with gains that probly arent all that great, and you may find that the car is actually *slower* in most typical 'street' situations

if u wanna race it, strip it bare (coz its free) and go run some numbers

thank you for reply, my last ride is a 135i and a evo9. the 135i like NA, no turbo lag at all. :)

13 is too lean at the top end.. if it is actually that lean at 7-8000rpm you will kill your engine very quickly. get it on a dyno asap.

OK, the engine just finish rebuild. 13 is very lean I think, but my friend saw a lot black smoke when i push hard. and the 13 is for 410kw tune, I haven't see the 380kw dyno chat yet, but i guess they should be simily. maybe the 380kw's tune is richer.

OK, the engine just finish rebuild. 13 is very lean I think, but my friend saw a lot black smoke when i push hard. and the 13 is for 410kw tune, I haven't see the 380kw dyno chat yet, but i guess they should be simily. maybe the 380kw's tune is richer.

410rwkw on 600cc injectors.. :)

Dont flog it until a retune. Before you retune it though, get some bigger injectors.

Enjoy!

some hard push on street should be allright I think. but of cause no track work, I will definite take it to retune before any track work.

sounds fine to me, 13 is ok and 90% duty is ok

plonk it on a dyno for $50 insurance, but sounds fine

i wouldnt mess with the tune, unless something horribly is shown on the dyno check

Wrong.

:):blink:

Bye bye engine.

You can and will do some major damage unless it's fixed up.EG track day.

Either clean up the tune on the 600cc injectors with less boost etc.

Or upgrade your injectors and fuel system if it needs it.

Mine ran in the high 12's-low 13's a/f when I got my car, as it still had the jap tune. Drove it round for 6 months.

Ignition timing/detonation will do more damage than a leaner a/f.

Just my 2 cents (not worth much lol)

Cheers

:):blink:

Bye bye engine.

You can and will do some major damage unless it's fixed up.EG track day.

Either clean up the tune on the 600cc injectors with less boost etc.

Or upgrade your injectors and fuel system if it needs it.

Mine ran in the high 12's-low 13's a/f when I got my car, as it still had the jap tune. Drove it round for 6 months.

Ignition timing/detonation will do more damage than a leaner a/f.

Just my 2 cents (not worth much lol)

Cheers

thank you, i really confuse about the AFR, like my evo, its run 13-12 afr and 227awkw on SJ's dyno). but when I move to QLD, I did a dyno check, its run low 11 and high 10 afr and 195kws on Chiptorque dyno. same tune, different number.

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 other problem was one of those "oh shit we are going to die moments". Basically the high spec Q50s have a full electric steering rack, and the povo ones had a regular hydraulic rack with an electric pump.  So couple of laps into session 5 as I came into turn 2 (big run off now, happily), the dash turned into a christmas tree and the steering became super heavy and I went well off. I assumed it was a tyre failure so limped to the pits, but everything was OK. But....the master warning light was still on so I checked the DTCs and saw – C13E6 “Heat Protection”. Yes, that bloody steering rack computer sitting where the oil cooler should be has its own sensors and error logic, and decided I was using the steering wheel too much. I really appreciated the helpful information in the manual (my bold) POSSIBLE CAUSE • Continuing the overloading steering (Sports driving in the circuit etc,) “DATA MONITOR” >> “C/M TEMPERATURE”. The rise of steering force motor internal temperature caused the protection function to operate. This is not a system malfunction. INSPECTION END So, basically the electric motor in the steering rack got to 150c, and it decided to shut down without warning for my safety. Didn't feel safe. Short term I'll see if I can duct some air to that motor (the engine bay is sealed pretty tight). Long term, depending on how often this happens, I'll look into swapping the povo spec electric/hydraulic rack in. While the rack should be fine the power supply to the pump will be a pain and might be best to deal with it when I add a PDM.
    • And finally, 2 problems I really need to sort.  Firstly as Matt said the auto trans is not happy as it gets hot - I couldn't log the temps but the gauge showed 90o. On the first day I took it out back in Feb, because the coolant was getting hot I never got to any auto trans issues; but on this day by late session 3 and then really clearly in 4 and 5 as it got hotter it just would not shift up. You can hear the issue really clearly at 12:55 and 16:20 on the vid. So the good news is, literally this week Ecutek finally released tuning for the jatco 7 speed. I'll have a chat to Racebox and see what they can do electrically to keep it cooler and to get the gears, if anything. That will likely take some R&D and can only really happen on track as it never gets even warm with road use. I've also picked up some eye wateringly expensive Redline D6 ATF to try, it had the highest viscosity I could find at 100o so we will see if that helps (just waiting for some oil pan gaskets so I can change it properly). If neither of those work I need to remove the coolant/trans interwarmer and the radiator cooler and go to an external cooler....somewhere.....(goodbye washer reservoir?), and if that fails give up on this mad idea and wait for Nissan to release the manual 400R
    • So, what else.... Power. I don't know what it is making because I haven't done a post tune dyno run yet; I will when I get a chance. It was 240rwkw dead stock. Conclusion from the day....it does not need a single kw more until I sort some other stuff. It comes on so hard that I could hear the twin N1 turbos on the R32 crying, and I just can't use what it has around a tight track with the current setup. Brakes. They are perfect. Hit them hard all day and they never felt like having an issue; you can see in the video we were making ground on much lighter cars on better tyres under brakes. They are standard (red sport) calipers, standard size discs in DBA5000 2 piece, Winmax pads and Motul RBF600 fluid, all from Matty at Racebrakes Sydney. Keeping in mind the car is more powerful than my R32 and weighs 1680, he clearly knows his shit. Suspension. This is one of the first areas I need to change. It has electronically controlled dampers from factory, but everything is just way too soft for track work even on the hardest setting (it is nice when hustling on country roads though). In particular it rolls into oversteer mid corner and pitches too much under hard braking so it becomes unstable eg in the turn 1 kink I need to brake early, turn through the kink then brake again so I don't pirouette like an AE86. I need to get some decent shocks with matched springs and sway bars ASAP, even if it is just a v1 setup until I work out a proper race/rally setup later. Tyres. I am running Yoko A052 in 235/45/18 all round, because that was what I could get in approximately the right height on wheels I had in the shed (Rays/Nismo 18x8 off the old Leaf actually!). As track tyres they are pretty poor; I note GTSBoy recently posted a porker comparo video including them where they were about the same as AD09.....that is nothing like a top line track tyre. I'll start getting that sorted but realistically I should get proper sized wheels first (likely 9.5 +38 front and 11 +55 at the rear, so a custom order, and I can't rotate them like the R32), then work out what the best tyre option is. BTW on that, Targa Tas had gone to road tyres instead of semi slicks now so that is a whole other world of choices to sort. Diff. This is the other thing that urgently needs to be addressed. It left massive 1s out of the fish hook all day, even when I was trying not too (you can also hear it reving on the video, and see the RPM rising too fast compared to speed in the data). It has an open diff that Infiniti optimistically called a B-LSD for "Brake Limited Slip Diff". It does good straight line standing start 11s but it is woeful on the track. Nismo seem to make a 2 way for it.
    • Also, I logged some data from the ECU for each session (mostly oil pressures and various temps, but also speed, revs etc, can't believe I forgot accelerator position). The Ecutek data loads nicely to datazap, I got good data from sessions 2, 3 and 4: https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-2?log=0&data=7 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-3?log=0&data=6 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-4?log=0&data=6 Each session is cut into 3 files but loaded together, you can change between them in the top left. As the test sessions are mostly about the car, not me, I basically start by checking the oil pressure (good, or at least consistent all day). These have an electrically controlled oil pump which targets 25psi(!) at low load and 50 at high. I'm running a much thicker oil than recommended by nissan (they said 0w20, I'm running 10w40) so its a little higher. The main thing is that it doesn't drop too far, eg in the long left hand fish hook, or under brakes so I know I'm not getting oil surge. Good start. Then Oil and Coolant temp, plus intercooler and intake temps, like this: Keeping in mind ambient was about 5o at session 2, I'd say the oil temp is good. The coolant temp as OK but a big worry for hot days (it was getting to 110 back in Feb when it was 35o) so I need to keep addressing that. The water to air intercooler is working totally backwards where we get 5o air in the intake, squish/warm it in the turbos (unknown temp) then run it through the intercoolers which are say 65o max in this case, then the result is 20o air into the engine......the day was too atypical to draw a conclusion on that I think, in the united states of freedom they do a lot of upsizing the intercooler and heat exchanger cores to get those temps down but they were OK this time. The other interesting (but not concerning) part for me was the turbo speed vs boost graph: I circled an example from the main straight. With the tune boost peaks at around 18psi but it deliberately drops to about 14psi at redline because the turbos are tiny - they choke at high revs and just create more heat than power if you run them hard all the way. But you can also see the turbo speed at the same time; it raises from about 180,000rpm to 210,000rpm which the boost falls....imagine the turbine speed if they held 18psi to redline. The wastegates are electrically controlled so there is a heap of logic about boost target, actual boost, delta etc etc but it all seems to work well
    • hahah when youtube subscribers are faster than my updates here. Yes some vid from the day is up, here:  Note that as with all track day videos it is boring watching after the bloopers at the start.  The off was a genuine surprise to me, I've literally done a thousand laps around the place and I've never had instability there; basically it rolled into oversteer, slipped, gripped and spat me out. On the way off I mowed down one of the instructor's cones and it sat there all day looking at me with accusing cone eyes as I drove past. 1:13:20 was my fastest lap, and it was in the second session, 3rd lap.  It (or me!) got slower throughout the day as it got hotter.      
×
×
  • Create New...