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Today I re-tested my car’s acceleration times over 5 runs after 1800km, with stock air filters in place for the past 500km.

My 0-100kph times ranged from 4.37ces to 4.55 sec. I tried everything and every combination: stall against the brake to 2400RPM (limit) ; step of the brake and hit the gas. No real difference.

My car engages quite well and after 10-20m or so it bogs down for about 1 sec before taking off again with real momentum.

It refuses to accelerate from a dig in a linear fashion.

This bog-down happens in first gear so it has nothing to do with a gear change.

It seems that after the initial launch something in the ECU shuts down or retards the timing, before it resumes on its ballistic trajectory.

I spoke to Mathew at Col Crawford who will be doing my first service next Wed-Thurs. We will go for a test drive and also compare with the demonstrator car.

It’s a real disappointment so far!

" My car engages quite well and after 10-20m or so it bogs down for about 1 sec before taking off again with real momentum."

Same here ........Talked to the Dealer and they are not forthcoming if they do know anything that can be done......

I also think we are running very rich....back of my car has lots of soot on panels and I have

read that this one area is fine tuned with the accesport and new maps ...not saying that this is the cause

of that slight hesitation but hey it will help give even a better response......and keep that black soot down..

Edited by Godcla
mechanically it sounds like the car could be quicker off the line

but it sounds like the ECU is holding it back somewhere / somehow

This sucker runs so rich (veeery safe, no risk of detonation with this baby!) that for the first 2 seconds it feels like it is choking on its own vomit... :)

This sucker runs so rich (veeery safe, no risk of detonation with this baby!) that for the first 2 seconds it feels like it is choking on its own vomit... :blink:

Nissan Australia pharked it - de-tuned the boost to 12 Psi for hot Aussie summers so VR38DETT's do not ping and implode, and I bet you money this is an issue and reason why your one is bit slower to 100kmh than what the JDM's or USDM's are getting.

Nissan Australia pharked it - de-tuned the boost to 12 Psi for hot Aussie summers so VR38DETT's do not ping and implode, and I bet you money this is an issue and reason why your one is bit slower to 100kmh than what the JDM's or USDM's are getting.

Could well be...but the maps available from Cobb deal with this issue also for US and Euro.....??

sounds like there would be lots to gain if you replaced the stock ecu with a stand alone tunable ecu

are there any plug in stand alone units from hks, motec, autronic etc?

i know mines did one, but it sounds like a mines locked, mines tune workshop access only ecu

Today I re-tested my car's acceleration times over 5 runs after 1800km, with stock air filters in place for the past 500km.

My 0-100kph times ranged from 4.37ces to 4.55 sec. I tried everything and every combination: stall against the brake to 2400RPM (limit) ; step of the brake and hit the gas. No real difference.

My car engages quite well and after 10-20m or so it bogs down for about 1 sec before taking off again with real momentum.

It refuses to accelerate from a dig in a linear fashion.

This bog-down happens in first gear so it has nothing to do with a gear change.

It seems that after the initial launch something in the ECU shuts down or retards the timing, before it resumes on its ballistic trajectory.

I spoke to Mathew at Col Crawford who will be doing my first service next Wed-Thurs. We will go for a test drive and also compare with the demonstrator car.

It's a real disappointment so far!

How are you measuring your 0~100km/hr times?

This morning i thought i would give it a crack in my ADM R35 (given my 2 year old woke me up at 4am! i was at a loose end) so i used my vbox/driftbox thingo, dunno if they are accurate for this sort of thing?

Anyway first run i got a 3.8, and then a 3.7 - not sure i could easily go faster than this though, unless i am missing something.

I did have a couple of runs where it seriously bogged down like you describe above. I think it is detecting wheelspin and retarding power (even when it was in 'R' mode, it can still happen). Also, have you tried launch mode? You should be seeing 3000rpm or thereabouts. If you are in Sydney i would be happy to show you how it's done in my car anyway.

How are you measuring your 0~100km/hr times?

This morning i thought i would give it a crack in my ADM R35 (given my 2 year old woke me up at 4am! i was at a loose end) so i used my vbox/driftbox thingo, dunno if they are accurate for this sort of thing?

Anyway first run i got a 3.8, and then a 3.7 - not sure i could easily go faster than this though, unless i am missing something.

I did have a couple of runs where it seriously bogged down like you describe above. I think it is detecting wheelspin and retarding power (even when it was in 'R' mode, it can still happen). Also, have you tried launch mode? You should be seeing 3000rpm or thereabouts. If you are in Sydney i would be happy to show you how it's done in my car anyway.

That would be great! Send me a PM with your email address and we'll get together.

I am using the GTech Pro RR which in the past has been pretty consistently accurate with many cars. My car bogs down EVERY TIME. I tried every launch combination possible over 12 runs on two different occasions. There is no wheelspin at all. I have not switched the VDC off though, as we have been assured by Kazutoshi Mizuno that it is not necessary to achieve the 3.5 sec.

My car takes off very smoothly for 1 sec, bogs down for 1sec and then goes ballistic. Time after time after time, like clockwork.

What fuel are you using? I have been using Woolies Caltex98 from the start. I just filled up with BP98 and will give it a go. Maybe Caltex98 is a bit dodgy and my ECU pulls back timing?

I am clutching at straws here as you can see.

Today I will get my mate, who bought his GT-R the same week as mine, to try my car. His GT-R wheelspins from the start and accelerates in a totally linear fashion without any hesitation.

sounds like there would be lots to gain if you replaced the stock ecu with a stand alone tunable ecu

are there any plug in stand alone units from hks, motec, autronic etc?

i know mines did one, but it sounds like a mines locked, mines tune workshop access only ecu

The HKS GT570 kit comes with a piggy back job, problem fixed, 16 pounds no problem, 355 kilowatts and 840 newton metres at the wheels...

That would be great! Send me a PM with your email address and we'll get together.

I am using the GTech Pro RR which in the past has been pretty consistently accurate with many cars. My car bogs down EVERY TIME. I tried every launch combination possible over 12 runs on two different occasions. There is no wheelspin at all. I have not switched the VDC off though, as we have been assured by Kazutoshi Mizuno that it is not necessary to achieve the 3.5 sec.

My car takes off very smoothly for 1 sec, bogs down for 1sec and then goes ballistic. Time after time after time, like clockwork.

What fuel are you using? I have been using Woolies Caltex98 from the start. I just filled up with BP98 and will give it a go. Maybe Caltex98 is a bit dodgy and my ECU pulls back timing?

I am clutching at straws here as you can see.

Today I will get my mate, who bought his GT-R the same week as mine, to try my car. His GT-R wheelspins from the start and accelerates in a totally linear fashion without any hesitation.

I'll send you a PM.

FWIW, i havent switched off VDC, i've just put it in 'R' mode. I think i am running BP98, but to be frank it's been a few weeks since i've driven the car, and i cannot rememer. However, i doubt you will see significant variance from the mainstream 98 fuels. Could be something odd with yur car. We'll see.

I'll send you a PM.

FWIW, i havent switched off VDC, i've just put it in 'R' mode. I think i am running BP98, but to be frank it's been a few weeks since i've driven the car, and i cannot rememer. However, i doubt you will see significant variance from the mainstream 98 fuels. Could be something odd with yur car. We'll see.

Thanks for the PM. Email sent.

Ha, ha, what a coincidence. My son who drives EVO X told me that the Woolies Caltex 98 I've been using was causing problems in his EvoX and that many guys on his forum swear by BP98.

I immediately refilled my car with BP98.

Even though it probably takes a few hundred klicks for the ECU to re-adjust, today I tested my car again, after only 15km with the BP98 in the tank.

The first run, with a passenger 65kg and a full tank, all "R", but transmission on Auto cancels out "R" transmission. Launched against the brake with 2400RPM stall. The first run 4.04 sec!

Five more runs with different combinations, all 4.22-4.19sec range. Big improvement on 4.35-4.45 sec previously.

The prevoius launch sequence of QUICKISH START-BOG-TAKE OFF changed to a GENTLE START-FLAT SPOT-TAKE OFF sequence, presumably BP98 octane is higher than Caltex98 and the ECU does not retard timing as aggressively. Still, this initial flat spot hesitation is costing me at least 0.5 sec.

My mate, who bought his car at the same time but did not bring it today, did four runs in mine and said that his GT-R takes off without any initial delays and flat spots. It just rockets away from standstill.

It will be interesting to re-test my car after next week's service when it has had a chance to fully digest the BP98 fuel. I keep my fingers crossed.

]What fuel are you using? I have been using Woolies Caltex98 from the start. I just filled up with BP98 and will give it a go. Maybe Caltex98 is a bit dodgy and my ECU pulls back timing?

Last year High Performance Imports did a fuel test and the results varied enormously.Personally I wouldn't put caltex in my lawn mower.Where is their motorsport history apart from sponsoring Shell fueled race cars. I know my mates Ducati wont run on it.Ive only used BP prem in my 35 and never felt any lag.For want of a better word when nailed from a standing stop it "BARKS" and just goes and goes till I get scared and have to go home.

Thanks for the PM. Email sent.

Ha, ha, what a coincidence. My son who drives EVO X told me that the Woolies Caltex 98 I've been using was causing problems in his EvoX and that many guys on his forum swear by BP98.

I immediately refilled my car with BP98.

Even though it probably takes a few hundred klicks for the ECU to re-adjust, today I tested my car again, after only 15km with the BP98 in the tank.

The first run, with a passenger 65kg and a full tank, all "R", but transmission on Auto cancels out "R" transmission. Launched against the brake with 2400RPM stall. The first run 4.04 sec!

Five more runs with different combinations, all 4.22-4.19sec range. Big improvement on 4.35-4.45 sec previously.

The prevoius launch sequence of QUICKISH START-BOG-TAKE OFF changed to a GENTLE START-FLAT SPOT-TAKE OFF sequence, presumably BP98 octane is higher than Caltex98 and the ECU does not retard timing as aggressively. Still, this initial flat spot hesitation is costing me at least 0.5 sec.

My mate, who bought his car at the same time but did not bring it today, did four runs in mine and said that his GT-R takes off without any initial delays and flat spots. It just rockets away from standstill.

It will be interesting to re-test my car after next week's service when it has had a chance to fully digest the BP98 fuel. I keep my fingers crossed.

No idea if its safe or not for R35's but half a bottle of octane booster and try again? At least if it solves the problem and you get more time out of it you will actually know thats the problem for sure.

No idea if its safe or not for R35's but half a bottle of octane booster and try again? At least if it solves the problem and you get more time out of it you will actually know thats the problem for sure.

I haven't used any octane boosters in my cars since the 98 fuel became available a few years ago.

Clearly all fuels are not equally good.

Similarly, not all octane boosters are all they claim either. Which one do yo know to have the best "kick" in terms of octane numbers increase per bottle?

I haven't used any octane boosters in my cars since the 98 fuel became available a few years ago.

Clearly all fuels are not equally good.

Similarly, not all octane boosters are all they claim either. Which one do yo know to have the best "kick" in terms of octane numbers increase per bottle?

Nulon Pro Strength, you should be able to get it at most of the bigger servos. FWIW i switch between Caltex and BP (only) & i havent really noticed a difference. I dont think you would notice knock retard events (due to detonation brought on by low octane) as you've described. It would be less dramatic, switching to a lower timing table and gradually switching back to the higher timing table as knock events disappear over a period of time. I wouldnt think you would get sudden KR like that (where the car noticably bogs or decelerates) *only* on launch and no other time. Does it happen any other time? I bet it doesnt. It really just sounds like intrusive traction control to me. Do you use 'R' mode? Could it be the surface you are on? What tyres do you have, are they shagged? And what about tyre pressures, you havent inflated them to 40+ or something? I think GTR's have 29-ish or thereabouts recommended. Anyway, some stuff to ponder.

Edited by LSX-438
I recorded the following 0 - 100kph times using a GTech pro RR device (settings RRR):

Automatic mode with launch control 3.764 seconds -flat surface

Automatic mode with no launch control 3.900 - flat surface

Manual Mode with launch control 3.820 -flat surface

Manual mode without launch 4.064 - uphill

This is for an ADM, premium, 22 degrees.

Tests were conducted at the track.

When the HKS 570 kit and Cobb custom tune (Croydon racing developments) are installed next week, I will post the enhanced 0- 100kph numbers for comparison purposes.

Latest 0 - 100 (no Launch control), HKS bits, no Cobb or exhaust.

0 - 20 metres 1.872

0 - 100 3.228

Latest 0 - 100 (no Launch control), HKS bits, no Cobb or exhaust.

0 - 20 metres 1.872

0 - 100 3.228

That is truly fantastic! Congratulations.

How exactly does your engine make use of all this extra HKS "plumbing" to achieve these numbers without a new map? Or did I miss something and there is an HKS tune in the package?

What do you expect Cobb AP will do? :dry:

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