Jump to content
SAU Community

Recommended Posts

I just gave my car a little right foot on the freeway in 4th gear and noticed i was hitting 10psi at 4000rpm instead of after 5000rpm.

So I'm guessing my lag issue is all in the tune. Can it really make that big of a difference

I just gave my car a little right foot on the freeway in 4th gear and noticed i was hitting 10psi at 4000rpm instead of after 5000rpm.

So I'm guessing my lag issue is all in the tune. Can it really make that big of a difference

Lag will be less in higher gears. This is because there is more load on the engine in higher gears. It wont be the same in every gear.

What gear does it take till 5000rpm to hit boost?

In 1st and 2nd i'm not getting 10psi till after 5000rpm just noticed this morning in 4th and 5th im getting 10psi around 4000rpm.

So theres slightly over 1000rpm difference, don't forget Stao said this turbo should be getting 20psi by 4300 so i would epect 10psi by say 3200 - 3500

With the stock comp housing, you ended up with half mm each side of the intake pipe. lol. But do run it with 3inch intake pipe, stock pipe will restrict power flow.

Because the stock turbo intake is being used it will need to start at 2.5" or 60mm (turbo end) and then increase to 3" as quickly as possible. Something like this is as good as I can find:

http://cgi.ebay.com.au/ALLOY-INTAKE-PIPE-4...=item25597be9f9

Is there any advantage to increasing the pipe size to 3" if its restriced to 2.5" at the turbo intake anyway?

Edited by Harey
In 1st and 2nd i'm not getting 10psi till after 5000rpm just noticed this morning in 4th and 5th im getting 10psi around 4000rpm.

So theres slightly over 1000rpm difference, don't forget Stao said this turbo should be getting 20psi by 4300 so i would epect 10psi by say 3200 - 3500

Im not commenting on the overall responsiveness of the turbo, but I could imagine somewhere near 1000rpm difference in lag between 1st and 4th gears.

ok so then its still has extreme lag.

Any one got a dyno sheet of the ATR43G3 showing boost and rpm?

This has power and speed.

http://www.digi-hardware.com/images/dynosh...rwkwcompare.JPG

Post up yours and we can compare.

This has power and speed.

http://www.digi-hardware.com/images/dynosh...rwkwcompare.JPG

Post up yours and we can compare.

No Dyno yet in the process of raod tuning the car, maybe i haven't been aggressive enough on the timing

Also going to replace my oil drain as i suspect maybe there is a kink in it

Edited by Crans
if you dont understand that boost repsonse is different in 1st and 2nd to 4th and you don't know how fast turbos spool up exponentially, tuning your car yourself is going to end up in tears

Yes i understand boost response is different between the gears and exponential growth in spool. I just didn't realise there would be over 1000rpm difference between 2nd and 4th not to mention extreme lag is still a problem

I am only doing basic mapping on the street i.e. getting fueling as close to perfect as i can and getting some extra timing in to help response, the rest will be done on a dyno.

I have tuned other cars before with ok results and being very safe and reliable still.

Based on this dyno print out of boost vs RPM http://www.digi-hardware.com/images/dynosh...3boost15psi.jpg i should be making 6psi by 3000rpm and 10psi by around 3300rpm

Edited by Crans
most turbo cars with decent sized turbos will have 1500-2000rpm spool difference between 1st and 4th gear

OK cool i didn't realise the difference was that much.

Oh wow its not tuned yet!! I agree with other people here, spend the cash on a professional tune. A tune will greatly affect the response of a turbo. It will be worth its weight in gold.

I think its unfair to give Hypergear bad feedback without a proper tune.

Edited by Harey

Not giving bad feed back at all, when boost does come on it feels very strong. I am going to tune the car my self and get it checked and adjusted on a dyno.

Like a lot of people i would prefer to do most of the work my self and learn on the way.

Other thing needs to be mentioned is that ATR28G4 unit is running a .82 turbine housing. The one with full boost at 3500RPM is running on .63 turbine housing.

.82 turbine bousing based boost and power curve should be:

http://www.digi-hardware.com/images/dynosh.../atr43360hp.jpg

All the new ones now has the wastegate controller lever, which allows you to run 20psi+ in a steady curve.

Also get rid of your stock rubber pipe. You can't get a decent tune out of that, it will suck bend and suck it self partially shut in random shapes. impossible to get get a constant air flow and reading. I've chucked mine out and replaced it with a 3inch metal pipe. Heaps of difference in power and response.

Also get rid of your stock rubber pipe. You can't get a decent tune out of that, it will suck bend and suck it self partially shut in random shapes. impossible to get get a constant air flow and reading. I've chucked mine out and replaced it with a 3inch metal pipe. Heaps of difference in power and response.

You mean a metal pipe that is 2.5" at the factory turbo end and increases to 3"? Or are you not talking about a PU hiflow?

Something like this:

http://cgi.ebay.com.au/ALLOY-INTAKE-PIPE-4...=item25597be9f9

Edited by Harey
You mean a metal pipe that is 2.5" at the factory turbo end and increases to 3"? Or are you not talking about a PU hiflow?

Something like this:

http://cgi.ebay.com.au/ALLOY-INTAKE-PIPE-4...=item25597be9f9

No mine has a 3" inlet

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

    • Back again. I returned to Japan in Jul/Aug to spend time with the car on my birthday and remind myself what all the sacrifice and compromise is for. It happened to line up with the monthly morning meet in Okutama, which I have been wanting to go to for a long time. It's a unique event at a unique spot with really rare, interesting, and quirky cars. It's where all the oldheads and OGs gather. The nighttime scene at DKF certainly has its place and should be experienced if you're into cars, but there's too much bad attention and negativity around it now. IMO the better time is Sunday morning at DKF or Okutama; it's more chill and relaxed. I'm glad I was finally able to go, but not sure it's worth the drive from all the way from Nagoya immediately the day before, unless I was already staying in Tokyo for the days right before the meet, because you have to wake up quite early to make it in time. Funnily enough though I didn't drive the car all that much this trip because it was just too damn hot. While there were zero issues and running temps were nominal and the A/C was strong, RBs already run crazy hot as it is. Sure, it took it all like a champ but something about driving these cars in the ridiculous heat/humidity bothers me and makes me feel like I'm asking too much of it. I'm just me being weird and treating the car like a living thing with feelings; I'm mechanically sympathetic to a fault. Instead I was mainly driving something else around - a KX4(silver) 2001 X-Trail GT, that I acquired in May. There's a few different flavors to choose from with Xs, but visually it's the Nissan version of the Honda CR-V. Mechanically it's a whole different story as this, being the top-trim GT, has an SR20VET mated to a four-speed auto and full-time AWD! It was a very affordable buy in exceptional condition inside and out, with very low mileage...only 48k kms. Most likely it was owned by an older person who kept it garaged and well-maintained, so I'm really happy with how it all worked out. It literally needs zero attention at the moment, albeit except for some minor visual touch-ups. I wanted something quirky, interesting, and practical and for sure it handily delivers on all three of those aspects. I was immediately able to utilize the cargo and passenger capacity to its full extent. It's a lot of fun to drive and is quite punchy through 1st and 2nd. It's very unassuming -in the twisty bits it's a lot more composed than one would think at a glance- and it'll be even better once I get better tires on it(yes, it's an SUV but still a little boat-y for my liking). So...now I have two golden-era Nissans in silver. One sports car and one that does everything else; the perfect two-car solution I think👍 The rest of the trip...I was able to turn my stressed brain off and enjoy it, although I didn't quite get to do as much as I thought. I did some interesting things, met some interesting people, and happened into some interesting situations however, that's all for another post though only if people really want to know. Project-wise, I went back to Mine's again to discuss more plans and am hoping to wrap that up real soon; keep watching this space if that interests you. Additionally, while working in the tormenting sweatbox that is the warehouse, I was able to organize most of the myriad of parts that my friend is storing for me along with the cars, and the 34 has a nice little spot carved out for it: And since it can get so stupid hot in there, that made it all the more easy -after I was standing there looking at the car and said 'f**k it'- to finally remove all the damn gauges that have mostly been an eyesore all this time. Huzzah. The heat basically makes the adhesive backing on the gauge mounts more pliable to work with, so it was far less stressful getting this done. I didn't fully clean it up or chase the wiring though; that will happen once I have the car in closer possession. Another major reason to remove all that stuff is to give people less reasons to get in my car and steal s**t while it's being exported/imported when/if the time comes, which leads us to my next point... ...and that is even though it's time in Japan is technically almost up since it's a November car and the X would be coming in March, I'm still not entirely sure where my life and career is headed; I don't really know what the future looks like and where I'm going to end up. I feel there's a great deal of uncertainty with me and as a result of that, it feels like I'm at a crossroads moreso now than any point in my life thus far and there are some choices I need to make. Yes, I've had some years to consider things and prepare myself, however too much has happened in that time to maintain confidence and everything feels so up in the air; tenuous one might say. Simply put, there's just too much nonsense going on right now from multiple vectors. Admittedly, I'm struggling to stay in the game and keep my eyes on the prize. So much so in fact, that very recently I came the closest I ever have before to calling it quits outright; selling everything and moving on and not looking back. The astute among you will pick up on key subtext within this paragraph. In the meantime I've still managed to slowly acquire some final bits for the car, but it feels nice knowing there's not much left to get and I'm almost across that finish line; I have almost everything I'll ever want for my interpretation and expression on what it is I think an R34 should be. 'til later.
    • Thanks for that, hadn’t used my brain enough to think about that. 
    • Also playing with fire if they start to flow more air down low than what the stock twins can. It's not even up top you need to worry, it can be at 3000rpm and part throttle and it's getting way more flow than it should.
    • Any G40/1000 or G40/1250 results out there?  
    • You still want a proper tune on the stock ECU though. Stock tune + stock ECU with GT-SS/-9s is probably playing with fire if you're running more than stock airflow/power.
×
×
  • Create New...