Got My Gtr Back! New 2860 -5's

[Phatboy]

Got the R34 GTR back from the local tuner's, who happily has an AWD dyno. Stock engine.

Pre-existing mods

- Apexi PowerFC and boost control unit (re-tuned this time)

- HKS adj cam gears (re-adjusted for more initial response this time, was too retarded before )

- HKS split and dump pipes

- HKS hi-power catback exhaust

- Apexi pod filters

Was making 269 rwkw (at high boost apparently) from previous tuner when the car wasn't mine - see Dyno 1.

New mods which just went in:

- Garrett 2860-5 turbos (upgraded from stock turbos)

- PWR 700cc injectors (upgraded from stock injectors)

- Awaiting pair of Nismo AFMs (probably good for another 10awkw, says the tuner).

Currently making 290 awkw, which I guess is around 320 rwkw - see Dyno 2.

Unfortunately, it is hard to compare the dynos as one is RW and the other AW, and there is no RPM on the x-axis of Dyno 1. Personally, I feel the response is similar to before, maybe slightly laggier, but the mid-top end is a lot stronger. Let me know what you guys think of the tune.

By the way, I feel as if the idle is not as smooth as before - the rpms swing between 750-1000 rpm. Is that normal? Thanks guys, greatly appreciated.

Edited February 5, 2009 by Phatboy

[R33GTRKid]

that dip in the first curve and boost was horrendous.

The second curve is very nice, boost control looks v. good too, hits 17 psi and then holds an almost steady 16.5 to 17 there on which is pretty sweet.

Wait until R31 comes on here, he will tell you that you should be pushing 450rwkw etc etc. If anything, your tuner has been conservative with the boost but on a stock bottom end, you want engine longevity at the sacrifice of high boost I reckon anyway.

Looks like it would be pretty fun to drive, maybe have your high boost set up at 19 odd psi, and a low boost where it is now so that if you want to stretch her a little more you can flick it over, that should push you well over 300awkw. What AFR's are on dyno 2?

[Phatboy]

Hi, thanks for the opinion. I told him reliability was the first concern, so I wanted a very conservative tune. Second concern was response, and top-end power was of back-seat importance.

Yeah, I know the first tuner did a pretty lousy job. I just blanked-out the workshop's name before R31 gets on my case for spreading possible libel . I figured if I am going to re-tune the powerFC, boost controller and cam gears, might as well get a bigger turbo and injectors at the same time.

Sorry, not sure what AFR it is running at the moment. How do I find that out? Guess it will change anyway when the AFms go in?

[Adz2332]

Hey mate,

So your car still has a standered bottom end??

Some people said -5s you should at least see 340kws plus???

[Phatboy]

Hey mate,

So your car still has a standered bottom end??

Some people said -5s you should at least see 340kws plus???

Hi, yeah standard engine throughout.

-5s can go to 340+rwkw, but I think the awkw figure would be lower. I also wanted a very conservative tune and the Nismo AFMs are yet to go in.

[R31Nismoid]

You might tell him 450rwkw, seeing as your the one that loves making outlandish and factually incorrect claims because you simply do not know what you're talking about

Anyway Phatboy - with an intake temp of 54 degree, and ambient only 29, there will be a bit of correction factor applied. So the figure will be a bit higher than what it probably should be... why dyno operators do that i still dont know.

However, overall a good result for a bit over 1bar on a stock motor with AFM's limiting the show (i take it your tuner decided not to tune past them etc).

Response is reasonable, boost curve is very solid. About all you can ask for, so be happy as a pig in poop!

On the issue of the idle, it should be smooth. When im not having AFM's problems (almost fixed) mine idles better than it did with the factor ECU.

Are both your O2 sensors in working order? To test, just turn the O2 Sensors off via the PFC Hand Controller, and if the idle becomes smooth... they are the culprit.

If you dont want to test it the tuner can next time you go there. It wont pose a problem for normal driving however

Side note - if you wanna go for a buzz in my car with GT-SS/250rwkw lemme know.

We can compare response and what not if your bored one night

Your 150-200kg's heavier... but more power, so it should be in a reasonably similar ball park as ive less power but less weight.

Would be interesting!

[R31Nismoid]

I just blanked-out the workshop's name before R31 gets on my case for spreading possible libel .

It aint a problem if your simply posting up the result

It when people start launching into wild accusations, slander and so on that it becomes an issue.

[R33GTRKid]

Hi, thanks for the opinion. I told him reliability was the first concern, so I wanted a very conservative tune. Second concern was response, and top-end power was of back-seat importance.

Yeah, I know the first tuner did a pretty lousy job. I just blanked-out the workshop's name before R31 gets on my case for spreading possible libel . I figured if I am going to re-tune the powerFC, boost controller and cam gears, might as well get a bigger turbo and injectors at the same time.

Sorry, not sure what AFR it is running at the moment. How do I find that out? Guess it will change anyway when the AFms go in?

did he give you a second graph that showed AFR's as opposed to Boost?? you could ask him for em. Your AFR's may change slightly because the AFM's mainly restrict airflow rather than fueling, which could be the reason for the lowish boost levels, because he could not squeeze any more air past em. If he can up the boost, means more air, but then he should really compensate by adding more fuel to keep the same target AFR.

[R33GTRKid]

Nismoid, I see a common banter between us here, maybe ill wave the flag given you being in a position of power n all.

[R31Nismoid]

AFM's do not restrict airflow. Being you upgrade to Nismo items, which are exactly the same dimensions, and you can make over 400rwkw with them.

If they were a restriction you wouldnt be able to make substancially more metered power with something with the exact same dimensions.

So AFM's are not a physical restriction in terms of actual air flow to the turbo. Its debateable about the actual mesh, but i dont think thats been tested.

Unless you have meant that the stock AFM is restricting because its running out of tuning resolution from a voltage point of view (5.1v max)???

[R31Nismoid]

Nismoid, I see a common banter between us here, maybe ill wave the flag given you being in a position of power n all.

As long as i see incorrect/invalid information posted that misleads users, im going to point it out as being such.

Thats all.

[PHA71L]

very nice my 5s will be tuned tomora so it should be interesting to compair!

i to will have stock afm for now

im guessing around the same boost to... for now haha

[Phatboy]

On the issue of the idle, it should be smooth. When im not having AFM's problems (almost fixed) mine idles better than it did with the factor ECU. Are both your O2 sensors in working order? To test, just turn the O2 Sensors off via the PFC Hand Controller, and if the idle becomes smooth... they are the culprit.

If you dont want to test it the tuner can next time you go there. It wont pose a problem for normal driving however

Side note - if you wanna go for a buzz in my car with GT-SS/250rwkw lemme know.

We can compare response and what not if your bored one night

Your 150-200kg's heavier... but more power, so it should be in a reasonably similar ball park as ive less power but less weight.

Would be interesting!

Thanks R31. I am not technically minded enough to fiddle with the hand controller for fear of screwing up the settings, so I will talk to the tuner about it later on when I get the AFMs. As a side note, as previously posted a long time ago, the boost gauge in my MFD occasionally doesn't work (ie., not showing any boost), although it drives the same. Could that be related?

I might have to take you up on that offer during a random meet/cruise, although I'm afraid I'll pine for the SS's afterwards .

[Phatboy]

very nice my 5s will be tuned tomora so it should be interesting to compair!

i to will have stock afm for now

im guessing around the same boost to... for now haha

Cool. Will be interesting to compare dynos and first impressions. Look forward to it.

[Pattygtst]

phat boy have a look at the pfc faq sticky in forced induction.

You really cant screw anything up hey, its easy.

[R31Nismoid]

Thanks R31. I am not technically minded enough to fiddle with the hand controller for fear of screwing up the settings, so I will talk to the tuner about it later on when I get the AFMs. As a side note, as previously posted a long time ago, the boost gauge in my MFD occasionally doesn't work (ie., not showing any boost), although it drives the same. Could that be related?

I might have to take you up on that offer during a random meet/cruise, although I'm afraid I'll pine for the SS's afterwards .

Ye as Patty said - the FAQ does help a bit.

Its only a couple button presses and thats it, but fair enough if you dont want to touch it.

As for the MFD not working, thats probably related to the sender unit in the engine bay.

Check the Vac lines are on and its all connected up.

Otherwise possibly a slightly loose connection under the MFD?

[Piggaz]

So AFM's are not a physical restriction in terms of actual air flow to the turbo. Its debateable about the actual mesh, but i dont think thats been tested.

Ash, do you know off the top of your head what the results of that test was. I was half thinking about pulling mine off my Nismo's. Are they just there to cause turbulance for the sensor? It wouldnt hurt to get rid of the metal in the AFM's i would think?

[rtune]

I asked in another topic but no replies so I'll ask you instead it must be fresh in your mind..

do you feel any real boost in 2nd or 3rd gear? or does it really need 4500 in 4th or higher, to hit 1 bar?

[rtune]

As a side note, as previously posted a long time ago, the boost gauge in my MFD occasionally doesn't work (ie., not showing any boost), although it drives the same.

I had the same problem. Not zero boost, but it wouldn't show much action when it was definitely boosting great.

Turned out to be a worn sampler vacuum hose that goes to the MFD, due to movement and wear the rubber had torn

at the t-piece.. 2 seconds with a razor blade and all fixed. Even though it was torn, and failing to pass all the pressure

upstream, it was not leaking enough air to have any real impact on anything else.

[bigmikespec]

Ash, do you know off the top of your head what the results of that test was. I was half thinking about pulling mine off my Nismo's. Are they just there to cause turbulance for the sensor? It wouldnt hurt to get rid of the metal in the AFM's i would think?

Whether it is related or not I do not know, but in a wind tunnel they use mesh to "condition" the airflow. They also use honeycomb to a similar effect.

Mike