Dyno Query

[gotRICE?]

Before you all jump on the band wagon and get upset about the numbers, for me the peak is irrelevant. So lets pretend its normal and just look at the lines.

As RB25DET's on our dynapack hub dynos give more or less similar readings.

One more thing to point out, it was run in 3rd gear because it was hitting speed cut. Both the lower, and upper were run in third, and the torque works out to be around 353nm

So what im wanting to know, is what is the flat spot in the curve? And the drop in the curve on the lower line?

The upper line is after a light SAFC2 tune and about 5" advance across the whole rev range. So there was a definite improvement from around 4200rpm up, and it improved the dip.. if you can call it that.

Would this be the AFM maxing out? or could it be something else?

Mods are

Stock turbo running R32 actuator boost.

3.75inch Turbo back

FMIC

Apexi Pod ( lower line had stock airbox and Apexi Panel so more proof pods do jack shit )

Any ideas would be nice.

Thanks!

Edited May 10, 2010 by gotRICE?

[JonnoHR31]

stock ecu gayness, just what it does with more than standard boost. some people say you have to be running 12+psi, but realistically its different in every application and it comes down to overall airflow. this is my dyno grap when i had a stock ecu, not how as it started pulling timing the boost rose which had a snowball effect and made the ecu pull even more timing

[paulr33]

rich and retard or clutch slip

[Harey]

Nistune FTW! Most places will have install it and have it all tuned for $800. How much has the SAFC2 cost you so far?

[N I B]

AS above, Standard for Nissan ECUs when you start changing things. Z32 ECU with Nistune or a PFC will solve all your problems.

[Lukas 33]

AS above, Standard for Nissan ECUs when you start changing things. Z32 ECU with Nistune or a PFC will solve all your problems.

Vi-PEC ! It is absolutely amazing

[KiwiRS4T]

Nistune is not available for your car unless you swap out the ecu for a Z32 or similar. EFI can chip your ecu but you really need to have your car there for the tune. From the "what ecu" thread below:

ok i have a price from NZEFI ( which is a good performance shop in Christchurch )

They put a re map board and chip and tune it for $987.50,

or Shred in Wgn are Link agents!!

[gotRICE?]

Ok sweet so its relatively normal with the stock ecu

The SAFC cost me $250NZD and i installed it myself. Tune was done by a friend of a friend who has a Dynapack at his house. Cost $300NZD. We played around with it for a goo 4+ hours trying different timing and fuelling so it was worth the cost for me.

The plan is to get a G4 in the future to cover any sillyness that might occur

I'd have one now, but i had to decide between whether making the mrs hate me or having a mint running car. So ill have 5 days of sun on the beach ir Rarotonga to dream about what could have been LOL!

[Harey]

Ok sweet so its relatively normal with the stock ecu

The SAFC cost me $250NZD and i installed it myself. Tune was done by a friend of a friend who has a Dynapack at his house. Cost $300NZD. We played around with it for a goo 4+ hours trying different timing and fuelling so it was worth the cost for me.

The plan is to get a G4 in the future to cover any sillyness that might occur

I'd have one now, but i had to decide between whether making the mrs hate me or having a mint running car. So ill have 5 days of sun on the beach ir Rarotonga to dream about what could have been LOL!

5 days of Sun in May?? we have had a few days of sun over here but I doubt 5 days, and still not warm enough to hit up the beach

[jjskyline79]

Ok sweet so its relatively normal with the stock ecu

The SAFC cost me $250NZD and i installed it myself. Tune was done by a friend of a friend who has a Dynapack at his house. Cost $300NZD. We played around with it for a goo 4+ hours trying different timing and fuelling so it was worth the cost for me.

The plan is to get a G4 in the future to cover any sillyness that might occur

I'd have one now, but i had to decide between whether making the mrs hate me or having a mint running car. So ill have 5 days of sun on the beach ir Rarotonga to dream about what could have been LOL!

do you not have a wideband? You really need one to be honest the safc and or neo should be able to sort that blip out though if you have a mild tune say stage one. What do you mean when you say you tryied different fuelling? the SAFC or NEO are Air Flow Controllers you can not adjust duty cycle of injectors.

can you let me have you settings i might be able to help. are you useing 8 point or 16 point correction map

[STATUS]

unfortunately the std ecu has a huge dip in the ignition value on higher load areas of the map (R34 is worse) and your safc can do nothing about it as it only manipulates the airflow meter signal to the ecu. You need a ecu that allows ignition control.

If you follow the blue fake trace i did in paint across the r33 std ecu ignition map you will see the timing goees 26 - 22 -16 - 14 -20 - 28 and the bold timing figure give you that dip. Once tuned you smooth out these timing dips and bingo nice smooth power delivery.

Bear in mind my trace is rough and is only an example it wont correlate exactly to your rpm scale as i dont know the exact ecu model in your car and the timing scales are slightly different between ecu releases but the underlying issue is as described above.

[lookingforboost]

they all seem to have a dip like that in the curve i was suprised when i put my car on the dyno and i didnt have a dip at all

[Lithium]

do you not have a wideband? You really need one to be honest the safc and or neo should be able to sort that blip out though if you have a mild tune say stage one. What do you mean when you say you tryied different fuelling? the SAFC or NEO are Air Flow Controllers you can not adjust duty cycle of injectors.

can you let me have you settings i might be able to help. are you useing 8 point or 16 point correction map

We used a wideband, the AFRs looked fine there - Status' comment about timing explains a lot.

Cheers Status, that was very interesting! Strangely enough, my Skyline never did the same thing - however I don't believe I reached the airflow levels GotRice? is.

Gotrice? - lol.

[STATUS]

We used a wideband, the AFRs looked fine there - Status' comment about timing explains a lot.

Cheers Status, that was very interesting! Strangely enough, my Skyline never did the same thing - however I don't believe I reached the airflow levels GotRice? is.

Gotrice? - lol.

Yeah if you can hold it one load point lower (where yours probably was) it will make more power and no dip

the trick is to increase the boost until the dip appears then back it off and tune the safc there.... it will generally make more power on less boost.

[gotRICE?]

do you not have a wideband? You really need one to be honest the safc and or neo should be able to sort that blip out though if you have a mild tune say stage one. What do you mean when you say you tryied different fuelling? the SAFC or NEO are Air Flow Controllers you can not adjust duty cycle of injectors.

can you let me have you settings i might be able to help. are you useing 8 point or 16 point correction map

Sorry i didnt mean fuelling i meant airflow

It was tuned on a dyno as stated, so yes there was a wideband present

And Status, x2, that was interesting. Need to get me that G4!

Harey - Your in Raro? Theres no sun??

[jjskyline79]

Could i still have the settings though plz as well as the high low throttle %

[gotRICE?]

Well seeing as those settings cost me money...

Plus every car is different, so they wont be much use to you.

[jjskyline79]

Fair enough

I no each car is different i was hoping to help you and others further just need base figures to work with

but never mind thanks anyway

[chrisR34GTT]

Great explanations Trent, found I could actually understand what you were talking about. So thanks for that!

[Lithium]

I no each car is different i was hoping to help you and others further just need base figures to work with

Its been well established that its nothing to do with AFRs - Status posted up what the timing does at the rpm GotRice? had issues, and the S-AFC does not allow adjustments to timing and his AFRs were stable and sensible anyway so getting all bound up on S-AFC settings is creating a red herring.