Major Flat Spot

[fane]

Ok guys i need help with diagnosis. I have a huge flat spot since the installation of my hi-flow turbz.... Initial power is ok then it is a huge flat spot until right at the end of the rev range where it kicks you in the ass...

Other people's suggestions have been: coils, timing needed

Perf Mods:

Note: If not listed presume stock.

POD

Turbo Back Zorst

SAFC2 (afrs: 11.8 - 12)

Plugs gapped @ 0.61

Hi-Flow Turbo (54t comp wheel, T04e zorst wheel)

New 12psi Actuator

Ebc is closed completely and it hits 12psi at the start and then creeps up therough the rev range

Stock Timing

FMIC

BOV

Clutch

If you got any questons about car please ask, i want to find out how other people have gone with this setup and what the problem could be...

Like i said its been suggested that the coils are just too shit, but its not a violent miss....the car feels like it wants to go and has all this boost and noise but just doesnt go.....i had this same problem when i got fmic and ran more boost but didnt have SAFC to fix the afrs....but now the afrs are fine i dont know whats going on.... help me hehhe

Thanks guys,

Fane

[fane]

ps. i searched the forums but all the flat spots relate to stock turbo...and arnt as major....i am swapping afm on the weekend with a mate to test if thats dodgey....

[strutto]

Sounds like a maxed out AFM to me...

[Bass Junky]

Dyno chart?

[fane]

strutto: my mate that i bought the turbo off was running 360rwhp @ 16psi and i sure as hell dont have that and he has stock afm like me....

bass junky: no dyno mate....but i will get it on one soon....i dont have a licence at the moment, that makes it hard.....

the best i can describe it is like this dyno....in terms of power.... real late it kicks you in the ass.... what could it be...?

http://www.skylinesaustralia.com/forums/at...achmentid=25600

my boost feels like it comes on alot earlier and i have alot more early power and the flat spot seems to last longer.... what you guys reckon?

[strutto]

Did your mate still use the stocker ECU? Or was he using a PFC?

Cause the stocker ECU will go into overboost protection once the AFM starts maxing out... Bloody bane of my life ATM... The PFC doesn't do that...

You *may* be able to tune it out with the SAFC2?

[fane]

the afrs are fine so i dont know what else i can change with the safc....yeh my mate has a wolf....

so i cant upgrade to z32 and make afm not max out....even though the safc has part on it for z32....because they are the same size arnt they?

[RB20LagWagon]

size has nothing to do with resolution. the z32 has more scope for more power, however im not sure how it works with the safc, if its similar to the pfc then that should solve if the afm is maxing out. The size of the afm will not restrict anything until its the smallest part of the intake tract, have a look at the size of your turbo inlet, smaller then your afm aint it?

[fane]

RB20LagWagon: makes sense to me...

on my safc is hits 100% airflow early when it never used to hit 100%, it used to only get to about 98% before...never go over...now it hits it early and sits there....

is the z32 a plug in or is it solder job?

is there anyway of knowing that the afm is maxing out? is that 100% air flow on the safc an indication...

how does this explain my mate with the same afm? even tho he has the wolf...

[strutto]

The SAFC directly controls the AFM reading the ECU sees... So changing the settings on the SAFC will not only alter the AF ratios... but also the ECU's overboost protection...

RB20LagWagon is correct with what he says about resolution... The Z32 AFM can measure more air than the R33 one can... Neither of them should pose a physical air restriction at this power level though...

If your hitting 100% on the AFM reading on the SAFC, your maxing the AFM out... This is to be expected considering you were at 98% previously and you've increased the efficiency of the engine now (with the high flow).

I'm unsure whether its a plugin or solder in job... I'm sure it's been discussed on here before though...

Your mate with the Wolf isn't having the problem for 1 of 2 possible reasons:

1. Wolfs by default use a MAP sensor, not an AFM... Even though the AFM is still there, it's not providing any readings to the ECU...

2. The Wolf has been configured to use the AFM, but the Wolf doesn't have any overboost protection (neither does a PFC), so no crazy ignition retard when the AFM maxes out...

Hope that helps some Fane... I'm extremely interested to see how you go with this...

[fane]

i will let you know....im trying 2 things...aswell as a service and some fresh plugs im swapping afms with my best mates 33....test whether mine is buggered

and then i can get ahold of a z32 afm aswell..... i will keep everyone posted....if you get any other ideas i will be checkin this thread....keep them coming guys...

thanks for the help so far guys...

[strutto]

Heres another thought I had in a more than likely drunken moment...

IIRC, the SAFC2 has the ability to divide / half / multiply the AFM readings to suit engines with multiple AFM's (eg RB26DETT's) running with single AFM ECU's or vice versa...

So whats to stop us getting another R33 AFM, plumbing it in with another pod and a custom 2 x pod to turbo duct... Wiring it in with some power and ground... Wire the signal wire to the SAFC2... And then divide the signal by 2 in the SAFC and send that to the stock ECU... Double the resolution that way...

Unsure how it would work in practice though... Someone else can try that before I do...

[knore]

Heres another thought I had in a more than likely drunken moment...

 

IIRC, the SAFC2 has the ability to divide / half / multiply the AFM readings to suit engines with multiple AFM's (eg RB26DETT's) running with single AFM ECU's or vice versa...

 

So whats to stop us getting another R33 AFM, plumbing it in with another pod and a custom 2 x pod to turbo duct...  Wiring it in with some power and ground...  Wire the signal wire to the SAFC2...  And then divide the signal by 2 in the SAFC and send that to the stock ECU...  Double the resolution that way...

 

Unsure how it would work in practice though...  Someone else can try that before I do...  

Thats an interesting idea! hmm

[fane]

that is definately and intesting idea.... i cant see a problem with your logic either...

[fane]

if i put a z32 afm on my car then swap it on the safc so that it knows it a z32 afm will that fix my problem?

[ix9]

that's quite possibly the worst f*cken idea in the world.

Cars were designed the way they are for a reason.....

[strutto]

if i put a z32 afm on my car then swap it on the safc so that it knows it a z32 afm will that fix my problem?

Don't hold me to it... But I say yes...

You'd need to get it tuned afterwards though...

[strutto]

that's quite possibly the worst f*cken idea in the world.

 

 Cars were designed the way they are for a reason.....

Thanks for your support!!! :wassup:

Your car is obviously stock?

[fane]

thanks adrian will definately try that....

can anyone answer the z32 swap over question?

is it a plug in or solder job??

[strutto]

Heres a couple I found with a quick search... Not sure how helpful they are ???

http://www.skylinesaustralia.com/forums/sh...ead.php?t=39227

http://www.skylinesaustralia.com/forums/sh...ead.php?t=45501

http://www.skylinesaustralia.com/forums/sh...ead.php?t=52564

Keep us posted please?