Jump to content
SAU Community

Recommended Posts

hello.

recent dyno run of my r33 gtst displayed rather inconsistent air fuel ratio readings. not surprising given the lack of a/m management despite the state of mods. (about 240rwkw)

ranges from 12.1 to about 13.0. my understanding is that this is rich, what i found on my searches was that something like 14.7 is ideal.

opinions?

i do hope its not in fact running lean. because i just havent quite got the cash for ecu goodness.

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/
Share on other sites

post-40626-1215239765_thumb.jpg

bear in mind that the peak power is only at about 5300rpm 13psi, because the coilpacks fried themselves and the test was aborted. the AFR at this point is about 12.2. i will take it back soon and wind it right out to 18 or 20psi.

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3993883
Share on other sites

i'd be more worried about the shape of the boost plot( looks like that of a centrifugal supercharger), although it seems like your running out of fuel in the top end. your running standard injectors i would assume? seems like a big hump in the middle where it leans out, what sort of management are you using?

PS, how much power are you making? the graph says ~170 but you sy 240? your overall power curve seems a bit peaky also... more specs on your setup overall?

Edited by VB-
Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3993931
Share on other sites

theyre 440cc injectors i believe. i want to upgrade the fuel pump soon.

not sure what you mean in regards to the boost curve. i thought it looked ok except for at the end where the massive misfire wrecked the run. stock ecu. ive heard they generally run rich, so if its leaning out its because the injectors/pump arent big enough yeh?

it made 170rwkw at 150kmh, or 5250rpm. judging by the shape of the curve youd expect it to keep going up and make 230+ at around 6500 or so. remember the run was aborted due to misfiring.

kkr430 @ 16psi

injectors

greddy style ff plenum

3/3.5in turbo back

fmic

hks pod

atmo bov

'custom high-flowed' cat

i'd be more worried about the shape of the boost plot( looks like that of a centrifugal supercharger), although it seems like your running out of fuel in the top end. your running standard injectors i would assume? seems like a big hump in the middle where it leans out, what sort of management are you using?

PS, how much power are you making? the graph says ~170 but you sy 240? your overall power curve seems a bit peaky also... more specs on your setup overall?

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3993996
Share on other sites

yeah you should be all in by about 4000rpm with that turbo. take a look at the plot for boost, it just keeps climbing and climbing till redline, it should shoot straight up as early as possible, then hold flat at 16psi till redline (ideally, you wont get it perfect but should be able to get it damn close)

has your stock ECU been chipped or is it just a standard computer? i would expect with all those other mods that its at least remapped, if not, then you've really gone off track buying all those other mods and this should be addressed immeadiately, without management all you've done is thrown away your money till this point. what size are your injectors?

1. invest in a fuel pump

2. sort out the boost issue, do you have an electronic controller?

3. get the A:F ratio flat at 12:1 till redline

4. get it tuned properly. i dont know the specifics of your mods and what you told your tuner you wanted done, but it really does seem like a rush job (dare i say it, a poor effort?)

did you ask for a tune or just a power run? if tune, who did it? (this assumes you got remap at least)

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3994282
Share on other sites

yeah you should be all in by about 4000rpm with that turbo. take a look at the plot for boost, it just keeps climbing and climbing till redline, it should shoot straight up as early as possible, then hold flat at 16psi till redline (ideally, you wont get it perfect but should be able to get it damn close)

has your stock ECU been chipped or is it just a standard computer? i would expect with all those other mods that its at least remapped, if not, then you've really gone off track buying all those other mods and this should be addressed immeadiately, without management all you've done is thrown away your money till this point. what size are your injectors?

1. invest in a fuel pump

2. sort out the boost issue, do you have an electronic controller?

3. get the A:F ratio flat at 12:1 till redline

4. get it tuned properly. i dont know the specifics of your mods and what you told your tuner you wanted done, but it really does seem like a rush job (dare i say it, a poor effort?)

did you ask for a tune or just a power run? if tune, who did it? (this assumes you got remap at least)

what does that boost curve mean then? is it leaking? i agree its silly how late it reaches boost.

as far as i know the ecu is completely stock. i blew the stock turbo which took the engine with it, and replaced it with all that kit because i bought it all off a bloke as a package.

admittedly it is stupid, but i needed to get the car back on the road asap and so its not exactly an ideal situation.

as i said above, i believe the injectors are 440cc.

no i havent got an ebc, this along with fuel pump and maybe safc are on top of the shopping list. will an ebc improve the boost curve?

it was going to be tuned, but the coilpacks shat themselves. timed to perfection.

also, someone mentioned how can i run bigger injectors on the stock ecu. i dont know... why wouldnt you be able to?

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3994356
Share on other sites

u wouldnt be able to run bigger injectors becoz u wouldnt be able to tune wit the stock ecu...

or the fuel pump module/reg would adjust but i dont c how???

and would the spray from the injector be all ova the place???

well i dont get it..lol

can some1 else try explain this?

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3994495
Share on other sites

You need bigger fuel pump,Z32 AFM and PFC or remap ECU.

Std AFM is up to 300hp(220kw) max.

S-AFC can not handle Z32 AFM.

I am able to remap.

cheers. i will look into this stuff.

i checked out your topics about the remapping. sounds good. a lot cheaper than a pfc.

no one answered my question about the ebc though. will it improve the boost curve?

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3994641
Share on other sites

The boost problem is in the stock engine management, i had a similar problem. Replace the ECU and the tune should fix it.

You can't run bigger injectors on a stock ECU because you have no way to rescale them. Its the same if you put bigger injectors on an aftermarket ECU, it still wont run them unless you rescale them which you can't do on a stock ECU.

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3994709
Share on other sites

What type of boost controller are you fitting now?

Do you have boost gauge?

Normaly about 4000rpm max boost then come down.

If you come to me I will check for you.

id get one of the greddy ones. no i dont have a gauge, do i need one of those also?

while ive got you here, which fuel pump would you recommend? bosch 040/044, or the walbro in-tank or external? theyre cheaper than the bosch.

should i get a z32 afm before i come to you for remap?

thanks for your help, hopefully i can accumulate these parts over the next couple of weeks and come see you. do you install the pump/ebc/afm/gauge too? do me a nice deal lol.

...whod modify cars huh?

Link to comment
https://www.sau.com.au/forums/topic/226831-ideal-afr/#findComment-3995070
Share on other sites

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


  • Latest Posts

    • Seat of the pants assessment of the new intake: The car is way less "doughy" when hitting the loud pedal, especially off idle when stopped or in traffic, I did use a cheapo lazer thermal thingo to measure the temp around where the pod filter got its air, it was between 55 - 60°C, in saying this the car was shut off and not moving, so the OEM intake pipe was not supplying any fresh air to where the pod was when the car was at least moving A weird bonus was induction noise on the throttle in the cabin increased a bit,  I was worried that I was actually going to lose some of that induction noise I love so much, outside though, when I got the daughter to do a WOT drive by pass for me, the induction noise has increased alot when on the throttle, not quite ITB doort, but well up there I'm extremely happy with the results and have been exploring the country roads in the region  As for house mods: 1.New front fence is up and is awesome, it really upgraded how the joint looks from the street, and the added security is nice 2. Electricians have replace some interior lights, and with more lighting in the garage, a few new motion detecting lights out the front above the garage, front room, and at the front door, which I have already found heaps helpful coming and going, also now has fancy pants CCTV all round the house The only hold point for power though is the solar and batteries due to supply issues, although this will happen over the next few weeks 3. I have done a heap of landscaping out the front and I'm almost ready to do a new small retaining wall with some nice blocks to replace the brick and cemented in rocks around the raised garden beds cemented in river stone "was the fashion at the time" the house was built. I currently have a pallet of retaining wall blocks and 2 bulka bags of 20mm blue metal to replace the wood chip that is in the raised garden beds around the house 4. I now have 3 big raised garden beds for out the back to grow some vegetables, about 70cm high, 200cm long and 100cm wide 5. My 2 compost bins are already pretty full with brown, green and kitchen waste from the landscaping I'vedone so far, but they will probably take a few months to break down, so anything else that gets chopped, trimmed, and kitchen waste will just start filling the base of the raised garden beds to about 30cm before I start throwing 40cm of good compost, and stuff, for the vegetables to grow in, I'll need a few ton of compost and soil, but the local supplier can sent me bulka bags of the stuff Basically the logs, wood chips and a few strategically placed rocks for drainage, will give the beds some good organic materials down low to break down over time, and they will hold moisture during the warmer months to save the water in my big arse water tank if we don't get alot of rain So, all in all, the car and house mods are going well, and I'm really enjoying being retired, I sleep in too 0700 and slowly plod around inside until I feel like actually doing anything, and only work in the yard for as long as want, which has actually been alot over the last few weeks,  although when you look at it, it seems that not a huge amount of work has been done,  until I look at the before I started the work pics Happy days and good times indeed 
    • hahaha yeah. Plan is to get side skirts and probably just rear pods. But going to do them one-by-one. I've got a set that I really like from RHDJapen, but that one isn't shipped to AU. So need to find someone who can get it for me
    • Here's an idea, answer the questions I asked you as they are trying to work out WHY the LSD will be binding up in a straight line.
    • You haven't driven many modern cars then have you? Most of them have sfa steering feel with their stupid electric bullshit steering systems.
×
×
  • Create New...