Jump to content
SAU Community

Recommended Posts

Thats nice... Did you do that or Scotty?

What are you tuning on? I didnt think you had an emanage?

All mine I'm afraid. Scotty turned me up a beautiful "funnel on a flange" that was to go onto the turbo but I couldn't make it fit. I even cut his flange off and angled the funnel a little to see if I could clear everything but still no go. So I ended up making it, and all without a welder.

post-76144-0-35734700-1312373646_thumb.jpg

post-76144-0-45561400-1312373665_thumb.jpg

Oh, no E-manage, just voltage adjuster intercepting AFM signal. Have wideband meter so can DIY tune :rolleyes: .

3 inch dump 100 cpi racing cat , no resonator , varex 3 inch in 4.5 inch out cannon , sounds great . Had the wrong dump yet the guy at Bay Rd exhaust Cheltenham Melbourne 9585 4833 redesigned it , then he welded flanges on the cat and installed the varex for only $250 .So cheap.I would go to him if your in the area .

All mine I'm afraid. Scotty turned me up a beautiful "funnel on a flange" that was to go onto the turbo but I couldn't make it fit. I even cut his flange off and angled the funnel a little to see if I could clear everything but still no go. So I ended up making it, and all without a welder.

Oh, no E-manage, just voltage adjuster intercepting AFM signal. Have wideband meter so can DIY tune :rolleyes: .

Couldn't make it work? Shame, it took me hours to make. :rolleyes:

The first intake I designed failed because the airflow sensor was mounted on a similar bend, I hope you don't have the same issue mate. How does it drive?

Couldn't make it work? Shame, it took me hours to make. :rolleyes:

The first intake I designed failed because the airflow sensor was mounted on a similar bend, I hope you don't have the same issue mate. How does it drive?

Yeah, it was a shame as it would have been excellent - soooo smooth. Thanks again for doing that for me.

Mine drives nice. It does need some fine tuning to get the mixtures right, but in my short 15 -20km test last night I couldn't see any issues that can't be ironed out. Maybe it's because of the smaller bypass tube below the main one?

Yeah, it was a shame as it would have been excellent - soooo smooth. Thanks again for doing that for me.

Mine drives nice. It does need some fine tuning to get the mixtures right, but in my short 15 -20km test last night I couldn't see any issues that can't be ironed out. Maybe it's because of the smaller bypass tube below the main one?

i thought the bypass tube was cause it to go in limp, as its getting un metered air? or is that being fixed with the resistor

Leon, that IS awesome.

Nice work :)

i thought the bypass tube was cause it to go in limp, as its getting un metered air? or is that being fixed with the resistor

I'd think it would just run leaner wouldn't it?

I mean the AFM is metering x amount of air, thus would supply the "appropriate" amount of fuel for that air volume.

If the other 25% is not measured, just means that there would be more air for the fuel map quantity.

EGT would probably be higher so that might make the ECU have a hissy fit, but can't see an issue with bypassing the AFM.

Maybe I am missing something?

Leon, that IS awesome.

Nice work :)

I'd think it would just run leaner wouldn't it?

I mean the AFM is metering x amount of air, thus would supply the "appropriate" amount of fuel for that air volume.

If the other 25% is not measured, just means that there would be more air for the fuel map quantity.

EGT would probably be higher so that might make the ECU have a hissy fit, but can't see an issue with bypassing the AFM.

Maybe I am missing something?

oh fair enough, im just going into comparison to having a leak in the system. which caused mine to go into a limp but only up high in the revs

your probably right though.. u usually are lol

oh fair enough, im just going into comparison to having a leak in the system. which caused mine to go into a limp but only up high in the revs

your probably right though.. u usually are lol

Id have thought that it might go into limp mode also actually, if the O2 readings werent in line with what the ECU was expecting for a given AFM voltage

well my case.

i dont have a o2. i think the o2 only leans out the cruise(correct me if wrong)

i had a leak in my suction pipe as it wasnt secured properly. so it would only leak at high boost.

as soon as it leaked it was like the car hit a brick wall

i had a leak in my suction pipe as it wasnt secured properly. so it would only leak at high boost.

as soon as it leaked it was like the car hit a brick wall

thats after the turbo, its air that has already been metered, so the ECU knows about it.

this is tricking the engine into not knowing about the air passing around the AFM. its like having a leak in the piping BEFORE the turbo but after the AFM. it never gets under pressure

thats after the turbo, its air that has already been metered, so the ECU knows about it.

this is tricking the engine into not knowing about the air passing around the AFM. its like having a leak in the piping BEFORE the turbo but after the AFM. it never gets under pressure

where do you think a suction pipe is out of curiosity?

before the turbo, after the AFM.

did you read what i said? a pressure leak AFTER the turbo is completely differernt to one before the turbo.

a leak after it will cause the car to run rich as air is escaping; one before will cause it to run lean as there is more air in the system than it thinks is there.

I'm sorry I missed all this discussion - had to work away all day :down: .

Just to clarify, the bypass is so the AFM doesn't hit a voltage ceiling. I'm probably not telling you anything you don't know, but here is my take on it anyway, for those not sure what it's all about..

Background:

When you increase the size of the intake you get more air flow (obviously - that's what you did it for, right) & it is possible (likely) that the AFM will hit max voltage (~4.8V) before hitting full load - especially if you've done other mods. A few of you guys have experienced this already, hence the emanage. If you have a larger intake experiencing this, the ECU won't/can't increase injector pulse width (more fuel) if the AFM sits on max V.

Solution:

By sending some air around the AFM, the engine gets the extra air it needs but the AFM doesn't meter it, so the voltage is lower across the range (ie shouldn't hit voltage ceiling). The ECU reads this voltage as less load & will drive the injectors less ie run lean.

Now we use a voltage modifier (interceptor) to increase the voltage that the ECU sees from the AFM at a heap of (200+ in my case) load points by varying amounts depending on what your wideband meter is reading.

Progression:

This also allows someone to increase injector size & then recalibrate/retune. Now the good part. If you have a device that can send a "fake" EGO signal to the ECU for when in closed loop (cruise/light load), there's no reason why economy can't be retained (or bettered) even when increasing injector size with the factory ECU. My wideband meter does this!

There endeth the lesson.

Cheers, Leon.

before the turbo, after the AFM.

did you read what i said? a pressure leak AFTER the turbo is completely differernt to one before the turbo.

a leak after it will cause the car to run rich as air is escaping; one before will cause it to run lean as there is more air in the system than it thinks is there.

ok so what mine was, a leak before the turbo, after the afm.

up high in the boost it would set itself into limp after air crept through the silicone joiners..

sorry if i didnt explain properly birthday boy

This also allows someone to increase injector size & then recalibrate/retune. Now the good part. If you have a device that can send a "fake" EGO signal to the ECU for when in closed loop (cruise/light load), there's no reason why economy can't be retained (or bettered) even when increasing injector size with the factory ECU. My wideband meter does this!

There endeth the lesson.

Cheers, Leon.

So what is your Wideband O2 sensor.

Cheers

Andy

So what is your Wideband O2 sensor.

Cheers

Andy

http://www.14point7.com/SLC-Pure-Plus-2.php

Key Features

  • 0.01[Lambda] accuracy
  • Range; 0.68[Lambda] to Free Air, equivalent to 10.26[AFR] to Free Air for gasoline
  • Free Air Calibration of Lambda sensor capable
  • Digital display
  • USB connectivity
  • Multiple parameter display
  • Built in RPM pickup
  • Real-Time datalogging of multiple sensors @ 25 samples per second
  • Internal Memory for 2.9 hours of datalog storage @ 25 samples per second
  • Programmable Linear Output
  • Programmable Narrowband Output

Mine is the DIY version (of course, lol) & it doesn't come with the internal memory but otherwise the same. I need to have my laptop running in the car to log, but no big deal.

I have the boost sensor as well so it can be shown on the display as well as logged along with AFR, throttle opening, AFM voltage (has 2 x 0 - 5V inputs or G sensors). Having trouble getting RPM to register but haven't played with it for a few months. Must take another look at where I'm getting the signal.

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

    • ...just a note of warning, you shouldn't drive it about with the TCU in limp mode with only 3rd gear available ~ apart from the fact you end up sheering the ATF at the torque converter interface, the high clutch in these isn't especially the strongest, particularly bolted to the RB25DE mill...which is likely a 4AX01 box with lighter duty high clutch (the RB25DET got the bigger high clutch)...be careful out there...
    • Hoping to do similar mods to my RB20 once I get it running and reliable again
    • As you're looking at using a Link ECU, then large injectors are not a problem. But there's not really any need to go 1000s on an RB20 unless you're planning >>600HP on E85, which would seem unlikely. There are other options for injectors. The Xspurt ones are available from a number of places and you can get them in the mid 600s and 725cc, which is probably a sensible place to be. These are all EV14 based. If you are not using the stock AFM (at all, which would be the case with a Link) then a large turbo intake pipe to suit the ATR turbos is not an obstacle, so you should use one instead of a highflow. Results will be better.
    • Hey guys,  I'm after some advice and this here is the best place to get it imo. I was a member a looong time ago under another account, with a lost email address. Its nice to jump back on and see some of the same names still giving good advice.  I mothballed my car when i moved to perth in 2013, and after getting towed across the nullabor a few times it has officially done more km's on a trailer than under its own power. Now that i have started the process of tidying up and modifying it, i see the fruit available (and the fruiterers selling the produce) is different than back in the day. hence my questions, as i used to 'know' what to get and now, i'm not so sure. Engine wise the car (92 gtst) has a walbro 255, k+n, fmic, cam gears and and turbo back 3"exhaust. Wish list is a Hypergear high flow or ATR43G1, Link G4x and some newer injectors before a tune up. My goals are modest, only low 200's power wise. i know i could achieve this with less, but i've been swapping out old for new where i can. Every cooling hose has been replaced, along with mani gaskets, WP, thermostat and radiator, fuel pump and timing belt, tensioner and idler, and i rebuilt the steering rack. Regarding the injectors, the fruiterers all seem to sell what used to be considered quite large injectors. There are a lot of options for bosch 1000cc EV14's, and i would like to know if that is a suitable choice for my build. Is modern injector design good enough to run these at the low duty cycles that i likely would be? is there a downside to running a too large injector these days? or, would there be an upside to running a smaller injector at higher duty cycle? I can see that there are smaller injectors still available, but the ones i have seen specifically marketed for RB's are pretty large (see: https://golebysparts.au/collections/fuel-rail-injector-kits/products/nissan-rb20-fuel-rail-bosch-980cc-1150cc-injectors-turbosmart-fpr800-regulator-kit), and i dont know enough about them to say one not marketed for RB's would fit or not. I have searched the forums, and amongst all the posts on older tech, I did see gtsboy recommend EV14's, but no size was mentioned... again, i'm not clear on if the smaller size bosch injectors are also EV14's as they do look similar.  also, if someone can recommend a tuner familiar with RB's in the Geelong or West Melbourne area i'd appreciate it. Thanks in advance guys. Cheers, Rowdy  
    • FWIW the depth of the groove in the rubber pad is not super essential, the blocks are rubber and squish a bit. If you are worried an angle grinder will make a deeper groove quick smart
×
×
  • Create New...