Jump to content
SAU Community

Recommended Posts

warpz0r, my understanding is passing emissions does not necessarily mean absolute best fuel economy (hence your lean comment).

Ign and afr's affect the levels of different gas the motor expels.

It must be tuned correctly; and emissions test is not done on boost, so plug in the stock ecu and pass that emissions test. :dry:

Thats my limited understanding. :)

I haven't actually seen the ecu thread on calaisturbo.

The RB30DET actually runs fine behind an rb25det ecu, on boost afr's are quite nice and it simply just runs.

Providing the motor has been setup with factory like squish/quench there 'shouldn't' be an issue passing emissions on the stock ecu.

The Rb20DET ecu however struggles as its airflow map has not been designed to see anywhere near the airflow levels the 3ltr pushes at low rev's. as a result it fuel cuts very early in the piece with only 6-7psi on a stock rb20det turbo.

Then there's the cost of an emissions test.. So as Nismoid put it.. not feasible/possible :D

EDIT: I'm having a read of the ecu thread now.

http://www.calaisturbo.com.au/showthread.p...t=ecu+emissions

in NSW the emissions test is free...

so hyperthetically speaking - having my rb30det emissions tested using a rb25det ecu with stock injectors and my current turbo (hiflow) boost limited to a lower psi should get within an acceptable range providing i switch injectors to stock and maybe put a brand new cat converter in place?

in NSW the emissions test is free...

so hyperthetically speaking - having my rb30det emissions tested using a rb25det ecu with stock injectors and my current turbo (hiflow) boost limited to a lower psi should get within an acceptable range providing i switch injectors to stock and maybe put a brand new cat converter in place?

What about the fact that you have 0.5 L more capacity - it will be lean which increase HC which increases the chance of failing.

Why would it be lean?

Airflow is relative, it sucks x volts through the afm it drops in y amount of fuel.

On the stock ecu my afr's on cruise and light throttle etc were all perfect, on boost as I said prior it would fuel cut.

Another bloke in the early days of rb30det conversions simply dropped a rb30 bottom end under his r33 rb25det head, all still with stock inj, ecu, turbo etc.. AFR's were all good. Ran fine and with a slight increase in cas ign. timing it made close to 200rwkw, same as the rb25 he had prior just with a lot more area under the curve.

have noticed that lean ups the ratio of another gas .. cant remember which one..

this will sound bad, but to pass a CA18 in a sprinter we had a copper pipe attached from the turbo outlet pipe, onto the exhaust pipe..

so it basically pumped fresh air into the exhaust ready for them to read :D

i gues that would suffice if your desperate... just know how much Moanie on teh forums had to go through with Hitman to retune the car over and over to get it to pass and that was on a 240rwkw RB25

Why would it be lean?

Airflow is relative, it sucks x volts through the afm it drops in y amount of fuel.

On the stock ecu my afr's on cruise and light throttle etc were all perfect, on boost as I said prior it would fuel cut.

Another bloke in the early days of rb30det conversions simply dropped a rb30 bottom end under his r33 rb25det head, all still with stock inj, ecu, turbo etc.. AFR's were all good. Ran fine and with a slight increase in cas ign. timing it made close to 200rwkw, same as the rb25 he had prior just with a lot more area under the curve.

Really there was no jerky ness or drivability issues - its more to do with throttle enrichment as its based on TPS enrichment not airflow, also cranking fuel as its pulse width vs ECT.

No jerkyness, no dead spots nothing just smoot, like factory. it was all perfect.. Mine was on the rb20det pfc and this other dudes was on the r33 ecu. mr_rbman also ran his in on the stock rb20 ecu. Ran started and drove fine.

Prior even with the rb20det I had a cold start issue that too carried over to the rb30det where it would fire then stumble. The only fix was the pfc. I would have most definitely noticed any drivability issues as I ran the stock ecu on it for 10,000km's.

I've got vids of it driving.. Nice and smooth, if anything it felt as if it was punchier off idle with the stock ecu vs the pfc.

No jerkyness nothing smooth.. it was all perfect.. Mine was on the rb20det pfc and this other dudes was on the r33 ecu.

mr_rbman also ran his in on the stock rb20 ecu. Ran started and drove fine.

Prior even with the rb20det I had a cold start issue that too carried over to the rb30det where it would fire then stumble. The only fix was the pfc.

I've got vids of it driving.. Nice and smooth, if anything it felt as if it was punchier off idle with the stock ecu vs the pfc.

Fair enough - I've got to admit though I do almost halve throttle enrichment in both the PFC and standard ECU, but not in all cases.

Its a good discussion though as I will be trying to pass my rb30/26 with the standard ECU retuned by me.

Edited by rob82

yes the pfc does tend to run quite rich throttle enrichment, unsure on the stock ecu. But as you say if you pull nearly half then there must be a little head room where it just happens to work ok with the rb30det.

Care to share what values you found to be near optimal with the pfc? :D

Off the base pfc values mines running a tad less than std. But I still think it may be a tad rich, haven't really had much of a fiddle with accel enrichment as of yet.

yes the pfc does tend to run quite rich throttle enrichment, unsure on the stock ecu. But as you say if you pull nearly half then there must be a little head room where it just happens to work ok with the rb30det.

Care to share what values you found to be near optimal with the pfc? :D

Off the base pfc values mines running a tad less than std. But I still think it may be a tad rich, haven't really had much of a fiddle with accel enrichment as of yet.

Just as a guideline enlearn it until it drives shitty. It's different with different mods - injectors, airflow meter plenum size and so forth.

Any quick tips on how I should do this as there's the amount and decay value. I simply pulled out a little decay, made no difference to feel. :S

No pull the pulsewidth value out - the decay you need to have a drive and a feel and watch your mixtures with a wideband. The decay is mainly used to enrich for the time it takes the manifolds volume/ pressure to stabalise. So for a properly mapped system the mixtures wont change with any amount of throttle disturbance.

Sure you could tune it to meet an emmision standard, but what one, one from 10years ago?

It wouldn't go anywhere near meeting current emmisions standards for manufactured vehicles.

They had to build newer NEO engines for a reason and drop the SR20 altogether.

About all you can do is use a good 3way catalyst, set your ecu up for closed loop control to target a 14.7:1 AFR when cruising and enjoy reduced fuel usage and cleaner emmisions during this period when the engine is warm and knowing that your car would pass an emmision test for cars from 1986 that only required closed loop and a cat.

Better then not doing anything, but in reality a few modified cars contribute bugger all to greenhouse gas when compared to industry and coal powered power plants.

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


×
×
  • Create New...