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Tuning Rb25S For Eflex And E85 .


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From Guilt-Toys thread - he mentions setting cruise to 48 - 50 degrees with a RB30 on E85. See below:

"Set the gizzmo to record and went for a drive, car felt more responsive then before, felt like boost was commin on quicker, played back the quick drive and the knock did not go over 14, which is quite low for my RB30DET, so up goes another 10 deg over the whole map, i adjusted the idle back down 20deg, went for a drive and she is more responsive again! I could not believe it!

I was kinda thinking on the way home maybe the fuel i got is not e85, because i was thinking it cannot be that easy to convert over, untill i looked at the thermocouple EGT sensor and noticed exaust gas temps are down by a fair amount... ok it must be the real deal.

I noticed the cruise ign maps were set to 55deg so i dropped them down to around 48 to 50 in some parts and came home."

Edited by simpletool
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I think you'll find that extract was from the first time he put United E85 in his car ar Rozelle and then uploaded a map he made from pure estimation .

I'm not sure he ever showed any of his timing or fueling maps on this site . From what I remember him saying he was increasing the whole timing table by a sizeable amount and pulling back the extremes by probably similar amounts ie the idle and part throttle light load areas .

The other thing is that an RB30 is a 20% larger air pump than an RB25 is so you would expect it to make cruise type torque at small throttle openings and lowish revs .

He had the advantage of being a more experienced tuner than I am with access to a dyno which I don't . He would have had better petrol mapping and I'm sure thats a big advantage when you change fuels and in my case just upped the injector trims 30% . Adding this extra fuel across the board just allows for the difference in the heat value of the new fuel so you in theory end up with very similar lambda numbers .

As I said before with a PFC a Datalogit and enough injector making the change to E70/85 and having you car run acceptably is childishly easy - provided your petrol mapping was good . Mine was just sort of Ok and thats why I've been tapping down the road with a walking cane .

Obviously I need a propper tune on a chassis dyno with an educated operator . Also before doing that I need something a bit better than a 34 SMIC and that was someting Guilt already had done .

I'll see if I can cut and paste my current timing map , A .

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I couldn't bridge the operating system gap 7/XP and I normally run Datalogit from XP because I couldn't get Win 7 to work with the USB converter cable . Nowdays I just use a Serial cable because it never locks up or blue screens . I'll get around to trying the serial with Win 7 soon .

Anyway it occured to me that the Datalogit comes with various RB startup maps and I had a look at their RB25 ignition table which is along similar lines to mine but different in a few areas . Also their water temp enrichment and accel enrichment tables are slightky different to mine and I'll give them a go too .

On the fuel side they are a bit leaner than my figures at light loads and richer at high loads and I'll try theirs if the timing figues work out ok .

I had my Evo out recently and you forget how much petrol stinks compared to E70 and the same with petrol exhaust fumes , consumption and tuning antics aside the high eth stuff is nicer to work with IMO .

A .

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I decided to try the RB25DET defaults maps and with the Z32 and injector trim alterations it runs quite reasonably .

I would not hesitate to try this if you had enough injector and pump and had access to a Datalogit . I wouldn't thrash the thing without a propper tune but to just get around its quite reasonable . I didn't have the wideband in at the time and consumption looks a little higher than with my maps but I'm about to plug it back in and have a look at the Lambda numbers .

A .

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I'm starting to get what I think may be some missing at large throttle openings and on boost so need to look at new plugs and if its still there possibly coils .

I think the Sk33 had red Super Spark coils in it and they seemed to work well .

Pita job but am wondering what the sock strainer looks like on the 33GTR pump in my tank .

If I had to replace that I'd look at Tomei or Nismo direct replacements .

Just on coils is the coil loom available through Nissan here ?

Cheers A .

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Tuning on hold ATM because I'm having ignition system probs . The plugs were removed today and found to be the NGK BKR 7 heat range ones with big gaps . They were closed up to 0.8mm which showed a slight improvement but the issue seems to be the coils . They look very clean all over but that doesn't mean squat . SKs std coils were stuffed and they looked the same as mine so I'm ordering some pretty blue ones later today .

A .

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I had time to do some tuning today whilst running around and the coils have made a big difference . I was able to add more fuel in a lot of areas and it has made drivability better everywhere and mostly the mixtures are near where I think they should be . I didn't get a chance to load it right up but at least it doesn't break down with a bit of load on it .

I wonder how many RBs are running around with ailing original coils , I think mine were the cause of some degree of grief the whole time I've had this car .

I need to redo my petrol maps so it drives acceptably if I had to use PULP again .

Cheers A .

Edited by discopotato03
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PFC should have no issues in lambda mode, if someone reckons the pfc feedback is crap ask some of my E85 customers who are getting killer mileage... trust me it works better than many standalones in fact.

There are some steadfast rules to making it all work and honestly most dont adhere to them so its all turns to shit.

BTW all tuning must be done with feedback turned OFF.

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Yes I learn't earlier to turn the feedback off and leave it that way . Is there a way to set the target Lambda number you want it to use ?

I don't have any EGT test gear but I imagine it would be handy too .

Also playing with an RB25 is a pain coil and plug wise with the crossover pipe above the cam and coil covers . Must be real easy wth 26's .

A .

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Yes I learn't earlier to turn the feedback off and leave it that way . Is there a way to set the target Lambda number you want it to use ?

I don't have any EGT test gear but I imagine it would be handy too .

Also playing with an RB25 is a pain coil and plug wise with the crossover pipe above the cam and coil covers . Must be real easy wth 26's .

A .

Yeah only turn the feedback on once the tune is finalised.
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BCPR6ES are pretty common, they're what I use and are always on the shelf at supercheap. My sets usually last 20,000km at least and that's with 15psi @ 11.5:1 AFR on 98RON. I put split fire coils in ages ago. I reckon 90% of RB25 owners on here will have replaced coils by now. This is the first set I left at 0.8mm and I reckon I should have taken then up to 1.0mm, my fuel economy has suffered a touch.

A yep, replacing plugs does suck, especially if you've cracked an insulator and you don't notice and you have to clean it all up.

There's been heaps of discussion about copper vs platinum vs iridium plugs a few years back. Most seem to go with coppers and if your tuning is decent and rings are OK then they should last OK like mine.

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PFC should have no issues in lambda mode, if someone reckons the pfc feedback is crap ask some of my E85 customers who are getting killer mileage... trust me it works better than many standalones in fact.

There are some steadfast rules to making it all work and honestly most dont adhere to them so its all turns to shit.

BTW all tuning must be done with feedback turned OFF.

I have a Innovate Air/Fuel guage on my car that has a programmable output. Could this be a viable way of adjusting the closed loop side of things?

I am running a EMU. I could use the A/F target map to do it if I could find some way to disable the original narrowband as unplugging it sends the car mega rich. Does anyone know of a way to do this?

What sort of numbers seem to be working on the light cruise side of things? My car sits between 14.7-15:1 on the cruise so it's pretty much at lambda. It doesn't bounce around so I'm guessing the tune is pretty close and it's not being controlled too much by the narrow band.

On another note, I'm really going to have to start using lambda numbers in place of A/F, will make this thread easier to read without having to do the conversion in my head :)

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I'm running an Emanage Ultimate. It's good for what I'm doing but the feedback side of things can because bit tricky. The standard ECU does its own thing in the light load areas so adjusting these areas does nothing due to the standard feedback loop.

I've been running the innovative MTX-L for almost a year with no problems. I like the fact that you can calibrate it. The AEM type say that don't need to be re calibrated but they both use the same sensor? I feel that if one goes out of calibration they both will and only the innovative let's you recalibrate it. They all seem to have reports of problems/failures but the innovative was the one I went for. Plus, I got a great price from the official Australian distributor.

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