Well I know the subject doesn't help much but maybe you guys can help out.

I just recently installed my RX6B kit and am having some trouble tuning the car. The problem is that I am having to take out more fuel up top than what I had programmed in with my upgraded twins. So much fuel that when I do a compare using the datalogit software to base 2.01 maps, that I have less fuel in the fuel correction cells than what comes stock in the 2.01 maps. The area that I am talking about is from around 7psi - 14psi and from around 4000 - 7000 rpm. I have had to pull fuel out of all these cells and I am still showing rich (10.5 on the wide band). I have stopped messing with it for now as this just doesn't seem right. I know everyone is going to ask what mods I have so here is how the car was before installing the single.

-360 hp from last dyno at around 13 psi
-street ported motor with 2 piece 2mm seals
-ported upper and lower intake manifolds with double
throttle removed
-dp/mp/cb
-550/1200 inj and upgraded fuel pump
-greddy fmic and type s blow off valve
-intake of course
-power fc/datalogit/wideband
-upgraded twins with t25 exhaust wheels and super 60
trim compressor wheels thermocoated and and ported
and polished
-crane hi-6 with stock coils and magnecor 10mm wires
-ngk 9's all around
-underdrive pully kit for altenator and waterpump
-thermocoated hard pipes for all intake

with this setup, I had fuel maps that were a little rich to be conservative. all the cells in my fuel correction table were higher than what is there with the 2.01 stock map. When I went with the single, I figured they would end up being lean, and that I would have to add more fuel. What happened was just the opposite. In boost, I am way rich. I have pulled fuel out to the point that I am now below the 2.01 stock values. Cruising cells and high rpm low load cells have higher values than the 2.01 maps and seem to work fine. When I go into boost however it is a diffent story. I immediately make full boost and my air fuel reading on my wideband shows 10.5 and the cars feel flat. I am afraid to pull out more fuel at this point but everything seems to point in that direction.

When running larger secondary injectors, does the fuel correction map in the powerFC get thrown off? Is this normal to have to start from scratch and there is no reason to be concerned that my fuel correction table is below the stock map settings under boost. My actual base map is the same as the 2.01 default so I have not accidentally recalculated the base map. My inj. settings are as follows:

550 pri 100%
1200sec. with .08 lag
40% trans pri/sec
1.5 sec trans (ms)

I would like to state that I was concerned about backpressure issues when I saw how small the exhaust port is on the rx6 manifold. I got my hands on a B kit which I was told had a larger exhaust side than the A kits. I was leaning toward a gt35/40 but got a good deal on the RX6B from Japan and thought it would be somewhat close due to having the larger exhaust housing than the RX6A. This is not the case by the way. The b kits from Japan had a slightly larger compressor housing than the A kits( the 77ls vs the 76ls) and they mount down lower. The exhaust housing is the same.

Could it be that this turbo is creating more backpressure than my upgraded twins and this is what is causing my rich problem. Nothing else changed on the car other than installing the single. Also, I do not see alot of black smoke when getting on it. I would think if it was running real rich, that it would be throw some black smoke or is 10.5 ish still not rich enough to see in the rear view mirror. The car feels faster down low but flatter up top. It seems to not pull as hard above 5500 or so. The upgraded twins seemed to be weaker down low but had more breath up top. I did not want this to happen and was weary of getting the apex. It still could be a tunning problem, but I am wondering if I am just flowing too much for this turbo's exhaust side.


anyway, any help in any are will be appreciated

mike

 

I'm seeing the same thing you are. In the P17 row, the stock map runs from 1.36 to 1.41 after N10. My current map runs from 1.28 to 1.31 in the same region, and I'm still really rich as well (10.2). I've been hesitant to lean a lot more for the same reason as you, but my AFR readings from my DIY wb were confirmed when I had the car dynoed, and I have no signs of detonation. FYI, I saw a lot of soot come out the tailpipe on the dyno, but I don't see it driving.

I have a HKS t04e with 550/1300, dp, stock cat, cb, IC. Dynoed at 289 when my AFRs were in the high 9s. I've been thinking that my flow problems might be partially due to the cat, and I'm going to go with a high-flow in the next couple of weeks. Settings on the PFC are 0.2 lag, 40% trans, 0.98 ms transition. I have 4,7,7 on the overlap.

 

How does your car idle? Does it crank up good and idle nice and smooth? If not I'd check your coils and Crane to make sure your leading isnt messed up. If the leading is weak it might just not be combusting the fuel.

Also, you could have a boost leak. I know 2 people that have had a problem with the Greddy FMIC pipes poping off at the IC. They would still get boost it was just leaking real bad.

STEPHEN

 

Where are you placing the WB sensor?

 

car idles and starts fine.I just pu a new alternator on and rewired the crane and leading coil.I noticed a difference in how the car sounded,primarily due to the alternator,go figure.the coil ohm'd out OK.All the IC piping is tight with high end clamps.

As for the WB sensor it is in the stock position on the APEX down pipe,which does seem close to the turbine,about six inches away.

Mike

 

To see what is really hapening to your fuel levels in the PFC, you need to get a datalogic an do a recalc. You can not enter more than 149 in a correction cell. It is then easier to make adjustments on the fuel correction map as they will then be straight simple % changes. You also can then go look at the new base map and look at the fuel trends from low to high boost and low to high rpms.

Just like looking at split showed that the original maps were crap for IGT. Doing the recalc you will spot fuel irregularities.

ALso check your PIM maps to be set at 0. Recalc does not use or affect the PIM maps.

SPOautos is correct about misfire. It will cause lower(richer) AFRs.

I hope the single does not have more back pressure than your twins did, that would be terrible!!

Change to Taylor plug wires as they are better than magecor which I had first an through away.

 

Hey Chuck, Thanks for the info. I have not done a recalc yet as I was unsure what it would change. I will try it and see if it makes things easier to read. The fuel settings in question are in cells with #'s around 125 to 135. it's not where things are maxed out(149). The problem isn't really a problem in 1st or 2nd gear. I can spin the tires in 2nd gear by punching it at 4500 rpm. But when I am in 3rd or 4th and punch it, it goes real rich until about 7k where it finally comes back into the upper 10's/lower 11's where it should be. in the mid rpm's, it is off the scale on the wide band. I can lean it out with the correction map even more but I am already seeing #'s below a stock map and thought this was really odd.

I do not have any #'s in the PIM section at all. My timing map is good and I would think that spark problems would be in the upper rpm's.

The question about back pressure came about after seeing the exhaust inlet opening on this turbo. It seems rather small to me, as does the exhaust housing. even the downpipe starts out small and gets bigger. Everybody talks about how much air the 7 moves and not to get too small of a turbine. The reason I got the rx6b was because it was supposed to have a larger exhaust side than the A model. I wanted someting with good top end as well as good low end. This turbo pulls strong down low for sure and makes instant boost. It just seems to flatten out up top like my stock twins did. what confuses me is that if it makes so much power down low, then why is this where I am rich. I would think that I would need more fuel here to compensate for the extra flow, not the opposite.

please be aware that this is compared to my upgraded twins which were t25's with super 60 wheels. When both turbos were runing, i think they moved more air. I do not know if the difference was due to better intake flow or exhaust flow. Do you think the combined exhaust flow of the twins is greater than that of the apex? I know the path is less direct but which do you think flows the most air. Has anyone done any porting to the exhaust side and what effect would doing a clip have. I could easily sacrafice a little spool time for more upper end power with this turbo on my car. Like I said, it's not like I even have a turbo. The curve just feels flat with it falling off at the upper end sooner than before.

mike

 

If nothing has changed except swapping turbos, only two things can cause richer AFRs at the same boost;
(1) more restrictive exhaust which causes same boost pressure but less air flow, (2) more flow at same boost causing spark plug misfiring.

Now if you had changed the FP, FPR, or filter, these might cause higher fuel pressure than you had before.

Compare a new datalog run with an older one and compare the graphs for both AFR and boost pressure.

Make sure you are not really going into a higher P row were that is too rich.

 

I just took some boost readings at different places and came up with some alarming news. I recorded over 20psi at the compressor outlet where I have a nipple installed while only seeing 10psi max at the manifold as confirmed by both my power fc and my boost guage which are hooked up to two different locations on the UIM.

What gives.? This has to bad. At 0psi I am seeing 6-7 psi at the compressor outlet and at higher rpms and the same 0psi at the manifold, it has gone as high as 12 psi.

any help!!!!!