Tuned sr20 map help

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RaymondK
 

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Tuned sr20 map help

Post by RaymondK »

Anyone got a 400hp ish map I can have a look at before my primera goes on the rollers next week. First time doing at map myself.
I'm pretty certain it won't be the same as what mine will turn out to be depending on turbo exhaust etc etc but it's purely for me to look at over the next week.

So bin files much appreciAted guys...
Thanks
PL
 

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Re: Tuned sr20 map help

Post by PL »

What size injectors and what AFM are you running? How much boost? What fuel?

PL
RaymondK
 

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Re: Tuned sr20 map help

Post by RaymondK »

Hi Pete 550 injectors q45 afm 1.5 bar of boost 97 Ron unleaded.
Was just wanting a point of reference or even a starting point.
Type 4 p11 Sr20de(t)

Thanks
PL
 

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Re: Tuned sr20 map help

Post by PL »

Hi Raymond,

OK, I've dug out some maps that'll give you the idea.

First - for 550cc injectors I'd expect to see something like this:
SR20DET 550inj fuel map.jpg
(75.84 KiB) Downloaded 8583 times
And for the IGN something like this. These numbers were taken from an S13DE+T job I did once. If you're still running 9.5:1 compression then you'll be seeing IGN values down around this area. Once you go lower than 3 or 4 degrees you're pretty much at the stage where you either have to lower the boost, lower the compression or increase the octane.
SR20DE+T IGN map.jpg
(77.94 KiB) Downloaded 8583 times
Please disregard the load scales - yours will be different. Adjust your K Constant until it's reasonably sweet with the values in that fuel map (tweak injector latency to get idle/low load nice). Then adjust the load scales so that at full boost it runs over and just touches the last column.

PL
RaymondK
 

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Re: Tuned sr20 map help

Post by RaymondK »

Hi Pete that's a big help. I've got much lower compression now I've got
86mm pistons in there. Been talking to matt on another thread regarding
Bad starting poor idle etc so should hopefully be able to pull it all together
I've uploaded my bin aswell for comparison
Thanks
PL
 

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Re: Tuned sr20 map help

Post by PL »

If you have less compression then the IGN map numbers on the right half of the map will increase appreciably. I usually see about 10 degrees or so in the midrange on the 8.5:1 SR's and then you can usually sneak more timing in as RPM increases. Usually to 18 to 20 degrees up top. Depends on your ultimate boost level of course - but those figures would be representitive for 14 to 16psi.

The main point ot note (dunno how much SR tuning you've done...) is the shape of the IGN map. They always have a hollow in the midrange where max VE happens. But once you're over that the numbers can be increased again. Peak horsepower often increases quite a bit if you can get more timing in at high RPM. But detonation always limits things.

Anything you can do to get more timing in up top will get you a bigger peak HP number - if that's your thing. This is one of the reasons why they respond so well to E85. It often allows figures of up to 25 degrees IGN timing up top, which makes the power curve just keep going up where it would normally be nosing over and heading south.

PL
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Re: Tuned sr20 map help

Post by Matt »

Just posted in the other thread. Was suggesting go back a step and trying to get his idle and low load/rpm AFRs correct with proper K and latency value (0.5ms seems to low at the moment from the tune that was posted)
PL
 

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Re: Tuned sr20 map help

Post by PL »

I've not checked the tune but you usually want 1.5 to 2ms at idle.

PL
RaymondK
 

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Re: Tuned sr20 map help

Post by RaymondK »

guys thanks alot. I'll deal with the idle stuff mentioned by matt in the other thread.

I did find a big spreadsheet showing all the latencys. its does actually say 650... so I'm guessing I want way more in there for it to settle down properly

pete more timing for the win then! will that have an adverse affect on the torque figures?
RaymondK
 

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Re: Tuned sr20 map help

Post by RaymondK »

right guys just to confirm, ill set the injector latency to 650 which is the standard figure for the injectors apparently. Am I right in saying that should stay like that?

and i should be decreasing the K Constant to get the idle to sit properly? from there I can get the ignition timing totally sorted and it should match up with the timing reading on the gauge panel...

Pete did mention the latency should be up to 1500-2000 should I be changing the latency and leaving the K or the other way around.

honestly this should be the last question!!! dyno on saturday so just want it ready to go!
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Re: Tuned sr20 map help

Post by PL »

Don't get just too carried away with setting latency up front. I tend to use it as a trim to get low load/idle correct. I know that's not how it's done for aftermarket ECU's but that's what works best for these.

Here's what I do to rough things out:

1) Set the values in your fuel table for around what I posted in that image (ie: max about 35 to 40)
2) Run the car up and adjust K constant until you get your full load AFR's about right (I aim for 11.7:1)
3) Adjust load scales so that you just touch the last column on full boost
4) Adjust latency to obtain smooth idle/low load running (at whatever AFR works for your engine)
5) Now you can spend some time on the IGN maps. I add 2 degrees at a time to the whole right half of the map. Monitor torque and audible detonation as your add timing. Power will keep increasing (SR20's just lovvvve timing) until you approach knock threshold. Once you're close you can start adjusting on a cell-by-cell basis. Work out where the knock threshold is and make sure you back timing off until you're clear of knock.

* Make sure you have the correct VQ map loaded for your AFM.
* Monitor knock at EVERY step.

If everything is working properly on your engine (no air leaks, TPS adjusted correctly, base IGN timing correct, fuel pressure correct, decent plugs fitted of the correct heat range, etc. etc) then the first 4 steps can usually be achieved in about 10 minutes. Then you can spend hours getting everything tweaked to perfection!

PL
RaymondK
 

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Re: Tuned sr20 map help

Post by RaymondK »

all makes sense. the last thing that caught my eye when looking at the guide was the
accelaration increase fuel vs tps voltage. the table shown on the guide has the majority
of the table at maximum however the one on the P11 Sr20DE is up and down all over the
place. should I be setting it as per the guide of leave it be. the thing is the RNN14 standard
map is different again from this majority of them are set at 0.
RaymondK
 

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Re: Tuned sr20 map help

Post by RaymondK »

Failed at first hurdle. Cant get the motor to idle on its own... Soon as it dips below 1000rpm cuts out.
Also soon as the engine starts to heat up... If the engine dies
I can't get it going again but if I leave it alone to cool down itll fire up


Starting ismt great either when it's cold either take s a few rotations a pumps of the gas to get it started ans I have to hold it with the pedal

The mapping I've got Sussed but I can't set the base ign timing without it dying on me

Help!
PL
 

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Re: Tuned sr20 map help

Post by PL »

Was the engine running properly with standard injectors and AFM after NIStune board was fitted?

PL
RaymondK
 

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Re: Tuned sr20 map help

Post by RaymondK »

Ive had it idling ok with the same afm but with smaller injectors.... thats how I thought the K or the latency was off..
When you mentioned the latency should be 1500-2000 I though that might the cure. I havent tried that certainly but its the warm start problem aswell with smaller injectors thats why I assumed it was an ecu issue.

If there was an issue with the AFM would that not present itself on the voltage table and show an error code?

just seems to me its a fuelling problem. revving through the range its totally fine. just off load at idle it gets lumpy and shuts off. cold/warm enrich? the idle stabilization is having no effect either. or is it somethin even more primitive like the min TTP/max TTP off load...

if I can get the idle sorted then everything else will be sweet!
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