Rb20/nistune - Timing For Quicker Spool

[rx-line]

Hi Folks,

Curious as too what my timing should look like for building boost and why the factory maps have such high timing under little load. I have smoothed out the map a fair bit and reduced the 0 load side a few points.

With 93 octane and a little octane booster I am running 12.5 to 11.5 afr's as boost progresses. I have the turbo, injectors and all supporting mods to keep intake temps down and decrease detonation.

Should I program higher timing while 4000rpm-5000rpm (5psi-12psi) building boost to 15psi aorund 5600 and run more or less fuel in the transitioning period??

Is 22 degrees safe for the above statements?? What would a good timing map for a 20 look like?

RX,

[rx-line]

Also I am in the 88 column at max load. I am thinking as my MAF sensor is maxing out but AFR's are find and everything seems safe.

[Dose Pipe Sutututu]

Hard to say, but looks pretty flat.

Less timing will make the turbo come on a little quicker as EGTS are hotter and richer AFRS will increase torque but sacrifice some power.

Post up a map trace on like a 3rd gear pull.

[rx-line]

I will do that tomorrow, things seem conflicting in this subject. A bit of a trade off it seems. Ultimately I want low end power (something RB20's dont have much of) I just thought boost was the way to go. It has nothing below 4000rpm and takes off to space @ 5000rpm. Running 12.699 with 2.0sec 60 foot. in the 1/4. The 60 foot is either spinning on boost or bogging off boost depending on launch.

Rx,

[GTSBoy]

You can try it both ways, but really RB20s have so little torque off boost that you are best off trying to optimise the actual output of the engine in that "just-before-boost" area. By this I mean give it as much timing as it will take. Retarding the timing will indeed give higher EGTs and perhaps start to spool the turbo a little sooner, but it will feel less torquey because of the lack of timing. The factory maps have a lot of timing down low because the engine feels better that way.

You have to be careful loading in lots of timing in the 4000-5000 rpm band because that's peak torque, where it is most likely to ping.

Now, have you rescaled the load axis of your maps? I don't recall the RB20 max column being at 134. It's originally 128 isn't it? If so, and given that you have different injectors in there, then stuff (like the K factor) has already been fiddled with and it is very difficult to comment on why you are getting a TP value of 88 for max load. Maybe it's correct, maybe your AFM is maxing out. Can't tell from here. One thing I can tell you is that if you have a bigger turbo then you are almost certainly maxxing out the AFM. You can get pretty close to max just on the factory turbo and 13-14 psi.

[rx-line]

14psi on rb25det turbo had me hitting boost cut on a factory ecu but not on a mines tuned ecu. I now have a Holset Hy35. I have fiddled with the Kconst and Injector Latency from what is reported for GTR injectors to get it to idle and run right on the factory nistune maps.

I smoothed the timing out and fuel maps from there. I did increase load and rpm values to capture everything. Is there really a right and wrong with Injector Lat and Kconst if Afr's are correct?

I don't see a downfall of where I am at with the AFM, like i said timing and afr's all seemed good in high boost. Is there something else I should be looking at?

Thanks,

[rx-line]

Also What would you like me to trace?? I can't log Wideband but can log factory o2 if it even works on open loop?

3rd gear pull from 1500rpm to 8000rpm

RPM

Timing

MAF

Temp

Injector Duty Cycle

Anything else?? Or are you saying to trace timing?

[Dose Pipe Sutututu]

as you're about to do a 3rd gear pull press the t key and you'll see a cell tracer appear. It will highlight the cells you hit on your run.

Do a screen shot of that and post it up.

[rx-line]

The second timing trace obviously correlates with the recording of the 3rd gear pull. didn't go all the way to 8k.

The timing tapers off to 22deg in boost. Maf is maxing out at 7kish as you can see.

[rx-line]

Starting from about 2k rpm

[rx-line]

build me a map guys!

[GTSBoy]

Really? You're not worried about not listening for knock? I would never road tune high load timing.

[STATUS]

turbo, cooler and exhaust all have an effect on what timing you can run, a dyno is the only real way to tell what effects more or less timing are having. More importantly a good knock monitoring system is paramount.

many rb20s would eat them selves with that timing table.

[rx-line]

Really? I hear so many different things. And your right. The folks here in canada east who run the dyno shops are f**king moronic. I'd rather learn myself.

I have heard that the 20's love timing up top.

I have every mod done to the engine without opening it up. It's also in a 2400lb factory car (FB rx7) without power steering, AC pump, Clutch fan etc.

[Ben C34]

Every mod.

[rx-line]

I probably shouldn't road tune, but I work with what I have. It's either that or let a monkey tune it?

So any idea on timing? I had decreased the factory map by 3-4 points in certain areas and adjusted Afr's while gradually progressing the rpms and tuning accordingly. The timing is still not as high as it was from the nistune base map.

Bens probably gonna flame, But for reference purposes only, see attached picture. Can see holset and manifold we built with tial 38mm no other pics of new setup.

[rx-line]

So is there an aftermarket knock sensor?, I enabled knock tracing while running low timing and rich one time and it lit up everywhere. I am assuming that setting is too sensitive or the sensor is on the fritz. Not noticed as the knock timing map is the only timing map available?

[scotty nm35]

Grab a set of knock ears and have a go, what do you have to lose other than an RB20. Every tuner started somewhere, and there is only one way to learn the effects of too much timing.

I prefer less timing and all the boost personally, but as Trent said, every engine and modified part reacts differently, and good fuel is critical.

[Dose Pipe Sutututu]

that's a kind of timing map for E85, there's too much timing.,, but listen to STATUS, he does this for a living.

[rx-line]

I will do what I can to get a knock monitoring system in place. But I have two questions prior.

What would a safe map look like? Is it too high in all areas? off Load? On Load?

If my crank angle sensor was off center would it adjust my timing on the tables or just increase/decrease my timing depending on how much it's out?

This is of course why I had posted here, I appreciate the insight.

Rx,