Nistune Forums

That was kinda gonna be my next thing to try. It just seemed weird that I couldn't even adjust boost around the standard boost level.

I've gotta do some more work on that S15 soon (Z32/550's/2871R/FMIC and decent exhaust) so I'll play with the factory boost control system some more then.

I'll naturally have a trusty Turbotech ball-n-spring valve at the ready!

PL

ahh he has got all the bits.... thought i would beat you to it with my car... I would love to see what he gets especially with that turbo.... try to go down with the values instead of up and see if the duty / boost changes then the restrictor will work... I will do it on mine when i get some more time.... I get my z32 low mount custom manifold tomorrow... cant wait till it goes on on the weekend...

I suspect he'll get the same power as all the other SR's we've done with that combo - around 210rwkw on 16psi.

Good combo but even better with cams and more boost. I've actually done quite a bit of work on Graeme's other car. It uses Z32/550's/2871R but the 48 trim version. We were playing with it just the other day - check the results down the bottom of the page.

http://www.plmsdevelopments.com/customers/psi-510.htm

He's a school teacher so he's got holidays in a couple of weeks - that's when all the goodies go on the S15. And he told me that one would stay standard!

PL

I put the custom manifold on and what a mission.... re connecting the plumb back bov and pcv stuff seeing no one makes hose that is that flexible... the car is coming on boost alot earlier and I am tending to thnk thats why I am getting a lean patch mid throttle... and that it is a little laggy... however the manifold works well... lots of turbo induction noise.... I will get in contact with yavuz now... I wish i had an old map sensor to plug into the nistune to plot the boost v's afr.... but I dont.... still driving moderately and not standing on the throttle cause it leans up a bit... is there a way that i can graph the wideband and save it ?? do you normally use the average values or the peak values...

With regards to wideband, you can log and save current values

NIStune can also trace average/current/min/max values against a map

There is an also AFR graph of current values vs RPM which can be plotted

Hey Chris,

An improved manifold shouldn't create a lean spot - if you're getting more airflow then the AFM will just measure it and more fuel will be added. That's the great thing about AFM based systems. So there's something else wrong there.

How lean is it going? Grab us Wideband Input Trace from NIStune.

I actually took delivery of an Innovate LM-1 the other day and I'm living it large! I road tuned a U13 Bluebird (the SR20DET powered AWD one) using it the other day. I used the Wideband Input Tracer in NIStune and it worked to great affect. Just set it all up, drove around and let it fill in the AFR for each cell. Here are the pre-tune AFR's:

http://www.plmsdevelopments.com/files/afrs%20std.jpg

As you can see the results are not perfect - some cells are obviously wrong. I suspect that's due to the measurement delay of the AFR meter. But I didn't have a problem ignoring the obviously wrong ones and working with the correct data.

PL

This is my trace after a 30 min logging run, mostly open motorway, trying to set up lean cruise. I use a techedge wb sensor.

Looks about right. Did you have any luck getting lean cruise?

Funny how the subject quickly changes from getting horsepower to getting fuel economy when fuel prices go up!

I also played with lowering figures for accelleration enrichment but found that I couldn't take a whole lot out.

PL

yeah, money talks. haha. Running around 15-15.5:1 under cruise conditions.

I also have the ECUTALK setup in mine and it gives me instant and trip fuel consumptions so i can get the economy pretty good so far on a trip. Sucks it up if im up it though. Still lots better than factory though where it runs high 9's to low 10's A/F under only 7psi boost, now getting 11.5 to 12's with 10 psi in the VG.

My accel enrichment is on around 3% from memory but didnt want to alter that too much, waiting for a dyno upgrade here so i can do some good runs and set my ignition curves, should be this week. All my tuning on both my r32 rb20 and my vg30dett have been on rd.

How did you get around the fact that you can't run negative figures in the fuel table unless O2 sensing is turned on? I guess you could just turn the Closed Loop flag off, leave it active in the fuel maps themselves, and then run negative values? Guess I've answered my own question there!

I was thinking I could lower the K constant and that way values in the lean cruise area would still be positive even at very lean mixtures. I'd prefer not to adjust K for that though...

A great way to improve fuel economy is to run lots of IGN advance. It's amazing how much more advance they'll take at low load. We had my mate's CA detonating at very light cruise one day. It took a heap of timing to make it do it - but we succeded!

PL

Hmm, negative values have never bothered me, i dont turn the closed loop switch off and always leave it on in the fuel maps, i disable closed loop by disconnecting O2 sensor and it lets me adjust it fine (some values read -7 in filtered values).

I have adjusted my k value, but only to bring it in line with the true A/F ratios, went from i think 288 to around 295, not much at all (stock injectors and AFM).

It shows richer in some places on the A/F matrix that i posted but thats just acc enrichment i think.

I'm allways wondring how lean can I run safely while cruising at high speeds (low load high rpm sites). I get a little nervous when seeing lean AFRs past 3500 RPM.

Any thought on the subject?

Some late model OEM systems run as low as 16.5-17:1 under low load high speed cruise conditions, too lean for my liking. The relevant agencies have brought out another ADR to stop manufacturers using lean cruise mode as it increases combustion temps which increases NOx emissions.

I agree - past 3500 I'd be nervous about going leaner. Dunno what rpm you do at cruising speed (110kph here) but I'd be happy to run leaner than 14.5:1 up to about 100kph I reckon.

I reckon you'd wanna monitor EGT's to do it right.

PL

hey pete,

looing at that map... 13's and 14's when coming on boost (center of the map) ??? surely that isnt too good... also the variation of 13's 14's and 11's all in the off bost section... was this running a narrowband ? mine is alot better than that... however i fattened up the mid section of the map as i didnt like 14's when starting to boost....

O.K now back to the subject of boost control.... I have put the restrictors back in maybe you can correct me if i am wrong... there are 2 restrictors in the hoses on the s15 marked by white lines on the hoses... they vary in size one is 0.2mm and the other about 0.4mm... I put the 0.2 in the boost line before the tee peice... I also put the 0.4 in the actuator line... still used the standard tee peice... however in the boost line before the tee i also put a flow controller to help limit the supply of air to the actuator...

The reason was the quicker my car was starting to come on boost from plugging up the recirc hole in the bov and the new intake.. I found the result was awesome spool up but a massive spike to 15 psi and then as the car was reving out it dropped back to 10 psi with the turbo smart bleed system... (stock solenoid removed)

with the restrictor system it is comming on boost and holding boost... the mid section is not as wow as it was before but the top end is alot better not much of a spike... Now if i could only tune it the way i want it... I feel that the boost valve is maxed out so i definitely need the extra restrictor in the system however the internal wastegate is about 40% bigger than standard..

I changed a few thins in the maps but it is hard to see or feel the difference... I am getting a map sensor to map the boost in nistune.. so i can post some results... However it would be nice to see how the duty cycle is calculated does any one know ??