Boost Increase (Advice needed)

Pinkfluffybunnys · Post by **Pinkfluffybunnys** » Tue Sep 30, 2008 10:08 am

It’s not really that simple, not all motors are the same and because of the shape of combustion chambers, Sparkplugs and piston crowns there are no perfect AFR for any motor.

OK lets start at the beginning the best overall combustion AFR is 14.7:1 this AFR completely burns the available air and fuel (This is atmosphere dependant) but a N/a car normally runs 13:1 or 14:1 AFR and a turbo is normally around 11:1 and 12:1 this is because we are using the fuel to cool the combustion process and to slow down the flame front. Why are we doing this? Because we want to make the motor resistant to detonation and the amount of heat generated at 14.7:1 AFR.

Without getting into a long drawn-out discussion the best over all AFR for reliability would be a Rich around 10.7 to 11.8 on boost, but there are costs to running this AFR your performance will suffer so will you fuel bill and the motor could suffer from some bad choking over time without water injection.

Now for best performance look at around 12:1 to 13.5:1 , this is allot leaner allowing an increase in combustion chamber heat and pressure and an overall increase in power the down side to this the motor is way less resistant to detonation even with water injection also in both cases you overall timing will need to be looked at.

So you have to compromise what I have seen from my access to the big tuner maps is they run lean low down to increase the EGT and so the energy available to the turbo change then run slightly rich on boost around the 11:8 to 12:5 range

Gary57 · Post by **Gary57** » Tue Sep 30, 2008 10:37 am

I aim for 11.8 with W/M.

RB25SX · Post by **RB25SX** » Tue Sep 30, 2008 12:42 pm

Thanx, Now I know a bit more, never to old to learn.

Pinkfluffybunnys · Post by **Pinkfluffybunnys** » Mon Oct 06, 2008 10:11 am

YES…

I finally solved my problem this weekend, the new version of my management software allowed me to log Knock via the crappy Knock sensor cell specific so I can see any knock that it registers on the load / RPM chart. So In my testing to find out why I am getting this stutter I thought over the past few weeks because of the increased heat here in PTA that I was now knocking so I decreased my timing but after a few trips around the area logging Knock nothing was really shown so I started increase my timing in some cells from the very conservative timing of 19 Degrees after about an hour of road tuning the stutter has bee resolved and my fueling looked good at around 11.7 – 12:1 through the whole range at full throttle.

It amazing what a little timing can do , I have solved my back fire issue with the increase and when flooring the car in second on any type of smooth tar results in the back-end stepping out this is really destroying my tires but I cant stop doing it

phoenix s14 · Post by **phoenix s14** » Tue Oct 07, 2008 10:38 pm

will be checking my timing to make sure it is right as well... my car also has a lil pop or two quite often and also with the T3/T4 on 0.9BAR it does not just break traction... I have to make it happen...

my question is:
1. Does it happen since the output is low and popping due to timing?
2. Does this happen due to lag? (full boost only comes in from 3500+ RPM)
3. is it the bridgestone Touranza rubber being too grippy???

Also I have to be honest by saying I have demolished some scoob STI's, modded Focus ST's, G5 GTI's, MAZDA3 MPS's... so the power is there... since if I make it go I usually have to REALLY backoff else I end-up in a CLOUD of smoke...

Note: the car has not seen a Dyno and will only get a aftermarket management lil later... well month-end... so I have no idea what the output is but estimates by some people in the know who has driven the car was abt 180-190KW...

I am actually wanting to fit a smaller bearing turbo boosting the same but from far lower so boost does not come in so violently since I am gonna setup for drift...

Pinkfluffybunnys · Post by **Pinkfluffybunnys** » Wed Oct 08, 2008 10:41 am

1. Does it happen since the output is low and popping due to timing?

To be honest I can’t really say I’m sure you have wider Rubber on your car then I do (195 on my car) and it depends on the onset of torque. As for the popping it’s normal it has to do with the deceleration and fuel cut maps found in the stock ECU the deceleration map pulls timing based on table in the stock ECU it also cuts fuel to save you fuel on coasting the massive pull in timing normally results in bun burnt fuel hitting the exhaust system (Anti-lag anyone only joking)

Just chose a good management system,I have always been fighting for the Stock system as there is so much in there for example I will take just the map tables for the S14 you have:

Fuel Map (Normal fuel map)

Knock Fuel Map (increase fueling when knock is detected)

Timing Map (Normal Timing)

Knock Timing (Decrease timing when knock is detected)

High Boost duty (How the car controls you boost solenoid and the onset of boost)
Knock Boost duty (How the car controls you boost solenoid and the onset of boost when it detects Knock)

MAF Translation (Your VQ map)

Fuel Load Scale (Allows you to adjust you load scale entry points)

Timing load scale (Allows you to adjust you load scale entry points)

Boost load scale (Allows you to adjust you load scale entry points)

Fuel RPM scale (Allows you to adjust you RPM scale entry points)

Timing RPM scale (Allows you to adjust you RPM scale entry points)

Boost RPM scale (Allows you to adjust you RPM scale entry points)

Min Pulse Width (The lowest amount in milliseconds the injector can be open controls idle and closed throttle fueling)

Max Pulse Width (The highest amount in milliseconds the injector can be open controls idle and closed throttle fueling)

TP load limit ( AKA boost Cut)

Acceleration Increase fuel (self explanatory)

Temperature conversion Table (self explanatory)

VTC control Table (self explanatory)

Dwell Time (Coil Pack control)

Dwell Duty Time (Coil Pack control)

Temp enrichment table (self explanatory)

Idle gear timing (Ever wonder why you can’t boost in idle)

Idle speed RPM (self explanatory)

Idle stabilization control Map (self explanatory)

Throttle vs Coolant Temp enrichment table (Stops the bog when cold)

Fast movement enrichment table (Also for cold starts)

Cold timing advance (Also for cold starts)

Cold Main Enrich (Extra enrichment when cold)

There are a lot of management system out there that don’t offer this type of control and these are the secondary tables I mean the still injector latency tables and RPM and speed limit tables all I am say is chose a management system better or the same as you stock unit.

phoenix s14 · Post by **phoenix s14** » Wed Oct 08, 2008 11:00 am

Problem I have is the tuneability of the stock ECU...
Who knows how to tune it or has the right equipment to do so?

this is my problem since no-one I know can tune the stock one... if you cn help with this it will be highly appreciated...

I share your centiments on the stock ECU I believe Nissan spent alot of time and money on making it as smooth and as perfect as possible. But we as people wanting to modify the engine have the need to be able to "tune" the system of optimal efficiency.

Anyone know anyone that can actually do this???

veecee · Post by **veecee** » Wed Oct 08, 2008 11:31 am

although it does seem quite obvious, PFB "might" be able to help you???

Pinkfluffybunnys · Post by **Pinkfluffybunnys** » Wed Oct 08, 2008 11:34 am

You know who can tune it phoenix s14 … YOU CAN!!!

You seem like a smart guy if you have ever used a Computer you could tune. You will need one or two toys to get things right like a AFR Gauge (You already have one) and a good ear or a set of detonation detectors you can also use the stock knock detector

You will become the best tuner for your car because you will data-log and map not for 6 hours on a dyno but for days and weeks through hot and cold weather on different tanks of fuel. There will be no need to go back to the dyno to remap for that new exhaust or cam you can do it at home you can also see if it makes a difference, you can read fault code, monitor your engine, Pull consult gauges in real time that will give you all the feed-back from ever aspect of your car that the ECU monitors

There in no need to load a half hacked maps that kind of works for your motor so you can get to a dyno with the new management system, Just load you stock map you using now then data-log you AFR and start tuning them bringing them down from the Nissan 9:1 AFR to 12:1 and feel the power increase, You can even load already modified maps from big names like Mines, JUN and JWT on then you can modify those maps to better suit your car and your needs.

You can load a limited Map if your taking you car to the Mechanic and don’t want him to rip through the gears you can tune your highway cruse AFR to get better fuel economy the options are endless and all can be done by you don’t have to be a rocket scientist just a have little brains and the right tools

I mean I have been working on NIZAN-R car it basically only has a cone and a exhaust I have increased his fuel economy by almost 150Km a tank and increase his over all power and response by a large margin and this is a semi stock car. I have tuned my car to have good fuel economy and performance and I’m no engineer or mechanic I am an average Joe you don’t have to be a specialist as they say

Pinkfluffybunnys · Post by **Pinkfluffybunnys** » Wed Oct 08, 2008 11:41 am

although it does seem quite obvious, PFB "might" be able to help you???

It would be kick ass to work on an SR20

veecee · Post by **veecee** » Wed Oct 08, 2008 11:41 am

Pinkfluffybunnys wrote:You know who can tune it phoenix s14 … YOU CAN!!!

You seem like a smart guy if you have ever used a Computer you could tune. You will need one or two toys to get things right like a AFR Gauge (You already have one) and a good ear or a set of detonation detectors you can also use the stock knock detector

You will become the best tuner for your car because you will data-log and map not for 6 hours on a dyno but for days and weeks through hot and cold weather on different tanks of fuel. There will be no need to go back to the dyno to remap for that new exhaust or cam you can do it at home you can also see if it makes a difference, you can read fault code, monitor your engine, Pull consult gauges in real time that will give you all the feed-back from ever aspect of your car that the ECU monitors

There in no need to load a half hacked maps that kind of works for your motor so you can get to a dyno with the new management system, Just load you stock map you using now then data-log you AFR and start tuning them bringing them down from the Nissan 9:1 AFR to 12:1 and feel the power increase, You can even load already modified maps from big names like Mines, JUN and JWT on then you can modify those maps to better suit your car and your needs.

You can load a limited Map if your taking you car to the Mechanic and don’t want him to rip through the gears you can tune your highway cruse AFR to get better fuel economy the options are endless and all can be done by you don’t have to be a rocket scientist just a have little brains and the right tools

I mean I have been working on NIZAN-R car it basically only has a cone and a exhaust I have increase his fuel economy by almost 150Km a take and increase his over all power and response by a large margin and this is a semi stock car. I have tuned my car to have good fuel economy and performance and I’m no engineer or mechanic I am an average Joe you don’t have to be a specialist as they say

that, mabroo, has to be your best post ever.

if you had posted something like a while back, i would've changed my mind about the equipment i was buying!

although - you do make it sound rather easy! i really hope that it is this easy!

tell me - does nistune do anything for the 350Z???

Pinkfluffybunnys · Post by **Pinkfluffybunnys** » Wed Oct 08, 2008 11:51 am

that, mabroo, has to be your best post ever.

if you had posted something like a while back, i would've changed my mind about the equipment i was buying!

although - you do make it sound rather easy! i really hope that it is this easy!

tell me - does nistune do anything for the 350Z??

What can I say I have calmed down after that holiday; I was very agro before and tried to push my point a lot without explaining

Its not difficult at all Veecee I mean it like when you first start working on cars your scared and unsure of your self but once you do something small I see the change it becomes better.
I’m sure tuning is a skill but even the best tuners started with no knowledge and at the end of the day most of us don’t want to start a tuning shop we just want the best bang for our buck.

I mean take me for example I started tuning my car about 7 months ago before that I didn’t even know what a load Table, Or a fuel recover table was or how they work I looked at the program and thought to myself I have just wasted a money again but then you start learning and get more confidence and things get better

Not sure about the 350Z I will check

phoenix s14 · Post by **phoenix s14** » Wed Oct 08, 2008 12:05 pm

I don't mean to be a nagging noob but I really do not know how to interface and tune the data. I actually work in I.T. and just want to know how to hook upto the stock system and interface with it... if you okes can help with a how to it would be fantastic. I understand tuning and have been modding cars for a number of years but all has been sidedraught and carb fed... hence I am a noob when it comes to fuel injected systems and esp forced induction... however I have a solid mechanical back-ground and understand how things work and why. My problem is where and how do I adjust these maps etc... your help is much appreciated.

Sokar · Post by **Sokar** » Wed Oct 08, 2008 12:42 pm

phoenix s14 wrote:I don't mean to be a nagging noob but I really do not know how to interface and tune the data. I actually work in I.T. and just want to know how to hook upto the stock system and interface with it... if you okes can help with a how to it would be fantastic. I understand tuning and have been modding cars for a number of years but all has been sidedraught and carb fed... hence I am a noob when it comes to fuel injected systems and esp forced induction... however I have a solid mechanical back-ground and understand how things work and why. My problem is where and how do I adjust these maps etc... your help is much appreciated.

I think you may have mis-understood the guys, Pink doesnt interface with the "stock" system, His ECU is modified and has a port that interfaces with USB with tuning software written for that specific extra port.

You can just plug in to the stock ECU, its not 100% OBDII and doesnt have that function. The extra bits on Pink's car interface your laptop to the stock ecu. The diff between this and a dicktator for example is Pinks uses the stock maps and keeps all the stock functions.

Enzio · Post by **Enzio** » Wed Oct 08, 2008 1:47 pm

The wonder that is Nistune.....

Trying to save up for that myself. Phoenix - go to the Nistune website and read, you'll find all the info you need there.

I downloaded all of the manuals, etc. and for price vs features I think the Nistune system rocks!!