Wow, it's been a long time

I didn't realize that I have not posted anything on this blog for more than 6 months. After my engine blew, I have been busy getting it fixed. Getting involved in a road accident didn't help either.

My second son also came into my life and he's so cute that he takes most of my time now.

However, recently, after an oil change, my car began to misfire quite badly. I went back twice to my workshop and they found my spark plugs totally black, indicating that I've been running really really rich. Well, that was because I wanted to really boost up the car. I think I have to go back to basics now.

I'm going to review my old posting and probably start with my MAF scaling first. Lots has changed especially when my engine blew and I replaced my engine block, pistons and crank shaft.

I hope I can get my car back in order again. Post again soon.

Blew my engine yesterday *sob*

It was a sad day yesterday as I blew my engine at PG. My water temp was 107C and I think my oil temp was 130degrees. It was my last lap and I wanted to push it..sigh. Should not have done so.. :-(

I broke 1 conrod, a second conrod almost broke (not moving freely), my crankshaft bearings and ceased 2 pistons. sigh..

It will cost me 2.8K to rebuild the engine. To put in forge pistons would cost be 4.5K (including re-boring to 92mm) but I dun think I want to do that as I'm going to sell my beloved soon.

Pictures to follow..

Some settings for Blitz SBC-iD

3rd Gear
85/20 1.84
83/17 1.80
83/25 1.85
80/30 1.79
80/32 1.80 -> But spike in 4th Gear

Blitz SBC-iD

Finally figured out why I could not hit 1.8 bar.. I had my boost controller limiter turned on :-(

Now that I can hit 1.8 bar, it's back to tuning boost. I found this reference useful for tuning boost using Blitz SBC-iD:

Setting the Blitz SBC-iD in manual mode

Setting
0. Put the controller into MANUAL mode. In manual mode you need to enter 2 numbers: SET and GAIN. SET determines a boost "ratio", and does not mean boost PSI.

1. Begin with SET=10 and GAIN=5.

2. In a higher gear (3rd or 4th), run the car to see what boost level the SET number corresponds to by watching what steady/stable boost level is reached. Increment the SET by 10 with each run till you reach the boost level you want. Write down your boost vs. SET for future reference, in case you want to change your boost in the future. If you overshoot the boost you want to reach, just back it down and fine tune as necessary. If you notice boost spikes, then you have set the GAIN too high, you do not want spikes at this point since that makes it more difficult to see the steady/stable boost level.

The reason why you should use the higher gears is because in the low gears, things can happen too fast to figure out what the steady/stable boost level is. Now that you have figured out the SET (boost ratio) that will give you the boost level you want, the next thing to do is to work out the gain:

3. Make runs in lower gear (1st or 2nd), increment GAIN by 5 with each run till you see boost spikes. Then fine tune it till there is little or no boost spike. This is your optimum gain setting for that boost level.

The reason why you should use the lower gear now is because boost builds much quicker in the lower gears, so there is a higher tendency to boost spike.

When setting your boost controller, always have a passenger set the controller and watch the boost gauge for you, the driver should keep his eyes on the road!

Common problem
Sometimes if the gain is set too high, it may appear to have the same effect as the duty cycle. If you notice (especially in the higher gears) that you initially hit the boost level you want, but then it starts tapering off, then you might have set the GAIN too high and SET too low.

Written by Aikmeng Kuah, SPL PARTS INC.
Jul 25 2003
Copyright SPL PARTS INC.

Richer please

Here's the log I mentioned in my previous post


Before&After

Lean?

I did several 3rd gear pulls today and found out that I'm running pretty lean ~ 12.5 at WOT - strange! Why did overhauling my gearbox caused this to happen? I'll need to retune my open loop map now.

Got my car back!

My car is finally fixed. It took 3 days and 2 nights and cost me S$1.9K. Ah Boon changed my 4th and 5th gears and the sleeve and hub of my 3+4 and 5+6 gears. The car feels much smooth when changing gears and 5th gear slots in like a breeze. I have to run-in the gearbox for about 1 week. Till then no revving the car beyond 3000rpm :-)

Gearbox repair

Just sent my car to Ah Boon to fix my gearbox. After stripping it apart, Ah Boon told me the 4th and 5th gears are in terrible shape. The hub and sleeve is gone and the gears are also damaged :-( It could cost up to 1.8K to fix. Sigh.. Wish I had more money to buy my R35 GTR - my dream car!

Pop Sound

Sometimes when accelerating and letting go of the accelerator, I can hear a pop sound in my exhaust. I used to think that I was running rich and that was the sound of detonation but now I've realised it has to do with my open loop fueling map. If I set it such that the map is progressive and smooth, I do not have such problems.

Just a note :-)

A bit lean

My last changes shows that I'm running abit lean:




So, I'm going to richen up the areas which my logs shows that I am running too lean:
(I'm aiming to hit about 12 - 12.3 AFR)

Before:


After:

Rescale my Timing Table

Here's how I rescale my timing table in Excel:



My original Timing tables:




My new Timing tables:



Let's see how this works out :-)

Day1 of Open Loop Rescale

Car feels quite good after rescaling of my open loop table. I'm going to do the same for my base timing table next.

Rescale my Fuel Table

Here's how I did the scaling via Excel:


My original Fuel Table:


My New Fuel Table: (I've richen up the higher end cells but the lower end cells will be running abit lean. I've also increased my rpm to 7800 to match increasing my rev limit).


Since I'll be running abit leaner, I'll need to do more logging to see how the car behaves.

Feedback after scaling 0.5

Well, today I drove quite abit to JB to test my rescaled map. (20090214_RescaleLoad.hex). It feels a bit down on power but there's no knock and no CEL errors about running lean.

I'm going to see if I have enough data to scale my higher end MAF and also give a try at rescaling my fueling and timing maps to cater for higher loads.

Here's my log analysis:

Going to rescale by 0.5

In my previous post on how I overcame the 300g/s limit, I rescaled by multiplying all instances of engine load by 0.7 (see here) But it's not enough.. so I'm going to rescale it by 0.5 this time around.

I'm going to use the map "20090130_300gAVCS-revlimit.hex" as my last map (the one after this) did not feel so good. This map runs kind of rich though but I'm going to re-tune fueling anyway.

I used Excel to copy the original values, rescale it and then paste it back to romraider:


And here's how it looks like (top - 0.5, middle 0.7, bottom - original):

Hit MAFv of 4.72 !

I was just reviewing my last dyno pull and realised that I've hit my MAFv limit of 4.69. Looks like I have to rescale further. I've added some analysis of my own:

Rescale my Fuel Table

I noticed that my g/rev load can hit > 2 (see below)


So I decided to rescale my open loop fueling:


My rescaling is based on increasing the differences slightly between cells:


Let's see how this goes :-)

Dynoed at 351bhp@6168rpm, 4502Nm@5502rpm

Here's my latest dyno runs. Both are quite close in figures except that the first graph is more smoother.

Raise my rev limit from 7600 to 7800 rpm

I'm raising this by 200rom at the same time I am tuning my AVCS.

Here's the stock setting:


Here's my new setting:

AVCS affects fueling

Since I am increasing my VE with AVCS timing, I need to add more fuel. I've had this map for a few days but I am still having knock across the ranges.



I'm going to set my tip-in at the 5.2% cell. Let's see if this works since the smallest throttle % where knock occurred happened at about 4%.