Converting your 1G to speed density (MAP)

[Mike Meron]

refreshing information, grassroots racing at its finest
nothing quite like reinventing the standalone, although you dont get the same mad props

[Vlad Busta]

Hey there guys, this topic has been dead so I figured I'd bring it back to life.  I've been running the speed density code for a while now.  I've been through 88 iterations of the code and am still modifying.  

I've now figured out how to implement the extended maps to the speed density bin.  Now I have much more adjustability.

Features of the custom Busta SD chip are:

-water injection activated via the purge solinoid at greater than 3000 RPM, greater than 75% tps and greater than 10 psi.
-studderbox and NLTS with knock elim on studderbox.
-timing retard to 10 degrees while on the studderbox to help build boost.
-CEL shift light.
-knock type fuel cut (if more than 20 knock counts then ecu cuts fuel).
-phantom knock elim code using map instead of E1 (g/rev).

For those interested in converting to speed density I recommend you get an Ostrich emulator and the Tunerpro or dsmap software.

For everyone's references I'm running about 30 psi no knock with the extended maps Busta custom SD chip.  Mods on the car are:

3" full exhaust
680 cc injectors, 255 wally re-wired, spoolin up FPR
kinetic FMIC
water/meth injection
GT-14 dual bb turbo at ~30 psi

Did I say that SD is the sh*t!  

Later, Vlad.

[Martin Raska]

What kind of timing and fuel type with 30 psi?  What is the rate of water/meth injection?  Are you not worried at all about cutting fuel due to knock leading to more knock?

[Vlad Busta]

Hey there Martin, the timing maps being used are the ones included in the extended maps guide.  As for fuel, I'm running 94 and currently the fuel map is set to 14.7 below the 4th row and 11 anything above.  The car is currently locked in open loop.

I think I have a McMaster Carr #5 nozzle with a Sureflow pump set to 100 psi.  I was just running straight meth but I might go to a 50/50 mix to be safe/cheap.

That's a good point about cutting fuel when knock is detected.  I was thinking if the car hits fuel cut most of us would take our foot off of the gas  :wink:

Later, Vlad.

[John Hartman]

well, if it cuts fuel, there is no danger anyways, because to have damaging detonation, you have to have fuel. If its cut fully, even if you kept your foot in it, you will just be letting air in, but you will have no fuel or boost pressure.

What you might want to do to make it less sudden and more freindly is to have it cut spark to 1 cylinder when it hits say 10 counts of knock, 2 cylinders at 15 counts of knock, 3 cylilnders at 20 and all 4 at 25.  This way the guy won't have to fully lift, just let it breathe and go back to driving.  It will make the car more usable, not just sudded nothing.

not sure if its technically possible, but if so, it might be quite a nice feature.

If not individual cylinders, maybe a pulsed ignition and fuel cut thing?

[Scott Girvin]

OEM waste spark would not allow a single cylinder shutdown.

[John Hartman]

ahh, for sure  

Ok, then howabout, at 6 counts, pulse spark to 2 cylinders, then the next 2, so its fairly soft, not a harsh thing at all, but gets your attention.  Then at 10-15 or so counts, it alternates between 2 sets of cylinders being killed, more harsh and noticable, but still not pulling your eyeballs out of your eyesockets. And if you still are being a dumbass and keep your foot into it, at 25 counts, well, fuck ya, full spark cut  

[KevinBuckham]

Is the meth injection providing enough fuel to make up for those 680cc injectors?  I found at much lower power numbers I was at 100% duty cycle, so I assume the shortfall is from the 50% injected methanol?

Do you know how what percentage of fueling you are getting from the methanol at 30 PSI?

[John Hartman]

Kevin, you are maxing out 680's?  Wow, thats some serious power.

With water injection, typically you can go leaner even if you are just injecting pure water as the detonation threshold is much higher.  You may be adding fuel just to get rid of knock?

[KevinBuckham]

Haha, I was at 85% duty cycle on my Big 28 on C16 at roughly 11:1 -> 11.5:1 A/F and that was "only" at 25 PSI.  That should be significantly lower airflow than a GT-14 at 30PSI.  (I was running stock base fuel pressure with a rewired "Supra" Nippon Denso pump.)  With those duty cycles I was trapping 107-108MPH with a completely full weight 2G pig.

I am fairly confident that I would be close to overrunning 650/680 cc injectors fairly easily now with water injection and 94 octane pump at much lower boost levels.  (Mind you I have extra displacement now.)

[Kristopher]

FWIW a 2.3L, 8.5:1, GT35R, 720cc, 255hp, 20psi, 92 octane will hit 85% IDC easy.

[Scott Girvin]

The exhaust side will be a big factor in that equation. The -14 hot side is brutal and wont flow nearly as much as a full T3 or T4 GT35R...I had one.

[Vlad Busta]

I tried turning up the boost to 30 psi but I would get a studder at RPMs above 5000.  Problem is that I'm blowing out my spark I think cause when turning it back down to 25 psi it's all good.

Looking at my logs I'm running the injectors at about 18 ms at WOT top of 2nd gear.  AFRs are at 11.

Later, Vlad.

[John Hartman]

Vlad, gap your plugs down to .25 or .26  Give it a shot, I have had a spark blow out problem too and have read about lots of others.

Its easy, free and will probably take care of your problem.

[Vlad Busta]

Hey there John, I've tried gapping my plugs to .25 but no dice.  Kinda hard to run 30 psi lately anyways so I'll wait for drier conditions  

Still trying to tune in my cruising VE but WOT is pretty much bang on.

If you're scared about having to adjust for mods added and such maybe an AFC can be used off of the map sensor input but instead of using hz set the afc to use bar.  Just a thought.

Later, Vlad.