Hey guys,

Didn't want to steal the guys 'tuning for autoX' thread above.
Searched for this topic and didn't find a whole heap regarding the actual tuning.

I'm about to start tracking/road-racing my car late Jan and was wanting to run my tune past some of the experts on here that do this for a living.

- Firstly, i'm running ~26psi peak, 22psi taper on my street tune with 11.6-11.5 afr's, and zero knock.
I've purposely tapered the boost down as i'm basically at ~90% IDC's with that boost on stock injectors, and dont' want to scale the new ones til after.

- Do I keep the existing boost level of my street tune, and dump the AFR down to ~11.2's, and go for it from there?
OR
- Keep the existing AFR and drop boost to a flat 22psi?
OR
- Drop both AFR's and boost?

I'm open to all suggestions, this is my first track day, so I realise power isn't really that important at all, however the car is pretty light on power mods, so the boost makes up for it.

Mods are: 3inch downpipe, catless, JDM catback, pod, metal intake, 3-port.
Stock 9.8 turbo, dump, piping, etc.

Car is on Aussie 98 which is basically your 93, weather will be most likely mid, high 80's.

Here's a VD of the current street map.


Cheers.

 

If its 11.5 now its safe to road course.. i would leave it where it is. if not 11.2-11.3 should be plenty ok egt wise.

 

Reckon I should drop boost back to 20ish?

 

no way.

 

Lol...my intial thoughts too, but i'm worried about the heat build-up after 10min of solid lapping.

 

Here's a quick 2-3-4 pull of the current state of tune too.

 

Personally I have always dropped 1 psi then my street boost level for extra margin of safety on road courses

 

if you're going to run that kind of boost on 93oct I would at least spike the tank with some high octane race gas for insurance.

I recently made the mistake of running 26-27psi on straight 93 at the end of the season last year. it took less than 2 - 25 minute sessions to blow a head gasket. up until that point I had always spiked my tank with 100oct unleaded and ran ~22-24psi while on the track and never had an issue. I suspect the failure was due to the enormous amounts of heat generated at those boost levels that you just can't duplicate on the street.

my car has the normal track/cooling mods (brake ducts, oil cooler, fmic) and I was also logging at the time it happened. oddly there wasn't any knock recorded, only a sharp spike in the coolant temp scaled value, from 181 to about 23* in the blink of an eye. very weird. learn from my mistake and either run normal boost and/or spike the tank!

since this is your first time you probably won't be going faster than your equipment... yet. so, my advice would be to drop the boost to 20psi peak, listen to your instructor, and just focus on driving the car smoothly. as weird as it sounds, the last thing you need to go faster around the track is more power.

 

Cheers mate,
I've been tossing/turning over this one, dont' want to drop the boost but i've constantly had this thought that it needs to be back around 20 where it was before. lol

 

^^ what did i tell ya haha drop it down a little... u wont notice any noticible better times with 26psi than on 20psi on ur first track day

 

26 to 20 is a big drop.. you will notice it. drop it 2psi and call it a day imo. that will richen the AFR up and the timing will be good to go as well.

 

drop it 2 psi and be done with it.. it will be overly safe 2psi lower with richer AFR by default. no point in remapping if you dont have to

 

Ok checking back in with what I think is the final result.
Did some logging/tuning in the middle of the day today, was ~83*C, nice Aussie summer day.

Dropped boost to ~22psi peak, ~21psi held from 4k to cutout.
This 3-port is pretty mean when used properly, holds boost better than most a/m EBC's i've seen.

Pulled a degree and smoothed some of the timing in the 3.5-4k and 5.5-6k zone as it was a bit knocky at times.

So final a/f and boost graph.


And just to show off, 3 back to back boost curves over ~20mins.

 

see at 6500 rpm it went a little lean (not much but could be enough), looks like it pulled timing as you have a huge dip in your hp. Do you have the raw data log

 

make the rest of the afr curve match the dip at 4k now.