Retune for pulley drop?

[2007gpgt]

Do I need to get a retune to drop from stock to a 3.6 pulley? I have an overkill pcm

[thomas mcnulty]

Colder plugs and colder stat, you already have the tune

[2007gpgt]

Already got tr6 plugs and i heard a colder stat is pointless

[Fivefingerdeathpunch]

It is.

Got anyway to scan for KR?

Overkill tunes tend to run pretty rich, I bet with a drop to a 3.6 it will be fine.

[2007gpgt]

Ya I have aeroforce gauges

[Z34Phoenix]

is it 100% needed? no. would it be a good idea. YES. I tune my car once a month as a minimum for the change in weather.

by the way what 1.8RR do you have? did you feel any gain with them?

[2007gpgt]

I dont have a tuning program and nor do I know how to tune.. Is it hard to do? Should I invest in hp tuners now and learn because I plan on doin more mods in the future..

I have the yella terras.. It seems to pull harder in the higher rpm and it changed the exhaust sound a bit..

[Tuner-Extraordinaire]

You need a tune yes

[Z34Phoenix]

if you do plan on a lot more mods and know you will be needing more tuning then I would suggest getting a tuner. keep an eye open for a used one to save some money. i got mine in 2005 for my DOHC. there wasnt anyone out there who did tuning for it at the time. later DHP did sell a hand full of pcms for that engine but no info on results was ever posted. with learning how to tune i was able to make a new spark table that released untapped power the DOHC had.

but yes if you can find one at a good price get one and start learning. if it is a dhp i dont mind helping you with a few of your first tunes to get you started. any and all changes i will explain to help you learn.

[mechguy]

I tune my car once a month as a minimum for the change in weather.

Please explain, why do you do this every month or oftener?

Also, during this monthly calibration, what changes are you typically making in the PCM? That's assuming no engine mods have been completed since the last time.

[SnowFlake]

No reason to change your tune once a month. Give yourself some headroom and change your pulley if you absolutely have to.
OP you shouldn't be running colder plugs or a smaller pulley, get some headers.

[mechguy]

Well let us see what Z34 has to say.

[Z34Phoenix]

my normal tuning is just MAF tuning and some minor work in the spark table. i like having my trims very close to 0 at all times. im always toying with the spark table too and seeing where i can pull more timing here and there. this is how i was able to build the DOHC spark table that i have used on many peoples PCMs. that spark table on the DOHC really wakes the car up down low and adds the missing low end the engine has always needed. Im hoping i can pull some magic on this engine as well testing diff ideas out.

when you have your own tuner you can afford to run a tune that is much tighter and closer to the Kr limit. but means you need to watch the aeroforce like it is one of your mirrors while driving. im a perfectionist. i never want to leave it be.

[mechguy]

I understand that you have optimized the timing. That is desirable.

I don't understand your tuning every few weeks for "weather" changes. Even if it was necessary, you could re-tune and the day following, temperature could be more different than the previous entire month. Thankfully it is of no benefit.

We have MAF and IAT sensors to help with this.

My car uses the same tune from -40*C to +40*C.

Years ago we tuned high-performance small engines quite frequently. Their carbs had no idea what the air density, humidity, or IAT temp was.

[Z34Phoenix]

pressure temp and humidity change and effect the tuning. it will cause the trims to change slightly and like i said i like to have them at or as close to zero as i can. yes there have been times where i tune and then a day or two later weather changes drastically and i would have been better off just leaving it...

yes bottom line there is no real benefit to tuning as much as i do. it may help others who are new to tuning learn more and it gives me a chance to try different ideas to make more power and have the car perform better as in better shift points.

[gtpsleeper]

just to add to the tuning so often thing...

mech, I would agree with you in saying that assuming mods are not different that it really is not needed to tune so often...

BUT... it really depends on ones setup...

For example, I personally tune in open loop and run ethanol. I re-tune ( that is to say I make a couple maf adjustments ) about every month or so as needed for 2 reasons..

1. the e85 blend changes according to the time of year and thus fueling needs to be changed slightly...
2. in open loop Ive noticed you have to keep an eye on it more as you dont have your 02 making adjustments for you and temp,humidity,etc has a little more of an affect on it...

That being said, a car in closed loop running year round premium from a consistent pump may not need to be kept up as much as someone like me, but it could.

OP... tuning software is one of the best things you can invest in... personally HPTuners, my wideband and my aeroforce were the best investments I ever made for my car... if I could do it all again I would have done those first...