Gauge

iTrader: (3)

Hey guys,

I'm a total newb to tuning, but I think I am getting a general understanding of how it works. I have a Procharged LS1 pushing about 14psi, and it was (until yesterday) running on a 1-bar MAF tune. Yesterday, I changed to a 3-bar SD tune.

For starters, I changed to the SD tune and then copied my 100 kPa line in my VE table to higher pressures in the 3-bar tune. I had to do this column by column putting the values in the row that reflected the boost I run at that RPM. Then, I interpolated between that value and the 85 kPa line. I feel this should be a good starting point.

I have two main questions at this point. The first is, what should I do with my spark while I'm trying to get my AFR dialed in? It's my understanding that a good practice is to pull all the timing out, dial in your AFR, and then put the timing back. I'm good with that, but I'm not sure what to drop it to and what ranges I should bother changing... perhaps change any value that represents the car being in boost or WOT to something small like 6 degrees?

My second question is in regards to the MAF. My understanding is that the MAF is only referenced when in closed loop mode, and the car runs in open loop mode when at WOT. Therefore, is there really any need for me to fail the MAF and disconnect it? Clearly, it will be saturated when I'm pushing 14psi, but it shouldn't have any effect at that point in time, correct?

Thanks in advance for any advice!

moehorsepower

iTrader: (3)

SD + MAF does not equate, its either or..and if you are running 14 lb why did you go with a 3 bar instead of a 2 bar?

Gauge

iTrader: (3)

SD + MAF apparently does equate as I'm running a MAF now. I forgot to fail it in my tune, so when I unpluged the MAF, the car died. I left it in and drove around for a while. Clearly, it's using the MAF at this point. When I said I went to a 3-bar SD tune, I meant it was the 3-bar SD upgrade in HP Tuneers. I believe that just means that I *can* run SD, not that I have to.

I went with a 3-bar so I'd have room to grow. Plus, in the right weather, I think the car sees 15 psi (i.e. cold air). So, I also would like to have the safety margin in case I exceed 1 bar of boost.

02blackbeauty19

iTrader: (22)

I have run both a MAF and a 2-bar sensor together. It was a hybrid tune. I completely switched to a OLSD tune about 6-8 months ago.

Gauge

iTrader: (3)

Any thoughts on what to do with timing while I get the VE table dialed in?

wilson34

iTrader: (7)

You can start around 10* or whereever you feel comfortable.
As for modifying the 105kpa and up table, copy your 105kpa numbers and paste them to the 105kpa column in the boost table. Then paste those numbers to the right column and multiply by 10%. Then just interpolate b/t 105kpa and the right most column.

moehorsepower

iTrader: (3)

Yes, I ran MAF + 2 bar since around 98, My point is that usually speaking of Speed Density, this is without a MAF, has nothing to do with what MAP you are using..

Frost

iTrader: (45)

You lose a TON of bottom resolution with a 3bar sensor.... you don't have a turbo, it's not like your D1sc is going to run off and make 20psi on you.

I don't EVER use a 3bar OS unless it's really needed. You really don't need it at 15psi with a blower.

If the MAF is still active, the VE is irrelevant, and the tune has to be a PE hack for fueling. It's not a bad thing with a supercharger, it's just not dynamic once you max the MAF out. You have to be tuned for the most drastic of conditions to be ok in the rest.

It's never a mystery whether the MAF is being used or not... if P0101-p0103 are not set, the car is not in SD.

02blackbeauty19

iTrader: (22)

Frost, would you recommend it for a turbo car? I know for a blower car its not NEEDED because its linear airflow, but thats not the case with a turbo car.

I have a 2-bar MAP in mine and on high boost, I may see 19-20 psi. Is it time for a 3-bar MAP and tune?

Thoughts?

Frost

iTrader: (45)

I'd be running a 3bar for that kind of boost and especially with a turbo.

02blackbeauty19

iTrader: (22)

Kinda what I figured. It's already on the way.