klrz28

MY 383 we built has only been tuned for wide open throttle. It runs pretty good on the street drive ability wise. But should I send the computer out to pcmforless or somewhere else for a tune? Am I losing anything by keeping it the way it is? Advantages or disadvantages?? Will it run much better sending the computer out?

bobdec

Depends on who and how you were tuned for WOT.. Usually tuners start with idle, get normal operating conditions tuned correctly, and then they tune PE mode with a wideband. I'm thinking if you order a mail order tune it could alter some of the overlapping settings from you current tune. Yes you should benefit with a complete, idle,driving & PE tune. Especially since your only in PE 5% or less during street driving. However using two tuners could be tricky as each does not know what the other has changed. IMO it's best to use one or the other for a complete tune, not splitting them up.

klrz28

I was thinking of getting another computer and sending it to pcmforless and use that one for street driving. And the wot tune for the dragstrip since I do t have a laptop to tune it my self.

Injuneer

Why would the PE tune for the track be any different than the PE tune for the street?

bobdec

Fred, I agree, as a better response to the OP I should have said.. in my view there is really no such thing as just a WOT tune. In reality a WOT tune should include everything from idle, normal driving and PE mode. And a basic tune (mailorder) tune should include idle up to normal driving plus 'a guess at PE mode', depending on the tuner. There there are only two tables used in PE mode that require tuning. And because O2 feedback and BLM updates shut off in PE mode you need a dyno with a wideband for accurately tune those two tables. Mailorder can not provide that level of tuning. Chances are a mailorder tune may overlay some of the OP's current tune that was most likely done on a dyno /wideband. He really should check w/current tuner first.

klrz28

I was just saying thinking of getting another pcm. When the car was tuned it was really for only 2 hours on the dyno for tuning time. So it should be fine the way it is for the street or should I just drive it the way it is?

Injuneer

How does it drive on the street? Does it have a decent idle? Does it surge below 2,500 RPM? Does it get fuel mileage commensurate with the modifications? Run lean or rich? Pull well at low RPM? Cruise in O/D with no problems?

klrz28

On the street it drives really well doesn't idle too bad. Once in a great while it acts as if it might die then come back to normal. Idles around 900. Doesnt surge too bad. Fuel mileage is pretty good especially on freeways w 6spd and 3.42 gears. It doesn't really pull til its above 3500 or so.

bobdec

At 900 idle you must have a cam, and maybe valve train mods ? Is TB and intake stock ? Assume headers also ?? Someone must have tuned idle if it's up to 900, unless it was done with TB stop set screw and that will cause problems..

Injuneer

If RPM is being read from the stock tach it will typically read high by 100-200RPM. Might actually be idling at stock 800RPM for an M6.

Orr89rocz

Being that it was on dyno for 2 hours it probably already had a few part throttle runs in it and a rough map and/or maf tune on it to get it 'close'. You kinda have to have the part throttle stuff figured out somewhat well before being able to go WOT. Rest of time was spent on dialing in air fuel and timing at WOT. Not bad but not perfect either.

To get proper street tuning in, you really need to spend time on it. Lots of logs to cover all driving scenarios and really play with air fuel and timing to see what it likes. AE enrichment stuff for throttle transitions also needs to take place on the street in a loaded environment. Dyno's cant load a motor like the street unless its a mustang type dyno with a big brake on it that can do heavy load situations.

But generally, idle tune and part throttle takes time to really dial in to your specific wants and needs. Not something a mail order can do well. Sometimes close but never 100% perfect.