ls3 cpu multiple tunes

[diesel25lrs]

Not sure if this is the
Spot for this or not.... I want to be able to store & quickly change up to 4 different tunes for different applications. I know people do this but am i stuck with a small laptop running HPtuners software or is there a small handheld guys are using?

[Samckitt]

When the chips in the computer were removable, there was a box that you could put multiple chips in it & turn a knob to get differrent tunes. Haven't heard of doing it with PCMs that chip is not removable.

[dontlifttoshift]

I know the SCT tuners for the mustangs can carry a bunch of "tunes".....I would think something like that exists the for gm.

[andrewb70]

I am just curious, what would be the purpose for this?

Andrew

[diesel25lrs]

Scot- That's exactly what I'm looking for- turn a knob or push a button to quickly change to a different tune- just like you can turn on/off performance mode in new cars but not necessarily for traction control.

Donny- I would think so as well- I'm looking for what guys have experience with though...I think I'll give Summitt a shout this afternoon.

Andrew- I want it for different applications, Hwy cruising/long road trips/better gas mileage, All out power for dragging, & de-tuning for autocross maybe down to about 500RWHP or whatever I figure out the sweet spot is.

[andrewb70]

......

Andrew- I want it for different applications, Hwy cruising/long road trips/better gas mileage, All out power for dragging, & de-tuning for autocross maybe down to about 500RWHP or whatever I figure out the sweet spot is.

Josh,

I understand your intent, but what you are saying makes no sense. The beauty of tuning an EFI system is that it can be set up in such a way as to give you different AFR for different conditions. For instance, you can tune for a leaner AFR during highway cruising by leaning it out during light load, medium RPM operation. In the same tune, you can also specify that under WOT, the AFR will get richer to optimize power. There is no need for different tunes, just one proper tune.

I have a stock GM ECU (E67) and under WOT it AFR is about 11:1 (yes, little fat) and while driving on the highway it bounces between 14.5 and 15.0. I know this because I have a wideband O2 sensor and gauge installed in the dash.

As for "de-tuning" for autocross, that is what the gas pedal is for. The gas pedal is not an on-off switch, so if you want less power, don't step on it hard...LOL

Andrew

[wiedemab]

I had an SCT chip in my '89 Mustang with 4 different settings. one was a Valet - rev limited it to 3500 or something. One was a 93 octane tune (which was the default setting), one was a "race gas" tune, only difference was more aggressive on the timing......can't remember what the other position was.

The entire time I owned the car, I never once switched it - -maybe it was just me, but I just ran 93 octane and let it ride. It got great mileage on the highway cruising - to Andrew's point, that is all part of the tune. It's just my opinion, but I would get a really good tune and just leave it, which may be your only option for the GM ECU

[diesel25lrs]

Thanks guys- makes sense! That doesn't help my leadfoot problem in the heat of battle inducing spinouts though! Guess i'll have to work on that...

[rallystyle]

i know for the ls1 ecu tunedbyfrost has a setup so you can have 2 chips for tuning. i have not sceen anything for other ecus.

http://www.tunedbyfrost.com/products_df01.htm

now if only someone would make something that would alow the computers to read a 5v for wideband feedback.

[diesel25lrs]

Are the chips in ls1/2 ecms removable by chance? No chips in ls3... Internal

[andrewb70]

Thanks guys- makes sense! That doesn't help my leadfoot problem in the heat of battle inducing spinouts though! Guess i'll have to work on that...

This can be overcome with practice or by racing a Miata...

Andrew

[andrewb70]

Are the chips in ls1/2 ecms removable by chance? No chips in ls3... Internal

There haven't been any removable chips in automotive ECUs since IROCs...

Andrew

[diesel25lrs]

Thanks guys- makes sense! That doesn't help my leadfoot problem in the heat of battle inducing spinouts though! Guess i'll have to work on that...

This can be overcome with practice or by racing a Miata...

Andrew

I could definitely use the practice but not a miata! Lol...

[Norm Peterson]

There might be one aspect about different tunes where you'd choose a different one for autocross than for normal street driving.

If the EFI setup in question is a drive-by-wire throttle instead of a mechanical cable, the rate of throttle opening is not directly tied to the rate of pedal movement. If you slow the early throttle plate motion down relative to the tip-in pedal movement you'll get better resolution down in the low throttle opening range. This would be particularly appropriate where you've got way more power available than you can possibly put down in 2nd gear, where just a slight twitch might be too much. Terry Fair went through this too-sensitive throttle thing when he was building up his Mustang for STX, where you can't crutch overly aggressive electronic throttle behavior with R-compound tires.

On the street (and particularly for the street-racers and stoplight wanna-be's), somewhat faster than stock early throttle plate opening seems to be the preference.


BTW, there is at least one situation where slowing down the initial throttle plate opening on a strictly mechanical throttle actuation can be beneficial at autocross. An overly large throttle body relative to engine displacement will behave somewhat similar to the way a too-fast-too-early electronic throttle will. Too much, too soon - driveability and your run times suffer. Been there.


Norm

[diesel25lrs]

Norm,
Thanks much for your input! This is exactly what i was thinking but couldn't articulate! Knowing that this car will be a torque monster down low due to the charger, i can foresee second gear tight turn spin outs all due to quick throttle blips! I won't want to come out of the corner slowly but it will be hard to massage it at the same time in that range....if i can tune it to really just knock off some of the power for this particular range during events that is what i want? It is FBW...

[Wheel Werkes]

With HP Tuners you can upload as many tunes as you want once they are already set. But there isnt a switch like a standalone can have. But it only take 30sec to 1 min to upload a new tune. For you low end torque issue with spinning out throttle control is key. Now you can have timing pulled in that certain range in the rpm band so that you do make less power. The best way to find where is to log with the hptuners.

It'll definitely takes a little bit of time to tune it that way you want but its definitely feasible. Then just upload you street tune after and call it a day. You you theoretically only need 2 tunes.

[diesel25lrs]

David,
Thanks for the response! I recently ran into a local tuner that just told me the same thing and is going to hook it up for me!

Josh

[Wheel Werkes]

No prob Josh

[MonzaRacer]

In older GM and Honda units when we burned larger and larger chips with files that were tiny, it left lots of room on the chip, all you had to do was make sure the computer got the right hex address y way of resistors and a dip switch or rotary switch. when most GMs and Hondas could have one or two n a 64k or 128k o even smaller ram chip, indexing hex addresses for multiple bins was an easy to do back to back testing. burn 4 or 5 programs, change shift points, NOS/Vtech/Boost control etc.
Then turn off car, turn or flip switch and retest or race.
Heck guys I have used timing to dial in many of a drag car, pull two degrees here add one there. On static timed vehicles had great time, watch everyone blow tires off on track that had no bite from lack of "glue" and pull degree or two out and hook while everyone else blew off tires. Add timing back on top side if needed but if track didnt bite, generally whole track was green or slick.
Also if your car runs differently in cold climates, or with or without water/methanol injection, etc.
Moates.net is where I learned about the switched proms. but now I personally like Megasquirt, cheap laptop and list of msq files and your off and you can datalog, and diagnose as needed and it doesnt take very new laptop, heck even atom net books will do things needed.
Good Luck
Lee

[Boostable]

Certainly a different application, but I have this exact type of setup in my GMC 2500HD Duramax. I have a 5 position rotary switch that allows me to change tunes on the fly. Stock, Light Tow, Heavy Tow, Street Tune, Race Tune. Every tune has different characteristics and HP/TQ levels. It great and I use it frequently. I don't think an NA application would have much if any use for such a setup, but seeing as I am building a turbo car it would be fantastic to have a similar setup. Unfortunately I have no current knowledge of the similarities or differences between the ECU's.