Tuning

[Bama99z]

Ok guys i am thinking about having my computer re-tuned. I have a bone stock 1999 LS1 is it worth the money? How much extra HP can i expect. I purchased a Superchip Cortex hand held but have later heard that i wasted my money? Any info would be greatly appreciated.

[0rion]

there's a little to be picked up there but honestly I would wait until you do some mods first. Do you have plans for any mods? Are you an auto or manual car?

[Hi-Po]

there's a little to be picked up there but honestly I would wait until you do some mods first. Do you have plans for any mods? Are you an auto or manual car?

Almost the exact post I just wrote out in a diierent section. Wait for mods i you plan any.

[Bama99z]

Sorry guys that i didn't inform you but i have an automatic. Future mods would be Lt's ORY first them Cam & Heads. I am working a deal on a set of P/P 241's are they an upgrade over my factory 853's or would i be better off with aftermarket?

[0rion]

It would depend on who did the headwork really. Heads can make or break you. There's nothing wrong with home ported heads but for me personally I would want to see flow numbers.
I would say wait until you at least have the headers before worrying too much about the tune. You can gain a bit being an auto by removing torque management and firming up the shifts but HP wise you'd be better off to wait until you get a few mods done. Try to find someone that'll give you a tune for the headers and then cut you a nice break when you do your other mods. Have you given any thought to a stall convertor? I would probably put that right at the top of the list if I were you. No easier way out there to shave half a second for the money than a stall.

[mrr23]

back when my 00 formula was stock, i was using the vinci handheld tuner. i went to the track to do some testing for them. by using the hiperf/stock cam setting with enhanced shifting and firmness, i picked up .2 and 1.4 mph. so yes tuning can net you some gains. how much? really don't know for sure.

[nillam1]

Ok guys i am thinking about having my computer re-tuned. I have a bone stock 1999 LS1 is it worth the money? How much extra HP can i expect. I purchased a Superchip Cortex hand held but have later heard that i wasted my money? Any info would be greatly appreciated.

I would still use it, I know everyone on here is hardcore and will chew my ass of for saying this because it leans the motor out but I have been using my Superchips tune and cold air tuned Granatelli MAF sensor for a couple years and my car runs awesome. Ya I said it, I use a Handheld with Granatelli MAF!

[dklowrider]

I would still use it, I know everyone on here is hardcore and will chew my ass of for saying this because it leans the motor out but I have been using my Superchips tune and cold air tuned Granatelli MAF sensor for a couple years and my car runs awesome. Ya I said it, I use a Handheld with Granatelli MAF!

why would you want to do something to your car that leans the motor out? an engine only runs properly with a specific a/f ratio, and lean means it aint there.

[mrr23]

why would you want to do something to your car that leans the motor out? an engine only runs properly with a specific a/f ratio, and lean means it aint there.

it depends. usually the tune from the factory is on the rich side. so, leaning it out can make more power because you aren't wasting fuel.

[nillam1]

why would you want to do something to your car that leans the motor out? an engine only runs properly with a specific a/f ratio, and lean means it aint there.

My engine runs great, thanks!

[Frost]

My engine runs great, thanks!

post a wideband log and prove it! (not saying it's not possible, it's just not probable)

[dklowrider]

it depends. usually the tune from the factory is on the rich side. so, leaning it out can make more power because you aren't wasting fuel.

ive been under the impression that most vehicles are a little lean from the factory cuz the emissions output is the high priority. i know the H D company does it. then you can open up the intake and exhaust and tune it to where it should be.

[Frost]

ive been under the impression that most vehicles are a little lean from the factory cuz the emissions output is the high priority. i know the H D company does it. then you can open up the intake and exhaust and tune it to where it should be.

No because lean has the potential to hurt cats, and the EPA is more worried about saving them than fuel. WOT is FAT OEM.

[nillam1]

post a wideband log and prove it! (not saying it's not possible, it's just not probable)

If my engine runs great, what do I have to prove? If I ever get it logged I will.

[Hi-Po]

If my engine runs great, what do I have to prove? If I ever get it logged I will.

Prove you engine is running optimal/good. You posting a WB log would prove, yes or no. Im guessing no.

Let me just run this by you. I have had some tuning issues. And I have ran my engine at less then optimal,WOT&lean. Both a tad to rich and a Tad to Lean. I never would have know different without the wideband and a logger. Thats just it. Period. You may think your car runs great, as I did mine.

In reality, there is alot to be changed. Not only a change in engine safety but usally some great awesome responsive horsepower.

[pajeff02]

OK --educate me and correct any misperceptions I set forth:

Our cars come equipped with narrow band O2 sensors. One upstream of the converter to report A/F to the PCM and one downstream to compare against the upstream sensor. The downstream sensor simply tells the PCM that the cats are, or are not, working properly. You can tune out or sim the rear O2's and this is commonly done for header and ORY installations or cat deletes.

1. If you install a wideband O2 -- is it still talking to the PCM, or is this a stand alone that is installed in addition to the existing narrow band?

2. HP Tuners appears to be the preferred editing software and allows you to log sensor data and see what is actually happening. I assume this is not something for the mechanically/mentally inept as you could probably make a mess of things in a hurry if you do not know what you are doing?

3. To log A/F, I assume programs like HP need a wideband installed?

4. The PCM is utilizing "look up tables" to set engine controls based upon sensor data it is receiving. A "tune" makes modifications to the tables and alters timing, injector pulse width, etc... What else is being modified?

5. I understand that you can also utilize a speed density tune -- more common for modified high output engines -- which deletes the MAF and instead utilizes MAP data to control the engine. Is O2 sensor output still being utilized by the PCM with a speed density tune?

Sorry for the long post - but the tuning question got me thinking about a lot of questions that I have had...

[mrr23]

1. stand alone.

2. if you can learn http://www.centralfloridastreetcars.com/hptuners.htm others use EFILive

3. if you want hptuners to log it, yes. if not, Innnovate sells one with it's own display. i used PLX with gauge

4. whatever needs to be modified to get the engine to work properly. refer back to #2.

5. if you are using SD closed loop, yes.

[pajeff02]

1. stand alone.

2. if you can learn http://www.centralfloridastreetcars.com/hptuners.htm others use EFILive

3. if you want hptuners to log it, yes. if not, Innnovate sells one with it's own display. i used PLX with gauge

4. whatever needs to be modified to get the engine to work properly. refer back to #2.

5. if you are using SD closed loop, yes.

Thank you. I just took a peek at the link you posted and answered another question already about torque management. I'll bookmark it for future reference. When one is accustomed to tuning an engine with a dwell meter, timing light and a vacuum gauge -- the learning curve here is pretty steep!

[mrr23]

yes it is. firebirdjones would know about that as he converted from carb days to EFI.

[dklowrider]

it depends. usually the tune from the factory is on the rich side. so, leaning it out can make more power because you aren't wasting fuel.

No because lean has the potential to hurt cats, and the EPA is more worried about saving them than fuel. WOT is FAT OEM.

thats very interesting. my original comment was related to running lwith a lean condition, if the intent was to say leaning out as compared to factory settings, that would be different and my comment was not appropriate obviously.