tuning a brand new vehicle, why ?
02-01-2013, 01:12 PM
#1
tuning a brand new vehicle, why ? have a general tuning question,
I read that if anyone is looking for more performance such as more hp or better fuel mileage everyone says to get their vehicle tuned. And this is even for brand new vehicles. My question is how is this possible? I won't get into specifics and name names but it seems to involve logging data that you send back to the tuner company which then sends you a file that you re-flash your PCM with and will give you whatever performance option you asked for, i.e. more hp and less fuel.
Now I was born at night but not last night, I'm a little skeptical
I've read a couple of books so far and just got gm master efi tuner, I think I generally get what's going regarding how the PCM controls A/F ratio and ignition timing over all driving conditions, transmission shifting, and so on. But the way some people rave about tuning especially for a brand new vehicle or one less than 3 years old, they are basically saying the OEM did it wrong are they not?
I suppose there's a few areas on this topic which are plausible such as if you just wanted all out power then yeah you can make sure ignition timing is maxed out without knock for 93 octane gas, A/F is set a little leaner for max torque and you disable any kind of torque management stuff, but it's at the risk of higher exhaust temps & emissions and reduced engine life- an obvious concern for an OEM and warranties.
But I don't get how some people can claim a tune will make a vehicle run better all around including get better fuel economy.
I read that if anyone is looking for more performance such as more hp or better fuel mileage everyone says to get their vehicle tuned. And this is even for brand new vehicles. My question is how is this possible? I won't get into specifics and name names but it seems to involve logging data that you send back to the tuner company which then sends you a file that you re-flash your PCM with and will give you whatever performance option you asked for, i.e. more hp and less fuel.
Now I was born at night but not last night, I'm a little skeptical
I've read a couple of books so far and just got gm master efi tuner, I think I generally get what's going regarding how the PCM controls A/F ratio and ignition timing over all driving conditions, transmission shifting, and so on. But the way some people rave about tuning especially for a brand new vehicle or one less than 3 years old, they are basically saying the OEM did it wrong are they not?
I suppose there's a few areas on this topic which are plausible such as if you just wanted all out power then yeah you can make sure ignition timing is maxed out without knock for 93 octane gas, A/F is set a little leaner for max torque and you disable any kind of torque management stuff, but it's at the risk of higher exhaust temps & emissions and reduced engine life- an obvious concern for an OEM and warranties.
But I don't get how some people can claim a tune will make a vehicle run better all around including get better fuel economy.
02-01-2013, 01:38 PM
#2
I agree with showroom to tuner, Ive looked at it like this, even brand new cars have alittle orange peel in the clear coat and need alittle polishing to perfect it, just like a factory tune, a good dyno tune for better mpg's and alittle more hp/tq is the best thing to start with on a brand new car (putting aside someone who's bolt on happy and starts off with headers/cai etc etc), if you can get even 3mpg more and alittle more hp/tq from it.. why not do it? Also take into consideration elevation, factory tunes dont take into account where you live, FL to CO, different elevations = "slightly" different tunes, might seem overly picky but its true.
02-01-2013, 02:29 PM
#3
Isn't this the whole point of computer controlled EFI systems using a MAF (mass air) sensor along with a MAP sensor and air intake temperature sensor ? It takes into account things like elevation and air temperature, when I start my car whether i'm in Florida at sea level and 100F or in Denver at 5000F and 32F the car idles and runs super smooth.
02-01-2013, 02:44 PM
#4
Figure about 200k cars come out with the same exact tune. You can always fine tune them in which results in a smoother,faster more efficient car.
I'll say we've tuned a ton of cars, probly 2k +. I garrenty no 2 cars have the same tune, even though alot have the same exact mods.
We tune alot of brand new vehicle's, some with less than 200 miles on them. Pretty common response from the customer is
1- vehicle drives alot smoother
2- throttle response is noticably better
3-gas mileage is better
4- for the racers- car is alot more consistant throughout the day, before the times would drop as more passes were done.
Thats just the basic stuff.
I'll say we've tuned a ton of cars, probly 2k +. I garrenty no 2 cars have the same tune, even though alot have the same exact mods.
We tune alot of brand new vehicle's, some with less than 200 miles on them. Pretty common response from the customer is
1- vehicle drives alot smoother
2- throttle response is noticably better
3-gas mileage is better
4- for the racers- car is alot more consistant throughout the day, before the times would drop as more passes were done.
Thats just the basic stuff.
02-01-2013, 02:46 PM
#5
Correct me if i'm wrong but i don't think this is true.
Isn't this the whole point of computer controlled EFI systems using a MAF (mass air) sensor along with a MAP sensor and air intake temperature sensor ? It takes into account things like elevation and air temperature, when I start my car whether i'm in Florida at sea level and 100F or in Denver at 5000F and 32F the car idles and runs super smooth.
Isn't this the whole point of computer controlled EFI systems using a MAF (mass air) sensor along with a MAP sensor and air intake temperature sensor ? It takes into account things like elevation and air temperature, when I start my car whether i'm in Florida at sea level and 100F or in Denver at 5000F and 32F the car idles and runs super smooth.
02-01-2013, 02:48 PM
#6
Figure about 200k cars come out with the same exact tune. You can always fine tune them in which results in a smoother,faster more efficient car.
I'll say we've tuned a ton of cars, probly 2k +. I garrenty no 2 cars have the same tune, even though alot have the same exact mods.
I'll say we've tuned a ton of cars, probly 2k +. I garrenty no 2 cars have the same tune, even though alot have the same exact mods.
02-01-2013, 03:11 PM
#7
Don't forget that most people have different tastes, where a tune will allow for the "personality" of the vehicle be more to what the buyer wanted. That is why they are called Custom tunes...
Some people like firmer shifts, some people like no speed limiters, some people want different shift points, Some people go and put 33 in tires on the truck right of the showroom floor and want the speedometer right, and the shift patterns corrected.. There are lots of reasons..
Some people like firmer shifts, some people like no speed limiters, some people want different shift points, Some people go and put 33 in tires on the truck right of the showroom floor and want the speedometer right, and the shift patterns corrected.. There are lots of reasons..
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02-01-2013, 03:14 PM
#8
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GM has two goals that are more important to them
than performance. CAFE and low warranty costs.
CAFE pushes them to shift early (automatics), limit
how soon PE rolls on (trucks) and so on.
Warranty is why every car and truck comes out with
more WOT enrichment than it needs, even without
any fuel trim carryover, and less timing than it could
stand.
Then you pad on some engineering worst case for
production variability and you've left a lot of goodness
on the table for the sake of the occasional bad apple.
And of course if you actually had a bad apple you'd
be wanting to get rid of a worm or two. Either way
you can find some significant improvement in both
raw performance and general drivability (shiftpoints
and such) if you bothered to look.
than performance. CAFE and low warranty costs.
CAFE pushes them to shift early (automatics), limit
how soon PE rolls on (trucks) and so on.
Warranty is why every car and truck comes out with
more WOT enrichment than it needs, even without
any fuel trim carryover, and less timing than it could
stand.
Then you pad on some engineering worst case for
production variability and you've left a lot of goodness
on the table for the sake of the occasional bad apple.
And of course if you actually had a bad apple you'd
be wanting to get rid of a worm or two. Either way
you can find some significant improvement in both
raw performance and general drivability (shiftpoints
and such) if you bothered to look.
02-01-2013, 03:25 PM
#9
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Location: Fort Myers, Florida
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I see it as if it was built so perfectly as we think the factory did it why do we install minor bolt ons?
Cousins challanger is a mopar upgraded car with a different intake and exhaust. Car came with a different tune loaded on it already. But we he got retuned the car was a whole different car.
Even the factory upgraded tune was not good enough and a mail order tune offered better gains in fuel mileage and how the car ran and idled
Cousins challanger is a mopar upgraded car with a different intake and exhaust. Car came with a different tune loaded on it already. But we he got retuned the car was a whole different car.
Even the factory upgraded tune was not good enough and a mail order tune offered better gains in fuel mileage and how the car ran and idled
02-01-2013, 03:41 PM
#10
what fine tuning is done that results in a smoother, faster, more efficient car for a new unmodified car?
My primary reason for asking all this is I don't understand what is being done or what can be done to increase gas mileage over oem programming that won't result in bad things like increased exhaust gas temps and reduced catalytic converter life, and certain higher exhaust emissions. My understanding which I believe is true is the OEM tune is conservative so that under pretty much any driving condition the engine will be reliable and durable, that's done by keeping A/F richer under certain conditions to keep exhaust temps cooler to protect the catalytic converters. Or at least that what I remember reading. And I think it's obvious considering when an OEM is selling however million cars having a warranty that you have to take certain driving conditions into consideration. But what I keep hearing is that the oem tune is "too conservative" like it's bad and the reason an aftermarket tune will result in such an improvement in fuel economy, I find that hard to believe. I mean aren't the OEM's under pressure to also get the best fuel economy possible? And now I'm talking specifically highway driving under steady state low load. Is it that you can just reprogram a slightly higher A/F ratio under part throttle low load conditions over what the OEM had it set to and not hurt anything... other than your warranty if GM finds out you had the PCM flashed ?
I would think that the OEM tune would already have the A/F for this driving condition set as lean as possible, no? And ignition timing would be running the best possible advance for the octane fuel being used and it knows this from knock sensors picking up the start of detonation ? And then you have the O2 sensors reporting oxygen content which tells the PCM to adjust A/F ratio for the given driving condition, right?
I hope this reads ok, it seems hard to type what i'm thinking and wanting to ask and not be a novel.
Last edited by 1 FMF; 02-01-2013 at 03:48 PM.
02-01-2013, 06:39 PM
#11
GM has two goals that are more important to them
than performance. CAFE and low warranty costs.
CAFE pushes them to shift early (automatics), limit
how soon PE rolls on (trucks) and so on.
Warranty is why every car and truck comes out with
more WOT enrichment than it needs, even without
any fuel trim carryover, and less timing than it could
stand.
Then you pad on some engineering worst case for
production variability and you've left a lot of goodness
on the table for the sake of the occasional bad apple.
And of course if you actually had a bad apple you'd
be wanting to get rid of a worm or two. Either way
you can find some significant improvement in both
raw performance and general drivability (shiftpoints
and such) if you bothered to look.
than performance. CAFE and low warranty costs.
CAFE pushes them to shift early (automatics), limit
how soon PE rolls on (trucks) and so on.
Warranty is why every car and truck comes out with
more WOT enrichment than it needs, even without
any fuel trim carryover, and less timing than it could
stand.
Then you pad on some engineering worst case for
production variability and you've left a lot of goodness
on the table for the sake of the occasional bad apple.
And of course if you actually had a bad apple you'd
be wanting to get rid of a worm or two. Either way
you can find some significant improvement in both
raw performance and general drivability (shiftpoints
and such) if you bothered to look.
I see it as if it was built so perfectly as we think the factory did it why do we install minor bolt ons?
Cousins challanger is a mopar upgraded car with a different intake and exhaust. Car came with a different tune loaded on it already. But we he got retuned the car was a whole different car.
Even the factory upgraded tune was not good enough and a mail order tune offered better gains in fuel mileage and how the car ran and idled
Cousins challanger is a mopar upgraded car with a different intake and exhaust. Car came with a different tune loaded on it already. But we he got retuned the car was a whole different car.
Even the factory upgraded tune was not good enough and a mail order tune offered better gains in fuel mileage and how the car ran and idled
Very simple things like allowing for quicker throttle opening rates will provide for a whole new/better driving experience, over the factory calibration on even the stockest of vehicles.
02-02-2013, 08:35 AM
#12
The factory does not tune for fuel economy. They tune for green house gases.
We add fuel to gain gas mileage.Vehicle's pick up faster which saves gas.
Longivity? Don't think so. I'm sure some tuners can kill new cars quickly by lack of knowledge. The reason GM put counters in.
We add fuel to gain gas mileage.Vehicle's pick up faster which saves gas.
Longivity? Don't think so. I'm sure some tuners can kill new cars quickly by lack of knowledge. The reason GM put counters in.
02-02-2013, 01:20 PM
#13
this sounds contrary to all logic but one of the easiest ways the manufacturers could increase c.a.f.e. mileage would be to get rid of emmisions laws completely.
what 2 basic parameters are emmisions laws concerned with ?
CO levels (carbon) = from excess unburned fuel/rich condition
NOX (nitrides of oxygen)= NOX emissions increase with temperature which happens when the fueling gets leaner or timing is greater ( or both lol)
The oems in the US have to tune to not go over the levels required for either parameter which means the calibrators are directed to come up with a palatable compromise from the start.
some of the same vehicles we have here run on tunes that dont have to meet the same strict nox emissions in other countries utilizing what is called lean cruise ( at least in GM vehicles) which allows you to run afr's greater than 14.7 to 1 and in some low load circumstances closer to 17 to 1 such as coasting , idling .
I have no knowledge of any vehicles in the US that have turned this logic on
but yes there is code allready in your GM pcm that can enable it to get better mileage with no additional parts/$$ needed
theres also catalyst efficiency self test which is basically a big fuel dump event, with cats removed this test isnt necessary , this would of course be "for off road use only"
as for the stock tune in regards to power , the OEM calibrators are assiged to build a tune that will keep cars from having warranty issues , keep them running within federal emissions and cafe guidelines whether they are being run in death valley on a 140* day , international falls minnesota when its -60* , at 7,000 feet elevation in the mountains , at -1800 density altitude at Atco in december lol with 2,000 miles of wear on them or 300,000 miles of wear and even compensate to a point for people that dont keep up with maintenance items.
Someone tuning for power can ask themself am I a big boy if this breaks a rear/trans after removing torque management and altering abuse modes , upping shift pressures , shortening times to shift ? any one thats ever done these thing to an ls vehicle will tell you its a different vehicle allready.
Then if you get a wideband on the car and tune the afr to be safe and adjust timing on pump premium theres gains to be made whereas the factory has to be conservative for the moron who pumps regular gas in their premium fuel only car because they saw someone on the news say you dont need it.
OEM's use widebands when they develop the tune then sell you a car with narrowbands because they are cheaper and more accurate at cruise where economy numbers come from so all your wide open areas of the tune are an educated guess based on data from the R&D cars with all the conservative fudge factors for temp ,altitude ,fuel quality etc.. baked in
there is always some power left on the table when you properly tune your car , in your location with a wideband for fueling and scan logs for timing advance , knock retard levels etc... to make sure your not going to cause engine damage.
Will a tune on a stock car take it from 300 hp to 400 hp , not likely but making it feel like its made a significant gain while getting conservative gains in et's or dyno numbers will hapen every time someone who understands the concepts tunes a car - myself I am still at hobby/hack level lol and have only tuned a couple of my cars and a friend or 2 , but theres a couple guys above in this post that would definately prove the gains on a stock car to you via dyno or track if you brought them a stock car and gave them a couple hours with it...
Last edited by murphinator; 02-02-2013 at 01:25 PM.