Some basic questions
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Le Mans Master
Joined: Oct 2001
Posts: 8,448
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From: Alaska
Some basic questions
First, if I decide to supercharge my 2013 GS I seriously doubt there will be any other engine mods down the line with the exception of headers.
With the A&A system there is an $1,100 up charge for the 8 rib vs the stock 6. Is there any reason I would actually need the 8 rib design?
Second, we live at 7,000 feet so if the system is installed and tuned for our elevation what happens when I drive down to sea level, which happens a couple of times a year? As elevation decreases the car would be running leaner and leaner. Will it have the ability to reprogram its self ?
With the A&A system there is an $1,100 up charge for the 8 rib vs the stock 6. Is there any reason I would actually need the 8 rib design?
Second, we live at 7,000 feet so if the system is installed and tuned for our elevation what happens when I drive down to sea level, which happens a couple of times a year? As elevation decreases the car would be running leaner and leaner. Will it have the ability to reprogram its self ?
Advanced
Joined: Oct 2014
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yes the car runs a little leaner and will need to be checked at sea level being they high up in elevation.
Check out presence distribution. he has bad *** pricing on A&A and ECS kits... You wont need the 8rib setup for your goals!!! Just keep the 6rib and roll with it.
shoot mike an email.
mike@presencedistribution.com
he can hook it up for you!! and save you some cash
Check out presence distribution. he has bad *** pricing on A&A and ECS kits... You wont need the 8rib setup for your goals!!! Just keep the 6rib and roll with it.
shoot mike an email.
mike@presencedistribution.com
he can hook it up for you!! and save you some cash
Race Director
Joined: May 2004
Posts: 16,667
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From: Raleigh, NC
St. Jude Donor '15
First, if I decide to supercharge my 2013 GS I seriously doubt there will be any other engine mods down the line with the exception of headers.
With the A&A system there is an $1,100 up charge for the 8 rib vs the stock 6. Is there any reason I would actually need the 8 rib design?
Second, we live at 7,000 feet so if the system is installed and tuned for our elevation what happens when I drive down to sea level, which happens a couple of times a year? As elevation decreases the car would be running leaner and leaner. Will it have the ability to reprogram its self ?
With the A&A system there is an $1,100 up charge for the 8 rib vs the stock 6. Is there any reason I would actually need the 8 rib design?
Second, we live at 7,000 feet so if the system is installed and tuned for our elevation what happens when I drive down to sea level, which happens a couple of times a year? As elevation decreases the car would be running leaner and leaner. Will it have the ability to reprogram its self ?
All cars made today have the ability to adjust to changing conditions.. the adjustment is called fuel trims and they adjust constantly when driving
If during normal driving (perhaps at lower elevation than it was tuned at) the car figures out it needs to add 7% more fuel to stay at 14.7:1 (stoichiometry), it will also add 7% more fuel during wide open throttle to stay on the safe side. Not sure how much you know about tuning, but the point is it will adjust TO AN EXTENT. I mean I wouldn't want something that was tuned on the ragged edge at 7000 feet to be driven off a trailer at sea level and go gangbuster or anything.. but within reason, it will be fine.
Team Owner
Joined: Nov 2007
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From: Gilbert AZ
ECS kits are great. I've had both and like the ECS kit a lot more.
If you get a good tuner, and keep it really safe, you maybe ok going to sealevel. As long as you aren't close to injectors limits or pump limits and they set the maf curve decently you won't have an issue, or shouldn't, that being said, I wouldn't get on it when going down to sea level.
Car does NOT adjust WOT fueling, so it will not "self tune" when you drive down. (well it would only apply postive LTFTs, assuming tuner keeps those on, a lot turn off LTFTs). GMs are not like Ford ECUs that use widebands and adjust all the time. Maybe one day they will catch up.
If you get a good tuner, and keep it really safe, you maybe ok going to sealevel. As long as you aren't close to injectors limits or pump limits and they set the maf curve decently you won't have an issue, or shouldn't, that being said, I wouldn't get on it when going down to sea level.
Car does NOT adjust WOT fueling, so it will not "self tune" when you drive down. (well it would only apply postive LTFTs, assuming tuner keeps those on, a lot turn off LTFTs). GMs are not like Ford ECUs that use widebands and adjust all the time. Maybe one day they will catch up.
Last edited by Unreal; Oct 21, 2014 at 10:24 PM.
Race Director
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From: Raleigh, NC
St. Jude Donor '15
Straight from HP tuners:
http://www.hptuners.com/forum/showth...l=1#post244072
Also, I can't believe GM is still not using widebands.. especially on the C7's of all things
Team Owner
Joined: Nov 2007
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From: Gilbert AZ
Edited before you posted that, but that still isn't self tuning, or really enough. Doesn't address the issue that you will be on new parts of the maf/timing curve that have never been seen, and if you are at the limits of anything up high, you will surpass them when you go down. I've gone from 5000+ to sealevel many times, and wouldn't suggest anyone tuned exclusively at 5k+ feet go beat on it down low without getting it checked first. There is also a reason they run 91 at high elevations, but then if you go down and still have 91 that can cause issues.
Problem with using positive fuel trims, is they can be negative up high, so nothing added, then you do a pull once you get down, and you are lean. After driving a while they may go positive, but typically only for low throttle maf/VE areas. It is just a risky game to play. You may not have any + fuel trims at 10k+Hz where WOT at sealevel will be, and even driving around for a week may never see that maf reading in closed loop to get the fuel trims to adjust.
Problem with using positive fuel trims, is they can be negative up high, so nothing added, then you do a pull once you get down, and you are lean. After driving a while they may go positive, but typically only for low throttle maf/VE areas. It is just a risky game to play. You may not have any + fuel trims at 10k+Hz where WOT at sealevel will be, and even driving around for a week may never see that maf reading in closed loop to get the fuel trims to adjust.
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Race Director
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From: Raleigh, NC
St. Jude Donor '15
People don't NOT drive ZR1's to different elevations because they're afraid they're going to break something. Not a 100% correct analogy, but that's just my thoughts on it.
Team Owner
Joined: Nov 2007
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From: Gilbert AZ
Zr1s and OEM maps are tested and mapped for all elevations though.
I wouldn't be afraid of driving it anywhere, just wouldn't beat on it if you go from 5k to sealevel without checking it first, or making sure tune is on the very conservative side.
When I moved from Utah to Arizona, timing had to be backed off 2-3 degrees to be safe. Fueling was still pig rich, so even when it leaned out slightly, it was fine.
I wouldn't be afraid of driving it anywhere, just wouldn't beat on it if you go from 5k to sealevel without checking it first, or making sure tune is on the very conservative side.
When I moved from Utah to Arizona, timing had to be backed off 2-3 degrees to be safe. Fueling was still pig rich, so even when it leaned out slightly, it was fine.
Thread Starter
Le Mans Master
Joined: Oct 2001
Posts: 8,448
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From: Alaska
Edited before you posted that, but that still isn't self tuning, or really enough. Doesn't address the issue that you will be on new parts of the maf/timing curve that have never been seen, and if you are at the limits of anything up high, you will surpass them when you go down. I've gone from 5000+ to sealevel many times, and wouldn't suggest anyone tuned exclusively at 5k+ feet go beat on it down low without getting it checked first. There is also a reason they run 91 at high elevations, but then if you go down and still have 91 that can cause issues.
Problem with using positive fuel trims, is they can be negative up high, so nothing added, then you do a pull once you get down, and you are lean. After driving a while they may go positive, but typically only for low throttle maf/VE areas. It is just a risky game to play. You may not have any + fuel trims at 10k+Hz where WOT at sealevel will be, and even driving around for a week may never see that maf reading in closed loop to get the fuel trims to adjust.
Problem with using positive fuel trims, is they can be negative up high, so nothing added, then you do a pull once you get down, and you are lean. After driving a while they may go positive, but typically only for low throttle maf/VE areas. It is just a risky game to play. You may not have any + fuel trims at 10k+Hz where WOT at sealevel will be, and even driving around for a week may never see that maf reading in closed loop to get the fuel trims to adjust.
I'll be the first to admit I know very little about car computers and fuel injection systems. But why can a stock car go from sea level to 12,000 feet without being retuned yet some of you guys are saying to be cautious if I add a SC?
Last edited by Snowwolfe; Oct 22, 2014 at 05:06 PM.
Team Owner
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From: Gilbert AZ
You don't need higher octane at higher elevation. 91 at 5000ft is like 93 at sea level.
Why can you do it in a stock car? Because they map and adjust the tune for zero to 12k ft. Get your tuner to do that, and you are good to go, but it is typically hard to find someone to drive to top of pikes peak and then to sea level tuning. OEMs do that.
Not saying you can't, as long as it is set up extra safe, but just be careful when going down to lower elevations. Don't just expect everything to be safe.
Why can you do it in a stock car? Because they map and adjust the tune for zero to 12k ft. Get your tuner to do that, and you are good to go, but it is typically hard to find someone to drive to top of pikes peak and then to sea level tuning. OEMs do that.
Not saying you can't, as long as it is set up extra safe, but just be careful when going down to lower elevations. Don't just expect everything to be safe.
Thread Starter
Le Mans Master
Joined: Oct 2001
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From: Alaska
Gotcha, you were suggesting you only need 91 instead of 93 at 7,000 feet. I didn't think it through and at first thought you were saying we needed higher octane at higher elevation.
My bad.
My bad.
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From: Raleigh, NC
St. Jude Donor '15
Zr1s and OEM maps are tested and mapped for all elevations though.
I wouldn't be afraid of driving it anywhere, just wouldn't beat on it if you go from 5k to sealevel without checking it first, or making sure tune is on the very conservative side.
When I moved from Utah to Arizona, timing had to be backed off 2-3 degrees to be safe. Fueling was still pig rich, so even when it leaned out slightly, it was fine.
I wouldn't be afraid of driving it anywhere, just wouldn't beat on it if you go from 5k to sealevel without checking it first, or making sure tune is on the very conservative side.
When I moved from Utah to Arizona, timing had to be backed off 2-3 degrees to be safe. Fueling was still pig rich, so even when it leaned out slightly, it was fine.
edit: also see a "VE Initial Correction Factor" with Barometric pressure vs. coolant temps being shown. Not sure if that is related or not
Last edited by schpenxel; Oct 23, 2014 at 12:17 PM.
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From: Raleigh, NC
St. Jude Donor '15
You're talking about adding 100+ HP to an otherwise stock engine.. all of that is taking away from the safety margins built in for the engine internals by GM
i.e. perhaps it was designed to be an output of 400hp from the factory with a 60% "safety factor", so lets say it's good for 640hp before you start breaking stuff. With a SC added maybe that puts you at 600hp.. not a whole lot of safety net left, thus the tune needs to be very accurate when you're actually making that HP. These numbers are totally made up and off the top of my head, so do not take them literally, but hopefully you get my point
Not trying to scare you.. ECS and A&A both have tons of stock engine cars on the road that have gone years without issues. The point being is the more power you make, the harder it is on the engine. The chances of something breaking do go up the higher you go HP wise.
The more accurate the tune, the better your chances
Team Owner
Joined: Nov 2007
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From: Gilbert AZ
Just curious, what table accounts for altitude change? It is some sort of multiplier or what? I've seen "BARO" a few times on some of the pages in HPT but haven't had a chance to really look at them in detail. Wasn't sure if that was how it's done or something else
edit: also see a "VE Initial Correction Factor" with Barometric pressure vs. coolant temps being shown. Not sure if that is related or not
edit: also see a "VE Initial Correction Factor" with Barometric pressure vs. coolant temps being shown. Not sure if that is related or not
If you are only tuned up to 11500HZ on the maf table, but go down and are now running in the 11500-13000 range that has never been tuned or seen before, that is the big risk. Plus you move down into new load cells on the timing map. It should be ok if the tuner sets it up correctly, but I wouldn't just assume so and risk a motor on it. Log it, and see. Odds are it would be safe as long as tuner continues a sane maf curve and smooths it nicely/etc, but that is still a risk.
It would be like tuning at 80% throttle, and then extrapolating for 100%.