Tuning for more power, with warranty?

chipsterguy

Active member
Avanti, it is abundantly clear you are against tuning the turbo diesel MB. We got that. Thanks for your input, it is certainly an interesting perspective.

You have not persuaded me against tuning my engine. I am in favor of tuning. The warranty is one factor among many. The tune is not illegal and does not break any laws in the US. Not sure what further points you are trying to make, but it appears to be beyond the point of diminishing returns. Sounds to me like you are evangelizing at this point... and I am clearly not interested in that.
 

avanti

2014 GWV Legend 3500 I4
Avanti, it is abundantly clear you are against tuning the turbo diesel MB. We got that. Thanks for your input, it is certainly an interesting perspective.

You have not persuaded me against tuning my engine. I am in favor of tuning. The warranty is one factor among many. The tune is not illegal and does not break any laws in the US. Not sure what further points you are trying to make, but it appears to be beyond the point of diminishing returns. Sounds to me like you are evangelizing at this point... and I am clearly not interested in that.
I am neither for nor against tunes. I am against breaking our environmental laws.

I am also against inaccurate information on this list. As I have documented, unless your so-called "tuner" has gotten an explicit EPA or CARB exemption for your specific vehicle/engine combination, a "tune" constitutes tampering under the CAA and is most certainly illegal in the US.

Ask your friends at "Green" Diesel Engineering.
 

Wrinkledpants

2017 144WB 4x4
Maybe I'm wrong, but I feel like there is a difference between tuning any vehicle with the emissions controls in place, and tuning with a reduction or defeat of those controls.

GDE's tune allowed for disabling DEF injection. Renntech is huge. If they were tuning diesels with a goal of disabling emissions, they likely would have been visited by the EPA by now.
 

Wrinkledpants

2017 144WB 4x4
Well, last night I overwrote my OE Tuning tune with the Renntech HHT. First of all, if you have a tune, make sure you flash the stock tune first or you are going to have some troubles. I went around in circles a few times before getting it sorted out.

The Renntech definitely does not have as much power as my OE Tuning tune. I probably lost close to 2 seconds to 60mph. But while area under the curve is less, the deployment of the power is supremely better. Boost comes on much smoother and in a much more linear fashion, versus the stepwise fashion of the stock tune and the steep second order curve of the OE tune. Power and torque at low RPMs is significantly improved. Shift logic is improved, kick down happens sooner and more naturally, holds gears more intuitively.

I back my van into my RV storage on the side of my house, but first I must go over a tallish curb. I typically back the van against the curb and then roll up it. With the stock tune I had to get a rolling start in 2wd. If I backed it up and then stopped with the tires touching I could mat the throttle and sometimes it would not build enough boost to crawl up. With the OE tune, it would ramp up and sometimes get some boost surge followed by the bypass valve fluttering but would climb it. With the Renntech it just rolled right up from a stop. No F's given. The torque hits WAY earlier in the RPM band with the renntech and it is easy to meter it out.

I used to drop the van into 4 low just to make it smooth getting over the curb into my side yard. This is not required with the Renntech. Which leads me to this; the van will by IMMEASURABLY more capable off-road. The torque arriving earlier in the RPM band will pay huge dividends for picking your way over obstacles and maintaining momentum in the van, as well as restarting when momentum is lost. This is probably going to be the single most significant upgrade in terms of off-road capability of the van.

Lastly, I bought the black Friday speed bundle from Owl Vans which includes the power pedal. Ill be selling it. The throttle mapping of the Renntech is smooth, predictable and well metered. Once again Renntech has proven themselves Master Benz Tuners. Great product.

EVERYONE with a 6cyl sprinter that has any aims of tackling the road less traveled or whose van is punching above its GVWR should not consider this optional, but required. My Van is a whole new animal and drives the way i've always thought it should.
How is the down shifting when coming into an uphill corner after slowing (like a sweeper right hand at a light?). That's the one place where I feel like the lockdown his horrid when at elevation. We spent 3 weeks in the Carolinas, and the van drove amazing with the thicker air. Here in Denver, the thin air results in horrid turbo lag. Your other descriptions now have me rethinking my decision to not tune. I may have to call our local dealer at Westminster to see if they support it.
 

avanti

2014 GWV Legend 3500 I4
Maybe I'm wrong, but I feel like there is a difference between tuning any vehicle with the emissions controls in place, and tuning with a reduction or defeat of those controls.

GDE's tune allowed for disabling DEF injection. Renntech is huge. If they were tuning diesels with a goal of disabling emissions, they likely would have been visited by the EPA by now.
Well, it's complicated...

The CAA prohibits changes not only to physical emissions devices, but all "elements of design", which include software modifications, so generally, ANY modification from the configuration that was originally certified are prohibited.

However, there is also class of configuration called "Adjustable Parameters" which provide some leeway. Here is what the Act says about them:

Adjustable parameters.
Engines that have adjustable parameters must meet all the requirements of this part for any adjustment in the physically adjustable range. An operating parameter is not considered adjustable if you permanently seal it or if it is not normally accessible using ordinary tools. We may require that you set adjustable parameters to any specification within the adjustable range during any testing, including certification testing, production-line testing, or in-use testing. You may ask us to limit idle-speed or carburetor adjustments to a smaller range than the physically adjustable range if you show us that the engine will not be adjusted outside of this smaller range during in-use operation without significantly degrading engine performance.

In other words, you CAN alter adjustable parameters, but a parameter only qualifies as such if it has been tested to certify that all available settings of the parameter meet the emissions requirements.

So, you are correct that it is possible that the Renntech tunes only alter adjustable parameters, in which case they would be legal. This is probably true of the products that they advertise as "50 state legal". But, the Sprinter product is not one of these. Somehow, I suspect that there is a reason for this.

As for Renntec being "huge", this is no evidence that they are within a law. If you browse the list of recent enforcement actions here:
you will find many companies much, much larger than Renntech (Cummings, for just one example).
 

RVBarry

Well-known member
I thought turbo engines are supposed to resist altitude effects, and that the boost sensors or wastegates are tuned to absolute pressure, not relative. Right?

Isn't that supposedly why Aspen PD had Saab Turbos?
 

Wrinkledpants

2017 144WB 4x4
I thought turbo engines are supposed to resist altitude effects, and that the boost sensors or wastegates are tuned to absolute pressure, not relative. Right?

Isn't that supposedly why Aspen PD had Saab Turbos?
It's gauge pressure, not absolute. Turbos will lose less HP per elevation gained compared to NA cars, but they are not immune. It's hard to put a number to how much turbos loose due to efficiency maps being unique to each turbo design.
 

OffroadHamster

Active member
"tampering with an emission control device on a motor vehicle by removing it or making it inoperable"

The tune we are talking about here does neither of these things. I'm struggling to understand your perspective, you are concerned with our environmental laws, presumably because you are concerned about the abysmal trajectory of our planet, yet you disagree with making a vehicle run cleaner because it is, what? Against the letter of the law? But compliant with the intent?

Our emissions laws being based on pollution per gallon is bankrupt and has allowed the auto industry enormous leeway to continue to produce vehicles that are bad for the planet. The EU's standard of pollution per mile traveled has much less petroleum industry influence. A tune which does not disable or remove any emission control device while improving fuel economy is surely compliant with the intent of the law, which is to reduce pollution.

The EPA's testing protocol allows vehicles to run clean at specified test points while puking black soot and nitrogen oxides elsewhere in the power band. Whats your high ground here? Or are you simply arguing a point for the sake of the thing itself? Im struggling to understand your reasoning here....

How is the down shifting when coming into an uphill corner after slowing (like a sweeper right hand at a light?). That's the one place where I feel like the lockdown his horrid when at elevation. We spent 3 weeks in the Carolinas, and the van drove amazing with the thicker air. Here in Denver, the thin air results in horrid turbo lag. Your other descriptions now have me rethinking my decision to not tune. I may have to call our local dealer at Westminster to see if they support it.
Its markedly better. In that situation I used to get turbo flutter. The van bogs and doesnt shift so you kick the accelerator, then it downshifts, lurches, and you ease off the gas and get that annoying turbo flutter, during which it may upshift again. That is all but gone now, as the power delivery is much more linear so you have the throttle control to compel the shift. Also since there is substantially more power at low RPM's the accelerative difference before and after shift is much closer so you dont get the initial lag followed by lurch....,just good power followed by better power.
 

OffroadHamster

Active member
It's gauge pressure, not absolute. Turbos will lose less HP per elevation gained compared to NA cars, but they are not immune. It's hard to put a number to how much turbos loose due to efficiency maps being unique to each turbo design.
When I tune for elevation, I run slightly richer mapping. At altitude the turbo is doing more work on the air and you get slightly higher charge temps than you do at lower altitude. Also, high elevations are generally drier which can increase cylinder temps slightly. My mapping typically drops AFR's progressively from 11:1 to 10:1 in open loop fueling (high load/requested torque) at high elevations. I typically have a blanket 2 deg of timing pulled as well. I can run sea level mapping, however, the tune will be noisy and feedback knock will pull timing (not ideal as it takes a while for those values to make their way back out of the knock learning), and it ends up being harder on your oil change interval.

With an altitude map, at 10K feet I am probably taking a 10% hit in power, versus an NA car that has lost roughly 30% of its power. Factory mapping of a typical turbo engine at 10K feet is probably closer to 12-15% power loss vs sea level. Still substantially better than an NA engine.
 

avanti

2014 GWV Legend 3500 I4
"tampering with an emission control device on a motor vehicle by removing it or making it inoperable"

The tune we are talking about here does neither of these things.
You choose to consistently ignore the carefully curated references to the actual law and its accompanying regulations which I have provided. Instead, you keep repeating obvious falsehoods in contradiction to this information.
I am going to stop wasting my time.
 

OffroadHamster

Active member
And ours hopefully! You chose to ignore that this thread is about warranty and tuning, and not your CAA Crusade. You likewise ignored my genuine curiosity on what your real concern or point is?

Like I said, make another thread before another productive thread on tuning gets shut down by you, Orion, or the Grand Tour..... Ride that high horse elsewhere.
 

Wrinkledpants

2017 144WB 4x4
"tampering with an emission control device on a motor vehicle by removing it or making it inoperable"

The tune we are talking about here does neither of these things. I'm struggling to understand your perspective, you are concerned with our environmental laws, presumably because you are concerned about the abysmal trajectory of our planet, yet you disagree with making a vehicle run cleaner because it is, what? Against the letter of the law? But compliant with the intent?

Our emissions laws being based on pollution per gallon is bankrupt and has allowed the auto industry enormous leeway to continue to produce vehicles that are bad for the planet. The EU's standard of pollution per mile traveled has much less petroleum industry influence. A tune which does not disable or remove any emission control device while improving fuel economy is surely compliant with the intent of the law, which is to reduce pollution.

The EPA's testing protocol allows vehicles to run clean at specified test points while puking black soot and nitrogen oxides elsewhere in the power band. Whats your high ground here? Or are you simply arguing a point for the sake of the thing itself? Im struggling to understand your reasoning here....



Its markedly better. In that situation I used to get turbo flutter. The van bogs and doesnt shift so you kick the accelerator, then it downshifts, lurches, and you ease off the gas and get that annoying turbo flutter, during which it may upshift again. That is all but gone now, as the power delivery is much more linear so you have the throttle control to compel the shift. Also since there is substantially more power at low RPM's the accelerative difference before and after shift is much closer so you dont get the initial lag followed by lurch....,just good power followed by better power.
Damnit, lol. Now this is on the ever growing list of mods.
 

Wrinkledpants

2017 144WB 4x4
When I tune for elevation, I run slightly richer mapping. At altitude the turbo is doing more work on the air and you get slightly higher charge temps than you do at lower altitude. Also, high elevations are generally drier which can increase cylinder temps slightly. My mapping typically drops AFR's progressively from 11:1 to 10:1 in open loop fueling (high load/requested torque) at high elevations. I typically have a blanket 2 deg of timing pulled as well. I can run sea level mapping, however, the tune will be noisy and feedback knock will pull timing (not ideal as it takes a while for those values to make their way back out of the knock learning), and it ends up being harder on your oil change interval.

With an altitude map, at 10K feet I am probably taking a 10% hit in power, versus an NA car that has lost roughly 30% of its power. Factory mapping of a typical turbo engine at 10K feet is probably closer to 12-15% power loss vs sea level. Still substantially better than an NA engine.
Now you're just talking dirty. I'd be curious to see MAF values at elevation on a tune vs stock at sea level.

Have you had enough cold weather starts to know if the "no-throttle" issue when cold and at elevation has been improved? I've experienced this progressively worse between 5k and 8K ft.
 

OffroadHamster

Active member
Now you're just talking dirty. I'd be curious to see MAF values at elevation on a tune vs stock at sea level.

Have you had enough cold weather starts to know if the "no-throttle" issue when cold and at elevation has been improved? I've experienced this progressively worse between 5k and 8K ft.
No, not yet, but tomorrow I am driving to Flagstaff and it should be cold enough and high enough to get an idea. Ill definitely go out early and cold start her and see what I get and report back. It would be great if that was resolved, its super annoying when you cant get over a bump of snow or ice in the morning.
 

OffroadHamster

Active member
Ok - Overnight cold soak to 22 deg one night, 17deg the next. We were staying in Williams and my NIST calibrated WeatherMeter Altimeter pegged the house at 6945ft. House had a 40ft drive with a 15% slope. Fired the van up, immediately dropped it in gear in RWD and attempted to climb. At first just the typical no movement condition, but revs crept up after about 3-4 seconds with the throttle matted and the van easily walked up the drive. Did this two mornings in a row.

I believe that the no power/movement condition in cold temps at altitude is resolved. After I drove up once, I backed down and put the van in 4lo for S&G's and the van quickly built enough boost to ease up the driveway. I then placed the front tires against a curb and the van easily pulled itself onto it. I did all this within 60-80 seconds of starting the van.

Ill post more feedback after I go skiing next for some 8-9K foot altitude data.
 

gltrimble

Well-known member
Ok - Overnight cold soak to 22 deg one night, 17deg the next. We were staying in Williams and my NIST calibrated WeatherMeter Altimeter pegged the house at 6945ft. House had a 40ft drive with a 15% slope. Fired the van up, immediately dropped it in gear in RWD and attempted to climb. At first just the typical no movement condition, but revs crept up after about 3-4 seconds with the throttle matted and the van easily walked up the drive. Did this two mornings in a row.

I believe that the no power/movement condition in cold temps at altitude is resolved. After I drove up once, I backed down and put the van in 4lo for S&G's and the van quickly built enough boost to ease up the driveway. I then placed the front tires against a curb and the van easily pulled itself onto it. I did all this within 60-80 seconds of starting the van.

Ill post more feedback after I go skiing next for some 8-9K foot altitude data.
Have you tried shutting the engine off and restarting. I recently did this at about 6000ft altitude with a cold engine after the throttle failed to respond. After second start throttle responded normally. I originally thought my throttle problems were a combination of altitude and cold outside temperatures. After multiple occurrences i determined it was a combination of cold engine, <100F, and altitude, >5000ft. Warming the engine was a solution to the no throttle problem but could take 10-15 minutes to reach 130F. Restarting takes a few seconds.
 
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gltrimble

Well-known member
What are the "no-throttle" and "no power/movement condition" issues you guys are referring to?

Thanks!
For me the “no throttle” problem occurs 100% of the time when the engine is cold and elevation exceeds approximately 5000ft. As @Wrinkledpants states the problem seems to get progressively worse with elevation. During this past summer I camped at Big Pine and Onion Valley both close to 9000ft elevation. Each time the throttle refused to budge the van until the engine reached almost 130F. At lower elevations like Lassen National Park, 5000ft, the issue goes away much quicker. The problem appears to only happen on 4x4 vehicles. More recently I tried something I read about, shutting the engine down and restarting. It worked but my data set is still limited on this. Obviously the problem can not be repeated by the dealer unless your dealer is above 5000ft elevation. Still looking for a permanent solution to this issue.
 

99sport

Active member
For me the “no throttle” problem occurs 100% of the time when the engine is cold and elevation exceeds approximately 5000ft. As @Wrinkledpants states the problem seems to get progressively worse with elevation. During this past summer I camped at Big Pine and Onion Valley both close to 9000ft elevation. Each time the throttle refused to budge the van until the engine reached almost 130F. At lower elevations like Lassen National Park, 5000ft, the issue goes away much quicker. The problem appears to only happen on 4x4 vehicles. More recently I tried something I read about, shutting the engine down and restarting. It worked but my data set is still limited on this. Obviously the problem can not be repeated by the dealer unless your dealer is above 5000ft elevation. Still looking for a permanent solution to this issue.
Can you describe in a little more detail what you mean? My van (2005 T1N) has had a similar issue at 10,000 feet on a cold morning. I once had the throttle pedal completely ineffective - that is I pushed it to the floor and the van simply idled, although it was a completely normal idle, it behaved as if the pedal was not connected to anything.

I've had other issues at altitude where the van dies when put it in gear on a cold morning at altitude, and also rough running when first started. My solution has been to let the engine warm up for 10 or 15 minutes on high idle. My issues are only at 10,0000 ft - I've not (yet) noticed any issues at 5,000 ft.
 

gltrimble

Well-known member
Can you describe in a little more detail what you mean? My van (2005 T1N) has had a similar issue at 10,000 feet on a cold morning. I once had the throttle pedal completely ineffective - that is I pushed it to the floor and the van simply idled, although it was a completely normal idle, it behaved as if the pedal was not connected to anything.

I've had other issues at altitude where the van dies when put it in gear on a cold morning at altitude, and also rough running when first started. My solution has been to let the engine warm up for 10 or 15 minutes on high idle. My issues are only at 10,0000 ft - I've not (yet) noticed any issues at 5,000 ft.
My issue is similar to yours with regard to throttle pedal response but outside temperature does not seem to be a consistent factor. Altitude and cold engine are involved all the time. Engine idles fine. Engine will rev in neutral but do nothing in drive or reverse. Others reporting similar issue are mostly later model, 2015+, 4x4s. Allowing the engine to warm up is always a solution but it should not be the only solution.
 

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