Discrepancy in power gain, same turbo different cars, altitude and air density is a big reason for a lot of it.

[RAAMaudio]

I was searching for air density for my area and found this simple and easy to use info and thought it might help a few realize why their is such a difference. I notice a dramatic increase in power when I go from here at 4700 ft to near sea level in the Sacramento CA area.

In the middle of tuning the GT2560R and just started on top end power, 91 octane for now, will tune for 50/50 meth next then 100% meth.
Showing 265WHP at the moment and expect more soon, corrected for sea level would read 300WHP.

http://www.mountaincanyonflying.com/DA%20Workbook.pdf


I miss the EFR, Vdyno showed over 305WHP here on 91 octane, corrected would of been around 345 whp....

HMMM, somehow that does not seem right on just 91 Octane...... but the car was quick and at sea level damn quick and did not spin the 225 Rival S tires in second gear!

 

[Brura22]

I was searching for air density for my area and found this simple and easy to use info and thought it might help a few realize why their is such a difference. I notice a dramatic increase in power when I go from here at 4700 ft to near sea level in the Sacramento CA area.

In the middle of tuning the GT2560R and just started on top end power, 91 octane for now, will tune for 50/50 meth next then 100% meth.
Showing 265WHP at the moment and expect more soon, corrected for sea level would read 300WHP.

http://www.mountaincanyonflying.com/DA%20Workbook.pdf

Yeah 4700 ft is pretty freaking high in terms of air density and oxygen in the air.
You'll DEFINITELY see a power drop lol.

Which pump are you gonna run the 100% meth through.


Sent from my iPhone using Tapatalk

 

[RAAMaudio]

I added more info on the first post, EFR showed 309 WHP, would of been 350 corrected on just 91 which seems quite high on the stock fuel system.
---------

I have the AEM WMI kit, I do not want to run 100% full time due to safety issues even though I spent a huge effort building separate sealed SS and aluminum enclosures into the spare tire well, one for the tank, pump and batter to separate them in case of a crash, then covered with a screwed on lid, foam and carpet.

I am going to check the flash point that for each percentage point of water to meth and see how high I can go safely over 50% if possible then run that full time.

 

[1azst]

I'm only getting 320-330 vdyno (dhm 360) at 7000' with 50/50 meth, but I have 300+ from 5k up. I'm happy with it, and Ron at dhm's driveability is perfect.

 

[RAAMaudio]

That is damn good power at that altitude, you would be hanging on to your butt at sea level or just spinning the tires to much with what the math says you should be close to 400WHP

I am seriously considering swapping to the same turbo, by the time I sell the GT2560R with billet wheel it would be around $1k tuned which is 1/50th of what I have invested in this car. That would equate to just over 350WHP at my altitude. WMI kit already installed, buried in separate sealed safe containers in the tire well.

 

[1azst]

.....Gtx....2860..... Gen 2...?..........Do it.......

 

[STAZ15]

I bought the 2554r for a great price off of a fellow forum member but now that I'm reading about the 2560 and even the x47 I think I may have made a mistake :/ no matter at 2300 ft above sea level I should be making decent power


Sent from my iPhone using Tapatalk

 

[Brura22]

I run 80% meth 20% distilled water in a sealed 6 gallon fuel cell tank.
I feel pretty safe about it


Sent from my iPad using Tapatalk

 

[RAAMaudio]

Cool about the tank but what about the engine bay, I found my line popped out of the connector the other day, really odd as nothing can get to it, etc.....spraying 80% into an engine bay might be quite a fire hazard
but I have not found the right place to work this out yet. I know 50/50 is quite difficult to light off but 80/20 might still be safe.

I only have a one gallon container as had other things I needed the space for, pump, battery, too bag(I always carry tools except on track in a highly modded car) small tire pump and patch kit as do not carry a spare, Li jumper battery, emergency cold weather gear, or hot weather, or...depending on season, it all fits in the tire well after I cut out half the bottom so everything sits flush with the metal floor of the hatch area.

I did run the line under the car safely attached on the fuel line runs. I have a second rubber hose going forward as using the WMI container for window washing duties as well.

---------------

I did the air density calc and it shows at 60 degrees to add 1500ft so the WHP came out to 310 at sea level on the GT2560R, which is still being tuned.

On the EFR it shows 362 WHP.

Question is, on 91 octane, no WMI, stock fuel system, the numbers seem really high, but then again, the highest HP per turbo version cars posted may all be at low altitudes.

---------------

 

[Brura22]

Cool about the tank but what about the engine bay, I found my line popped out of the connector the other day, really odd as nothing can get to it, etc.....spraying 80% into an engine bay might be quite a fire hazard
but I have not found the right place to work this out yet. I know 50/50 is quite difficult to light off but 80/20 might still be safe.

I only have a one gallon container as had other things I needed the space for, pump, battery, too bag(I always carry tools except on track in a highly modded car) small tire pump and patch kit as do not carry a spare, Li jumper battery, emergency cold weather gear, or hot weather, or...depending on season, it all fits in the tire well after I cut out half the bottom so everything sits flush with the metal floor of the hatch area.

I did run the line under the car safely attached on the fuel line runs. I have a second rubber hose going forward as using the WMI container for window washing duties as well.

---------------

I did the air density calc and it shows at 60 degrees to add 1500ft so the WHP came out to 310 at sea level on the GT2560R, which is still being tuned.

On the EFR it shows 362 WHP.

Question is, on 91 octane, no WMI, stock fuel system, the numbers seem really high, but then again, the highest HP per turbo version cars posted may all be at low altitudes.

---------------

Of course it seems high. vDynos and online calculations can never be as accurate as a real dyno run.


Sent from my iPhone using Tapatalk

 

[RAAMaudio]

True in theory but I have seen some big discrepancies in real dyno runs as well, worst case was all out cheating customers by spraying intercoolers with NOS to make bigger numbers that were promised but the build and tune could not support. Same shop I witnessed that in also blew to built engines one day pushing the tune way to far just to give the owners a piece of paper showing numbers not supportable, both built engines, both lied to and said it was the owners fault for abusing the cars before the tunes. This was the day after they blew my engine and I was lied to about it as well but I caught them and was reimbursed because I wrote a demand letter and took a really bad ass buddy with me, I was not able to get contact info on the two unlucky guys to let them know what happened.

Of course many dyno operators are honorable but some still might not be totally competent, different dynos give different results, some may not load the car properly....

Vdyno and real dynos are just tuning tools as mentioned a huge number of times, Vdyno is sure simpler to use and costs, nothing so I really like it a great deal and it is good enough to know what is happening with tune changes which is the most important part. I also use Race Tuner but have not updated the AP as I want to look at all the data though I do not plan to make tuning changes I like to keep what I paid for.

If somebody ever does real testing on such things and proves they are a plus instead of negative part I will change my opinion and retract my statements, of course

 

[ColoradoST]

Ah elevation... I'm at 5000ft and making 215whp, with my x37 on e30. I am also using the stock intake which might make a difference? Can't wait to drive to sea level and feel the power.

 

[RAAMaudio]

215 seems pretty low, look at the thread covering all the turbos, find the one with the highest power level as close to see level, do the math and see what it says, if higher altitude ones also compare, if what it should be then done, if not you might want to look into a different tuner as I have found a huge difference in the one I am now using over the others, PD-Tuning. Still working on the tune, bottom end came up around 30ft lbs at 3k and 50ft lbs at 4k RPM making the car far more drivable and fun. We just started on the top end but weather and pending move into a different RV and preparing my truck for delivery to the buyer is taking up all the time, etc....

Intake will not make much if any difference in most cases, a DP can help, ported manifold is a good thing but not mandatory though I would always do so.

 

[ColoradoST]

Cars at sea level with the same turbo are making around 280 whp. So I'm getting about 65-70 less, which is about 13hp per thousand feet.

 

[RAAMaudio]

The correction factor shows you should be getting 232.4 whp compared to 280 at sea level at the same air temp they made there runs at.

Air Density adds to the effective altitude, hotter weather really takes a toll on power at high altitude, the link shows how to calculate it.

------

Back when I had a highly modded Forester XT that did a 1.6 second 60 ft launch on a parking lot (305 wide slicks at each corner, 4:44 gears, JDM STI drivetrain) it was quite impressive. I drove down to sea level and tried to jump out into a busy highway and got on it normally and nearly went right off a big bank on the other side of the road, it took off so much quicker at nearly zero compared to 5200 ft where I lived at the time I shocked me.

 

[Brura22]

True in theory but I have seen some big discrepancies in real dyno runs as well, worst case was all out cheating customers by spraying intercoolers with NOS to make bigger numbers that were promised but the build and tune could not support. Same shop I witnessed that in also blew to built engines one day pushing the tune way to far just to give the owners a piece of paper showing numbers not supportable, both built engines, both lied to and said it was the owners fault for abusing the cars before the tunes. This was the day after they blew my engine and I was lied to about it as well but I caught them and was reimbursed because I wrote a demand letter and took a really bad ass buddy with me, I was not able to get contact info on the two unlucky guys to let them know what happened.

Of course many dyno operators are honorable but some still might not be totally competent, different dynos give different results, some may not load the car properly....

Vdyno and real dynos are just tuning tools as mentioned a huge number of times, Vdyno is sure simpler to use and costs, nothing so I really like it a great deal and it is good enough to know what is happening with tune changes which is the most important part. I also use Race Tuner but have not updated the AP as I want to look at all the data though I do not plan to make tuning changes I like to keep what I paid for.

If somebody ever does real testing on such things and proves they are a plus instead of negative part I will change my opinion and retract my statements, of course

LOL I wouldn't consider that a power "discrepancy" cause in truth they ARE making that power. But they're also idiots and will blow their shit up after 1 pass.
So while they're complete idiots, they're still making that power...

Where as some of these vDynos are set up completely wrong and displaying power that is never actually reached lol

 

[RAAMaudio]

Good points there, I have to agree

 

[ColoradoST]

Just hit a dyno this morning and got 238.22 hp, which is close to the predicted power level. The car also did 238 ft/lb of torque which is a little low (compared to a Cobb stage 3 Fiesta which got 270 ft/lb). The car was also running lean, so need to figure that out.

 

[1azst]

Did you dyno at a similar elevation?

 

[ColoradoST]

Yup same elevation 5000ish feet.