Tested RaceChip with Vbox after 10,000 miles.

[onfireX5]

Still very impressed with RC. 10,000 miles later it's still as smooth as stock but faster !

[Alan l.]

Good to hear. Still on D setting i presume?

[onfireX5]

Yes. A 1.3 second reduction in 0 to 100 mph is enough for a true daily driver and vacation ride for me. Plus there have been issues with the M5's pushing boost and blowing coils. Not to mention diff and trans failures. 20ish psi peak with a drop off at the shift seems to be the sweet spot.

[TraderJMF]

I wonder what you would run in the 1/4mi with this set-up?

[onfireX5]

Vbox at my elevation is 11.8-11.9 at 115-116mph. Sea level would be quicker/faster.

[birk1]

Originally Posted by onfireX5

Vbox at my elevation is 11.8-11.9 at 115-116mph. Sea level would be quicker/faster.

I have a few questions please. I am not new to tuning (hp tuners etc...) on many many cars. On my last E70 X5m I had a reflash from AA and it was ok. I am at 5600ft so it just never seemed to feel lively.

Question: explain how the race chip can be adjusted for high altitude or is it worth the trouble? I am looking at the Dinan stage 2 tune also but racechip seems like a win to me for my F86 at 620 bucks and adjustable.
Are the adjusting instructions included?

Am I missing something or is it really what it appears?

Thanks for the info
Ryan
Denver COLORADO

[onfireX5]

Quick answer to a very technical question:

Rounded numbers for reference only :

Take a pure stock X5M to a Dynojet Dyno at sea level in North Carolina and it Dyno's 515 rwhp. SAE corrected.

Drive it to Denver and it Dyno's 505 rwhp SAE corrected.

You think that is pretty close but the X5M feels way under powered while driving it around Denver. How could that be ? Only 10hp down ?

Now you look at the Dyno sheets and the NC sheet shows a 20hp correction factor to equalize it to SAE sea level conditions. You look at the Denver sheet and it has a 120hp correction factor to equalize to SAE sea level. That is the true lost power due to the low air density in Denver.

17 psi in NC makes much more power than 17psi in Denver due to more air density in NC (more 02 in the mass air flow).

The X5M software will slightly compensate with mass airflow correction offsets (slightly increased boost in Denver), but not significant numbers.

So you add RC in Denver and Dashcommand to measure boost. For example let's say you are logging 18psi pure stock. RC default setting of B increases it to 19.5 psi peak. I would go up by one click and retest until you are 2.5 to 3psi over stock. Just turn the knob to c. Test. D, test etc. That will help you offset the low air density at high elevation. If you happen to drive it to sea level , just don't do wot runs at it will be fine or just click it back to B, or put the bypass plug in it. All very simple.

[birk1]

Thank you.
This makes perfect sense. I lived in Houston for 2 decades and moved to altitude 3 years ago. I have had many supercharged vettes and a turbo 997.1. I had the pcar when I moved here to Denver and I noticed it lose some boost when I got here. I went to an SUV after that for the snow and got my E70.
I recently traded my E70 in for a F86 and I have the mod bug and would like more power. After the AA tune install on my last truck I wanted to find a better option for the F86. I was looking hard a Dinan but the racechip sounds like a very solid tuneable option for high altitude to get my boost up to what I want safely.
I will look into it - I have a data logger to get things dialed in.
Thank you for the help
Ryan

[LBBX5M]

Originally Posted by onfireX5

Still very impressed with RC. 10,000 miles later it's still as smooth as stock but faster !

still can't beat my 3.6 Bro.

[onfireX5]

You're too FAST !

[mirob]

Originally Posted by onfireX5

Vbox at my elevation is 11.8-11.9 at 115-116mph. Sea level would be quicker/faster.

What elevation are you at?

[onfireX5]

2080ft MSL. DA in the summer is around 3800

[vvcobravv]

Originally Posted by onfireX5

Quick answer to a very technical question:

Rounded numbers for reference only :

Take a pure stock X5M to a Dynojet Dyno at sea level in North Carolina and it Dyno's 515 rwhp. SAE corrected.

Drive it to Denver and it Dyno's 505 rwhp SAE corrected.

You think that is pretty close but the X5M feels way under powered while driving it around Denver. How could that be ? Only 10hp down ?

Now you look at the Dyno sheets and the NC sheet shows a 20hp correction factor to equalize it to SAE sea level conditions. You look at the Denver sheet and it has a 120hp correction factor to equalize to SAE sea level. That is the true lost power due to the low air density in Denver.

17 psi in NC makes much more power than 17psi in Denver due to more air density in NC (more 02 in the mass air flow).

The X5M software will slightly compensate with mass airflow correction offsets (slightly increased boost in Denver), but not significant numbers.

So you add RC in Denver and Dashcommand to measure boost. For example let's say you are logging 18psi pure stock. RC default setting of B increases it to 19.5 psi peak. I would go up by one click and retest until you are 2.5 to 3psi over stock. Just turn the knob to c. Test. D, test etc. That will help you offset the low air density at high elevation. If you happen to drive it to sea level , just don't do wot runs at it will be fine or just click it back to B, or put the bypass plug in it. All very simple.

17psi is 17psi no matter what sea level you are at... Air density is air density, if you are in a higher altitude the turbos will spool to a higher rpm to compensate.

[vvcobravv]

Originally Posted by birk1

Thank you.
This makes perfect sense. I lived in Houston for 2 decades and moved to altitude 3 years ago. I have had many supercharged vettes and a turbo 997.1. I had the pcar when I moved here to Denver and I noticed it lose some boost when I got here. I went to an SUV after that for the snow and got my E70.
I recently traded my E70 in for a F86 and I have the mod bug and would like more power. After the AA tune install on my last truck I wanted to find a better option for the F86. I was looking hard a Dinan but the racechip sounds like a very solid tuneable option for high altitude to get my boost up to what I want safely.
I will look into it - I have a data logger to get things dialed in.
Thank you for the help
Ryan

Superchargers are belt driven. Unless your supercharger is tuned with a pulley past peak PSI at sea level to engage a wastegate it will only produce its peak PSI at sea level, if you go to a higher elevation the supercharger inherently will drop PSI accordingly. Since turbos are exhaust driven they can spool past the mechanical RPM of the crank or belt. Temperature can rob turbos of efficiency at higher altitude because the turbo is working harder to generate the same PSI at sea level.

http://www.engineeringtoolbox.com/ai...ume-d_195.html

[onfireX5]

Originally Posted by vvcobravv

17psi is 17psi no matter what sea level you are at... Air density is air density, if you are in a higher altitude the turbos will spool to a higher rpm to compensate.

Not exactly.

17psi at sea level has a much higher O2 level than 17psi at Denver. I have taken my boosted car to a 3800ft track then the next weekend to a sea level track. Both tracks make a baseline run on wastegate springs only. The boost psi will log the same psi at Both tracks. That is true.

But the power difference is huge. Generally 0.40 reduction in terms and 4mph gain.

Mass Air Flow creates power......not psi.

[vvcobravv]

So I'm not being an ass here or anything, but what I said is science and it's called Boyles law...

17psi at sea level has the same O2 count as 17psi at 5000ft. The reason you're slower at higher altitude in a turbo vehicle is due to additional lag from the turbo having to spool to higher rpms to create the same amount of boost.

"Altitude

Now, as the air density changes (let’s say goes down, as with higher altitudes) the thermal energy needed to turn a specific RPM decreases, causing an increase in turbine shaft speed. According to Kurt Henderson, Engineer – Accelerated Innovation at BorgWarner, “A good rule of thumb is that the turbocharger speed will increase 1 to 2 percent every 1,000 ft of elevation increase.” If you are someone who lives close to sea level and you are talking to a guy on a forum who lives in Denver, the same turbo isn’t going to perform the same. Being 5,000 feet lower in elevation than the guy in Denver means the turbo will be spinning roughly 5 to 10 percent slower for the same power. That may or may not seem like a lot, but it may result in the same amount of boost coming in 200, 300 or even 400 rpm later. When cruising on the freeway (low RPMs) or taking off with a trailer hooked up, that’s a huge difference! To get the performance he is getting, you may need to step down one or even two sizes just because of the altitude of your location."

http://www.dieselarmy.com/engine-tec...turbochargers/

Originally Posted by onfireX5

Not exactly.

17psi at sea level has a much higher O2 level than 17psi at Denver. I have taken my boosted car to a 3800ft track ftthen the next weekend to a sea level track. Both tracks make a baseline run on wastegate springs only. The boost psi will log the same psi at Both tracks. That is true.

But the power difference is huge. Generally 0.40 reduction in terms and 4mph gain.

Mass Air Flow creates power......not psi.

[onfireX5]

Sorry, but you are confusing two variables. BL is relative to volume and pressure. Not mass air flow with delta densities.

Kurt Henderson gives a great explanation on turbo lag and some of the causes.

Volumes have been written on density altitude, mass airflow and the effects on horsepower.

https://m.youtube.com/watch?feature=...&v=bYcM0SoMhPs

Watch my car above that I hand built, hand turned and tested 3 different turbo systems on it along with 8 different turbochargers on it. I've logged 100's of passes from -1400ft DA to 5000ft DA. All with the same projected results of DA.

If psi is psi (it is not) how do you use BL to explain that 12psi with one turbo system made 650 hp and 12psi made 960 hp at the SAME ELEVATION ? Only variable changed was the system. Can not use turbolag as an excuse as it does not materially effect peak hp, just how long it takes to get there. If psi = psi it would have to flow the same. But it does not due to mass air flow.

NHRA is in Vegas this weekend. Why is the mph slower on all cars ? Even at higher psi ? Because the density altitude is higher than 2 weeks ago in Florida.

Not going to argue with you about the subject anymore. We all study and believe what we want to believe, But I do hope you research the subject some more. I'm also an engineer (35yrs experience) , but I learn something new every day.

Good luck.

[birk1]

Thanks everyone
I ordered some boost adding mods today
Have a set of BMC filters for more air = more air
Racechip from Ben @ RG = lots more boost from the air
Eisenmann Race from Ben @ Rg= fast noice.

Fun stuff car modding is

[arrivederci]

Originally Posted by birk1

Thanks everyone
I ordered some boost adding mods today
Have a set of BMC filters for more air = more air
Racechip from Ben @ RG = lots more boost from the air
Eisenmann Race from Ben @ Rg= fast noice.

Fun stuff car modding is

I'd love to get a chance to check it out once you get 'er done...

[birk1]

Sure thing.
Parts come in tonight.
Will install it all this week

PM me

[birk1]

Question for the educated.

I plan on setting my chip at D

Is this a poor idea at 5500' and 91 octane?

Thanks for the help in advance
Ryan.

[onfireX5]

Can you check boost psi ? Dashcommand?