[SquiddyB6S4]

This is my first post here. I have a GTechRR which I use for performance gain monitoring.

I ran some runs in second gear with Shell 87 octane/RUL, some runs a few days later with Shell 93 in second, and continued one run into third. Plotted below are the best runs:

Notes:
87 octane runs made in 62*F ambient
93 octane runs made in approx 76*F ambient
Apparently I didn't hold the 93 octane runs quite as long, and I certainly didn't hold third gear till fuel cut.
Runs were made very close to sea level, and relative humidity has been 60-80% lately here in FL
Weights used before each run come from local certified scale, accurate to within 10 lb +/-

Peak Numbers:
Shell 87, Second Gear: 152.9whp/167.1wtq
Shell 93, Second Gear: 176.8whp/171.5wtq
Shell 93, Third Gear: 187.7whp/184.7wtq

Discussion:
As you can see, the third gear run made more power by a nice margin, even though wind resistance really picks up at those speeds. Also, the 93 octane does not appear to create any difference below 4,000rpm. I have been putting regular in the car mostly, as I did not feel a gain and could not justify the extra $5 per tank for performance that I either was not using or was not seeing. I will continue with regular from here on out.

Also, using a very fair (in my experience) 15% drive line loss factor, this is about 221bhp. Even at only 10% loss, that's still 209bhp. Either way, Hyundai is understating the performance on premium. Although, to be fair, they are branding it as 201bhp on 87 octane, which is clearly well overstated. But anybody thinking that a turbo car running 18psig is going to perform well on RUL doesn't deserve the extra horsepower anyway.

Conclusion:
So that's it. Enjoy, or don't. Just the data I have collected.

 

[cruisn76]

24HP more on 93 shell is huge jump. Didn't think it would produce such a gain above 4000rpm. In Canada we only have 91 @ shell so I wonder if that number is going to be lower. But seeing the difference between 87 and 93 already makes me a happy guy since I fuel up with 91 ethanol free shell since after my first oil change.

 

[wbw]

Welcome, and thanks for the graph and the write-up. Interesting.

 

[Turbosocks]

thank you very much for the data! That is very interesting and enlightening!

 

[iVeloT]

thank you very much for the data! That is very interesting and enlightening!

Shell 93 is the only gas that ran through my car other than the free tank of whatever the dealer gives you for free 87 oct...
I felt a difference just in regular everyday driving going from 87-93

Thank you for the data it backs up my butt dyno!!!

so with this 3rd gear on shell + torkme pipe we should be sitting somewhere around 190 whp for practically no money at all.

EDIT: im a tard i should read fully rather than skim nvm

 

[JGunz18]

Hmmmmmmmm........Interesting. I wish I had access to a dyno to run trails on every little thing :crazy: You should buy a bunch of products & start double checking their advertised claims for shyts & giggles...Since you have the access :cool2:

 

[SquiddyB6S4]

24HP more on 93 shell is huge jump. Didn't think it would produce such a gain above 4000rpm. In Canada we only have 91 @ shell so I wonder if that number is going to be lower. But seeing the difference between 87 and 93 already makes me a happy guy since I fuel up with 91 ethanol free shell since after my first oil change.

If it helps any, fuel "octane" ratings can be misleading. Here in the US, we use (R+M)/2. Some other countries use RON only for octane rating. RON is typically a bit higher than MON, so the US rating method will read a bit lower than most other countries. Some recent data I saw showed our Shell 93 V-Power at around 98 RON, which sounds reasonable for an (R+M)/2 of 93. It also showed about 11% ethanol, contrary to the "at most 10%" stated on the pumps. So my 87 octane fuel might be similar to a 91 RON, if that's what Canada is using as a standard.

And the numbers themselves may be low or high for any individual testing setup, but at least it lays down baseline data on my device for any future improvements. I have done some datalogging on the ECM as well, and have seen manifold pressures in excess of 215kPa (16.5psig). I have not paid attention to logs of the lambda value, but I have seen other's dyno sheets showing it pegged rich at a 10:1 AFR, so I am thinking that there is some serious power to be had from a proper tune. The only thing I can think of that would make an OEM do something like that is to keep cylinder temps down, presumably to prevent damage. OEMs do not provide rich fuel mixtures if they can help it, since rich mixtures drag their CO2 emissions numbers up and fuel economy numbers down.

 

[SquiddyB6S4]

I joined because I figured this might be of interest for the community, so you are welcome.

Hmmmmmmmm........Interesting. I wish I had access to a dyno to run trails on every little thing :crazy: You should buy a bunch of products & start double checking their advertised claims for shyts & giggles...Since you have the access :cool2:

Sorry, absolutely not. This is my DD, which I bought for getting around and holding reliability for a long time. I bought the extended warranty, and received a good price on the car as well. It is not a car that I would consider "good" - hesitation is bad in low boost areas of map, rattles started after only 500 miles, starting off in first gear is ANNOYING - but it's about as good as it gets for the price, and I also feel it represents good value for what you get. It comes with leather seats, a nice touchscreen stereo with decent sound and bluetooth. But as much as I would love to piggie or gut the cat out and see if it picks up a boat load of torque, this thing has to retain its warranty and stay reliable and low cost.

My previous DD was an LS400, which by my math cost me approximately $0.35 per mile to own and operate during the time I owned it, including cost to buy, sale value, fuel, maintenance, repairs, upgrades, etc. I can beat that with this car, but I need to own it for a long time and be frugal.

Now, if you want to bring your car to me, I will be happy to set up the test for you. I can do back to back tests with the same car in the same conditions on the same day, and I've used my GTechs enough to know how to make the cars respond best, calibrate to the devices properly, etc.

 

[Triton05]

Man.. I should bring back some of my old threads and say " told you so " when no body believed me. That and Solo 3" actually putting down 16 WHP more than stock... when the haters said it wouldn't help at all. SMH...

Thanks for taking the time to prove what I had been spouting off over the last 8 months. . .

 

[VeeTee]

So why would Shell 93 be different than let's say Speedway 93 or someone elses for that matter?
Is it about the additives that Shell uses? Shouldn't a plain 93 have the same rules and guidelines or purity limits as another 93? I mean, isn't this regulated at all?

 

[SquiddyB6S4]

Man.. I should bring back some of my old threads and say " told you so " when no body believed me. That and Solo 3" actually putting down 16 WHP more than stock... when the haters said it wouldn't help at all. SMH...

Thanks for taking the time to prove what I had been spouting off over the last 8 months. . .

I assume you mean that you tested high octane with the exhaust, but not each separately. I hope you were not "spouting" without backup. But yes; and I would also argue that the high test is responsible for most of that gain. The factory exhaust on this car looks more than adequate, and the 2.5" diameter probably leaves little on the table to a 3" setup. I'd be willing to bet that most of the exhaust gains to be had lie in the cats - they are very small in flowable area. When the factory warranty runs out, you can bet I will be buying a larger catalyst unit, and maybe fabricating a new turbine outlet to go with it.

So why would Shell 93 be different than let's say Speedway 93 or someone elses for that matter?
Is it about the additives that Shell uses? Shouldn't a plain 93 have the same rules and guidelines or purity limits as another 93? I mean, isn't this regulated at all?

First off, Shell is what is known as a top tier supplier of fuel. The auto manufacturers set up a voluntary set of standards in response to intake valve deposit concerns on their new cars, and only a few fuel suppliers have decided to meet those standards. NOTE: As is common, it probably costs money to simply be tested for compliance, so some vendors may meet the standards, but not want to pay to prove it. NOTE: What the auto manufacturers refuse to admit is that GDI, in all of its names across the industry (FSI, SkyActiv, etc), is the primary root cause of the intake tract deposits. The auto makers don't want to have to provide free cleanings, or admit fault in their new technologies. As far as I know, the only manufacturer that has solved this issue is Toyota, who uses a combination of GDI and a single, intake manifold-mounted fuel injector. If it's anything like their older models, this injector is for cold starts, but covering the intake runners and valves in fuel regularly does help keep oil coke from the PCV system from solidifying in those places.

In any case, I doubt that there is a measurable difference between 93 octane brands. Any difference based on the brands would almost assuredly be smaller than you could consistently measure on any dynamometer or other sensitive device, and would certainly be less than the minor differences in atmospheric conditions. Each dyno run will be a few HP off from each other anyway due to instrument precision and the wide variety of correction factors employed by modern ECMs.

 

[Ranger052]

So why would Shell 93 be different than let's say Speedway 93 or someone elses for that matter?
Is it about the additives that Shell uses? Shouldn't a plain 93 have the same rules and guidelines or purity limits as another 93? I mean, isn't this regulated at all?

^^^^^^^

I always use BP 93 so I would like to know that as well

 

[JGunz18]

Where are you in FLA???

 

[Triton05]

I assume you mean that you tested high octane with the exhaust, but not each separately. I hope you were not "spouting" without backup. But yes; and I would also argue that the high test is responsible for most of that gain. The factory exhaust on this car looks more than adequate, and the 2.5" diameter probably leaves little on the table to a 3" setup. I'd be willing to bet that most of the exhaust gains to be had lie in the cats - they are very small in flowable area. When the factory warranty runs out, you can bet I will be buying a larger catalyst unit, and maybe fabricating a new turbine outlet to go with it.

Independently.

I noticed back in Feb when I got my car, that going from 87 to Shell 93. I got a substantial boost in mid - top end power (along with slightly better gas mileage). Caught flack for it.. because people didn't realize at the time that the car is designed to auto adjust timing for high octane fuels.. ( now with your dyno data, this officially backs up my claim )

Then when the Solo Exhaust first came out.. we had tons of haters.. mostly people who jumped on the Magnaflow bandwagon. The argument was that 3" cat-back was too big and wouldn't yield any gain due to so much lost back pressure.

SO.. we had a member dyno his stock catback vs Solo 3" and got 16 peak whp gain... Now, most people love Solo, not only for the great top end performance, but the mean ass sound it makes when you get on it.

 

[ee_man]

The most interesting this to me is the shape of the torque curves at the 5K range. I have seen multiple graphs where the torque falls into the dip in power we all know but then doesn't come back up, like the 87 octane run. On my car, it feels like the torque comes back some like the 93 octane run shows, and since I run 91 (I haven't seen 93 over here) I would guess that is the case. Very useful data.

As for the difference between 3rd and 2nd gear, how does air drag get factored into the setup? If the GTechRR thought the air drag was much higher than it actually is you could easily see 3rd gear with a bunch more power than 2nd.

 

[SquiddyB6S4]

The most interesting this to me is the shape of the torque curves at the 5K range. I have seen multiple graphs where the torque falls into the dip in power we all know but then doesn't come back up, like the 87 octane run. On my car, it feels like the torque comes back some like the 93 octane run shows, and since I run 91 (I haven't seen 93 over here) I would guess that is the case. Very useful data.

Don't let the butt dyno fool you as to what's happening with power/torque. The human body senses jerk very well, and acceleration okay, but not force alone. You can hit a dyno day usually for $40 or $50 and get a couple runs in. Just bring a water spray bottle and hit your intercooler before each run, since sitting there getting strapped down will probably let it heat soak.

As for the difference between 3rd and 2nd gear, how does air drag get factored into the setup? If the GTechRR thought the air drag was much higher than it actually is you could easily see 3rd gear with a bunch more power than 2nd.

The GTechRR is a reasonably high precision set of three axis accelerometers, combined with a decent data acquisition setup. So the car is moving to collect data. Therefore, since 3rd tops out somewhere around 95mph, wind resistance [to this poop-shaped car] is much, much higher than it is in second gear at only 55-60mph or so. Recall that aerodynamic drag force is a product of the cube of the speed through the fluid. At 60mph, aerodynamic drag force is usually negligible, and we do not bother to calculate it. At 95mph, that is a whole different story. Aerodynamic drag at that speed is most definitely significant. So showing a gain in third is impressive, as the car is accelerating harder in third despite the increased wind resistance. The device makes no correction whatsoever for wind resistance; it assumes zero resistance from wind, which should actually make it read lower at all times than a chassis dynamometer of similar calibration. In reality, in my experience, it tends to read similar to a dynojet in second gear runs, where resistance is low. I have run both of my GTech units against chassis dynamometers before.

Eventually, I will track down or measure the pertinent aerodynamic data for this car, as I have my previous cars, use its power/torque curve and gear ratios and tire size to generate a forward thrust force vs. speed curve, and then plot that against estimated aerodynamic drag force vs. speed. From there, you can easily estimate the top speed of the car with any given dyno sheet, not to mention pinpoint the best shift points for each gear, and of course you can integrate the area between the curves to closely estimate acceleration times, using approximations for wheel spin where necessary. But I'm in no rush as this car will likely remain bone stock for a long, long time.

 

[ee_man]

Recall that aerodynamic drag force is a product of the cube of the speed through the fluid.

The drag force is actually a square of the velocity (F = 0.5 * Cd * A * p * v^2), the drag power is the cube (P = F*v). Anyway, I was just curious what the GTechRR is doing about wind resistance and you cleared that up nicely for me, thanks. I'm not criticizing at all, that is very good data, I was just curious why 3rd read so much higher, now I am even more curious.

 

[Jacksonville MatteVT]

For all of you non Astrophysicists and non "big bang theory" TV show watching individuals I will some it up for you. If you want the extra performance spend the extra coin at the gas pump. Any questions???

 

[swordfish]

I will some it up for you.

Some or Sum?

 

[zexz1000]

Depends on where you're from.