GRM guessing game with prizes*

181
177
3.14159265359

161.803399

100x Golden Ratio tune

Bobzilla wrote: Oh, I'm already thinking that maybe this is a bad idea and think 159 is enough. Then I think about that and realize the folly of my ways. Plus, the factory tune is terrible. by 3k rpms it's stupid stupid rich. And that's all Korean cars. Rich is safe, so more richerer must be betterer. I might even see better highway economy.

So, that's why no matter how I drive I get ~30mpg in my Accent.

42

To infinity, and beyond! Those are my two guesses.

griffin729 wrote: 161.803399 100x Golden Ratio tune

Bobzilla wrote: Oh, I'm already thinking that maybe this is a bad idea and think 159 is enough. Then I think about that and realize the folly of my ways. Plus, the factory tune is terrible. by 3k rpms it's stupid stupid rich. And that's all Korean cars. Rich is safe, so more richerer must be betterer. I might even see better highway economy.

So, that's why no matter how I drive I get ~30mpg in my Accent.

SORTA. In my old Elantra, 3400rpms was the cross over point where it would go to WOT fuel maps at all throttle/load settings. That was 78mph. Cruise at 80, you'd get 28mpg and the bumper would be black. Cruise at 76 and you'd get 36mpg. The Wife's auto-Rio does alright at about 35mpg but she drives under 70 most times and is super easy on the throttle. I drive it and get 31.

I like this game!

167

169

187

It just got strapped down. Numbers soon. It's 45* and a light rain. This would be the perfect day to get big numbers on a turbo car.

Bobzilla wrote: Oh, I'm already thinking that maybe this is a bad idea and think 159 is enough. Then I think about that and realize the folly of my ways. Plus, the factory tune is terrible. by 3k rpms it's stupid stupid rich. And that's all Korean cars. Rich is safe, so more richerer must be betterer.

You, the individual, don't have the onus of having to write a tune for the dumbest, most mechanically insensitive person to buy the car. Or have to balance exhaust geometry that gets the catalyst close enough to light off fast for good marks on the Federal emissions exam, against keeping the cat from OVERheating when some doofus runs at WOT for minutes at a time. Because that cat has a federally mandated warranty so it BEST live a long life.

Multiply by a fudge factor to compensate for eventual MAF drift, false air leaks, O2 drift making the fuel trims off, weak fuel pump pressure, and so on and so forth.

I get all that. And the Koreans have been focusing on emissions and reliability over everything else as well. But single digits?

Yeah, that's a little bit much. Mazda didn't even go that rich trying to keep the RX-7s' cats alive.

Did you check the mixtures before the cold air intake? The pipe shape before and after the MAF can have a dramatic effect on airflow measurement. Generally speaking, ANY car with a different airbox from OE really should get its tune fixed.

No MAF on the Theta. No I've not had this on before intake etc. apparently this isn't uncommon for hy/kit to be stupid rich and the turbo cars are even worse. That's why the 1.6t veloster can find 40+hp with a tune alone.

182 189 197

199, 176, 182

Wheres the freaking numbers bob? Ive got to know who wins this imaginary prize!

Ok results are in. Today's baseline was 3 less than Tuesday at 156. Tuned is 163. Torque is 162 and at 2k is putting down 140 which it does not dip below until 6200. Throttle response is better, redline is up 500 to 7200 and afr are in double digits.

Did not make my mythical 170 to the wheels but after putting 100 miles on it very satisfied.

So I won the non prize prize??

You get an Internet cookie.

Technically whomever guessed 166 of the Tuesday baseline would also be right!

So I'm home. Quick test shows the new redline puts the top of 2nd gear at 67mph and you can actually hear/feel the rev cut. Unlike before when you just realized you're no longer accelerating or making new noise!

Overall the car drives great. It's tuned right and I'm very pleased with the guys at Bloodtype Racing.

Here's the graph:

and the last video of it on the dyno:

https://www.facebook.com/bob.miller.1804109/videos/10207739797985976/

Well, I was close.

Whats with the goofy dip at 6100?

Must be something mechanical, as I would've thought that could be tuned out...

The dip was a question as well. Apparently it did not happen in 3rd gear, only in 4th. The theory was the speed of the dyno (~120-125 at that point) caused an issue with the engine because of mass etc. Basically, a wierd dyno related non-issue. I understand that 3rd likely did break my magical number that I dreamed up but isn't as valid due to mechanical advantage over 4th gear.

interesting. Did you/they check 2nd? I guess for autox thats where it really matters if it happens or not.

Also, re: gearing. I THINK the gear shouldn't change the HP readout on the dyno. It would change torque, but it would also change the rpm of the rollers (3rd gear would give higher torque and lower RPM than 4th gear). That way it cancels out in the HP calculation.

I think most dyno pulls are done in 4th because it allows enough time at each RPM to actually measure something. Many cars have 1:1 4th, but final drives are all over the place and therefore I do not believe 4th is used just because of the 1:1 thing.

I've checked 2nd for top speed with the new rev limit which is now 67. Before was 63 so that's an extra 4mph and an audible note when you hit it.

Wow, I thought my car was torquey, that's an awesome power curve!