Drove cross-country fully loaded; unloaded car now bogs in 1st
 

So I'm making an excruciatingly slow move from Boston to New Mexico, and step one was to move my FR-S ('13, automatic) before the snow set in. So back in October, I loaded it up with as much stuff as I could fit inside and drove four days across the country.

The trip went fine and the car performed as expected. It certainly felt more sluggish than usual, but that seemed right given how much extra weight it was carrying.

But when I unloaded and started driving around Santa Fe, I noticed that the car is waaaaaaaaay more sluggish in 1st gear than it had been before. Where I used to be able to spin the tires from a standing stop, the car just bogs now for a few seconds before the RPMs catch up. This happens whether I'm driving full auto or in fake manual.

There's also a slight whining sound that seems like it might be coming from the transmission, but I have no idea whether it's related to the bogging down or something that was always there that I'm psychosomatically associating with the bogging.

Once it gets up to speed it seems to perform as normal. On a recent trip out to NM I was doing 110mph on a deserted back road with no worries at all, and the car felt fine. There aren't any warning lights on the dash, either.

I haven't taken it in to get looked at yet because, well, the car's in Santa Fe and I'm in Boston, but of course my mind is running through worst-case scenarios—major transmission work, engine work, etc.

Anyway, can anyone suggest less awful alternatives for the symptoms? I'd love to set my mind at ease.

Thanks!

Shot in the dark but what about the elevation change? My FRS is auto and all done up and I cant spin my tires from a stand still but I lose close to 30% HP at my elevation VS sea level.

Yeah, that's definitely a factor and I've considered it. Santa Fe is at 7,000ft and I was at 0ft before. But the difference seems really, really stark to me—too big for altitude alone to account for, I think.

I'm driving the car to LA in February, so I guess I'll be able to tell if it's back to its old self when I get to sea level again—assuming the dealership in NM doesn't find anything wrong.

Yeah I never was able to spin the stock tires even will full catless and stage 2 tune. speaking of tune maybe it has not had time to adjust/learn?? I am also only at just over 1000 meters up.

And mine also makes a whining noise, more when it is cold (very slight noise though) and it comes from the engine. It sounds like a totally normal car noise.

There's probably a formula on the web somewhere with which you can calculate your horsepower loss as altitude increases.






Remember at about 11,000 feet there's not enough oxygen in the air for some people to stay conscious, so it doesn't surprise me that at 7K the engine feels weak.

The loss of power a mile above sea level is dramatic. Not to worry. You'll adjust. :)

7000ft ?

You lost like atleast 30hp bro, Air density is like 85% of what you had @ that altitude.

This is all very comforting, yet also very disappointing.

Thanks, guys.

I suggest disconnecting the Neg battery cable for a half hour. reconnect and drive. It may adjust quicker. I also suggest a K&N drop in filter if you have the stock filter in there.

Different octane rating or poor quality fuel ??

Yep when I visited NM my car felt absolutely deadpan at elevation.

I believe you are now also on 91 octance vs. the 93, the manual mentions that the car may have less power on 91.

Made the trip between Abq and San Diego at least 15 times in my 240Z. It was always an eye-popper coming back down to sea level.

wtf we lose that much here?

I plan on taking a road trip from Edmonton to LA or San Diego

You are at 670m in Edmonton haha. Yeah it makes a huge diffrence being up here vs sea level. FI does not suffer near as much as our poor NA cars :(

I will come for a road trip!! I wana feel what my car can really do! Allthough I am not sure it will run too well down there without a retune.

Definitely the altitude. I drove my car to NC to drive various driving roads there. I went up Mount Mitchell which was up to 6,578ft and the car was pretty gutless. I had intake, header back, stage 2 tune from delicious. You can calculate your density altitude which really determines your performance. You could be at 7000ft field elevation but your car could performing like it was at 8000ft due to non standard pressure and non standard temperature.

Yeah, that could be a factor too.

Yep, brings to mind when I drove my fully loaded (plus passenger) NC, miata, up to the top of Pikes Peak (elevation 14,100 ft); it made it (thanks to hi revs and lots of gears).

However, ol humfrz was moving pretty slow up there ..... :sigh:

Yep, OP, I'll buy into the octane difference, plus higher altitude, plus warmer air, plus dryer air ..... (dryer air - see who is payen attention .... :D)


humfrz

Maybe OP just needs to clean his lint trap.

Yaaaaa!..........Ultramaroon is payen attention ........ :thumbsup:

(actually ...... you got me there ...... :sigh:)


humfrz

I've done the math, it's: HP Loss = (elevation x 0.03 x horsepower @ sea level)/1000

So 7000 *.03*200/1000 = 42 HP lost, seems a little high to me, but im sure there are other factors in there.

It's actually really cold in Santa Fe right now—colder than Boston. Air is definitely drier and thinner, though!

Did you move down for good? I miss NM.

To my knowledge, the automatic transmission does whine. It's a normal trait of it.

did you put the wrong fuel in it???

I'm moving for good at the end of January, but actually won't be there full-time until April because the gf has a gig in LA for two months. Pretty excited to be going back, though.

I mean...

https://www.instagram.com/p/-r6BZlriVS
https://www.instagram.com/p/-p4rILLiXH
https://www.instagram.com/p/-nqbWCriX1
https://www.instagram.com/p/-h1ffFLiZX

Definitely not. But it is 91 instead of 93.

A few months ago I drove from Milwaukee to Portland then back, noticed a big difference in MPG and performance once I hit the higher elevations. Ran 91 to 93, no ethanol all the way.

So stoked for you. Planning on climbing Santa Fe Baldy when it warms up?

I loved hiking the Pecos.

When I drove back from CO, going over the Continental Divide in the Eisenhower Tunnel, I got passed by a semi.

That's how little pickup NA cars have at altitude.

-alex

So, update: I went to LA for two months with the car and it was back to normal. It totally is the altitude. Now I'm back in NM and it's bogging again. Maybe I'll try to get it tuned, I dunno.

Really glad to be back here, though!

So, for our cars (stock), take your elevation in thousands of feet and multiply by 6 for power loss :)


Taking a trip to the summit of Everest, expect to lose 6x29=174 hp...wow! Good luck making it there, though. Ok, enough of the surreal...