Mechanical overrev, 9k - Page 2 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

Ultramaroon · 05-09-2021, 10:38 PM

Quote:

Originally Posted by ZDan

TL/DR, it's still happenin and it aint' fuel starvation (I don't think)

How's the dipstick reading? What's the oil temp?

ZDan · 05-09-2021, 11:09 PM

Quote:

Originally Posted by Ultramaroon

How's the dipstick reading? What's the oil temp?

Plenty of oil, if anything too much, it was reading low so I added some but I think I misread so now maybe it's 1/2-quart HIGH.

Oil and coolant temps same as always, nothing untoward there.

jflogerzi · 05-09-2021, 11:13 PM

Get the log to the tuner. They would be able to tell you. No sense us guessing

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ZionsWrath · 05-10-2021, 01:17 AM

I money shifted mine and it ran fine. But two years later engine started knocking. Did track days in between never over revved it again. Not sure if related but probably was, car had 56k miles with a few dozen track events.

CSG Mike · 05-10-2021, 03:09 AM

You can't starve a full tank but you can starve at 7/8 tank under the right conditions

ZDan · 05-10-2021, 02:26 PM

Quote:

Originally Posted by CSG Mike

You can't starve a full tank but you can starve at 7/8 tank under the right conditions

Hmm, the only stints when this happened were ones where I didn't start with a full tank...
New Hampshire Motor Speedway turn 6 is a banked left-hander which blends into turn7, combined turn is >180 degrees. But I've never had fuel starvation here before, even on Hoosier A7s last year. I was running Nankang CR-1s yesterday.

CSG Mike · 05-10-2021, 05:30 PM

Quote:

Originally Posted by ZDan

Hmm, the only stints when this happened were ones where I didn't start with a full tank...
New Hampshire Motor Speedway turn 6 is a banked left-hander which blends into turn7, combined turn is >180 degrees. But I've never had fuel starvation here before, even on Hoosier A7s last year. I was running Nankang CR-1s yesterday.

Interesting. How's steering angle different with the two cars? Are you steering more on the Hoosiers?

Best practice may be to run a full tank or a secondary pickup.

ZDan · 05-10-2021, 05:41 PM

Quote:

Originally Posted by CSG Mike

Interesting. How's steering angle different with the two cars? Are you steering more on the Hoosiers?

Same car, same setup, I'd guess I may be cranking in more steering angle for max grip with the Nankangs.

Quote:

Best practice may be to run a full tank or a secondary pickup.

Full tank works as I need a full tank for my min. weight for time trial anyway.

Hopeful that it is indeed fuel starvation, I sent data files to Zach, looking forward to see what he thinks.

rice_classic · 05-10-2021, 06:38 PM

I don't think it's fuel starvation if it correlated with an over rev. I wonder if there's any trouble codes that have not resulted in a CEL that can be seen via techstream.

jflogerzi · 05-10-2021, 06:44 PM

Quote:

Originally Posted by rice_classic

I don't think it's fuel starvation if it correlated with an over rev. I wonder if there's any trouble codes that have not resulted in a CEL that can be seen via techstream.

ecutek would should show these as well which he has access too.

rice_classic · 05-10-2021, 07:25 PM

Quote:

Originally Posted by jflogerzi

ecutek would should show these as well which he has access too.

I'm aware - it was more focused on seeing if there's anything he can get insight to prior to waiting for a tuner to review things.

ZDan · 05-11-2021, 06:56 AM

Tuner sez "100% typical fuel starvation". Whew... Honestly I've never felt like I had more grip railing around NHMS turn 6 than on the CR-1s, I'm liking these tires a lot so far. Still, fuel starvation at 7/8 tank?! I might hafta do something about that before Palmer if only to avoid paying for at-the-track fuel for every session!

ZDan · 05-11-2021, 07:09 AM

Quote:

Originally Posted by rice_classic

I don't think it's fuel starvation if it correlated with an over rev. I wonder if there's any trouble codes that have not resulted in a CEL that can be seen via techstream.

The issue also correlates with not starting session with a full tank. But yeah, the 1st time it happened was only a few laps after the overrev. Engine sounded extremely valve-noisy to me but then I listened to my bud's same-year 86 and it makes the same noises (mostly injector noises I think). We have similar setups, and our acceleration plots fell right on top of each other so my engine is performing normally otherwise.

Still, I was thinking that maybe VVT mechanism(s) might have been damaged and might quit "VVTing" after a few laps, but why would it reliably fail at exactly the same spot on the track every time? @CSG Mike's post about starvation "under the right conditions" is hugely encouraging. Heavily banked 180-degree left-hand NHMS Turn 6, with a little flat table top I use at track-out, while continuing left into Turn 7, on tires that honestly feel faster and more confidence-inspiring here than even 8-cycle Hoosiers I was on last fall, might all add up to "the right conditions".

jflogerzi · 05-11-2021, 11:04 AM

Quote:

Originally Posted by ZDan

Tuner sez "100% typical fuel starvation". Whew... Honestly I've never felt like I had more grip railing around NHMS turn 6 than on the CR-1s, I'm liking these tires a lot so far. Still, fuel starvation at 7/8 tank?! I might hafta do something about that before Palmer if only to avoid paying for at-the-track fuel for every session!

Your post made feel better about my money shift lolz

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05-10-2021, 01:17 AM	#18
ZionsWrath Thanks Join Date: Apr 2013 Drives: BRZ Location: NY Posts: 4,163 Thanks: 5,989 Thanked 3,100 Times in 1,498 Posts Mentioned: 38 Post(s) Tagged: 3 Thread(s)	I money shifted mine and it ran fine. But two years later engine started knocking. Did track days in between never over revved it again. Not sure if related but probably was, car had 56k miles with a few dozen track events. __________________

05-10-2021, 06:38 PM	#23
rice_classic Senior Member Join Date: Jun 2012 Drives: Nevermorange FRS Location: Seattle, WA Posts: 4,160 Thanks: 755 Thanked 4,200 Times in 1,803 Posts Mentioned: 77 Post(s) Tagged: 1 Thread(s)	I don't think it's fuel starvation if it correlated with an over rev. I wonder if there's any trouble codes that have not resulted in a CEL that can be seen via techstream. __________________ SCCA T4 - FRS

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