My engine failed while autocrossing

[ACT86]

Not a comment against FA24 reliability, but regarding the comment above I’ve been to Lotus track days for many years and yet to see an engine fail. They literally live for the track.

[EAGLE5]

Originally Posted by autoracer86

Those techs are not really used to swapping motors or rebuilding them. Look at all the valve spring recall issues from motors rebuilt by dealers.

Some of them are. I specifically asked about this when the dealer did my recall. He said something along the lines of how they have a tech who isn't the Toyota master mechanic but does engine race builds as a hobby do the actual work, and they just have the master mechanic come over and wave his hands as a blessing. Been a few years and my car is still running, so... shrug.

Originally Posted by CSG Mike

For the guys who think FA20 failure rates are high, you guys should check out the failure rates of Corvettes, Lotuses, Porsches, etc., on track.

I specifically do not want to like your posts, but... fuck.

Not to mention BMW.

911s are wonderful because if the motor blows and the rears lock up then the car slams back first into the barrier and your track insurance takes care of the rebuild.

[Desertnate]

Originally Posted by CSG Mike

I can all but guarantee you that even intermediate level autoxers are more abusive to an engine than I am.

In this context what would you call "abuse"? Not getting the car properly warmed up? Poor starting/shifting technique? The basic abuse seen running a course, i.e. frequent, fast transitions across the whole RPM band with bounces off the rev limiter? Does this mean you drive it a certain way, or you simply won't compete in a car that isn't heavily modified to eliminate weaknesses?

I'm genuinely curious and open to learn. After a few years and slowly improving results, I'd like to think I'm starting to crack into the "intermediate autoxer" category.

[ZDan]

Originally Posted by ACT86

Not a comment against FA24 reliability, but regarding the comment above I’ve been to Lotus track days for many years and yet to see an engine fail. They literally live for the track.

We had an Elise engine with rod knock on Sunday at Palmer. Apparently operator error though, he ran it low on oil!

[CSG Mike]

Originally Posted by Desertnate

In this context what would you call "abuse"? Not getting the car properly warmed up? Poor starting/shifting technique? The basic abuse seen running a course, i.e. frequent, fast transitions across the whole RPM band with bounces off the rev limiter? Does this mean you drive it a certain way, or you simply won't compete in a car that isn't heavily modified to eliminate weaknesses?

I'm genuinely curious and open to learn. After a few years and slowly improving results, I'd like to think I'm starting to crack into the "intermediate autoxer" category.

This. Bouncing off the rev limiter is VERY hard on the engine. It unfortunately is unavoidable if you want to go fast in AutoX in many classes.

[Stephen02]

Originally Posted by Unplugem

Your signature says you have a 07 GT3... What in the world were you doing autoXing the economy car? Hop in the purpose-built Porsche racecar and dust everyone at the event. You don't often hear of Mezgers having these problems. Even your RX7 would have held up better than the Subaru economy car.
I understand that many people track and autocross BRZs and 86s because it's all they own/can afford. However, you apparently own a 997 GT3 and RX7. Those are much better cars for performance events; you picked the wrong car out of your garage!

Exacly! These cars were made for the grocery store parking lot not the autocross parking lot. Silly OP.

[SCFD]

Originally Posted by CSG Mike

This. Bouncing off the rev limiter is VERY hard on the engine. It unfortunately is unavoidable if you want to go fast in AutoX in many classes.

Even with the FA20? I've hit the rev limiter a few times during autocross or track and it feels very "soft" on this car. I don't know how to describe it but I assume it's something with how Subaru tuned it.

[M0nk3y]

Originally Posted by SCFD

Even with the FA20? I've hit the rev limiter a few times during autocross or track and it feels very "soft" on this car. I don't know how to describe it but I assume it's something with how Subaru tuned it.

It's still sustained rotating components going 7800-8000 RPM, for extended periods of time.

I popped a rocker when I went to FI (and thus completely naded the engine), but I blame it on the 3-4 years of National AutoX rev'ing to 8k all the time.

Engine had 35k miles on it

[cmiovino]

It pains me inside to hold at the rev limiter on some courses ~2 seconds. That's about the limit for just holding it vs going to 3rd. Sometimes it's not worth it to do the upshift and subsequent downshift. In fact, you could argue that in an autocross situation where you might not be rev matching 100% correctly, you're then putting strain on the transmission/syncros. But hey, I guess all autocross is strain and wearing out parts, isn't it?

I've mentally found myself backing off at the limiter and not just holding my foot flat to the floor, but this loses you time and with autox and being competitive, that can be tenths pretty easily.

At heart, I'm too nice to my cars. I'll put longevity and wear above time a lot. I know most people I run with don't give to craps about it and will be trading the car in 2 years later, so they don't care at all. I get the "limiter is there for a reason and you can be on it all day with no problems. It was designed like that" argument all the time.

[cmiovino]

Originally Posted by SCFD

Even with the FA20? I've hit the rev limiter a few times during autocross or track and it feels very "soft" on this car. I don't know how to describe it but I assume it's something with how Subaru tuned it.

There are soft and hard limiters. These ones are soft, meaning you hit it and instead of hitting a wall and literally feeling the car kinda jerk you forward, it just keeps you going at that maximum speed for 2nd.

In other cars with a hard limiter, usually cable driven throttles, the limiter cuts fuel and other weird things.

End of the day, being at 7500 RPM for extended amounts of time can't be good in the long run. Yes, they're designed to hit those revolutions/speeds, but only temporary. Where as on the complete opposite spectrum, anywhere up to about 5k, you can pretty much stay at all day long with zero issues. Think about cruising at 3-4k on the highway for hours. Totally normal.

... and then double that. It's not just doubling heat and wear for ~2 seconds. It probably goes exponentially up.

[blsfrs]

Originally Posted by cmiovino

It pains me inside to hold at the rev limiter on some courses ~2 seconds. That's about the limit for just holding it vs going to 3rd. Sometimes it's not worth it to do the upshift and subsequent downshift. In fact, you could argue that in an autocross situation where you might not be rev matching 100% correctly, you're then putting strain on the transmission/syncros. But hey, I guess all autocross is strain and wearing out parts, isn't it?

I've mentally found myself backing off at the limiter and not just holding my foot flat to the floor, but this loses you time and with autox and being competitive, that can be tenths pretty easily.

At heart, I'm too nice to my cars. I'll put longevity and wear above time a lot. I know most people I run with don't give to craps about it and will be trading the car in 2 years later, so they don't care at all. I get the "limiter is there for a reason and you can be on it all day with no problems. It was designed like that" argument all the time.

Correct me if I misunderstand, double clutching and rev-matchings are separate techniques for different purposes.

Double clutching is for matching gear speeds when down shifting. You push the clutch in, briefly take the car out of gear, let the clutch out, rev the engine to match the lower gear speed, push the clutch back in and down shift. This was a critical skill before the car gods invented synchronizers.

Typically rev-matching (Heel/toe: a skill at which I suck) refers to matching the engine speed to the drivetrain speed after downshifting and before you let the clutch out. there by not upsetting the car. Cars can be like girlfriends, we don't want them upset.

[cmiovino]

Originally Posted by blsfrs

Correct me if I misunderstand, double clutching and rev-matchings are separate techniques for different purposes.

You may be right. I don't think there's time at autocross you'd have time to double clutch. It's hard enough to be turning, clutching in, downshifting, maybe trying to rev match, and getting it into gear. Double clutching hasn't even crossed my mind and I've been doing this well over 10 years now lol.

I think it's more important to be rev matched at least slightly close to get back into 2nd, usually heading into a corner or mid-corner. I know a lot of people don't and just slip the clutch. That adds more clutch wear over the long term and can upset the car if you're totally out of whack with revs/speed.

Could just be me, but I've always felt getting into a gear at a "weird" speed doesn't feel right. I'm not sure of the mechanics behind it given at the point the clutch isn't in play. For example, getting into first at anything over 5mph seems to be hard-ish. At 10mph, good luck. Other gears seem to sometimes do that too. Could just be me though. I'd assume it's the syncros having to do more work to snync things up, but without the clutch connecting the two, theoretically there shouldn't be any issues with wheel speed, right?

Someone enlighten us.

[Ultramaroon]

Originally Posted by blsfrs

Correct me if I misunderstand, double clutching and rev-matchings are separate techniques for different purposes.

Double clutching is for matching gear speeds when down shifting. You push the clutch in, briefly take the car out of gear, let the clutch out, rev the engine to match the lower gear speed, push the clutch back in and down shift. This was a critical skill before the car gods invented synchronizers.

Typically rev-matching (Heel/toe: a skill at which I suck) refers to matching the engine speed to the drivetrain speed after downshifting and before you let the clutch out. there by not upsetting the car. Cars can be like girlfriends, we don't want them upset.

^^^ this is spot on

[Clipdat]

GRANNY SHIFTIN, NOT DOUBLE CLUTCHIN LIKE YA SHOULD