Stress on engine during autocross.

TennTechMan · Post by **TennTechMan** » Thu Dec 04, 2008 9:50 pm

I voted yes mostly because I would never drive my car nearly as hard on the streets as I do at an autocross. How much of a difference? Probably not much. There's probably more variation in engine life within factory build tolerances.

This is assuming we're talking about vehicles manufactured within the last 15 to 20 years.

steverife · Post by **steverife** » Thu Dec 04, 2008 10:12 pm

EliseAutoXr wrote:I think what this question is REALLY bringing out is how each of us drive differently during the normal day-to-day driving.

That's probably true.

I don't think I've even had my foot to the floor in the Mazda outside of autocrossing and my one trip to the drag strip.

EliseAutoXr · Post by **EliseAutoXr** » Thu Dec 04, 2008 10:35 pm

steverife wrote:
EliseAutoXr wrote:I think what this question is REALLY bringing out is how each of us drive differently during the normal day-to-day driving.
That's probably true.

I don't think I've even had my foot to the floor in the Mazda outside of autocrossing and my one trip to the drag strip.

I'm on the floor every chance I "need" to... you know, to get into fast traffic or the light changed to green or just left a school zone.

gbwrx · Post by **gbwrx** » Thu Dec 04, 2008 10:49 pm

I voted no because I don't think that an autocross could cause anymore stress on an engine that could happen on the street. I don't drive my car as hard as I use to (especially when I first got it) but 90-100 MPH driving to an from BMS the whole way is probably more stress than the actual autocross that I was going to.

lcoleman · Post by **lcoleman** » Fri Dec 05, 2008 1:54 am

I voted no, because in theory you could put just as much stress on the engine on the street...however, most people aren't ballsy (stupid?) enough to push that hard on public roads.

I don't think running at high RPM's or under load is what hurts the engines--they're designed to do that for extended periods anyway: think Autobahn driving. I'd say the only real danger to your engine in autocrossing is crankcase oil starvation in high-G turns...of course, this only applies to wet-sump cars, so C6 Z06s and the like need not apply.

Post by **thrdeye** » Fri Dec 05, 2008 11:24 am

Mark, I worded it that way on purpose. My point is that if a stock car drops a piston on an autocross course, there was a problem from the factory. The dealer would consider autocross as "abuse" according to the 3 tech posting in the thread I mentioned.

Car in question had 11k miles on it and lost 2-3 of it's ringlands. Subaru sent letter to custer telling them to bring car in for a reflash due to bad factory tuning - car ran lean. People in thread found out he had autocrossed the car 6-8 times and immediately jumped his ass for it, saying that caused it. No way autocross is going to cause the engine failure.

I remeber learning to drive my car I bounced the thing off the limiter in neutral who knows how many times cuz I had no idea what I was doing.

backpacker6 · Post by **backpacker6** » Fri Dec 05, 2008 12:32 pm

Will you post the link to the thread? I'd like to check it out.

/please

Post by **thrdeye** » Fri Dec 05, 2008 1:40 pm

http://forums.nasioc.com/forums/showthr ... ?t=1633519

Here it is. I don't believe Subaru should buy the car back....I think they handled it well. I was just pissed at the people that jumped the guys ass for autocrossing the car. They said something about rallycross, but the snow thing he did was just snow on pavement from what I can gather....

He has autocrossed for 10 years. Anyway. There are three/four service guys and a bunch of mods that like to kiss each other's ass so enjoy.

Dentspeed · Post by **Dentspeed** » Fri Dec 05, 2008 1:47 pm

Those models sux!

Post by **thrdeye** » Fri Dec 05, 2008 2:01 pm

Dentspeed66 wrote:Those models sux!

I really like them, but not if they dun blow'd up!

Scuffcakes · Post by **Scuffcakes** » Fri Dec 05, 2008 2:10 pm

Wow. A whole lotta idiots in that thread. So much so that I couldn't continue reading it. What do these guys to with their WRX's & STi's? I'm guessing that they just trailer them to car shows. Maybe Subaru should stop using motorsports in their advertizing. It just makes people want to do apparently stupid things with their cars.

01badz28 · Post by **01badz28** » Fri Dec 05, 2008 2:21 pm

Scuffcakes wrote:Wow. A whole lotta idiots in that thread. So much so that I couldn't continue reading it. What do these guys to with their WRX's & STi's? I'm guessing that they just trailer them to car shows. Maybe Subaru should stop using motorsports in their advertizing. It just makes people want to do apparently stupid things with their cars.

I don't know what else you would do with them, staring at a Subaru for too long can induce vomiting.

Seems like everyone in that thread is either 1) a factory technician or 2) a dumbass. (Barring Chris).

Post by **thrdeye** » Fri Dec 05, 2008 2:31 pm

Okay I just watched the snow cross video...looked awesome...snow on pavement.

Horrible abuse. Surprised that any car could survive something like that!!

MARKP · Post by **MARKP** » Fri Dec 05, 2008 5:07 pm

thrdeye wrote:Car in question had 11k miles on it and lost 2-3 of it's ringlands. Subaru sent letter to custer telling them to bring car in for a reflash due to bad factory tuning - car ran lean. People in thread found out he had autocrossed the car 6-8 times and immediately jumped his ass for it, saying that caused it. No way autocross is going to cause the engine failure.

I agree.

Oberstwill · Post by **Oberstwill** » Fri Dec 05, 2008 7:05 pm

Well my motor has not suffered from auto-xing, but apparently it might have been a factor in some axle failure, or just helped to exaccerbate a pre-existing condition with that part.

East Tennessee Region SCCA

Stress on engine during autocross.

Is the stress on a stock engine during autox any different than what could occur on the street?