[NickyRacerBoy]

Originally Posted by dotfiles

As others have said why would you even raise the stock limiter? These motors aren't continuing to build HP over 62-6400RPM. Keeping the motor safe is more important than being able to get a couple extra MPH out of each gear.

I RAISED IT 125 RPMS for 4th gear only...that's it.

"Every minute" I was mechanically over revving it? That statement is not accurate. Yes, turn 1 I did over rev it.

[TrackClub]

Originally Posted by NickyRacerBoy

I RAISED IT 125 RPMS for 4th gear only...that's it.

"Every minute" I was mechanically over revving it? That statement is not accurate. Yes, turn 1 I did over rev it.

I stand corrected: every minute and a half. Meaning each lap pretty much.

[NickyRacerBoy]

Granted I know Camaro is nothing like my 2016 GT3 RS but I believe that the cam phasers in these LT1 can be partial blamed. Yes I over revved it..

[6spdhyperblue]

Cool gt3, not sure what I’m supposed to take from that.

The cam phasers aren’t to blame, the same would happen to a ls1. You over revved the heavy valve train of large valved pushrod engine. The large valves that provide the low end grunt we love. The philosophy from the ls7 brought c5r lots of success and reduced maintenance intervals with broad power curve applies to this engine. Doesnt need to rev. Watch pobst hot lap, doesn’t rev too much. It happens, that’s racing, ppl lose motors, it sucks. Hopefully you’re interested in camming it and/or 408ci and making it run more how you like it.

If you haven’t had the pleasure of a cammed ls/lt its pretty amazing

[NickyRacerBoy]

Originally Posted by Nicul15

Cool gt3, not sure what I’m supposed to take from that.

The cam phasers aren’t to blame, the same would happen to a ls1. You over revved the heavy valve train of large valved pushrod engine. The large valves that provide the low end grunt we love. The philosophy from the ls7 brought c5r lots of success and reduced maintenance intervals with broad power curve applies to this engine. Doesnt need to rev. Watch pobst hot lap, doesn’t rev too much. It happens, that’s racing, ppl lose motors, it sucks. Hopefully you’re interested in camming it and/or 408ci and making it run more how you like it.

If you haven’t had the pleasure of a cammed ls/lt its pretty amazing

Yeah shit happens. Need to get the braking done first.
My excuse...LOL....forst session of the new year...

I am sucking it up, I did even bother calling the dealership to warranty it...
New motor will be in this weekend. I do all work myself and there is a lot to these cars....E-steering etc.....lots of shit in the way.

New motor is stock cubes and just forged pistons and rods. Comp cam phaser limiter with total delete. New heads, I even trashed my intake manifold and air filter! In the trash can it went. The broken shit was packed in there. Guess it would with no intake valve in the head, back flowed. Small cam spring retainers ....normal shit


OH AND BTW I MEASURED PISTON THE VALVE CLEARANCE 95 THOUSANDS. That should be plenty for that missed shift...

[6spdhyperblue]

Cool build, glad to see you’re doing it yourself too. Did you go aftermarket cam?

[SSDan]

Originally Posted by NickyRacerBoy

Need to get the braking done first.
My excuse...LOL....forst session of the new year...

I think everyone is beating you up on this like you were purposely over reving the engine. As I watched the video It appeared to me your over revs were from engaging the clutch too soon for a 4th to 3rd downshift while scrubbing off a lot of speed to make that low speed turn at the end of the straight away.
If you could discipline yourself to not engage the clutch when going into 3rd until you were below 100 mph you would avoid the mechanical over rev.
Easy for me to say when I'm not in the seat facing down that turn and doing all the things needed - braking, downshifting, hitting the apex - etc.
Its just a timing thing on the clutch release. I'm sure you will get it down with the new motor once you are back out there. Good luck with the build.

[baron95]

Believe it or not it is all connected.

You are starting the downshift at the end of the straight already above redline. (I understand why you did it - I have other posts saying that it seams the shift from 4th to the very long 5th is death for the Camaro SS in acceleration).

If you were in 5th gear, you'd be below 5,000 RPM, and would either do 5-4-3 or 5-3 (which is a slower move than 4-3). People tend to develop these timing cues on track. You can't really watch the speedo on your downshift. It is moving too fast under heavy brake. Most people do it based on timing. Some (very few) use reference markers to clutch out.

You get used to the time it takes to do 5-4-3 or slow 5-3 at the end of a typical track straight ~140-145MPH. Now all of a sudden you start stretching 4th, perform the fastest downshift 4->3 and clutch out with the same timing. Now you are still too fast for 3rd.

It feels good. You are less busy at the end of straight. Instead of 4-5-4-3, you now only need to do 4-3. You can devote more brain cells to watch the markers. You start braking later, downshifting faster.

The little over revving becomes a larger overrevving. 7200 on a 6,600 redline is a serious ˜10% over rev.

Boom.

I probably have corrected over a dozen students who were over revving on downshift. Most let the clutch out very slowly, so there is little to no shock to the engine - but I still remind them that they were starting clutch out at too high a speed.

This scenario, that contributed to your engine failure, is much more common than you think. Every time you stretch 4th you need to be very, very vigilant.

Don't beat yourself up. It happens to the best drivers. I too raised the redline of my Coyote Mustang GT to 7,350 (˜5%) RPM with a tune that made it develop meaningful power to deal with the very short Mustang gears. Luckily I never blew my engine, but I did have an early clutch failure - possibly the slight over-revving contributed to it.

[TrackClub]

Words of wisdom. I would add: Fine to run it out in 4th but no reason go push to redline. Watch the revs and hold at 6000. Then downshift as late as possible before turn in. Rev match makes it easy and safe. No reason to downshift early. Ciao!

[NickyRacerBoy]

Originally Posted by Nicul15

Cool build, glad to see you’re doing it yourself too. Did you go aftermarket cam?

Yes I did. I worked with Lonnie @ Texas Speed to come up with a "torquer cam"

Originally Posted by SSDan

I think everyone is beating you up on this like you were purposely over reving the engine. As I watched the video It appeared to me your over revs were from engaging the clutch too soon for a 4th to 3rd downshift while scrubbing off a lot of speed to make that low speed turn at the end of the straight away.
If you could discipline yourself to not engage the clutch when going into 3rd until you were below 100 mph you would avoid the mechanical over rev.
Easy for me to say when I'm not in the seat facing down that turn and doing all the things needed - braking, downshifting, hitting the apex - etc.
Its just a timing thing on the clutch release. I'm sure you will get it down with the new motor once you are back out there. Good luck with the build.

THANKS!
Yeah I kinda felt like a punching bag a little..LOL..

Yes I stretched 4th gear out.. cause going into 5th, I thought, would be a waste. I betcha RPM transmission make a 5 and 6 gear set that is not over drive. I know for a fact that they do for old T56. I think its called M12....

Originally Posted by baron95

Believe it or not it is all connected.

You are starting the downshift at the end of the straight already above redline. (I understand why you did it - I have other posts saying that it seams the shift from 4th to the very long 5th is death for the Camaro SS in acceleration).

If you were in 5th gear, you'd be below 5,000 RPM, and would either do 5-4-3 or 5-3 (which is a slower move than 4-3). People tend to develop these timing cues on track. You can't really watch the speedo on your downshift. It is moving too fast under heavy brake. Most people do it based on timing. Some (very few) use reference markers to clutch out.

You get used to the time it takes to do 5-4-3 or slow 5-3 at the end of a typical track straight ~140-145MPH. Now all of a sudden you start stretching 4th, perform the fastest downshift 4->3 and clutch out with the same timing. Now you are still too fast for 3rd.

It feels good. You are less busy at the end of straight. Instead of 4-5-4-3, you now only need to do 4-3. You can devote more brain cells to watch the markers. You start braking later, downshifting faster.

The little over revving becomes a larger overrevving. 7200 on a 6,600 redline is a serious ˜10% over rev.

Boom.

I probably have corrected over a dozen students who were over revving on downshift. Most let the clutch out very slowly, so there is little to no shock to the engine - but I still remind them that they were starting clutch out at too high a speed.

This scenario, that contributed to your engine failure, is much more common than you think. Every time you stretch 4th you need to be very, very vigilant.

Don't beat yourself up. It happens to the best drivers. I too raised the redline of my Coyote Mustang GT to 7,350 (˜5%) RPM with a tune that made it develop meaningful power to deal with the very short Mustang gears. Luckily I never blew my engine, but I did have an early clutch failure - possibly the slight over-revving contributed to it.

Helpful and useful posts like the above is why I hang here! Thanks. I usually hang with the guys at Phoenix Racing, Joe Aquilante.
That old man rolls!

Originally Posted by TrackClub

Words of wisdom. I would add: Fine to run it out in 4th but no reason go push to redline. Watch the revs and hold at 6000. Then downshift as late as possible before turn in. Rev match makes it easy and safe. No reason to downshift early. Ciao!

[6spdhyperblue]

Yes I’ve swapped m12s in before and the 5th gear is much closer to 4th. It is good for road racing but enjoy the mn6 stock gearing for dd. I do believe the m6 gearset in the zl1 is different

If I dragraced a zl1 m6 I would trade with you

Or we just heard Richmond is going to offer new rear gears. Throw in 4.10s and you should be all set

[wnta1ss]

I suspect that the forces being reversed, ie the rear wheels pulled the rpm up that high not normal acceleration, possibly contributed to the failure.

[TrackClub]

Originally Posted by wnta1ss

I suspect that the forces being reversed, ie the rear wheels pulled the rpm up that high not normal acceleration, possibly contributed to the failure.

Yep rev limiter protects a motor during acceleration.

Sorry about the punching bag thingy Nicky Ricky Bobby.
Best of luck on your rebuild! Just stay away from 10% over revs

[Idyll]

Why in the world are you tracking a Camaro when you own God's chariot?