[Cthulhu]

I was around 4-5K rpm when I downshifted without blipping the throttle enough. I normally rev match and get off the clutch in about half a second, so i came off the clutch very quickly (and my revs had fallen pretty low). I heard what could best be described as a crack, and the car obviously jerked.

No CEL, and everything seems fine, but I'm wondering what that sound was, now. Could it have been the clutch pad spinning slightly while clamped under pressure (ie: the plates are squeezed together, and there is a force mismatch, so the pads break loose momentarily)? Do you guys think it was something like a mount or drivetrain component snapping?

Should I be worried? Because I am... anic:

 

[apk919]

I was around 4-5K rpm when I downshifted without blipping the throttle enough. I normally rev match and get off the clutch in about half a second, so i came off the clutch very quickly (and my revs had fallen pretty low). I heard what could best be described as a crack, and the car obviously jerked.

No CEL, and everything seems fine, but I'm wondering what that sound was, now. Could it have been the clutch pad spinning slightly while clamped under pressure (ie: the plates are squeezed together, and there is a force mismatch, so the pads break loose momentarily)? Do you guys think it was something like a mount or drivetrain component snapping?

Should I be worried? Because I am... anic:

Have you got the original engine mounts? If so, a rev mismatch causes the engine to move quite a bit in the mounts, potentially putting strain on the exhaust system (which has been known to crack).

 

[Cthulhu]

Yes. I have the original mounts that would come on a factory 2007 Exige S with both the touring and track pack.

Where should I be looking? I'm checking the manual right now, but please let me know the stress points I should be concerned with. I know that if I only broke a mount or two, I wouldn't hear horrible noises, but if the engine broke loose, I would. So visual inspection is a must.

It sounds like my rear clam is coming off this weekend, but let me know if inspection of the stressed parts does not require clam removal.

Thanks..

anic:anic:anic:

Oh, and how cheap are engine mounts (just the parts). Can I fabricate them from steel or something? What is the exhaust thing that could have cracked?

If I cracked my exhaust then it sounds like a huge 2bular exhaust and better engine mounts are absolutely 100% mandatory, and that the purchase would be 1000% rational

 

[chapster5]

Oh, and how cheap are engine mounts (just the parts). Can I fabricate them from steel or something? What is the exhaust thing that could have cracked?

You can get some newley designed ones these days, that stop your engine from violently jerking when you shift gears, cant remeber where you get them now, there somwhere on this forum.

Good luck with finding the problem

 

[def]

In terms of the exhaust system (not sure where else to check)....

Can probably check everything from the headers to the exhaust tips for cracks, I guess the cat (around it) has been known to crack, near the u pipes?

I still think the manly mount inserts are a great product for those who autox or track even lightly. The extra vibration at idle doesn't bother me personally, and I have extra reassurance that my car won't light on fire (hopefully)

 

[Cthulhu]

Rear clam is coming off this weekend I guess. There's no way to do a full inspection without taking off the rear clam.

If my exhaust is cracked, it may be a J.B. Weld and ziptie job (LOL, shut up, I'm actually serious about the J.B. Weld) and an S2 or tubular exhaust on my xmas wishlist.

The sector 111 engine mounts I saw were $399 for a set. I'll have to search the forums a bunch, but if anyone knows of cheaper alternatives that are just as good, please let me know. Oh, I also noticed that the sector 111 ones do not require my engine to be lifted. This is ideal since I don't have an engine crane.

<sigh> I wanted to take my rear clam off to clean everything up and take pictures... but I didn't want it to be like this... It wasn't supposed to be this way! It was supposed to be out of love! Out of love!!!

It sounds like it shouldn't be anything WORSE than a cracked exhaust, though. A cracked exhaust is bad, but not as bad as your pistons smashing...

 

[apk919]

Yes. I have the original mounts that would come on a factory 2007 Exige S with both the touring and track pack.

Where should I be looking? I'm checking the manual right now, but please let me know the stress points I should be concerned with. I know that if I only broke a mount or two, I wouldn't hear horrible noises, but if the engine broke loose, I would. So visual inspection is a must.

It sounds like my rear clam is coming off this weekend, but let me know if inspection of the stressed parts does not require clam removal.

Thanks..

anic:anic:anic:

Oh, and how cheap are engine mounts (just the parts). Can I fabricate them from steel or something? What is the exhaust thing that could have cracked?

If I cracked my exhaust then it sounds like a huge 2bular exhaust and better engine mounts are absolutely 100% mandatory, and that the purchase would be 1000% rational

As said above, check the catalytic converter, and the coupler between the headers and the pipe leading to the cat.

It's unlikely that you'll break the stock engine mounts; they're so soft that the engine winds up hitting the firewall or stressing the exhaust before overstressing the mounts. I've got Innovative 60A mounts, which adds vibration at idle, but has much less flex in the drivetrain. The engine mount inserts remove a lot of flex too, and add less vibration.

 

[Cthulhu]

Ok, those are the mounts I was looking at, but yeah... expensive. I'll probably take my rear clam off today, since I'm trying to only drive my car to work on tues/thurs (60 miles round trip to work).

I'll post some high-ish res pictures in this thread (1200x900 should be ok), and even if I don't see anything, I'll wait for you guys to look over everything before I start remounting the clam.

For the record: I'm blaming this downshift FAIL on a fly-by-wire throttle lag error, not an error on my part. ROFL.:nanner2:

 

[apk919]

...
For the record: I'm blaming this downshift FAIL on a fly-by-wire throttle lag error, not an error on my part. ROFL.:nanner2:

More excuses: Turn Zero Technical Resources :: Racing Excuse Generator -poke-

 

[def]

^ LOL

 

[Cthulhu]

I think I need to recalibrate my telemetry *mumble mumble*. The latency of my throttle response is causing non-driver-induced downshift errors...

LOL @ the excuse generator. Umm... it also had something to do with thermal distorion of my left adjustable seat rail