so i got my car tuned today on COBB. these cars dont make power! 288 whp and 301 wtq. anyway driving home and it started popping. it was wet so i wasnt getting on it. i pull off the highway and get to a back road and try to pull under a bridge so i can call a tow truck. but before i could get to the bridge my car starts misfiring and knocking. the car fills up with smoke and i coast under the bridge.. get it towed back to my house pull the spark plugs out of it along with the valve cover stick my cool light camera down in the 3rd cylinder hole and spin it over... no movement. all other pistons were fine.. well they moved. didnt see any holes or oil.. it was idleing when it let go. just thought id share my day with you guys
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
snapped 3rd cylinder rod today
- Thread starter NAisBST
- Start date
shane02pro5
25ish_psi
- :
- New Caney TX
Ouch...sorry to hear!
It's not what you are doing when the engine lets go, it's what the engine has been subjected to over extended time. Cumulative effect. Not uncommon for a performance tuned or race prepped engine to let go under light load due to high load conditions in the past when the engine was being operated in unsafe conditions or due to a gradually failing part, IMHO.
The list of options posted does not suggest that the recent dyno should have been any higher, depending on the state of tune, and assuming reasonable boost levels.
A downpipe and free flow exhaust would not cause it to go zoom, zoom, boom, unless boost was raised significantly above stock levels. Nor would the presence of a FMIC, even in combo with the downpipe. Mods list does not say anything about intake, but I'm assuming a good SRI or CAI.
I am a bit concerned about the Standback. It's a good product, but very difficult for users and even pretty good tuners to tune properly and safely for our car. I guess OP went to AP somewhere along the way. We don't know what tune he was running in the past with the Standback or more recently with the AP.
A good tune can help keep things safe. A bad tune, even with mimimal mods makes for a grenade or a slowly ticking time bomb.
With my mods and no tune, stock ECU and stock BPV, I'm putting out 270-275 whp and about 290-300 lbs torque, running 13.4 - 13.5 quarters in good track conditions at 106-107 and really running nicely with great power once in third gear and higher, especially 4-6.
I'm at 26,000 miles with mods in place for all but the first 5K or so.
I'm just wondering if past tunes, especially aggressive boost levels and lean tunes, if they were involved, or upping safety limits for fuel cut, if done, eventually had their toll. Just speculation.
Personally, I don't see the point in trying to go above 300 whp in a FWD daily driver anyway. The traction limits are exceeded before you get to the maximum bolt on limits for safe operation of the motor. Hell, I break traction very frequently in third gear as it is now. I really don't know how I'd use more power on the street.
Very sorry to hear about the outcome. Teardown and careful inspection will tell the story. Does sound like you'll find that a rod let go.
The list of options posted does not suggest that the recent dyno should have been any higher, depending on the state of tune, and assuming reasonable boost levels.
A downpipe and free flow exhaust would not cause it to go zoom, zoom, boom, unless boost was raised significantly above stock levels. Nor would the presence of a FMIC, even in combo with the downpipe. Mods list does not say anything about intake, but I'm assuming a good SRI or CAI.
I am a bit concerned about the Standback. It's a good product, but very difficult for users and even pretty good tuners to tune properly and safely for our car. I guess OP went to AP somewhere along the way. We don't know what tune he was running in the past with the Standback or more recently with the AP.
A good tune can help keep things safe. A bad tune, even with mimimal mods makes for a grenade or a slowly ticking time bomb.
With my mods and no tune, stock ECU and stock BPV, I'm putting out 270-275 whp and about 290-300 lbs torque, running 13.4 - 13.5 quarters in good track conditions at 106-107 and really running nicely with great power once in third gear and higher, especially 4-6.
I'm at 26,000 miles with mods in place for all but the first 5K or so.
I'm just wondering if past tunes, especially aggressive boost levels and lean tunes, if they were involved, or upping safety limits for fuel cut, if done, eventually had their toll. Just speculation.
Personally, I don't see the point in trying to go above 300 whp in a FWD daily driver anyway. The traction limits are exceeded before you get to the maximum bolt on limits for safe operation of the motor. Hell, I break traction very frequently in third gear as it is now. I really don't know how I'd use more power on the street.
Very sorry to hear about the outcome. Teardown and careful inspection will tell the story. Does sound like you'll find that a rod let go.
Last edited:
Sorry to hear. I am resigned to keeping the car near stock: It seems inevitable that our engines will go at some point. I know a lot of guys are arguing that these are still a small percentage, but the evidence suggests weak internals. Hopefully things will work out and you get a new engine under warranty: Fingers crossed. This happened right after a tune too, which is supposed to prevent this from happening.
- :
- 2007 MS3
This happened right after a tune too, which is supposed to prevent this from happening.
As was pointed out earlier, it is entirely possible that this had nothing to do with the current tune.
On the other hand, it might not have been a very good tune.
There was another thread where a member got a tune done and when he posted the specs, he got warned that it was probably dangerous, because the so-called tuner did little more than bump his boost levels up. Nothing was done to actually tune the program for safety and/or efficiency.
Without the specs of the OPs tune, we have no way of knowing how good it was.
As was pointed out earlier, it is entirely possible that this had nothing to do with the current tune.
On the other hand, it might not have been a very good tune.
There was another thread where a member got a tune done and when he posted the specs, he got warned that it was probably dangerous, because the so-called tuner did little more than bump his boost levels up. Nothing was done to actually tune the program for safety and/or efficiency.
Without the specs of the OPs tune, we have no way of knowing how good it was.
that was me, my original tune was a grenade.....20psi with an intake, afr's in the 9s. creeping to 22 by redline.
http://www.mazdas247.com/forum/showthread.php?t=123743268
Im now making the hp in my sig @ 18psi with the mods listed
Last edited:
SPEED DEMON
Member
- :
- 08 ms3, 08 cx7, 91 roadster
This is why I'm not upping the boost untill my engine is fully built, tune or not. My car runs fine with the stock tune with my mods.
Mod list: cp-e nano, htp inlet, mdr fmic (protege garage), speed action dp, turbo smart bov set to 50/50.
The only complaints are my mileage is cut in half, the car always has carbon build up on the back bumper, and It shoots flames when I get on it.
Mod list: cp-e nano, htp inlet, mdr fmic (protege garage), speed action dp, turbo smart bov set to 50/50.
The only complaints are my mileage is cut in half, the car always has carbon build up on the back bumper, and It shoots flames when I get on it.
This is why I'm not upping the boost untill my engine is fully built, tune or not. My car runs fine with the stock tune with my mods.
Mod list: cp-e nano, htp inlet, mdr fmic (protege garage), speed action dp, turbo smart bov set to 50/50.
The only complaints are my mileage is cut in half, the car always has carbon build up on the back bumper, and It shoots flames when I get on it.
do you have a dh or the like to monitor, only reason im asking is "running fine" usually isnt really too accurate.
SPEED DEMON
Member
- :
- 08 ms3, 08 cx7, 91 roadster
DH said the lowest my fp droped was 1400 psi at wot. When I dyno'd (mustang dyno) the afr reading at the tail pipe was 10.7 at wot.
As was pointed out earlier, it is entirely possible that this had nothing to do with the current tune.
On the other hand, it might not have been a very good tune.
There was another thread where a member got a tune done and when he posted the specs, he got warned that it was probably dangerous, because the so-called tuner did little more than bump his boost levels up. Nothing was done to actually tune the program for safety and/or efficiency.
Without the specs of the OPs tune, we have no way of knowing how good it was.
Good points: I totally agree with you. The point I was trying to make is that this is evidence that a Protune or the like is not the panacea for blown engines that they are made out to be. Stock ecu, OTS or Protune it's all still a gamble without internals.
A protune (or any other tune) is only as good as the tuner. There are plenty of "professional tuners" out there that aren't "expert tuners".
Just because you paid someone to tune your car doesn't mean they did it right.
+++1000000 see my earlier post
Similar Threads and Articles
- Replies
- 2
- Views
- 590
- Replies
- 11
- Views
- 4K
New Posts and Comments
- Replies
- 38
- Views
- 6K
- Replies
- 11
- Views
- 3K
- Replies
- 2
- Views
- 2K