Thoughts on this ECU dump....

[meat]

I'm looking at a 2006 Elise. The car has approx 4400 miles and has been tracked quite a bit.

Here is the ECU dump data that I recieved from the owner.

Last 0-100kmh - No data
Last 0-160 - No data
Number of Standing starts - No data
Max RPM 1 - 9481
Throttle position - 1.5-15% - 92.53
Coolant Temp 3 - 92.29
Coolant Temp 1 - 91.66
Coolant Temp 4 - 91.04
Coolant Temp 5 - 91.04
Coolant Temp 2 - 90.42
Max RPM 2 - 8710
Max RPM 3 - 8700
Max RPM 4 - 8695
Max RPM 5 - 8690
Max RPM Engine hours 2 - 58:40
Engine Speed - 2500-3500 RPM - 49:37
Max RPM Engine Hours 1 - 48:39
Wheel Speed - 0-30kmh - 46.36
Max RPM Engine Hours 5 - 46:33
Max RPM Engine Hours 3 - 45:44
Engine Speed - 4500-5500RPM - 4:41
Engine Speed - 500-1500 RPM - 36:34
Max RPM Engine Hours 4 - 33:14
Wheel Speed - 90 -120kmh - 31:38
Wheel Speed - 120-150kmh - 3:10
Wheel Speed - 60-90 - 27:45
No coolant temp issues.

I'm not entirely sure how to read this data, but the 9481 rpm max in first gear is obviously popping out at me. Seems I should have the owner do a compression/leakdown test? Any other feedback you can provide?

Thanks

[MattG]

It's not the first time we've seen this...I think it's fairly common for there to be an electronic glitch resulting in an incorrect rpm reading. It might have been a missed shift, but is also very likely just an electronic glitch.

[Dragon]

I wouldn't be worried about the rpm... In fact I would say buy the car because of it... If it didn't drop a valve at that rpm then you know it has good strong top end... ...

[Mr. Know]

Originally Posted by meat

Max RPM 2 - 8710
Max RPM 3 - 8700
Max RPM 4 - 8695
Max RPM 5 - 8690

Electronic glitch or not, the other readings in the dump are more concerning...every one of them are over the limiter.

[ChrisB]

Those are the top 5 RPM readings, not the RPM in a specific gear. There have been glitches as Matt mentioned, though the obvious ones have impossible readings like 13,xxx RPM. A real 9481 is not likely without damage, but I suppose possible.

[craracer]

Is a limiter that allows you to go over the limit really a limiter

The revs listed are not related to a particular gear as previously mentioned

[meat]

Thanks for the clarification on the what the numbers represented on the max revs.

No limiter can stop a mechanical overrev (on a downshift).

[turbophil]

I kinda doubt the 9 gerr was a glitch... That's very obtainable on 5-2 shift. I know three people that have done it. All 3 survived. 1 has a noisy engine now, but still run fine and no visable damge was done (with valve cover removed), the other two survived just fine... 13,xxx is obviously a glitch---- 9,xxx I think is a bad shift, IMO...

If the engine sounds ok, it's probably fine...

2 more pennies

Phil

[robains]

Geez Phil!!

Certainly worth more investigation. Valve tips breaking are a common failure for those of us that track frequently and live above 8000 rpm.

Toyota (actually Yamaha) originally designed the engine to rev to 8400, during it's life in a Celica GT-S it was reduced to 7800 twice and the final GT-S year run it was at 7800 rpm (Lotus leave the Toyota internals untouched).

You might also ask if the car ran a stand alone ECU or had been reflashed. My hunch is these are bad downshifts -- not great, but not as bad as if they were "normal" max rpm shifts under load (or extended rpms for tracks where it's faster to hold higher rpm).

Two big concerns will be valve tips and oil pump gears. You might not be able to identify potential valve tip problems with the valve cover off unless it's real obvious. As for oil pump gears -- if the car has an oil pressure gauge, check for erratic oil pressure readings (40-85 is the norm with variance for temp and oil viscocity).

And finally, since the car has been tracked a lot, does it have a Accusump and/or high capacity baffled oil pan (like a Moroso)? Since it's not Forced Induction you probably don't need to worry about fuel starvation/delivery issues that could cause detonation.

Also ask the owner what his/her lap times are at the tracks he/she frequents, that will help you detemine just how hard they were pushing the car.

Rob

[turbophil]

Hey Rob

We're both saying the same thing in that it's probably not a glitch at a paltry 9,4XX revs... I "just sayin" that if it didn't break at that moment then it *probably* won't from that particular instance... Looks like that over-rev happened several engine hours ago as well... That's why I say it's probably fine as long as the engine isn't making not-so-funny sounds...

To the OP, if it worries you at all, walk away. It's not like there's a shortage of these cars for sale

Happy hunting,

Phil

Edit: Besides, everyone knows the 05 car is the best NA car to get anyway, so you should move on with just that bit on knowledge... Only reason not to get an 05 car is if you wanted a SC car

Edit 2: And even if you did want a SC'ed car, you should still buy the 05 since you can make more power with the aftermarket kits than the OEM stuff...

Edit3: I'm done editing this post

[SteveLevin]

I can tell you that I've done an inadvertent 4-to-3 upshift in my SRF and gotten 7400rpm on an engine redlined at 6000, and it survived (although it pumped up the lifters and clattered for a moment. a couple of minutes later it was fine. Although when it was torn down a couple of months later, there was definite signs of damage...but then again, it was a 3+ year old engine.

The bad news is that a friend, on a newer motor, did the same thing and got 7300rpm and broke the engine.

In short, sometimes you get away with it, sometimes not. Compression and leakdown combined should give you a rough idea, although certainly you have to figure that engine might not survive another massive overrev.

Steve

[charliex]

its not out of the realm of possibility for the occasional wierd 06 ecu ones, even though they tend to be 10K+,which is an impossible reading on the stock ecus, but i've seen lots of ecu's with confirmed misshifts and 9K+ readings.

its why the limiter isn't able to stop all over revs since its still an electronic limiter, and not a mechanical one.

usually when you see an overrev there's a couple of high's set, one is sometimes just an anomaly, which is fixed in the newer rev's of the ecu code, but the others are fairly high too, but the time they're read at makes me think its a bit odd, spot 2 occcurred at a different time to 1,3 4 and 5.

it'd be worth while doing a test on it, if it were 10K plus then definitely a misread, 9K plausible.

[Jack]

Originally Posted by Mr. Know

Electronic glitch or not, the other readings in the dump are more concerning...every one of them are over the limiter.

Those are all (except for the 9K+ rpm reading) w/in the range of the limiter ... 8500 RPM limiter lets the car go above for ~ 3 secs. Hitting 8700-8800 rpm's is not due to an over-rev mechanical mis-shift.