strato58

I've noticed some things that just don't seem to jive and wonder if this box is really keeping an accurate count...I have my doubts.

MKIVdan

Thanks TT - Picking up the car tomorrow.

Craig T.

Not to hijack, but how does this open look? the one in level-4 was at 300 hours. I'm thinking of buying this car.

saabin

What's the total hours now?

Looks good to me..

Craig T.

I don't know the hours, but it's 28k miles

PorscheStrong

Craig T - that looks really clean

TT Surgeon

Craig T, that report is benign. That car is begging you to buy it!

PorscheStrong

Here's one simple way to think through the math...

If range 1 and 2's tend to represent hitting the red-line events, and 3+ tend to be money-shifts, looking at the 1's and 2's gives some (albeit, not perfect) perspective on how aggressively it was driven.

The rev count represents one ignition per piston firing. In a four-stroke engine, each piston fires once every other revolution. Accordingly, at 6,500 RPM's, which is approx red-line, each piston fires 3,250 times per minute; with 6 pistons, that's 19,500 ignitions per minute, or 325 per second. If the average red-line lasts a second, that's 325 ignitions per red-line event. Bear in mind all these rates assume 6,500 RPM's.

So if a car happened to be 7 years old and hit the red-line once a month, that would be 84 red-line events at 325 apiece, or 27,300 ignitions on the report.

Caveat: All of this is an over-simplification - at higher RPM's, there would be more ignitions per unit of time, and the ignitions wouldn't be evenly distributed across the rev range. And this says nothing of the money-shift math, but perhaps it gives some perspective.

Doc V.

Engine redline for the 997.1 Turbo is 6,750 rpm.

PorscheStrong

NickS - good catch, though for whatever reason, mine looks like 6,500. In either case, the math (as amended above) is at least reasonably illustrative.

Team Plutonium

This!

wistful

So a recent PPI on a 997.1 TT showed up these numbers. should I be concerned?
# of ignitions
1 - 13072
2 - 2318
3 - 391
4 - 99
5 - 5
6 - 1

Operating hours@
1 - 1299hrs
2 - 1299hrs
3 1257 hrs
4 1193
5 1193
6 251
total hours 1307

dont those numbers seem kinda high?

LexVan

Those ignitions are not too high. But the severity of the over-revs are. Looks like the most recent money shift at hour 1,193. It was 114 hours ago (maybe like 4,000 miles ago). So, it may have survived OK. But, within the last 8 hours and <300 miles, someone has been banging of the rev-limiter in range #1 and #2. I forget what he max is on range #1....but it's getting close to max count.

Can you buy a powertrain warranty as a hedge? Personally, I'd pass.