newme

Right, I know this topic has been discussed to death.

Still, how important can break-in really be?

Having only 300 miles, surely it can't be deadly to the Z to rev in the happy range every once in a while. Or for the odometer to point NE / East every so often.

I realize airplane prop engines are different (as in simpler because they MUST work), but a chat with a factory engine engineer at the air show a few weeks back - he says better to run the engine at high revs or the seals will not seat properly. So high revs are better than low for break-in.

FWIW, the folks at my dealership no break in is needed in the Z, but just in case just vary the RPM for the first few miles... :rolleyes:

Yet other owners say 500 miles of babying below 3k RPM, etc.

I appreciate good advice and this is not meant to attack anyone or any beliefs, but I was wondering if anyone had any actual, factual data as to the effects of break-in (or lack thereof) procedures.

Surely someone somewhere, at least the manufacturers, must have some hard data / graphs about this, no?

Thanks!

no cure

the key component that needs 'break in' is the differential. before the rear gears are 'seated' (ie "meshed", see ring n pinion shear effects) one should avoid "shocking" the diff. this actually is quite important, as those first few hundred miles can make a 100% difference in the overall life of the rear gears on an M6 C5... which is why they say "no hard acceleration for the first 500 miles..."

jerryv

Although our cars are built from virtually identical components, each one is different. Slight differences in tolerances, etc make each car unique. That's why you occasionally find a super-performer, and occasionally a real lemon. When I got mine, I didn't know for sure what I had, so I drove it very gently for the first 50 miles or so, then increasingly hard as time went on. My reasoning was that if something were going to fail, it would most likely fail early. I wanted to give all the moving parts a chance to develop broad, even wear patterns, so I varied the both the engine and rear wheel speed as much as was practical. I also wanted to just get used to the car .. the way it feels, sounds, etc. so I could develop a sense of what 'normal' was like.

I think there's really no way to know how much 'break-in' contributes to later performance, but to me, the idea of taking it easy at first, and gradually upping the ante just made sense.

blackshark

Took my '01 off the road with about 300 miles on it to put the roll cage in. Went racing. No problems.

Power Shifter

If there is a "true right" answer to this question I don't know. I vary my rpm as I breakin. I do not think about mph. I like to put a quick 50mi on and then let every thing cool a couple of times. I picked mine up and the second day was at the track(230+mi). The only time it has been to the dealer was for a defective brake booster. I belive the "secret" is to drive as smoothly as posible, track or street. That is what makes a fast one that is reliable. IMHO Ric

newme

Thanks for the replies!

Blackshark, is yours a track-only car? How is it holding up overall?

Powershifter, how many miles do you have on yours so far?

blackshark

Track only. Changed the oil every weekend and diff lube after 4 weekends. Other than temperature issues (Oil-304, tranny and diff) the car has been very reliable. Have Coolers lined up for next year which should cure the temp issues. I go through about 2 quarts of oil per race weekend, but that's expected. Lower front A-arm bushings take a pounding, but I've got a T1 kit which I'm buying from a friend of Farmer's that should help with that. Basically, bought the car, added a seat and rollcage. Bought a couple of sets of wheels and some Hoosiers from John at CCW. Some Hawks from Paul at VetteBrakes, threw a set-up on the car with the help of Gary at Hardbar and went racing. Got no complaints :yesnod:

Power Shifter

I have @16,500mi so far. I am very pleased so far, there is very little room for significant improvement in such a well balenced all around package. Ric

newme

Cool!

Done anything to the brakes? What fluid are you using? Stock pads & lines? Any fade issues after a few laps?

newme

Thanks Ric, encouraging news!

And by track I assume you mean drag strip, unlike BlackShark, correct?

Power Shifter

Correct.

blackshark

We ran Hawk brake pads all year. Started with HT - 9's went to HT - 10 and finished with HT - 12's, which were, by far the best of the lot. All compounds were very consistant for SCCA sprint type races (15- 20 laps, 30 - 45 minutes). The 12's were by far were the best stoppers of the lot (pretty pricey too), but as for the others, they weren't bad either. I would, and have, recommended them. Stainless brake lines of course and, of all things, Ford Heavy Duty DOT 3 Brake Fluid. Very good at a very reasonable price. I did scare my crew chief and team engineer (Gary from Hardbar) several times going deep into braking at the end of the front straight at Limerock. I've learned that if Gary says "Oh my God!" when you go into a braking zone, you're pushing it pretty hard. Brakes on these things are fantastic!

LT1driver

I like the old adage: break em in fast, run fast, break em in slow, run slow. I agree that most breakin for drivetrain other than engine since it is broke in at factory. :cheers:

yelloz06

I don't think Dave and the boys pulled 500 clicks out of their butt, there must have been a reason :) 500 and let 'er eat:chevy
:cheers: :chevy

davidmax

I', a believer of moderate break in.For the 1st 5,00 miles EZ off the line but once up to operating temp several runs to 5,000rpm and once or twice daily a 6,000rpm EZ launch no power shift through the 1st 3 gears and always vary your RPM most important on Hi-way go from 3,4,5and 6th every 30 seconds to 2 minutes.

Dump the oil at 500 miles and head to the race Track.ENJOY CONGRATS David S.

z06dailydriver

The difference between aircraft engines and and automobile engines is 1) a/c engines live at high rpm for 80-85 % of their life and are designed for that RPM. The a/c engine also operates at low temp at altitude and is designed with loose tolerances compared to automotive engines. I'm up to 2100 miles on my 02 Z06 and have not been back to the dealer yet. No clutch rattle, no oil leaks, no oil consumption. I do have a rattle in the mufflers, most likely needs adjustment. I practiced this wives tail for 20 years and all my cars engines lasted over 110K with the longest at 230K without mechanical problems or oil usage.

newme

Thanks for the great replies!

Moot point as of today, as I just passed the 500 mile mark a couple of hours ago.

Proud to say I did "comply" with the recommendations (mostly, and within reason).

Now I have an unfettered Z in the driveway... I suppose my next topic will be related to law enforcement and driver privileges preservation.

I think the rule of thumb at the moment is:
1) Pull over
2) Get out of the car
3) Put your hands on the roof
4) Wait for the officer to catch up and arrive :D :D

Chuck Harmon

I just hit the 500 mile mark tonight too. I had kept it pretty easy with no full throttle pulls and slowly built up from about 3000 max to 4000 rpm - until tonight! Full throttle, 2nd and 3rd gear on the on ramp. What a marvelous experience! My L88 may pull harder, but certainly not as smooth. What a truly fabulous car. Push it hard and then settle back at a gentile cruise of 75 mph sipping fuel at 25 miles per gallon!

Chuck