Why break in turbo?

Post by **240SXer** » Thu Jul 01, 2004 5:28 am

I just got my car back with the GT25R, i'm supposed to break it in for about 500 miles, (keep it below 4k), i'm just curious why. I know you're supposed to, but I don't really see why. Can somone offer some insight? I've only driven it about 35 miles

Post by **Hijacker** » Thu Jul 01, 2004 5:28 am

because the bearings haven't been seated properly yet. It's kind of like how you have to take it easy after an engine rebuild.

Post by **240SXer** » Thu Jul 01, 2004 5:28 am

I've also heard that running an engine hard during break in is good too.

Post by **Hijacker** » Thu Jul 01, 2004 5:28 am

the only person i've seen say that posted in the engine break in thread here on NICO. I doubt a shop will tell you to run an engine hard during break in.

As far as turbos go, I've heard conflicting reports on what to do. I prefer to be cautious. 500 miles is a little under two weeks of driving for me. I just finished rebuilding my turbo, and I had a mechanic telling me to take it easy down the block and back on the test run, and then I could crank the boost up after that. He said the bearings got themselves sat as soon as the turbo spooled up over 30,000 RPMs or so. I prefer to be a bit cautious and run it lightly for a few weeks. It's better safe than sorry.

Post by **msaskin** » Thu Jul 01, 2004 5:28 am

Every engine I've ever built I've broken in by running hard.

The transition between vacuum/boost (or vaccum/0psi on a N/A engine) is necessary to get the rings to seat properly. With normal rings you can get by with an easy break-in, but with close tolerance rings like Total Seal's, if you don't break the engine in hard, they'll never form a proper seal.

As for turbos...I've never heard of extended breakins. the usual process is to prime the oil system so that the turbo isn't starting "dry", and just drive it like you normally would from there.

~matt

Post by **240SXer** » Thu Jul 01, 2004 5:28 am

It's funny.. I've read that you do hate to break it in. I've read that you don't.... Garageworks who put it in told me to. So I will, because i'm sure it won't hurt. But I just don't get why. Why so many conflicting opinions....

Post by **stumpz** » Thu Jul 01, 2004 5:28 am

do half and half :-p

Website · Post by **SoCalS14** » Thu Jul 01, 2004 5:28 am

yea, its funny, because back when I use to run V8's engine builders seem to be split on the same issue...A Mopar fella said..."I run it hard..if its built right, everything will be fine...if its not...well back to the bench"...But the guy who built my Chevy said take it easy for 500 miles...who knows!

Post by **Hijacker** » Thu Jul 01, 2004 5:28 am

240SXer wrote:It's funny.. I've read that you do hate to break it in. I've read that you don't.... Garageworks who put it in told me to. So I will, because i'm sure it won't hurt. But I just don't get why. Why so many conflicting opinions....

I prefer to break it in, my mechanic friend told me not to. You could say I'm doing a half and half. I upped the boost after I put on a few hundred miles and everything seems ok. I would just rather be safer than sorry. It's not a huge deal to try and break it in.

EDIT: I forgot to mention that I am not running my final high boost setting I usually run (14 psi), I have it sitting around 10-11.

The reason why you'll find so many comflicting opinions is because everyone has an opinion. One person can tell you to do it this way, another person can tell you something completely contradictory. Or you end up with people like me who relate stories of conflicting opinions, but end up making it sound like they all came from me.

msaskin wrote:As for turbos...I've never heard of extended breakins. the usual process is to prime the oil system so that the turbo isn't starting "dry", and just drive it like you normally would from there.

I would just prefer to keep boost to a minimum for the first few hundred miles. When we reinstalled my turbo after the rebuild, I started the engine normally and let it idle for a few minutes while we checked all the inlet/outlet hoses for leaks. After everything checked out, I drove it around the block gingerally, and then drove it home after one last check. Since then I've driven it normally, I've raced it to redline, but I've done all that on low boost. RPMs of the engine are handled seperately by design than the RPMs of the turbo. A turbo wheel on average spins at 100,000 RPMs and the bearings spin at about one third that speed. I intentionally kept my boost low by lowering my HKS actuator as low as I could get it as to allow the bearings time to seat. I also went one more step and while I was prepping the turbo for rebuild, I soaked the new bearings and thrust washer in oil overnight while the CHRA, wheels/shaft and dogdish got a cold carb bath. By soaking the bearings, they will absorb more oil due to their porous nature and seat quicker.

Breaking in engines is different from breaking in a turbo, and I would rather not score a bearing or the shaft because I wanted to get boost happy before I've even gotten down the street with my brand new, expensive turbo. There's no disrespect in being cautious with a low tollerance unit like a turbo.

Post by **240SXer** » Thu Jul 01, 2004 5:28 am

The spring on the tial wastegate is only set to .4 bar (5.8psi), I'm running a .86 AR GT25R on the stock fuel system

My boost controler isnt even hooked up. So the most I can boost it up to is 5.8psi.. I just filled up the gas tank. So i'll finish this tank out driving around like a wuss, then i'll get on it. Should be about 300-350 miles.

Post by **Hijacker** » Thu Jul 01, 2004 5:28 am

sounds like a plan

Why break in turbo?

Why break in turbo?

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