Cal Club Autocross Forums

... for our Miata track car ... with stock engine internals. 100K on the engine

Any opinions on using thinner racing oils for a track car ... that is still being driven to the track. Maybe something like Mobil 1 10/40, or ... ?

The idea being that I'm wondering about a thinner oil to free up some HP.

I remember someone trying a Silkolene 0/5 racing oil that was only good for one track weekend. It poured like water. Not looking for something that extreme

The rule of thumb used when building my IT cars was to first have a reliable oil pressure gauge, then be able to maintain at least 10psi per 1000rpm. But then, they were Datsuns.

As bearings clearance with wear you usually have to go UP in viscosity, not down. I call it a bad idea to run lighter oil than you have for the first 100K miles. Remember too, that on the track (with you both driving), you'll see higher engine temps than you did autocrossing.

That's what I was wondering about ... thanks

As GRM says, they don't usually believe in oil additives, but this one gets a positive review from them:

http://grassrootsmotorsports.com/articl ... er-bottle/" onclick="window.open(this.href);return false;

When I lived in Germany, the Mercedes engineer builder of my friend's National Championship winning F-Vee engines was a big fan of Molycoat additive, and not just for re-build initial start up protection. I guess there has been some evidence of small oil channel blockage with too much Moly.

Remember that engine oil technology has come a long way in 20 years. And ignore any statement about engine oil that you saw in an oil company or oil additive ad.

IMHO, a 100K engine on a race track is an engine that's going to blow up any second. If you get only one track day past 100K miles you're money in the bank. I would not spend any time or brain cells trying to get an extra .5 hp out of the engine by using a special oil or some secret sauce. Run exactly what's listed by Mazda in the owner's manual.

Lots of high mileage Miata's on the track ... they're amazingly reliable. Not looking forward to it ... but a forced rebuild will eventually be welcomed. Peace of Mind provided by AAA Premium Membership and Free 200/100 mile towing!

Lots of high mileage Miata's on the track ...

Maybe, but no 100K engine that I know of is winning races with SCCA Club Racing. Not in SM, ITA, or STU. People may be able to do a track day with a 100K engine but they are not racing, at least competitively.

John Coffey wrote:

Lots of high mileage Miata's on the track ...

Maybe, but no 100K engine that I know of is winning races with SCCA Club Racing. Not in SM, ITA, or STU. People may be able to do a track day with a 100K engine but they are not racing, at least competitively.

I guess we'll find out next month, haha.

I never said we'd be competitive! We weren't here, we won't be there, but we will be having a LOT of Fun! :gpower:

John Coffey wrote:

Lots of high mileage Miata's on the track ...

Maybe, but no 100K engine that I know of is winning races with SCCA Club Racing. Not in SM, ITA, or STU. People may be able to do a track day with a 100K engine but they are not racing, at least competitively.

Well my miata has 127K miles on stock engine and is making a healthy 306 whp on 17 psi.
No I haven't won a SCCA championship but I'm sure that the car could win if it was driven by a more experienced driver...

I doubt if Mako's engine is making way less power due to the mileage...

A couple of years ago we went through the paddock and measured every Miata's compression that we could find ... simple compression test, no leak down, no oil injected into the cylinders. Everyone seemed low, including Tim Albin's fairly newly rebuilt National Championship winning CS engine. So we concluded that there was a problem with the test and we probably all had fairly normal compression. At that time we had over 90K on the engine

You could try Mobil 1 0w-40