Engine

Most early Stohr DSR’s still have the 99-03 style Yamaha R1.  Cars upgraded with the WF-1 engine bay most likely have a Suzuki GSX-R from 2006 or later on.   All F1000’s have the “New style” engine bay with Suzuki engine mounts. If in doubt, contact your engine builder and follow his recommendations to the letter.  Here are some basic guidelines if you are using stock engines, or have no engine builder:

Priming

If your engine has sat for some time, you should prime the system. After filling the engine oil, back off the oil filter approximately 1/8”, and place a pan underneath it.  Pull the spark plugs, and crank the engine until you have approx. ½ quart in your pan.  Tighten the filter, and crank until you see 15-20 psi on your oil pressure gauge.  Replace the plugs and start the car, looking for any leaks or pressure drops.

Engine oil level

The process for setting your engine oil level depends somewhat on your engine.  If in doubt, talk to your engine builder.

Wet sump

For all Suzuki wet-sump engines, set the oil level with the ENGINE RUNNING, WARM (at least 120* oil temp), at a 3000 RPM idle, and with the chassis on level ground.  Kawasaki and Honda engines should be similar.

For the 2007-2008+ Suzuki specifically, Rilltech Racing (www.rilltechracing.com/support ) suggests setting the oil level to the top of the sight glass while warm, and 3000 RPM idle, THEN adding another ½ quart on top of that. 

Properly maintained at this level, you should not have any issues with engine oiling, even at 3g+ of cornering the Stohr is capable of. 

TIP: Monitor your oil pressure logs closely on the data.  If you see any dips that do not correspond with a drop in RPM, such as in long corners, add another ¼ quart.

NOTE: You can definitely over-fill the engine.  Even ¾ to 1 quart too much will substantially sap your horsepower.  If your engine feels extremely sluggish, especially in high RPM or out of left-hand corners, you may have overfilled it.

Dry sump

Requirements vary based on the specific system being run, so consult any documentation that came with your particular dry sump system.  Typically, oil levels must be set with the engine warm and idling, and will typically be set near the top of the baffling in the oil tank.

See the maintenance schedule for recommendations on when to change oil.  See the Fluids section for recommendations on which oils to use in your Stohr.

Starting

Starting will depend on if you have carburetors or fuel injection. In either case, make sure the engine is in neutral before you try to start it!

Idle Speed

Idle speed is typically around 1100 to 1400 RPM. Use the throttle-set screw on the throttle bodies or carburetors to set this.  You may find that temporarily raising the idle speed will help starting on carbureted engines.  Leaving it higher (1500-1800) helps with starting on cold mornings too.

Run-In

Typically, engines from an engine builder do not need running in, as this has been done on the dyno. Check with your engine builder to be sure.  Obviously, used engines don’t need running in either.

Oil Pressure

Observed oil pressure on track and under load should be at least 50-55psi. When cold, idle pressures can be beyond 80+, so avoid revving the engine until the oil has warmed and is down in the 20-30psi range.  There is an oil bypass at approximately 70psi.  If you see more than this, your oil is still too cold, and you must reduce RPM until the engine has warmed up.  At hot idle, pressures can drop to 10psi or less – do not be alarmed!

Oil Temperature

Oil temp should be kept in the 220-230* range if possible, measured at the oil cooler output.  As high as 280* will not damage the engine if it is not for extended periods, but should definitely be avoided.  Dry sump oiling systems seem to run about 20-30* cooler.

Water Temperature

Water should be kept to about 190* - this is where these engines make the best power.  Try not to exceed 220* water temp, but 230-235 is not catastrophic if the coolant stays in the engine.  You may wish to remove the water thermostat – talk to an engine builder before doing this to make sure you understand why you would/wouldn’t want to do this.