Locost built from -96 Miata, Garrett Gt 2560 turbo, ebay intercooler, stock -96 motor with 100,000 + miles, exhintake cam, Toyota cops, 750 cc injectors at less than 50% duty cycle, log manifold made from weldels, external Tial 38 mm wastegate, MS3X running sequential injection and ignition on OEM Mazda 36-1 trigger wheel and oem VR sensor, 3" exhaust.



The car ran 1.32.585 around Road Atlanta on next day SCCA Track Trial event.

 

Very good stuff. Simple setup, yet effective.

 

I saw the pics on DIYAutoTunes facebook page last night. It all looks good.

Ohh snap I see Ben in the background.

 

Peak boost (due to your boost creep) is only ~175 kPa. So it's more like 8 psi of boost with a creep to 10.5 psi by redline. Really good numbers at this level of boost.

 

Yes,

The wastegate is plumbed from right after the turbo. The boost in the logs is recorded from the intake manifold. The difference is possibly slight restriction in pipes, intercooler, throttle body.
Tial wastegate has 12 psi spring and the hose is connected from close to turbo outlet to pressure side of diaphram of the wastegate. Top outlet of the wastgate is left open to atmosphere. No boost controllers whatsoever in the plumbing right now.
The boost gauge connected to the same line from turbo shows close to 12, range 11-13.

175 kPa is 25.3 psi so 10.8 psi is in the manifold, if atmospheric pressure is 14.5 psi.
Has anyone taken notes in the pressure loss between turbo and manifold? I presume ~1 psi is not bad at all.

 

Any idea what the weight is on that thing? Must be one scary ride.

 

Manifold pressure is the standard used to gauge boost generally, not pressure at the turbo outlet. However if you'd like to accurately compare turbo pressure to manifold pressure (to measure your losses), you can easily do so with the MS3X. Just plumb an external MAP sensor to the nipple on the turbo outlet and set it up on one of the spare analog inputs. You can then track manifold pressure vs turbo pressure in real time.

I would expect to see 2-3 psi of loss at 12 psi of turbo pressure.