Cold Water Performance

[Florida Paul]

Water in Tampa area down to 60 degrees. Was out on GTI 130 today and I host about 150 more RPM's (7350) and 56 MPH. Does ski performe better in colder water and why?

 

[mkov608]

Paul, I think any change in your performance would be based on a combination of factors, not only the water temp, but also the air temperature and humidity levels. Colder & drier the air is more dense and will yeild better performance. For example, you will expereince greater engine output on the same ski at sea level compared with a mountain lake in Utah, but you probalby already knew that.

Colder water temps mean lower exhaust gas temperature (EGT) and engine cooling system temperature which probably means a increased injector pulse witdh (more gas ... more power). So, the ECU lets the fuel flow until the some predeterminded limit is hit, RPM, EGT, cooling system temp etc.... On a hot summer day, the EGT or cooling system temperatrue may be the controlling factor, but on cold winter day, the controlling factor may be RPM. It's all based on the really smart folks who built and programmed the ECU. Perhaps someone out there has the specfic details for fuel mapping.

 

[red2blue]

Water in Tampa area down to 60 degrees. Was out on GTI 130 today and I host about 150 more RPM's (7350) and 56 MPH. Does ski performe better in colder water and why?

Some peeps...myself included, run a rear air intake. With the risk of water ingestion very real...why?

Colder air...denser charge...more hp.

Try out a less restrictive intake and you'll see better performance over oem...in any given conditions.(keep in mind, your ski ain't gonna set records) Throw on a denser charge...even better. Something to look up...the RAD...relative air density. In a wide range of conditions your ski will perform differently. Sometimes..like today...ran like a scalded dog. Other times like...oh....100% humidity in 95* August heat in south Florida....it'll run like dog....period.

Welcome to the beginning lecture of Modding 101.

Just remembered...there's a calculator on-line somewhere...includes Atmospheric pressure...temp...humidity...altitude...all factors in internal combustion engine performance