Has anyone installed a supercharger and used their G35 coupe for winter driving? I would like to know how your coupe performs off the line and overall handling and what type of supercharger you have installed. Please let me know.

Tat

 

Tire friction coefficient decreases with temperature from the optimum 170-190F. Summer tires will decline dangerously as the temperature drops below 50F...........what might have been 0.9G at 90F can drop below 0.35G [at 35-40F] a number worse than warm rain 0.45-0.55G.

 

i have a stillen stage 2 and it runs a lot stronger in the cold then in the heat.i also use winter tires because of the no traction issue,but overall no problems in the winter.

 

Base on temperature density increases: 1% per 11F decline in air inlet temperature so in theory the power would increase 1% per 11F.
109F declining to 32F should be 7% more density~= 7% more torque assuming the MAF/ecu increases fuel by 7%.

Actually may happen without the fuel increase as super/turbo charged always use too RICH a mixture to cool...................you might see 10-12% more power from cooler temps.

 

Remember much cooler temps can also increase psi the blower can make . And if you are not tuned for the extra boost [ timing retard ] it can lead to motor failure .

 

The air being 5% denser [assumming a 60F tune point] at +5F should not affect the measured PSI materially..............a turbo works on the exhaust gas temperature differential and a supercharger the driven rpm.

Engineers calculate the density to correct the psi..............a hot less dense high psi charge is usual less efffective than a cooler denser LOWER PSI charge.

 

It's my understanding that cooler air does 2 things for you:

1- You are trying to increase the amount of Oxygen in your cylinders (O2 + fuel = explosion. More O2 + more fuel = bigger explosion = more power). Denser air contains a higher concentration of Oxygen by volume.

2- Cooler engines run better. I'm not sure about the physics behind this one, but ask any guy who's pushing his car to the starting blocks before a quarter mile run and they'll tell you they get an extra tenth of a second.

 

Yes colder is better for the air intake side of the engine but bottom end of an engine should be hot in order to work at optimum. Yes there are more factors than that but that is the basic idea.

I just installed a ATI Procharger and I love it car is faster than all hell. Still in the final tuning stages with the new injectors and exhuast. The cold air is always good but on boosted cars the boost level drops when the air is colder.

On turbo cars with nitrous intercooler chillers you have to up the boost level when you use it in order to correct the densor air flow.

 

I've got a stock Vortech maxing at 8 psi. Driving through the winter in NE with good snow tires on 17" alloy rims and a 70# sand tube in the trunk (absolutely necessary for slippery weather). The setup is fantastic and I love the way the car handles and accelerates. VDC saved my a$$ a couple of times, as well. Temps below about 35 degrees really boost the SC output but my A/F ratios have stayed identical to my summer readings. In short, don't worry about FI in the winter with the right setup.

 

Is that New England or Nebraska ???? Both are Ne. or NE

 

What controls the output boost pressure of the turbo is the wastegate. Boost entering the intake stream is fed through a vacuum line leading to the wastegate. The wastegate spring is compressed (spring stiffness sets the boost level) and actuates the wastegate arm, opening the wastegate. Once the gate is open, the amount of exhaust gasses that are bled off through the gate maintains the proper exhaust pressure in the turbine housing to hold steady boost. A stiffer spring is going to delay the opening of the gate longer (need more built up intake pressure to compress the spring) and this is what will cause more boost to be maintained.

Basically what I am saying is that this is why colder temperatures will not affect the amount of boost a turbo will generate. Boost SPIKE is another story though.

On a side note: What I just explained above is pretty much the reason why a turbo'd car doesn't suffer as badly in a high altitude situation as much as a NA vehicle would.

 

New England. Born in Boston and living in Amherst.