Technics

I plan on adding a turbo to my SC300 (when I find the right one) and since it will be my daily driver that means it will have to go through the harsh NY winters. This winter was particulary bad with countless inches of snow and way cold temps. Will a turbo be able to operate properly in these kind of conditions and will there be any reliability issues? My accord (with no mods) barely made it this winter and this car has never given me a hint of trouble. I can't afford two cars again (in the process of selling my Camaro).

sarita911

The turbo should run BETTER in the winter: the turbo will run cooler and the cold air is denser. Historically, turbos have trouble in the summer.

One thing you have to watchout for is water getting into cold air intakes.

DIrEctQL

Running turbo in winter is a problem. First problem is traction especally when you have twin sequential. Second turbo kicks in and you loose traction.

Now, when you say it's running better in winter.... well... yes, too well infact. You can melt the pistons! Full boost at 30 deg. F weather is pretty dangerious. The cylinders 5 and 6 can get really hot... melt the pistons.

Chris

Technics

I would be running a single turbo only. I doubt whether I could get up to full boost in the winter without crashing into something as the roads are too slippery. Even in my Accord the tires would spin in third gear, so I can't imagine a 300 or 400hp monster.

So basically as long as no water enters the engine the turbo should be alright in -20 deg weather? It was that cold this winter.

DIrEctQL

I don't think so... as mentioned, colder air yields more performance. The problem with traction would still exist, especally a high powered car.

I had a friend with a Supra TT who ran full boost on the highway in 30 deg. F weather. Pistons in cylinders 5 and 6 were melted.

Chris

Bean

iTrader: (1)

its because he ran too lean

with the super cool air; its denser; and therefore there's even more air in the car

if you plan on running it in the winter; i'd get an AFC or some fuel controller and make it run rich if you plan on gunning it occaissionally

SC300T

The afc will alow you to manually add/remove fuel, but could be harmful when trying to tune for a wide range of temps. The SAFC is just modifying the injector duty from the stock ECUs tables, which already include air density compensation. For an average system (like 440cc injectors and LS400 MAF with FPR) the stock ECU's fuel table will add appropriate fuel at cold temps to compensate (These systems work just fine as long as the fuel pressure doesn't fall).

The problem arises when a guy goes to the dyno at 80 degrees with small injectors and dials in his system with 20 psi of boost through ADDING fuel with an SAFC or other device, sees that his injector duty is at 85-90% and thinks its ok. He's thinking hes got 10% left, so all is good, right? WRONG. That same dyno run at 20 degrees shows that injector duty is maxed from twiddling with the SAFC. The SAFC is trying to add more fuel, but can't because the injectors are already wide optn. What happens is that with a stock ECU and unaltered fuel system, the tables will always supply enough fuel as long as fuel pressure is maintained. With an SAFC modifiying the injector pulsewidth, it can cause the injector pulsewidth to be pegged at 100% and still not supply enough fuel.

The jist of all this is to make sure your fuel pump can ALWAYS maintain stock pressure at 100% duty cycle, and to make sure that injector duty never gets near 100% in the coldest weather. Either that or don't boost when its cold.

IMHO, its also a wise bet to remove fuel with the SAFC if needed, but be extremely cautious when adding fuel.

Other systems like the AEM standalone ECU don't suffer these problems, as a 100% duty cycle condition would be easy to spot in the tuning process.

Bean

iTrader: (1)

true... injector failure would definitely cause this problem too

but i've also heard of Rx7s having this problem in the winter when they boost around