Im having a problem on my 87TII...
In the night my car pull like a beast, but the "ambiant" temp is much lower, like 45F...
But in the day, my dyno butt really feel that it dont pull as much as it did in the night...

And it do it everyday, and everynight.
My car have a BIG reaction to temperature change.
If its cold, it pull MUCH harder.

I dont know what can cause my problem, i have one sensor not connected(the one on the coolant pipe near the motor. I dont know if it can be related..
And im running with no emission, streight 3" exaust, streight intake with HKS filter and ported wastegate.


Temp here in Quebec;
DAY: 75F
NIGHT: 48

 

Ummm....the colder the air, the more dense the molecules, and the hotter, the farther away. Basically at night your placing more dense air in the combustion process. And on an engine that runs normally rich, that means more power. Not to mention the overlooked heat soak during the day.

 

Sounds like its your Coolant tempurature sensor located on the Waterpump housing??

 

You should read up on "boost creep" and "porting the waste gate".

In cold air, with your mods, the turbo will give out of control boost.

In those conditions you're on the edge of engine detonation.

 

Guess why i dont have talked about that....
Cause its all OK.
I have s-afc, walbro 255lph fuel pump, and ported wastegate
In 4 speed at 6500rpm i have like 10psi, but i give a good fuel compensation...
Tnx anyway!



But im pretty sure its not a "heatsoak" problem, cause i really feel the differance, in the night it really feel like 50 added whp...

 

Yeah, but what he do in the "ECU" ? Is it really important to get that one connected correctly? Cause im using the bung for my aftermarket coolant temperature...

 

As you see intake air temp can mak a big difference.
Maybe think about a CAI.

 

Wow that is a clean job. hugo let's do it.

 

I asked the same question to a buddy of mine and he said a new computer would take care of that. But yeah colder air does make more power.I think it seems faster at night time.

 

nobody know what this sensor "exactly" do ?

 

yeah man I have the same issues. I assume you are running the stock TMIC. and that is going to be one of your problems. You gotta figure your engine which creates a ton of heat is right below your intercooler and as we all know heat rises. And right above your intercooler is your hood which is getting blasted with sun/heat. So basically your intercooler is soaked with heat so it really isnt doing its best job at supplying cool air.