"Morning Horsepower"

[TurBoGs-T]

Now as we all know the cold weather contributes alot to the turbo. But i have noticed (since the change in weather in Maryland) that when i start up my car, for the first couple minutes of driving my car is Much,much faster and feels alot more powerful. If anyone know's what i'm talking about i really really want to know what i can do to make my car run like that all the time!!!!! I know it's weird but if anyone can relate thanks!!!!!!!!

 

[Thalomos]

My car feels slower when i just turn it on in the morning (of course i dont go into boost, but it feels slower at part throttle)

YOu shouldn't go romping on your car after you've just turned it on.. the oils cold... cold oil = bad. Plus head and block expand at different rate.

 

[95talontsi]

word me too, my car feels alot fast in the cold, after it's been turned on just before it's wholey warmed up.

 

[insane147]

i dont run a thermostat on my car and it hovers around 130 degrees in 80 degree weather. it is much better feeling like this, alot of people come to me raving about how much better it feels on the buttdyno, but i have no dyno pulls to state a fact. too bad its not good for an engine though (it MAY cavetate and flow too fast through the radiator, however i have never had a problem). i guess you want your water jackets around your pistons over 200 degrees so the rings seal better and the head as cool as possible, but our water flows going into the block first, cooling the rings instead of the head. i was pondering the idea of a reverse flow cooling system....ala LT1 vs. L98 and older small block chevys. that made huge improvements for them as it cools the head first, warding off detonation and heating the antifreeze on its way to the waterjackets where it should be of sufficent temp to allow for good seal and a cooler running engine...

 

[madmax]

There are intercooler sprayer kits that would help you attain that kind of performance in warm weather. I can't remember who here was putting them together though. If I remember I'll let you know

 

[2-0turbo]

Originally posted by insane147
i dont run a thermostat on my car and it hovers around 130 degrees in 80 degree weather. it is much better feeling like this

This is retarded. Do you know what a thermostat is for? Obviously not. There are other ways--better ways--to "go faster".

 

[insane147]

i would rather have my car run very cold on any day, period. yes i know what a thermo is for and could car less, i just know it runs much better with out it. and keep in mind when i see you say something i think is absolutly retarded, i will grill you on it. i did say it was not good for the car, moron. keep in mind i ran MID 7's in the eigth mile, unlike your 9. on a stock car with EVERY free mod (including thermo out).

 

[-=TWITCH=-]

I build the intercooler sprayers. makes your car run like its 10 deg outside even when its 100deg outside.



TWITCH
www.intercoolertechniques.netfirms.com

 

[InnerCircleVP]

I don't feel that morning horsepower at all. My car runs ruff when I first turn it on untill it warms up a bit. Maybe your just feeling the morning cool air compared to later when it warms up with the sun.

 

[95GST]

It's not good to go WOT before your car is warmed up
think cold pistons and thick cold oil, not very nice to your cylinder walls and oil pump at 7k.

 

[eXploitedGST]

yea my car does that two in the fall where it has extra power in morning. now that its always like 10 degrees out it drives like that everyware! even with the engine warmed.

 

[nine5raptor]

it's most likely that cold feeling is from the intake mani being cold. even if you warm the car up to operating temps with no boost the im still stays fairly cool. Once you start boosting though, you quickly heat it with all of the hot charged air flowing through it.

 

[RetardedAWD]

Originally posted by InnerCircleVP
I don't feel that morning horsepower at all. My car runs ruff when I first turn it on untill it warms up a bit. Maybe your just feeling the morning cool air compared to later when it warms up with the sun.

Morning Horsepower is the same for your car as morning wood is to you.

 

[Jaybone]

i like my morning HP gains, my car came with no thermostat in it.. just the copper ring... ... i did put one in thou...

 

[LaserRST]

Morning HP comse from the slack in the cylinders cuz the rings and piston has not expanded yet. This makes an engine more loose and revs harder with less drag. You will notice this alot on fresh rebuilds. If you lose power in the mornings means you lose compression for the same reason creating alot of blow by until the car heats up. No thermo is not a good idea as insane has stated. It will wear you engine alot sooner requiring for more frequent rebuilds. Sooner or later his car will loose its umph and will have trouble keepin up with NA's.

 

[CH152]

Running one with out a thermo if this is what you are talking baout is jsut like when agood one fails they have a safety feasture on them that leves them stuck open so the antifreeze can still circulate in the motor to cool it off. Though it will take a bit longer to heat up though. one got stuck open and we couldnt figure out why it wasn't heating quick. my friend popped the thermo off on his (1986 6000le ...) and it was stuck open of course we took it off later that day though. and replaced it. so kinda it actually like running without one if it is stuck open.

 

[REDBLUR]

Originally posted by LaserRST
Morning HP comse from the slack in the cylinders cuz the rings and piston has not expanded yet. This makes an engine more loose and revs harder with less drag. You will notice this alot on fresh rebuilds. If you lose power in the mornings means you lose compression for the same reason creating alot of blow by until the car heats up.

That is unture. Your so called morning horsepower is due to the fact that colder air means more dense air, which in turn means more molecules of oxygen per a given volume of air. You will see gains up to a certain temperature, I used to know it but have now forgotten it (I think it is around -10 degrees celsius, dont quote me on this).

Secondly, on a new motor or rebuilt motor, the most power is made not when it is first run, but 500-1000 miles after the rebuild when the motor is broken in. Although various factors can alter this, ie cromoly rings can signifigantly reduce the break in period.

It is actually quite the opposite of what you said, fresh rebuilt motors ofter run hotter than normal due to all the heat (hence friction) when the motor is broken in, rings seating, ect..

With the temperature of the combustion chamber, your pistons and rings heat up extremely fast. Ever notice how long it takes for piston slap to go away in the morning?? Probably not cause it happens so fast.

 

[nine5raptor]

umm substances are denser the colder they get until they go into solid phase, then you are stuck with the crystalline structure it makes.
They 'morning horsepower' you can feel anytime you start the car (doesn't have to be morning) and goes away after a few good pulls thus why I reasoned it to be:
"it's most likely that cold feeling is from the intake mani being cold. even if you warm the car up to operating temps with no boost the im still stays fairly cool. Once you start boosting though, you quickly heat it with all of the hot charged air flowing through it.(post 12)".
the only exception to the colder/denser rule is water do to the large gaps the hydrogen bonds make when it freezes.
the cooler intake temps are also better for knock which keeps timing up. When you start knocking, especially in a 95, the ecu pulls timing horribly.

 

[TurBoGs-T]

Did I just Coin a new DsmTuners Word "Morning Horsepower"??? !!!!!!!!!!!!

 

[REDBLUR]

Keep in mind your intercooler is subjected more so to the ambient temperature. Thus when it's colder outside it is much less likely to become heat soaked, or is heat soaked at a slower rate.

 

[2-0turbo]

Originally posted by insane147
i would rather have my car run very cold on any day, period. yes i know what a thermo is for and could car less, i just know it runs much better with out it. and keep in mind when i see you say something i think is absolutly retarded, i will grill you on it. i did say it was not good for the car, moron. keep in mind i ran MID 7's in the eigth mile, unlike your 9. on a stock car with EVERY free mod (including thermo out).

Good for you! Mid-sevens on stock car is great! So, to pick up 1.5 seconds in the 1/8th, all I have to do is pull my thermo?

Engines are designed with very tight tolerances. You know this, I'm sure. Aluminum expands at 3X the rate of steel, some highly alloyed aluminums excluded. On an ~3.4" diameter piston with about 0.0017 inches of clearance, if you don't warm it up to its design temperature, what is that going to do to your tolerances? Hum, they might be too large or go away entirely--depending on how things go. Most likely, since combustion temp is not going to change too much and your block is cooler, the clearances are going to "go away" and your are going to get excessive piston/piston ring wear.

You already know this though. I am sure when you had your engine built, you had your engine builder take this into account and adjust your clearances accordingly--oh wait, I just noticed you have a JDM engine in your car. That means you have already gone through one. You probably get pretty lousy gas mileage too, since your car never gets out of "warm-up" mode. I sold my last car with 195K miles on it--how many did your last engine have?

For the record, "Morning HP" comes from, as several have correctly stated, the higher density of air on a cool morning. A turbocharger is a basic airfoil (a centrifugal compressor) that moves air due to pressure differential. Anyone who has flown in a small plane (C152 or equivalent) knows they will climb like a bat-out-of-hell on a cold morning, because the wing is creating so much more lift in the dense air. Your turbocharger is more efficient on a cool morning, much like the wing of a C152. That is the reason for the increased HP.

And, that is why a C152 feels like a turd on a hot 95 degree day with density altitude hovering around 4000 feet, 950 feet MSL--same as our cars.

There are other issues like the heat soak of the manifold and intake, but removing the thermostat to keep those items cool is stupid. I'll say it again--stupid. For engine longevity, you would be better served with water injection or a more efficient intercooler to keep those things cool. You engine will not lead a long, happy life running it the way you are.

 

[out there]

i think the main reason your car can feel more perky in the morning (when it's cold) is due to several circumstances. 1) lower operating temp- the coolant is colder, the air is colder... more dense air and more hp. i would think a thermostat this is at least 10deg below stock would help 2) cold air outside- whether the car has a cai or not, this is going to give you more power, turbo or na. best example of this is the 86 sentra i used to own. very little power on a hot day, but in the morning in the winter... i could do 0-60 without getting bored waiting

 

[LaserRST]

Well the only arguement I have about cold air and cold engine is that if its just the cold air than the HP would be the same if not better when it heated up. A cold air intake with a running temp engine should produce better HP than a cold engine with a cold intake. One reason is proper feul atomization, and another reason is stable compression due to pistons expanded in the cylinders. And yes it makes a difference, that is why there is a minimum and maximum clearance for pistons and cylinder walls. I have rebuilt 6 different engines and can tell a difference when it is broken in by the way it runs when it is warming up. Drag takes away HP, 1lb off the crank = 6hp at the flywheel. Not to say that cold air doesnt produce Hp, it does thats what intercoolers are for, but morning HP is attributed to the fact that HP changes to engine temp. The originaly poster said for the first coupla minuites... ambient air temp doesnt change. Another reason could also be the 02 sensor needing to warm up causing a slightly rich AF ratio.

 

[TurBoGs-T]

Thanks Everyone!!!!

 

[NDgsx]

If your car runs significantly stornger when it's cold there are 4 reasons.
1. The ecu runs the car richer when coolant temps are under 176 degrees. Coolant temp doesn't always coincide with block temps. Drive the car for an hour to get the block hot. Let the car cool off for a while, until the coolant temp has dropped to around 100 degrees. Now drive the car. Still fast like it was when you started it up in the morning? Well your block is still warm and close to normal operating conditions. Your car seems faster because it is running lean normally.
2. The ic is cold.
3. The intake manifold is cold.
4. Underhood temps are ambient, it can be 180-200 degrees normally.

Running your car without a thermostat is not recomended. You want coolant temps to stay as close to constant as possible. If you really feel the need to remove the thermostat then at least put a restrictor in. Pick up the october 01 issue of Grassroots Motorsports if you want to know more about this.