42# injectors.. 440cc

GsiTurbo · Post by **GsiTurbo** » Tue Jul 04, 2006 11:45 pm

At this point, without proper settings, PLEASE do not boost your car. Maybe even run on a rich side to be safe. How far away is the nearest dyno facility?

Tom

Post by **PrecisionBoost** » Wed Jul 05, 2006 1:26 am

Dynojet... who has a plant in Montana.... shows two guys in Montana with an automotive dyno...

G & C Sales & Service
538 Lincoln Lane
PO Box 35500-218 59107
Billings 59105
Tel. 406-252-1240

Gerrard Classic Auto Collection
2200 North Fork Road
Big Sky, 59716
Tel. 406-995-9110

When I saw "Big Sky" I couldn't remember seeing a city with that name on my various trips.... so I looked it up and it's a tiny place with a population of 577 people!!

Why on earth would there be a company way out in the middle of nowhere have a dynojet??

Given the name of his company perhaps this guy has a few million dollars and has a dynojet so he can fool around with tuning the cars in his collection.

It's certainly closer to you than Billings but I guess you'd have to phone the guy to see how much he charges.... perhaps he might know a thing or two about tuning.... you never know.

MMamdouh · Post by **MMamdouh** » Wed Jul 05, 2006 11:37 am

didn't someone say that if the EGT goes above 950 your pistons will melt??

MMamdouh

klonek78 · Post by **klonek78** » Wed Jul 05, 2006 2:03 pm

MMamdouh wrote:didn't someone say that if the EGT goes above 950 your pistons will melt??

MMamdouh

you have right. many stock pistons can handle EGT up to 950degC - the best is max.900C, but over 1000degC pistons could melt in short time

DomWoo · Post by **DomWoo** » Wed Jul 05, 2006 5:37 pm

i think you guys were told wrong.. tom and chris both say that 900 to 1100'f rang is ok when boosting.. but 1200'f would be bad

i would have to wonder what the stock temp wuold be running at.. i bet its above 900'f seeing how when im not boosting its just like stock

GsiTurbo · Post by **GsiTurbo** » Wed Jul 05, 2006 6:09 pm

klonek78 is posting temp in Centigrade, while we told you in F... 900C is about 1652F, which is waaay to hot..or otherwise good to make a nice piston soup

Tom

DomWoo · Post by **DomWoo** » Wed Jul 05, 2006 7:16 pm

ahh i see now.. yes thats some nice hot temps.. i forget that everwhere else beside the USA uses Centigrade

klonek78 · Post by **klonek78** » Wed Jul 05, 2006 9:28 pm

GsiTurbo wrote:klonek78 is posting temp in Centigrade, while we told you in F... 900C is about 1652F, which is waaay to hot..or otherwise good to make a nice piston soup

Tom

you can be sure that almost each stock pison easly handle 900degC but over 950degC is too hot

i have almost 940degC at 210km/h and nothing wrong happens with my stock pistons

Post by **PrecisionBoost** » Wed Jul 05, 2006 11:14 pm

The magic number for aluminum piston damage is a constant 1250 degrees farenheit..... I also seem to remember Garret turbos being rated to 1260 deg F

The reason is because this is getting close to the melting point of the aluminum alloys they use in the pistons and turbos. ( alloys have a slightly higher melting point than pure aluminum)

For the record.... Pure aluminum melts at 1220 deg F ( 660 degrees Celcius )

Now.... just because your exhaust temp is 1250 deg F it doesn't mean immediate danger as the pistons are cooled by the oil, cylinder walls and most importantly the cylinder head.

I don't want to get too technical.... but this is where cylinder chamber design and quench pads come into play in the allowable EGT.

Basicly.... even if your running 1250 deg F temperatures not all of that heat energy will be transfered to the aluminum due to cooling from other parts of the engine.

900 deg F to 1100 deg F is a nice safe area.... at that temperature you shouldn't have to worry about detonation and or piston/turbo damage.

Above that... well.... your taking chances.... even if you don't run into melting pistons you will have to worry about pre ignition detonation.

900 deg C (1652 deg F) is way too hot.... even the diesel guys try to keep it under 1300 deg F.

1652 deg F probably won't kill the pistons right away (due to heat energy being absorbed by other parts of the engine) but it would certainly lead to deformation of the turbo since it's only cooling source is from the shaft running through the oil (and possibly coolant depending on turbo model)

I'm sure I don't have to tell you what happens when the turbo components start to deform at several hundred thousand RPM...... kaboom.... kiss your turbo goodbye

So again..... 1100 deg F or less is nice and safe.... which means you would be running a little rich on the A/F ratio.... you'd probably still be ok slightly above 1200 deg F but that is risking detonation during lean spots created during compressor pressure spikes ( which occur more than you might think....even with a good boost controller )

Nubira2.2 · Post by **Nubira2.2** » Wed Jul 05, 2006 11:56 pm

in other words 900 deg F to 1100 deg F is where we want to be with stock internals ?

and that temp is for each cylinder

Post by **PrecisionBoost** » Thu Jul 06, 2006 1:35 am

That maximum temperature of 1250 deg F is based upon a pyrometer installed in the exhaust manifold right after the collector.

This is for any type of internals... be it forged JE pistons or stock cast pistons..... and as I said before..... it's also for the turbo.

Water injection helps decrease exhaust gas temperatures as the water vapour sucks up heat during the combustion process.... but it will also decrease horsepower.

Having said that a turbo car is capable of more boost when using water injection so you can actually make more more power than the water robbed from the system.

Another good thing is alchohol injection..... alchohol cools things down and at the same time it's very flamable so it doesn't decrease power levels.

Alchohol makes less power than gasoline but it burns at a much lower temperature so it's the ideal choice for high end drag racers.

I can't remember the formula.... I think you need to inject 60% more alchohol to get the same power as gasoline..... so you need to increase the size of your injectors and fuel system (fuel pump and lines ) if your going to run alchohol in your drag racer.