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View Full Version : Small CC,Big Boost & Cast Piston's+ W.I


schwitzer turbo
29-08-2007, 10:00 AM
Hey hey all.

I have been leeching this forum dry for the last couple of day's but i havent found the answer im looking for regarding my specfic questions.

Here is the Scenerio (this is my car http://www.cardomain.com/ride/2581255)

I have a Hyundai 1500 SOHC 12V and My comp is 7.5-1. and i have been boosting the car 1.2 bars for the last 100 000km.
the clock has 240 000km on it and the motor has never been opened. the car comes Equipt with Low Comp CAST Pistons and i cant find a Forged Piston to suit. Now im Boosting 1.5 bar's everyday on pump gas(95) and the car is going great (plus 200bhp.)

my car is now using heavy oil consumption. and im about to rebuild Motor. i am going to ceramic Coat the Pistons for added durabailty and would like to use Pure Water Injection when Going Plus 1 bar to cool intake Temp/Help the Engine Last Longer. Im not to Concered about using water inejction to make more power. there are Plenty of guys in my neighbout hood running water meth with great power gain's (aquamist,snowboost,boost cooler etc.)

Okie now the Questions

if running just Water injection how many degree's would my charge temp drop?( i know each engine is differnt but what a Rule of thumb figure?

If i Get the Correct percentage of water Injection(ive read its like 10%-20%)Will my Feuling map need to be changed/will the car need tuning when adding just WI?(current map is 100% Rock Solid)

Will WI improve engine life?

JohnA
30-08-2007, 09:17 AM
Hey hey all.
Hey :smile:
...if running just Water injection how many degree's would my charge temp drop?( i know each engine is differnt but what a Rule of thumb figure?
It mainly depends on what the charge temperature is.
If your intercooling is effective and that temp is usually below 30C then don't expect much temp drop from the W.I.
If your charge temps are very high (say you have no intercooler) then the W.I. effect can be quite dramatic

If i Get the Correct percentage of water Injection(ive read its like 10%-20%)Will my Feuling map need to be changed/will the car need tuning when adding just WI?(current map is 100% Rock Solid)
There is no such thing as a universal 'correct percentage'
It all depends on what you are trying to achieve and what your pre-WI engine balance is like.
10-20% water to fuel ratio is used often under full boost to supress detonation that might otherwise occur.
Cylinder distribution is also very important.


Will WI improve engine life?
Under certain conditions, YES
If your engine was on the edge of detonation and the WI stops it from damaging itself, then YES

schwitzer turbo
30-08-2007, 11:42 AM
I do have a Big Intercooler but No Oil Cooler.I have recently Upgraded my Radiator to a Twin pass.
And the Car's Overall temp is Very Gewd/Im very happy with it. and have had all my Coolant/Temp Sensor's Replaced!

But My hood/bonnet Gets FARKing HOT, so hot i cant even Touch the Dip Stick!(it will melt your hand) And i do not have a Blown Headgasket i have had this check Multiple times(chemical test's too) and since i have had her she runs this hot. hence there is a concern.

and the car pulls stronger than ever. heat Gauge never goes over 50% temp is normily at 10-25%
I have Cowled/raised the Rear of the Bonnet as a Atempt to make things run cooler but it hasnt really worked.

If i inject 10% water will my feuling map need to be changed?

So 30C or less after intercooler is very Gewd?

JohnA what you mena by "Cylinder distribution " The way it is Injected?

JohnA
30-08-2007, 01:18 PM
I have Cowled/raised the Rear of the Bonnet as a Atempt to make things run cooler but it hasnt really worked.
Try fitting a bonnet vent, similar to the Mitsubishi EVO.
It will increase the efficiency of all radiators up front, and keep the engine bay cooler.

If i inject 10% water will my feuling map need to be changed?
It would depend on what AFRs you are running now.
If they are extremely rich (richer than 11:1) then it would be better to tone it down a notch.

So 30C or less after intercooler is very Gewd?
It depends on ambient temperature.
If it is 40C then your intercooler is out of this world :wink:
If it is in the low 20s then your intercooling is pretty good.
If it is freezing outside, then your intercooler is dead meat :!:

JohnA what you mena by "Cylinder distribution " The way it is Injected?
Yes, water doesn't follow tight bends very well. So if a cylinder gets most of the water and another one is effectively dry, you could get detonation from the 'dry' cylinder despite the WI pump working full-time.

Richard L
01-09-2007, 11:07 AM
I am a bit late to this discussion.

I am intune with JohnA 100% on this. Th ereason for the engien to run hot may be due to timing. Is it possibel to adnce the timing a tad withitu knock?

schwitzer turbo
01-09-2007, 04:03 PM
This car since it left the factory has run this Hot im in south africa and even the Guys who have these car in the UK that still have them stock standard run this hot..... They Reccomened a OIL cooler.

Im sure a Oil cooler would help the oil/turbo last longer but im sure the overall car we be just as hot and there are many people running fast/big turbo's with out oil coolers...

So the Only way to see the Tempreture drop when the Water Cooling is werking properly will be with a EGT?

My AFR is 11.2

JohnA
02-09-2007, 10:51 AM
If your oil temps exceed 120C often then you may want to fit an oil cooler (thermostatically engaged, so it won't keep the oil from warming up quickly)
If they reach 140C then you absolutely need one

After the turbo bearing the oil is very frothy and in a bad state as it returns to the sump, so that doesn't help.
With turbos I've only ever used good synthetic oils and keep changing them very often, especially after hard runs.

hotrod
03-09-2007, 10:41 AM
I pretty much agree with all the above. It is very hard to give a fixed formula for how much water is right for your needs.
It is always an experimental process. As mentioned above by John start out with the 10%-20% water to fuel range and see what the engine likes.
WI should lower your engine temps "slightly" but not a lot.

If you engine runs hot for everyone it is probably a characteristic of the engine and car configuration. Oil coolers would help but there are also some other things you can do.

Have you tried any of the cooling additives like Redline's "water wetter"?
What water antifreeze (ethylene glycol) are you running?

Here in the U.S. most folks run a 50/50 mix of antifreeze and water to provide freeze protection in the winter. A 25% antifreeze and 75% water mix gives noticably better cooling especially if water wetter is added to the mix as it improves heat transfer from the engine to the water.

Check your radiator to be sure you don't have a mineral build up in the radiator. If you do, you will need to clean the cooling system to flush out the mineral scale and give good cooling.

What thermostats are available for your car?
Many times you can help the situation by running a thermostat that is 10 deg F cooler than the factory setting.
What weight oil are you using? Sometimes excessively thick oil can actually make the engine run hotter.

They make special coatings that help with heat transfer that you can get the oil pan coated with and that will work much like an oil cooler to lower engine heat load.
http://www.techlinecoatings.com/articles/Coating_The_Oil_Pan_Article.htm

It would increase your water usage but a water spray on the intercooler and or the radiator might also help your engine heat issue, but that is not really water injection.

Water injection usually requires a "small" increase in engine ignition timing but this varies with the engine and the fuel air ratio so must be worked out by the tuner.

Hope that helps.

Larry