Gsr Turbo?

[SnailOnARampage]

Originally posted by heterosapian@Mar 18 2003, 04:15 AM
The B16 with its .2 fewer liters making more whp than both gsrs at the same amount of boost. The Si that made the 271 whp has some goliath heavy 18s on it too.

I realise there are many drivtrain and dyno facility factors in effect here, but this is a prety good indicator that 10psi is 10psi but 271-B16a2-hp isnt 260-B18c-hp

Look at the torque numbers instead. Torque is what is increased by the turbo, then the torque is multiplied by rpm and divided by 5252 to get horsepower.

In your stock GSR or b16a, for each foot lb of torque you increase, you will increase HP by 1.4

 

[Ractive78]

If I was to use my stock b18a for now,do you guys believe I should run 8 psi of boost with a t3 turbo?

 

[heterosapian]

as long as your cooling everything down well enough and maintain stoich a/f conditions you should be fine. You might want to retard the timing a bit with eight psi on a t3.

 

[posol]

Originally posted by heterosapian@Mar 18 2003, 05:51 AM
Gay-Lussac is Joseph Louis Gay-Lussac who established a logical and mathematical relationship between pressure and temperature when the volume is constant. When pressure is increased, the temperature is increased, when pressure is decreased, temperature will decrease

thats the thing though- VOLUME is NOT a constant.

 

[SnailOnARampage]

Okay, I just thought up a great analogy to explain what I am talking about.

Okay take the freaking Hoover Dam for example. and compare it to a turbo system. The colorado river (i think) is the normal sized turbo. The turbines at the bottom of the dam are the engine, and can only let so much water through. The amount of water they can let through is based strictly on the water pressure, because they size of the openings do not change. The higher the water is above the turbines, the more pressure is on the water that is flowing through them, so more water gets through...generating more power. Now if the water level gets too high, it flows through the spill ways and bypasses the dam all together.

Okay now that you have that all envisioned in your head. What would happen if you added the water content of the amazon river to the colorado river? (getting a turbo that is too big for the application) All that will happen, is that the water will come down and spill out of the water bypasses. It will not make the water flow any faster through the turbines, because the water level isnt raising due to the bypasses.

A turbo works exactly the same way.

You slap the optimum turbo on a gsr engine, set the wastegate to 5 psi, great, you are making tons of power without very much being wasted by being diverted by the waste gate. If you slap one big ass turbo on there, you still get the exact same amount of air getting into the engine (provided the smaller turbo was able to boost at the full psi at the redline) , because all of the excess created by the larger turbo is simply being re routed.

You can ONLY fit 500 cf/m into a GSR. A big fucking turbo will not change that. A small turbo will be able to move 500 cf/m at 5 psi. A big turbo will be able to move 500 cf/m at 25 psi. If your waste gate is working properly, your big turbo will NEVER exceed 500 cf/m at 5 psi. So what advantage do you have if you put a turbo capable of pushing 500 cf/m @ 25 psi if your waste gate is set at 5 psi. Well I guess if you consider LAG an advantage you could count that. The only time the larger turbo would be advantageous is if you set the waste gate above 5 psi. The larger turbo would be good all the way up until 25 psi on that specific GSR engine.

5 psi on a t888888889999399393939 is exactly the same as 5 psi on a t01 on a GSR as long as both turbos are able to push 500 cf/m @ 5 psi. You are no more likely to blow up the engine on the large if your waste gate works right.

Now guys get your shit together. This has gone far enough.

 

[SnailOnARampage]

Originally posted by pissedoffsol+Mar 17 2003, 11:23 PM-->

SnailOnARampage

@Mar 17 2003, 05:05 PM
The thing with turbos is, they do not actually cause the engine to accept more cf/m. They just pump in air at the same rate...600 cf/m for example, but that air is compressed so that it is more dense, therefore yielding more oxygen to burn.

this right here blows everything out of the water.

go look at a compressor map.

heres a t3 60-trim.

here's a big T70

the inner ring is the one too look at.

they do NOT pump air in at the same rate. In fact, rate has NOTHING to do with this. rate is dv/dt, or acceleration or velocity (i forget which.. calculus sucks).

anyway, my point is this. at any given psi, X turbo will make X cfm, where as Y turbo will make Y cfm.

X != Y

Look sol, all those charts prove is that a t70 CAN push more air than a t3. The problem is that if the extra air from the t70 can't go into the engine, it builds up pressure, and is expelled a different way.

 

[SnailOnARampage]

Originally posted by pissedoffsol@Mar 15 2003, 11:04 PM
-12 to 23213123123 psi

it all depends on the turbo size, the tune, who tuned it, and so on and so forth.....

my typical example.

10 psi on a 14g = 100 whp gain
10 psi on a t88 = 500 whp gain

This statement is probably true on a 10 liter engine, but it is NOT true on a 2 liter engine because of what I've explained above.

 

[posol]

Originally posted by SnailOnARampage@Mar 19 2003, 05:01 AM
Look sol, all those charts prove is that a t70 CAN push more air than a t3. The problem is that if the extra air from the t70 can't go into the engine, it builds up pressure, and is expelled a different way.

i want to know, whats stopping it?

there is no dam.
with the TB open 100%, whats to stop it?

 

[posol]

Originally posted by SnailOnARampage@Mar 19 2003, 04:56 AM
5 psi on a t888888889999399393939 is exactly the same as 5 psi on a t01 on a GSR as long as both turbos are able to push 500 cf/m @ 5 psi. You are no more likely to blow up the engine on the large if your waste gate works right.

5 psi is 5 psi is 5 psi. it's a PRESSURE.

http://www.hondalife.com/FlowvsBoost.htm

 

[posol]

http://www.gnttype.org/techarea/turbo/turboflow.html


more physics: High heat, high pressure, and low volume are all high energy states, low heat, low pressure, and large volumes are low energy states.

The exact same physical lays apply, just now in reverse: we take a low pressure, low temperature gas, do work on it with the compressor vanes, and get a high pressure, high temperature gas at the outlet.

 

[posol]

http://abe.sdstate.edu/classes/abe314/Comm...20on%20labs.htm

http://www.uniquemotorsports.com/subachad/...on_vs_boost.htm

http://www.stealth316.com/2-primer.htm

 

[SnailOnARampage]

I read over all 3 of those articles, and NOTHING in them contradicts what I am saying. The ONLY way a larger turbo will make more power with the same psi is if it does not heat the air as much as a small turbo does. Those articles still prove a maximum increase in engine power of 70 percent at 10 psi (assuming there is a good intercooler which cools it to just about the same temp as it was before it was compressed), and nothing in there says compression/heat ratios apply for a small turbo, and do not apply for a large one. Even if a larger turbo somehow managed to not increase heat at all, the maximum increase in torque at 10psi is STILL less than 70 percent.

 

[heterosapian]

QUOTE (heterosapian @ Mar 18 2003, 05:51 AM)
Gay-Lussac is Joseph Louis Gay-Lussac who established a logical and mathematical relationship between pressure and temperature when the volume is constant. When pressure is increased, the temperature is increased, when pressure is decreased, temperature will decrease  
--
thats the thing though- VOLUME is NOT a constant.

I understand that, my point was that there is no way to get around an increase in temperature when pressure is increased.

Snail, i'm assuming your point is that an engine can only displace a given volume and will not accept any more than that. Yes?
Well, AN ENGINE WILL ALWAYS DISPLACE THE SAME VOLUME GIVEN THE SAME CIRCUMSTANCES, boost or no boost, the density of the air inside the combustion chamber is all that changes. A larger turbo moves more air than a smaller and thus provides a denser charge and more power, there is absolutely no way to argue this point.

 

[SnailOnARampage]

Originally posted by heterosapian@Mar 19 2003, 11:26 AM

QUOTE (heterosapian @ Mar 18 2003, 05:51 AM)
Gay-Lussac is Joseph Louis Gay-Lussac who established a logical and mathematical relationship between pressure and temperature when the volume is constant. When pressure is increased, the temperature is increased, when pressure is decreased, temperature will decrease
--
thats the thing though- VOLUME is NOT a constant.

I understand that, my point was that there is no way to get around an increase in temperature when pressure is increased.

Snail, i'm assuming your point is that an engine can only displace a given volume and will not accept any more than that. Yes?
Well, AN ENGINE WILL ALWAYS DISPLACE THE SAME VOLUME GIVEN THE SAME CIRCUMSTANCES, boost or no boost, the density of the air inside the combustion chamber is all that changes. A larger turbo moves more air than a smaller and thus provides a denser charge and more power, there is absolutely no way to argue this point.

The ONLY way a larger turbo will provide a denser charge than a smaller one is if it is done at a higher pressure. You seem to be conveniently ignoring you common sense.

A large turbo can move lets say..... 1000 cf/m at 14.7 psi max
A small turbo can move lets say ...... 500 cf/m at 14.7 psi max

the larger turbo can:

1. be put on a honda engine and pump in 500 cf/m at 29 psi

2. be put on a honda engine and pump in 500 cf/m at 10 psi...with the rest being diverted by a waste gate

3. be put on a 1000 cf/m domestic engine, and move 1000 cf/m at 14.7 psi.

The small turbo can:

1. be put on a honda engine, and move 500 cf/m at 14.7 psi

2. be put on a honda engine, and move 500 cf/m at 10 psi, with the smaller excess being diverted by the waste gate.

3. be put on a 1000 cf/m domestic and run 7 lbs of boost.


Do you guys not understand that the excess cf/m moved by the larger turbo is either:

1. used to compress the air to a higher psi, aka, higher density (provided heat level is the same)

2. diverted by the waste gate.

 

[SnailOnARampage]

A larger turbo CAN NOT force more air into an engine than a smaller turbo, unless it is done at a higher pressure.

 

[posol]

Originally posted by SnailOnARampage@Mar 19 2003, 02:06 PM
The ONLY way a larger turbo will provide a denser charge than a smaller one is if it is done at a higher pressure.

that is simply not ture, and blows out all your reasons for it.

You seem to be conveniently ignoring you common sense.

come on now- no need for that here

 

[SnailOnARampage]

Okay....tell me why this is simply not true. Enlighten me.

 

[SnailOnARampage]

Originally posted by pissedoffsol+Mar 19 2003, 12:12 PM-->

SnailOnARampage

@Mar 19 2003, 02:06 PM
The ONLY way a larger turbo will provide a denser charge than a smaller one is if it is done at a higher pressure.

that is simply not ture, and blows out all your reasons for it.

You seem to be conveniently ignoring you common sense.

come on now- no need for that here

Yes that simply IS true. but perhaps I should rephrase it.

The ONLY way a larger turbo will provide a denser charge than the smaller one is:

1. If it is done at a higher pressure.

2. If it is done at a lower temperature.

Does a large turbo create less heat than a small one when compressing the same amount of air to the same pressure in the same amount of time? hell no.

 

[posol]

the thing i think you are getting mis-guided on is the fact that psi is the measurement of air NOT making it in.

 

[SnailOnARampage]

Umm...actually at a given temperature, the pressure of the air (psi) is what determines the density. So yes, the PSI is what determines how much o2 gets in the engine.

with 2 bodies of air, one being at 100 psi, and one being at 2 psi. If they are both at 70 degrees farenheit. The one at 100 psi is going to be one hell of a lot more dense than the one at 2 psi, there for will make one hell of a lot more power.