Gsr Turbo?

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Originally posted by pissedoffsol@Mar 19 2003, 11:33 PM

it makes it more dense, and puts off heat as its byproduct.

Yes it makes it more dense, but the density is proportional to the temperature and the pressure. If the temperature remains constant, what will determine the density is the pressure AKA psi
 
http://www.gnttype.org/techarea/turbo/turboflow.html

Okay guys, if you read over this website very carefully, and understand the equations, this "bigger always means more hp @ same psi" should stop.

I think we can all agree that how many pounds of air you can fit into an engine is what increases the power of an engine.

Here is the equation to determine it:

To get pounds of air:

n(lbs/min)= P(psia) x V(cu.ft./min) x 29
....................... (10.73 x T(deg R))

Okay, if you read that article, you will find that:
The variable P is pressure as in PSI (absolute pressure)
The variable V is volume, as in cubic feet per minute. (this is not changeable on a given engine without increasing displacement or rpms)
The variable T is temperature (absolute temperature)


okay, here we go:
24.7psi x 250cfm x 29 = 179075 ( 24.7 is 10 psi + 14.7, 29 is metric conversion shit)

10.73 x 550F = 5901 (10.73 is more metric conversion 550 is 90 degrees + 460 (to make it absolute))


179075/5901 = 30 lbs/min of air

A stock GSR running 10 psi of boost at the map sensor, with the air being 90 degrees F, will combust a total of 30 lbs of air per minute

If you leave the engine alone, there are only 2 variables you can control in this equation. PSI and temperature. You can control the temperature by getting a larger intercooler, and you can control PSI by getting a boost controller or a stiffer spring in the waste gate.

Using that same equation, you can find out how many lbs/min a gsr with no boost can run. That number is 18 lbs/min assuming its 90 degree air getting into the engine.

18 lbs/min vs 30 lbs/min

30/18 = 1.67 ....does that number sound familiar?

Now if you guys are still in question about the cf/m of an engine not changing, picture it this way. Pretend that I gouge out one of your eyeballs, stick my arm through your eyesocket until i can grab your brains, and then I scoop all your brains out. There's now nothing left inside your thickskull besides 5 cubic feet of air (you have a really big head). Okay, so its now established that your head holds 5 cubic feet of air. Now what I do, is I go get the biggest freaking turbo I can find, and I hook it to your eye socket. When it starts blowing, provided your head doesnt expand or explode, how many cubic feet will your head be able to hold? uhm 5 cubic feet, why would that change? So what happens to all the air that that big turbo pumped into your head? It is just compressed. Yes, a larger turbo can put more pounds of air into a given space than a smaller turbo, but it has to do so at a higher pressure.

A GSR engine can only accept...lets day 250 cf/m. Your waste gate is set at 10 psi. Your intercooler cools your air down to 90 degrees. So what if your turbo can push 750 cf/m at 10 psi. Since no more than 250 cf/m can go into the engine, the system builds up pressure. Since the system stops building pressure once it reaches 10 psi, the turbo is only running at part capacity.

on a 250 cf/m engine running 10 psi, the only difference between a 250 cf/m turbo @ 10 psi, and a 750 cf/m turbo @10psi, is lag. Lag is bad if you are looking to increase horsepower throughout your whole rpm range.

As for the relationship between cf/m and psi (assuming they are both intercooled to 90F):

30 psi on a 250 cf/m engine = 55 lbs/min
10 psi on a 750 cf/m engine = 91 lbs/min

So how do you increase the cf/m's of an engine? Increase RPMS, Bore it, Stroke it, or polish it (which doesnt actually increase displacement, but helps the other factors become more efficient)

You guys have got to remember that if a turbo is pushing the cf/m of the engine, at the waste gate's max pressure, getting a larger turbo will do nothing good for you. It will not increase the lbs/min of air going into the engine, and will not make your engine any more likely to blow up than the smaller turbo.


pissedoffsol, instead of getting the largest turbo you can find, lets do the math and figure out which turbo will push howevermany cf/m your engine moves at 10 psi. That way you reduce unnecessary lag, and increase the average horsepower of the engine.

Guys, I am sick of being called a moron. I am right. There is no doubt about that. If you need anything cleared up or explained better, please ask me, instead of telling me how stupid I am. If you want any references for those things that I am telling you about, please ask me for them, and I will do my best to get them.

As for you mwasnp, "do the math and then send me an apology" Your ignorance is not excuseable because you were sooo malicious about it. I really need to post those messages you sent me.

As for everyone else, nobody had explained the math to you yet


:D :D
 
I tell you what. Go to a dsm forum and tell the dsm guys that they make the same power with the same mods running 18psi on a 14b versus 18psi on a 20g. On second thought, dont do that, itd be pretty stupid.
I'm going to say fuck the laws of physics for a moment and speak as if I was ignorant of all things mathematical. I can tell you from personal experience that a larger turbo wil make more power at the same boost pressure. In fact, we ran rich on 3 fewer pounds when we swapped a 20g (and nothing else) for a ported and clipped 14b in my boys dsm and we still made significantly more power!
Actually Snail, you nkow what, youre right. You have revolutionized the world of honda performance forever and i thank you for that. I'm sorry but I can continue no more.
 
Allright you stupid ass here is what I was talking about,
1.8l Dynos

If all turbos make the same power why the fuck is that t4/60-1 making 319 HP on pump gas when the t3/t4 only makes 263 or so? Thats what a 150% gain over stock? Atleast nowhere near 70%. Its put to rest. Proven. And by the way hes not even tuned. He has a shitty fmu set up and a restrictive catback exhaust. If he went up to a 3" exhaust and used hondata or aem I am sure he would be at minimum in the mid 300's. And there is an itr posted that makes 295 @ the wheels with only EIGHT POUNDS OF BOOST.
 
And you dont get my apology because you're not right. You should apologize to me for making me waste my time to prove something that was obviously wrong. This whole post pretty much sucks, and I feel pretty stupid for taking this much time out of my day, and acting so immature. I will apologize for my initial message which was quite rude though.
 
Dyno chart 1:

221 ft/lbs

Very close to the 1.67 number, the difference probably comes from a few mods which increased the starting torque, or an overestimate when converting it from whp to crankhp

Dynochart 2:

295 hp @8500 rpms, which means he was making about 183 ft/lbs

dynochart 3:

277 ft/lbs @ 19 psi. does the phrase "yes it will make more power, but it has to be done at a higher pressure" mean anything?


Like I said like 6 million times, If you want to increase your hp with a given amount of boost, you have to either increase displacement or rpms.

The HP will not be increased with that 1.67 ratio because it is multiplied by the rpms. The higher the RPMs, the more power you get out of each lb of boost (look to the math of the 250 vs 750 cf/m engine) You will get more torque out of each lb of boost if you increase your displacement. However, given that your engine does not increase in size, the maximum amount of torque created by an engine is proportional to the PSI the wastegate is set at. at 10 psi it is no more than 1.67, and you guys have yet to provide anything that proves me otherwise.

Get started guys, stop calling me a moron, and go find yourself some dyno charts.
 
Someone find a chart that proves me wrong. Hell if anyone can do it, I'll behappy, cuz then I wont feel guilty about shutting up. However if I were to just shut up now, that would mean you guys would continue being ignorant about some very important stuff.
 
There were no further starting mods, he even had poor tuning. Dude face it you're wrong. He has a t4/60-1 turbo, and he is producing ALOT more hp and tq than any of those 250 hp gsrs you showed, with a STOCK BOTTOM END. No mods and small restrictive 2.5" catback. YOU ARE WRONG!
 
And he never converted from flywheel to whp, he had it dyno'd AT THE WHEELS. Quit making up bs, just face the fact you are wrong. There is a reason dsm people switch to larger turbos and DONT increase the psi they are boosting at....
 
Yeah, what was the ambient temperature? how big was his intercooler? Name allof his mods. How sure are you that his waste gate is functioning properly?
 
You're digging deep man. Here is a link to a gsr on 5.5 psi making 250 WHP!

gsr turbo

Stock internals, again a very large turbo, t3/60-1.
 
Originally posted by SnailOnARampage@Mar 20 2003, 04:26 PM
sol, buy your t66, take it to the dyno, and show us the charts.

i have and had 0 intentions on running a t66, nor will I for the sake of you.
franly, i don't give a shit what you think. Your math can make you happy all you want, but fact remains that you're wrong. mwswp jsut showed you a bunch of dynos, and yet, you are still running your mouth.

if EVERYHTING was equal like you said it would be, EVERY 10 psi stock gsr would = X power.
and its just not so.

get over it.
 
Ugh I hate to drag this bitch of a thread up again, but I figure it is for the education of hondaswap. Whether I'm right or wrong you guys all have the chance to look it over and decide.


You guys already know where I stand, but I would really like to know what principles lets a big turbo put more air in the same size engine than a small turbo, if both are reading the same pressure at the map, and are the same temperature.

Why does it change? I would like to know.

One thing you guys should all go look at is boyle's law. Good thing to consider when dealing with things like turbos.

http://www.aquaholic.com/gasses/boyle1.htm
 
Here are some statements you guys should look over. Please tell me which (if any) are wrong.

1. The relationship between pressure and density are inversely proportional and linear as long as the temperature will remain constant (boyles law...go look it up).

2. The displacement of an engine is a constant. It will not change unless you bore/stroke/rpm/make it flow better. It is a fixed figure, and at a given rpm it will always only accept x cf/ms of air.

3. Any amount of air over the x cf/ms will not be going into the engine.

4. Anything that does not go into the engine is built up as pressure.

5. At x psi the wastegate opens up and prevents anymore pressure from building up.

6. When the wastegate is open, it is diverting the exhaust away from the turbines, so it will not spin as fast.

7. When the air is diverted around the turbo, the turbo is not operating at full capacity.

8. When a turbo is not operating at full capacity, it is not pushing the amount of air that a flow chart says it can.

As far as heat is concerned in reference to the density:

9. If you compress the same cf of air to the same pressure in the same amount of time, the temperature will be the same.
 
Snails on a rampage is right guys.

PSI is PSI no matter what. A turbo doesn't produce a certain amount of PSI, its the restriction of the engine that produces a PSI, so 5 lbs on a small turbo and 5 lbs on a big turbo NEGATING AIR temperature, are the same exact thing. What PSI though does show is the restrictiveness of the AIR cycle into your car.


Think of a turbo car driving without a BOV and they power shift, What happens? The PSI skyrockets and the compressor surges, yet they weren't flowing more lbs of air per minute then before. The reason why this happened is you closed the THROTTLEBODY and since the same amount of CFMS were flowing , and less space (or more restirction) was put on the air the PSI subsequently went up.

Point of this is regadless the size of the turbo, your car is going to accept the same amount of CFMS, at a given PSI.

How can you apply this? (Very Basic) You have a car the flows 200 CFMs NA and you want to squeeze 400 cfms into the car. Well since your car flows 200cfms at absolute pressure, or atmospheric pressure, 14.7 psi whatever you want to call it. If you double Atmospheric pressure you double CFMs in air. So 400 - 200 = 200 cfms you want to add on, 200cfms divided by the ratio of 200 cfms@14.7 psi gives you 14.7 psi or you want to increase your ABS pressure to 29.4 you take away the atmospheric pressure (14.7) and your left with 14.7 psi


A bigger turboed car is going to put out a lil more horsepower not because of the amount of air but since the air is alittle cooler. Your still going to move 400cfms with the resistance 14.75 psi being applied against the manifold pressure.

IF you don't beleive me try this out. Get two INTAKE MANIFOLDS, one an (OEM) and another an EDLEBROCK. The edlebrock is going to make the same HP at a lower PSI then the OEM why? Because it can accept more AIR(CFMS) at a lower restriction (PSI)

Another example why do you think stock EVO's have a flat HP band? The Torque starts up fast and it slowly tapers off because the higher you rev your engine, the more air it can get in and spit out at a given amount of time which equates to the engine becoming less and less restrictive against air and requiring more and more cfms, and THATS WHY THE PSI DROPS


So leave Snails alone hes right. If anyone needs clarification on this, email me at mlyn@bellsouth.net, as well as I'm building a program for all of this.
 
holy old as shit thread batman.

and for the record. 10psi on a t25 does not equal the power of 10 psi on a t66
 
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