Why are you arguing turbos with me? <= confused

ORIGINAL: AudiCross

mmmm okay. Let me say this again. I said that it wont be making those AWHP number (300 ish) till 7k ish rpm. No, just no.I didnt say the turbo wouldnt spool till then and i didnt say it wouldnt have power till then. I was saying it would make max HP then. Here:: It all depends on the turbos compressor and turbine wheel sizes and housings. But to get strait to the point, here, a gt3076r with HKS t25 .72 housing

93 octane, 18, 20, and 23 psi


He is making +300whp from ~5k on. Sure it makes more, but it falls of at 8k as you can see. Smaller turbine wheels would spool faster, but also fall on their face faster and vise versa for larger turbine wheels. If you want, i can post a 2871r, it will hit 300whp before 4k and fall on its face by 7k due to the gt28 turbine wheel.


Biger turbo: Spools later, higher CFM. may not hit as high of boost Depend on the turbo. A properly matched turbo like a gt30r or gt35r would run well over 30psi unlike a gt28r or gt28rs, but will do it at much higher rpm's (putting much more air through the engine). this will make the powerband much steeper at the end (7k ish in this example). that is where you would past your 300 AWHP mark because above 5252 rpm the HP and torque curves switch and you dont have to make the same amount ot torque to get as much HP (that is y it doesnt take as much boost at high RPM's to make the power)

Smaller Turbo: Will spool sooner. Will generally give higher boost pressures but it does it at lower RPM's. This gives much mroe torque than the bigger turbo at high RPM's again wrong. The smaller the turbo, the higher the tq to hp ratio. Everything with a gt28 turbine (r-71r)and smaller will have either equal hp and tq, or more tq than hp depending on how small it is. Bigger turbos will still make more tq than the smaller turbo, but will have a higher hp to tq ration. People with med to large turbos dont have peak tq untill post 5252 also, but because of the HP=Torque*RPM/5252, it wont produce more horsepower at the given amount of torque. A smaller turbo can produce that horsepower at much higher boost but lower RPM's.

So please, read what i say before you go against it. I think ive been on here long enough that before you blow what i say off and make a snide comment, you re-read what you have just "read"

Well since what you said is either completly wrong or doesnt make any sense

 

The thread was about what puts strain on the motor. A gt30r would barly be working at 300whp. It doesnt get warmed up until you start pushing 25-35psi out of it.

 

you were just arguing that the gt30 series running low boost wouldn't hit max power till 7k

 

you want boost levels?

 

where you get that

You should put that in the newbie thread asap

 

lol, saved that as you as you posted it

and yeah thats a good idea

 

To end this thread, the larger turbo would barely be working, create far less heat, and be at far lower pressure. Plus it would be making less low end tq in comparrison so it would be easier on the rods. The revs have nothing to do with the arguement except that it would be pointless to get a 600hp to make 300whp since it would have less of a powerband and nothing down low.

Audicross, please read the turbobygarrett.com's turbo tech 101-103....PLEASE

 

Okay. So i went back and read what i wrote and what had been written in reply. cincyTT, sry if i offended you in my response, i looked back it your comments on what i said and mine on yours, we are on the same page here. I initially started my point on the stresses on the engine with lower boost, higher rpm and higher boost lower RPM. everything u responded to with red i agreed upon. im not sure hot the gt28 adn 30 turbo's got into the picture except that one is larger than the other. I wasnt talking specifics, like what turbo spools when and at what boost to give out what HP. I was making a generic statement:

lower boost at high RPM can make the same horsepower as higher boost at lower RPM. and i explained why. and i said why one would stress the engine in one way and one would stress it in the other. I have no experience with the GT series turbo's, so i which does what when. I understand turbo's, how they work and whatnot.

the ONLY thing i dont agree with is how you say the rev's dont have anything to do with the stress on the engine. if you honestly believe that, then screw turbo tech 101, you need engines 101...

 

You are claiming that reving the engine out to 6k+ will cause harm, that is BS. And as i said, rpms have nothing to do with this arguement. Power (TQ)at certain rpms on stock rods, sure, there is a problem, but thats not the arguement here, nor is a concern with drop in rods. Hell, if i wanted to, i could easily make 400-450whp on a stock block, just give me 7k-7.5k rpmsand a huge journal bearing turbo, still be safer than 350wtq before 3.5k rpms

 

i didnt say reving the engine that high will break it. It wears it a lot faster. Its like saying "Well, my rev limiter keeps me from going too high, so y not go to it every day??" The wear on the engine at high RPM's is substantial compared to at low RPM's. Sure it can do it, but it's safer to not. Throwing a rod at 7k is no fun. replacing a shattered piston skirt at 7k is not fun either.