A question for all you DSMers

[street_racer_00]

Okay, so I ran doors with a 2nd gen talon TSi last night...the only mods he had were a K&N cone filter and he had the boost upped from 12psi to 16 psi...well I talked to my "friend" this morning(he drives a N/A talon) and he says there is no way I shoulda kept up and that the car I raced was probably slow as fuck because 16psi is too much for a stock 4G63 and he probably blew a bunch of seals and had no compression...okay so my question is, is 16psi too much for the 4G63, or was this guy just butt-hurt? Thanks in advance

[drewh4386]

No it isnt

[street_racer_00]

okay, thanks.

[kjewer1]

16 is about as high as you want to go on the stock turbo, but you can run 30+ psi on stock blocks if the car is setup and tuned properly

[JoeWagon]

You have similar estimated 1/4 mile times as a near stock turbo DSM. I'm not surprised. Like 95 GSXracer said, in short... yes the guy doesn't know what he is talking about. Increasing boost to 16psi is exactly the right thing to do, and the guy you raced probably knows more about his car than your N/A friend. As for how much boost a stock motor can run... if you remember that boost doesn't equal power, you can run 30psi on a smaller turbo on a stock motor fine, but may not be able to run 20psi on a bigger turbo. In reality, I'm not the only person who has run 20+psi on a stock turbo and stock motor.

[street_racer_00]

Okay, I'll be honest, I'm an idiot when it comes to turbocharging...what does increasing the boost do? Doesn't it make more horsepower, at least in theory? I mean, I don't think you would up your boost and risk having something go wrong without it making you more horsepower...

[TreeFrog]

most boost is just more pressure on the air flow. more air flow means more power, if set up right. but a 16lb on this car is not the same as 16lbs on another. in therory a 14lb eclipse could be faster than a 16

[AngelOfNight 9]

Originally Posted by street_racer_00

Is 16psi too much for the 4G63t? Thanks in advance

No it isn't. I was pushing 16 with my old TC. As for him having his boost set to 16psi, alot of people exaggerate. When I first had my 91 TSI it was only pushing 8 and this other guy was claiming his 95 Tsi was pushing 16. Now I have AWD.. might I add and we were already coasting before we started to take off so he had the advantage. When he said go I just kept pulling on him.

[TsiTalon9587]

Originally Posted by TreeFrog

most boost is just more pressure on the air flow. more air flow means more power, if set up right. but a 16lb on this car is not the same as 16lbs on another. in therory a 14lb eclipse could be faster than a 16

Exactly, and not only is it in theory, it's true 100% when comparing two different setups(turbos, excluding other supplementle factors). Airflow is what makes power, and is more important. Like it's been mentioned, you can have a car that runs 20psi and make close to 400whp, and on a smaller turbo, run the same boost and make 300whp. To give you an easier understanding, at the same water pressure; which will put more water on a fire to put it out, a fire hose, or a garden hose?That analogy may help you understand what's being addressed here.

This is also the same reason that you cannot measure an engines maximum capabilities in psi, or cfm, or other measures. The only thing that can actually measured it's max output, is when it's measure in HP. This will always tell you the exact amount of stress that's being put onto the system.


Also, 16psi is not anywhere near the 4g63's capabilities, in simple terms. (provided supporting mods are in place)

[street_racer_00]

okay, okay, but on a stock 4G63 turbo, wouldn't 16psi be better than 14psi, all other things being equal? I'm so confused.

[wuman82]

If everything held equal. Meaning, same car, same engine, same turbo, same setup, then more psi=more power.

[kjewer1]

Originally Posted by wuman82

If everything held equal. Meaning, same car, same engine, same turbo, same setup, then more psi=more power.

On a restrictive setup, more boost may not net enough of an icrese in airflow to make any more noticeable power though. This applies in particular to maxed out turbos and restrictive setups. Take a 14b at 25 psi, raise it to 27. You'll only get it in the midrange, which will result in more torque, but no more peak power. And after boost drops you are creating a lot of heat, and could even drop hp a bit. Just for the sake of nitpicking

[street_racer_00]

Damn...forced induction is so complicated...lol

[10.5sec92AWDTALON]

There's a lot of things that come into play...you can think of boost gauge reading as air that is not getting into the motor also. A stock head for example can't flow as much air as a well ported one, so...say all things remain the same but port the head, your boost reading may have been say 20 but now it's only 18.. boost reading goes down but HP goes up as more air is getting into the motor.


Also with high boost levels on a small turbo the turbo will be out of it's flow map and the booseted air will be heated up equaling less true air flow into the motor due to the density of the compressed air being lower.

FWIW A 14b can run up to about a max of 25 PSI on a mildly modded motor.

[street_racer_00]

Okay, I don't know shit about DSM cars, either 1st or 2nd gen, but is the 14b the stock turbo on the 4G63?