vetboss

iTrader: (2)

Did not know QTP was a threat to my turbo? Please explain...


Looks are improtant to me, thats why I have an evo...I have a number of friends who have crapped looking cars with high HP, I just prefer a clean look and overall perfromance as well. IMO

Again, whats the deal with the QTP's?

ernald711

iTrader: (26)

I've been reading arourd Socalevo.net and most of us Socal guys (in WA for the military) used to all have one and it was a trend for a while before more info on it came out. It's not bad if your tuned. There is a backpressure myth that all Evo guys will debate over time and time again. Turbo cars need backpressure, turbo cars don't and so forth. The main thing i've read about is that the QTP (untuned) will create overboost in the turbo.

"For those who don't know why everyone is saying why you need to get a tune:

A turbocharger is a fan pump driven by exhaust gases. A turbocharger has a turbine and a compressor. The turbine uses exhaust rotate the compressor fan. The compressor then pumps air into the intake mani. The additional pressure makes use of more fuel equaling more power. The intake pressure must be controlled by controlling the rotational speed of the turbocharger by means of the wastegate by routing some exhaust away from the turbo to prevent over boost.

So when you decrease back pressure by getting a larger exhaust, you are allowing the turbo to spool easier without changing wastegate settings, and you may lean out your Air/Fuel mixture to the point where you may damage your engine. The leaner your Air/Fuel mixture, the hotter it burns causing pre-detination which causes your pistons / rods / bearings to become damaged.

In extreme cases the pressure could directly cause physical damage. " - Socalevo.net member

Here's the thread from Socalevo. The good stuff starts on the 2nd page.
QTP Cut-Out

Two tunes (or Maps) would be nice to where you can switch, but the majority would rather run a tune for the QTP open, meaning run rich when it's closed. Running rich is definitly way better than running too lean for the sake of the motor.

I'm more of a visual guy, and black and white numbers help me in making decisions. Here's a comparison pic. The baseline tune is the solid lines, while the QTP on the same tune is dashed. If you are really more concerned about this, I suggest you start a thread on the Evo Advanced side of the house, as this thread would no longer belong here. Sorry if i confused you more, but hope have helped you out in some way.

vetboss

iTrader: (2)

Interesting....I am (rather conservative like) tuned for 24PSI with the cut-out open. Then ran over on numerous logs out in the street with consistent results. I rarely run the cut-out open...in fact, I rarely drive the car...maybe once every 2-3 weeks for 100 miles or so.

On another note, that dyno data went from 77 degrees to 101 on comparison for ambient temperature (24 degree spread?)

ernald711

iTrader: (26)

Yeah, looks like they had to cool her down after that. But still, cooler and the QTP didn't produce great results on the same tune?

rush63

iTrader: (42)

That's why I posted this.

Or are you just looking for a single wall tip?

vetboss

iTrader: (2)

I got ~25WHP and slightly less WTQ on a flipped switch...same tune

thanks for the input

vetboss

iTrader: (2)

Rush...

Thanks for the links!

Single wall (with a little less?) tip....yes, I like the look of V-manracing exhaust (he posted earlier on page 1), he says its a magnaflow with a single tip...just waiting for him to chime back and tell me which it is. I wont order anything until I confirm some details. Check his album out and tell me what you think. I think it looks good close to stock just a more polished look and tucked noice under the bumper. If I can find out which one he has that matches the links you sent with the right tip, I'll order it and weld it on

I also saw Sgt petty 210's $25 ebay exhaust, but it looks a little too aggressive, slanted too much and I think it has got a burnt tip which is not what I am looking for...looks nice for $25 though

Also wanted to show my peeps at the p shop and let them chime in on which muffler would fit best, not look bulky, etc,etc.

limp_noodle

iTrader: (29)

Get a vibrant muffler and paint it black.

On my old sentra I just had a 3" turn down tip painted black. Maybe you can look into that. J bought be turn Dow. Section at pep boys for $8 then had my friend weld it on for me

vetboss

iTrader: (2)

I actually want some shine to it, so I want it to resemble the stock muffler and tip (smaller tip though).

Got a link for the vibrant?

limp_noodle

iTrader: (29)

http://shop.ebay.com/?_from=R40&_trk...All-Categories

v-manracing

iTrader: (4)

That is not my muffler... mine is a magnaflow 3" offset inlet and 3" center outlet oval muffler, My friend owns a muffler shop and that that's what he had in the shop. we put a basic 3" chrome tip on it, the tip was longer but cut to fit. it may of been for a truck. I'll send some pics of it .

vetboss

iTrader: (2)

Thanks man, look forward to the pics. Please get some shots of it from underneath or close to the ground so I can see what it looks like at the weld if possible.

But I';; settle for what you got when you get it

v-manracing

iTrader: (4)

pics are up

v-manracing

iTrader: (4)

here is my new setup after I got pulled over for illegal exhaust, sounds good and looks stock, 3" from turbo all the way to tip, the muffler has 3" inlet and outlet.

vetboss

iTrader: (2)

Thanks man, I assume this is the same picture that I saw in your album on your CP.

Any other shots, closer, below the bumper, and the weld spot would be nice too if possible

Did you saw a magnaflow or a dynamax the PM?