lol u need a nice a$$ whooping.

 

Apparently no one is reading the original post… the guy said there is a drastic change in the piping diameter due to creases/crimping in the bends….

 

you have noooo idea what your in for

 

GUYS READ MY POST

I HAVE FOLDS,BENDS IT LOSSES ITS SIZE DRASTICALLY BY .5"++ MAN ITS TERRIBLE ITS ENOUGH TO NOTICE TQ LOSS!!!!!

from my understanding an exhaust should never lose flow or velocity and should maintain its diameter throughout the exhaust..

My boy has a stillen on a rev-up and we have raced when i was running the topspeed and i would jump on him from the beginning and he gets me at top-end but he had headers and resonated high flow cats. I only had intake and catback at the time..

 

its finally im throwing it away or selling it to some 18yr old punk who just bought a g

 

Ever consider the fact that the car might feel softer in the low end because there is TOO MUCH piping volume? Add too large of piping and the exhaust gases cool in the pipes, cause turbulence, kill the exhaust velocity, and ultimiately results in weak idle to approximately 5000rpm performance. I have very hard time believing that the crimp bends are killing performance as you've added a true dual setup which can move a lot exhaust than stock. Two 2.5" pipes, even 2" pipes, will move a more air than a single 2.45" ID pipe (OEM).

You really need to post up some pics to help us understand just how bad these bends are.

FYI, on a naturally aspirated motor, bigger is not better and the ideal setup is to use larger piping near the motor and shrink it slightly has you move towards the exiting pipes. The key, like many have already stated, is exhaust velocity. Keep up the velocity and the system will perform. Make the pipes too much and the setup will make the engine feel like a dog until about 5000rpms.

 

used 2.5'' and the bends which there a many especially never muffler est. its decreased down probably to 1.5 in maybe 2 inches in diameter if i lucky

 

look at the pics i put in wrong place

https://g35driver.com/forums/showthr...=1#post3267755

 

Those bends aren't impacting performance at all. Those aren't "crimp" bends either. Years ago when I owned a heavily modded Maxima, a company (Warpspeed) made two different Y-pipes for the car. One y-pipe had mandrel bends and was stainless. Down pipe diameters were 2.25" merging into a 2.5" collecter. This was the high end y-pipe. The other option was an aluminzed pipe with 2.25" downpipes with crimp bends, just like yours, merging into a 2.5" collector. This was the cheap option and was 1/2 the price. Warpspeed sent one of my friend's each pipe and then told them to dyno each. The non-mandrel pipe made within 1whp of the mandrel pipe (13whp/10wtq). That's easily within dyno error.

 

thats only two pics there all over the place i took it at night the bends go throughout the exhaust i can feel it dragging especially when getting on it you can hear the exhaust leak sound terrible in cabin as though theres a rattle (everything is air tight shut). my friend noticed near higher rpms the exhaust shakes as though theres turbulence.

so if you make yourself air and from 2.5 to 2.00 then 2.5. then to 2.25'' then 2.5'' throughout the exhaust i can promise there were will be a hence in performance.

 

there no exhaust velocity in other words...

i much rather put the topspeed exhaust despite the 3'' extender which wouldnt harm it much cause its short

 

An exhaust leak will DEFINATELY hurt torque. You sure you don't have a leak at one of the flanges?

 

those pics aren’t what I was imagining from the original post...

Depending on what other mods you have, you could be running lean which will kill trq! The ECU will compensate and the car will feel like a slug! Bottom end suffers but mid is just horrible - when I first installed HFC the car would barely move from 70mph at WOT it took 5-10 seconds to get to 75... after A/F was adjusted there was bunches of trq!

Dyno with A/F and see if you are lean - get a tune to add fuel and you might be surprised at the results.

 

The easiest way to test for a leak is to let the engine completely cool, jack the car up and support it safely, start the car, and start running your hands over all connection points of the exhaust feeling for air movement (it's not going to burn you). An exhaust leak with have a really farty and wheezy sound.

If you're getting rattles, you need to check for clearance of the pipes between the chassis. There needs to be at least .5" of clearance between the pipes and chassis parts.

IMO, everything you're describing is the nature of the beast when it comes to true dual exhausts, especially with 5AT cars. The lowend and midrange seems to suffer until maybe you get the ECU tuned. As for the sounds and vibration you're feeling, I'd venture to say a lot of what you're "feeling" is the fact that the shop, like most aftermarket true dual exhausts, didn't use flex sections in the y-pipe. This will transmit more noise, vibration, and harshness into the cabin. As for the sounds, the VQ motor has some really odd metallic sounds when you open up the exhaust. You'll hear ringing, pinging, and rattles coming out of the exhaust under various load situations. That's just the nature of the firing order and thin wall piping. Lots of people mistake these odd sounds as broken cat bricks, loose exhaust components, and exhaust leaks. I think most people expect these VQs to have the fluid and healthy sound of a V8. It's not happening.

 

Thanks.........But if its obvious enough to notice the tq is a bit sluggish just after i put thge true dual on with these poor bends that lose diameter its safe to conclude that i am suffering from lose of tq from mid to WOT.

So, the solution to this would be to put on the exhaust i had before..

wonder if i should upgrade my test pipes from 2.25'' to 2.5'' ??? too free flowing??