I just installed OBX headers on my 5.5 and my flange (from front header to Y-pipe) is giving me hell. I changed the Dang gasket 2 times. they both leak air like crazy. idk. so i was looking under my car and thinking of a True dual set-up. Its possible. but its gonna be Pricey btu I dont care. Would i get Power gains or would i lose power?? btw im thinking 2.5 piping.

 

you would probably not lose power, since many NA 5.5's are currently running 3" setups (single pipe exhaust)with gains. As with most mods on maxima.org, someone ends up being the guinea pig with ideas such as these(if you go through with it I think you would be the first). If you end up seeing gains, I feel more people will follow. I don't know if in the case of true duals you would need to go smaller than what you are planning or not(to prevent the cooling of the exhaust gasses, which would slow them down and end up causing excess backpressure)

 

Yea, I was reading up on that. going with True duals. Gotta go with smaller pipes. but How small???

 

well if guys are seein gains with the 3" cattman it would make sense to go 1.5" and 1.5" but that just seems weird to say. Perhaps dual 2" would work, since that'd be equal to a 4" system

 

Yea, If i was to go lower then a 2.25. id wanna do Side exits with 2" cuz its cheaper. and slap magnaflow bullets on them 2.

or 2.25 dual to the Rear.

 

I don't know much about exhaust systems, but I believe staying close to stock (2.25") width pipe would probably give a good amount of flow. it will also depend slightly on the way it is bent(pressure vs. mandrel). If you go too tight, that will not let the gasses escape quick enough from your vq35, which will lead to some of the gasses being forced back(due to meeting with slower gasses slowed down by the restricted flow) or slowed down as well, causing some more backpressure. I don't really believe that 2.5" will make you lose power as the true dual exhaust systems for other vq35 cars(g35 and 350z) seem to make some power. These tend to have a crossover or x-pipe to blend the pulses, which supposedly allows for good flow, but you could try it without and see what gains you get.

 

if you search you will find that someone has done this already.

 

Did for about 2 hours. Saw it on a 4th Gen and 6th gen. but no 5th Gen's. There's Always a First!

 

It's been done on a 5th gen. Just need to search for it.

 

Ummmm......FAIL....

If you are trying to get the same total area of a 3" exhaust, two 1 1/2" pipes do not work since the area is proportional to the diameter squared.

To get the same area as a 3" pipe you would need two 2 1/8" pipes. But unfortunately the calculation is not that simple because the flow is not uniform over the cross section of the pipe. It require a calculation of laminar flow that I have not done since college, and I am not willing to pull out the old books at the moment to do the calculation.

But I would think two 2 1/4" pipes would be pretty close to the flow of a 3" pipe.

 

Be sure to join the two banks together with an X-pipe...are you gonna run 2 cats as well? I think running the pipes adjacent to each other will work better (BMW like)then ran into a dual in/dual out muffler would be it. There's really no room to place a muffler on the rear l/h side....

 

Would it be nasty to do Side exits? before the rear wheels.

 

meximax has done it. his is a 4th gen but it's a built 3.5 with a supercharger.

 

That would take away from the look of the car, don't bother.

 

I was talking to a guy who has it - Staticxout2's Profile ask him how he did it

 

5th gen true duals and x pipe with catman headers
http://www.cardomain.com/ride/3111237

 

True duals dont make sense with only one manafold/

 

What do you mean??? I don't think you meant manifold....

 

Make a nice y-pipe with a flowmaster merge collector.

 

A V6 has two banks, which ought to suggest something about the number of exhaust manifolds or header pieces.

FWIW, headers on an inline 6 can be broken up into "front 3 / back 3" that has essentially the same evenly-spaced 240° firing intervals in each that you get with each bank in a 60° V6.


I would think that a pair of 2" pipes would be sufficient for a mildly modified 3.5L V-type engine (1750 cc/bank), as a 2" single was entirely adequate for a 7500 rpm 2-liter motor.


Norm

 

Honestly, I was already thinking of a dual exhaust myself considering I'm coming from a V8 background... Always room to grow to become Maximus Beastliness... I don't think it will look all that bad wit side tips if you do it wit the style you want from your car in mind... Do it brotha... I endorse it... I'll be soon to follow, I need to get other mods before I begin to look at my exhaust right now... :-(

 

This is tempting.