Hi there, I was wondering, if I would put on 2 mandrell bent exhaust manifolds on my VQ30DE, and run complete exhausts from both manifolds to the back of the car (so every cilinder bank has it's own exhaust, no Y pipe anymore), would that make up some more HP? Or do the banks need eachothers backpressure to operate properly?

 

If you designed it with the right pipe diameter you would probably see some nice gains w/o much, if any, lose of the low-end. I bet it would sound pretty cool too!

I wanted to go with the cattman headers, but am worried about throwing CELs.

 

How could I found out what the best diameter would be for my dual setup? I think it would really rock not to only look like dual exhaust, but actually have dual exhaust. I could however use the cattman Y pipe and headers to, saw the Y pipe it's join point off and weld two new flenses, then I could design and weld some piping and find a way to place 2 muffler's and I would be all set, I would not place the Kat, it is a law in the Netherlands you should have one, but before the yearly checkup I can quickly put the original exhaust system on it, pass the test and change it back.

 

Nope, that would probably hurt performance. NOT a backpressure. A loss of scavenging effect issue

 

It would be alot of work for most likely a loss in performance. It would take a tone of test fitting and diameter testing to get it right.

 

But if you would get the right diameter, and the job was done right, could it make up more power then stock or single cattman exhaust?

 

I doubt it.

How many sets and dyno runs are you willing to try to find out? Consider that time and cost vs how much it would be just to buy a Warpspeed/Budget/Cattman Y and be done with it.

And you STILL would lose the scavenging effect. Which is the whole point

edit: just noticed your from NZ. Shipping/buying from the US might be alot. In this case. Just make your own Y pipe. That would be the best solution

 

Why not just buy the cattman headers and then the Custom Maxima dual cat back system? It would look nice, give you probably a 25-30whp increase, sound good, and cost you a lot less that developing your own "true" dual exhaust.

Just a thought

 

Ha you're dreaming. 15 hp maybe from the headers and 2-3 from the dualies.

 

Why isnt this posted in the maxima forum?

 

You think? Ive heard you can get almost 15 from a lone Y-pipe. I thought headers were good for about 20 and I would think you could get at least 5-8 from a catback.

This wouldent be the first time I was wrong though.

 

Do the 190hp VQs not profit very much from the exhaust mods?