Tony at Jotech told me today that aftermarket plenums are totally overrated and that almost all the dynos they have done with aftermarket plenum yield almost no results.

Is this true?

He said their tests included the Crawford plenum on a couple of 350Zs.

He told me to save my money and use it on something else. He encouraged an exhaust system and cats (which I plan doing anyway).

So according to him, the plenum is $300-$400 down the toilet.

Thoughts?

 

There's a lot of real world data here on the G forums regarding plenums, and Tony is a wealth of knowledge as well.

But think about this...he's there to sell products for Jotech. Jotech doesn't carry plenums, but they do sell exhausts and high flow cats right?

 

def not overrated, its the best bang for your buck mod, other than crawford cats

 

everybody has a different opinion on everything

thats why i listen to the majority, not just one or two people

 

Good point Moog.

 

The crawford plenum was the best mod i ever did!!! PERIOD!!! LOVE IT and would buy from Crawford again in a heartbeat! Actually, I am ordering their high-flow cats shortly! And yes, I feel the difference with the plenum, and noooo I am not one of those guys that puts a K&N on and feels a difference. I had a baseline dyno done and once my cats and exhaust are in, I will do a post!

 

I asked the question, because I have a stock 2005 G35 AT (stock...with the exception of the AEM intake).

I've got around $1000 to play with.

I haven't changed the exhaust system yet, but figured I would replace the cats first, then get a Crawford plenum.

I figured those two would be better than throwing on a Fuji or Borla exhaust system. I want to do aftermarket exhaust, but want to spend my money wisely.

Is this the right plan of attack?

Basically, pick one or two:

You have $1000 to spend.

1) Get the high flow Crawford cats and plenum

2) Get a Borla or Fuji exhaust system

 

Cat and plenum. Read the last 2 years of plenum results and you may agree. Read about exhaust and you'll get the best results IMO from the stillen - I simply represent that as the consensus and not from experince. IF you can handle the noise that is one hell of a bang for the buck exhaust apparently.

The Cats and Plenum do better in terms of raising the power peak for ponies and helping the engine get some life up high in the RMP band. That's sort of a fundamental improvement without all the noise. I bet you get as high as 20 ponies from the crawford cats and plenum. The standard bolt ons don't work too well for the VQ motor. I would read this forum for a while and figure out what happens from actual experiences. Take your time and enjoy.

 

Thanks SixFive!

 

Sounds like to me that the factory exhaust isn't really all that bad. I've yet to really hear anyone bash it. Otherwise, I would have thought more people would have told me to trash the exhaust system first.

So, I guess hi-flow cats and stock exhaust are better than stock cats and aftermarket exhaust.

 

from what im hearing and the resuls are still up in the air is that plenum spacers are not doing much for the '05's. As far as crawford plenums there stil lhasn't been anything concrete as far as '05 due to infiniti changing the plenum and making it better as far as i hear it.

 

thats what I was about to say. Didnt Infiniti upgrade the plenums for the '05 models? So an aftermarket plenum on an '05 would do very little to no improvments... right?

 

I felt the effects from my Crawford Plenum.

 

I felt a difference with my cats and plenum. From everything I read before buying, the worst part of the stock exhaust was the cats, not the cat-back. No dyno numbers, but the sound and performance of the cat/plenum combo were worth the money to me. I'll probably get the APS TD exhaust when it comes out.

 

IMO you will get better results with the cats and plenum vs. the exhaust. Do the cats and plenum first then save up for the exhaust.