theoretically.

with longer gears, come slower acceleration.


also to OP , with your g35X i wouldn't suggest headers, the gain is normally quite minimal and normally way top end.

also i thought they didn't fit auto transmissions?

 

Headers will fit the VQ35DE, regardless of tranny.

With regards to gearing, it's a very complicated thing and is dependant on exactly what type of acceleration or racing you plan on doing. For the 1/4 mile, the factory gearing in the X, rwd auto, and 6MT are pretty dang good. There is always a little room for improvement, especially if you plan to full out race the car in the 1/4 mile, but for a DD, the stock gearing is solid for the powerband of the car.

The only time gears would really be needed is if you dramatically changed the power delivery of the car. If you were to add cams, especially with an auto, gears are a necessity because you'll neuter low end power and some of the midrange power. But you'll gain upper rpm power and will extend the motor's ability to breath. In order to get into the new powerband (which will probably be wider as well), you need the torque multiplication of the deeper gears. Now if you've got a well sorted turbo setup, then the factory gearing might actually be a bit too deep. When you've got a fat and wide powerband, gearing isn't remotely as important because you've got a wave to torque to ride.

 

Thank guys. I appreciate all the info, i guess its a no no for headers. I see that some people say no because my car is a G35X. Whats the deal with my car being awd, is it faster than the rwd so i wont be able to feel it?Lol

Yes they fit automatic transmissions as DaveB said above. That is one smart guy i tell you.
No i dont plan on going forced induction unless i hit the lotto.


May i ask what bolt-ons u have? You have some good numbers for not being FI.
I dont know if i can reach your numbers but i have seen some people with my car put down 255 to the wheels. My friend has an 06z a/t stock and i just want to keep up with him because as of right now hes leaves me in the dust lol. The only time i pull is the first 1.5 seconds because of awd and stay next to him until 30 mph and hes gone after that. I plan on getting Osiris since uprev is here local.

 

If you are just getting headers just to get power out've them and just drive your car on the street, they're not worth it. But, if you were to drive the car in the RPMs where the headers made the gains, ie. RoadRacing, Trackdays, then yea! get them.

 

Couldn't disagree more. There are 80923498102934 things I would do for track days prior to this mod.

I have basically every bolt-on available except aftermarket headers + some that others typically don't. If you want the specifics I can pm you with them. Actually Uprev is in Austin, TX, but you do have a local tuner in NY (RT).

 

Yea can you pm me them please, yea I a meant local tuner.

 

Before and after Ichiba Headers (most similar to Stillen headers in terms of design) vs Tomei V2. Sorry, wish I had a stock vs Tomei V2 but i don't. Obviously the better one is from Tomei

 

Gabe....how did the cam install go? I am guessing red line is the tomeis?

 

Cams are not in yet, I'll see tomorrow. They pulled the top off already and started to swap it out.

 

Alright, thanks for the comparison.

 

I wasn't expecting much gains from the headers but I am very pleased to see that i got gains everywhere especially the torque. Comparing my results to other VQ35DE i was happy to see the differences. I'll let you know of the results or you can go here for some details about the dyno, the settings, so on so forth.

http://my350z.com/forum/northern-cal...ar-at-zcg.html

 

how do the tomei headers sound compared to your old ones? Any vids?

 

Tomei's are one of the 3 I would buy, but at ~1400-1500 installed the expense is too much at this point to justify them. I am glad that they are proving to be beneficial even on stock block DE's.

 

Been there, I did all essentials for roadcourse. wheel/tire, suspension, chassis and brake upgrades before doing any kind of power modding on the G35. IMO, headers made the most improvement in overall power usage on the track, powering out of corners and all. I had to make adjusments to my rhythm on the roadcourse after I had them installed.

Regardless, this thread is regarding whether the OP should get headers or not and not about what you would do before a trackday. I just gave scenario where headers could be put to good use.

 

Exactly, and the answer is unequivocally No at this point. I already pointed out that on a massaged motor, headers are worthwhile, but nothing short of that for the expense incurred.