how much time does it take to install headers on a VQ3.0dek Also is there anything i should look out for ( special tools needed ) and if i would need new head studs......

 

just did that last weekend. it took about 5-6 hours at a moderate pace. (with air tools and a rack)

First get the heat shields off. kinda a pain, but not bad.

then take the y-pipe off

You'll need to remove the crossmember under the motor. then take the (front and rear) motor mounts off the brackets. get the brackets off the engine and go to town on the manifolds. (swivels and extensions will be a life-saver) sometimes the nuts came off the studs, other times the studs cam out. either way you should be fine. mine went back together fine.

Also, if you're getting oem nissan gaskets (which you should) look into gaskets from an xterra with the 3.3 v6. I don't remember what year it was, but we happened to stumble upon these because they looked identical, but the part number was for the xterra, not the max. Anyway, they were about 8 bucks as opposed to the maxima's 25ish. worked fine.

EDIT: this was on a 97 vq30de, not de-k. AFAIK it shouldn't be any different though...

 

I'd put aside a full day, take your time, and have patience because it sure will get tested at many times during removal and installation.

 

a full day or two depending on how things go. it took me two because i was so frustrated.
removal of the the upper intake manifold +throttle body, radiator fans, lower crossmember and rear motormount, ypipe. tag and bag every bolt and hose because there will be a lot of pieces loose. when removing the lower crossmember, remember to jack up the tranny/engine so it doesnt fall down. using new gaskets will make things easier in the long run.
for tools: a slew of extensions, swivel joints, closed end swivel ratchet wrenches were my friend, an assortment of sockets, and lots of patients.

 

depending on the amount of time you have and tool you have accessable to you. It might be easier and faster to pull the motor and install the headers.

take a few hours to pull the motor. 20mins to install headers, another couple hours to drop back in.

a radical idea i know

 

If one has the tools to pull the engine then one also probably has the tools to do headers in the car relatively easily by dropping the cross member/using air tools...

 

very true. Having the tools and the space to use them are two different things.

But I imagine no one would pull the motor just to install headers. it was a wild out there suggestion. If he needed to change his clutch too then such a move could be better justified.

 

I'll add that there's more than one way to skin a cat. I never removed the lower cross member or messed with the motor mounts. I removed my MEVI to gain access to the tricky bolts.

 

^ ^ ^

me,too.... Lots of work, and tall jack stands, 3/8" flex-head ratchet, plumber's wrench, 6-pt sockets, lots of assorted swear words and tools, and patience..

Lots of patience....

.

 

mmmm dont think you will need to worry about those

 

dont forget WD40.. dont want a broken bolt or stud and break more things with anger ;D

 

have fun with the removal and install and like everybody said you need patience and make sure to ling everything up before you tighten any bolts down

 

that was my situation...too bad i didn't have the clutch yet! still don't

 

isnt there a specific pattern for tightening down the headstuds/nuts as well? i dont remember ever since i installed mine.

 

yes there is. its in the fsm

 

I have seen talk of headers, but I have not seen anything mentioned about any gains. Anyone have some before and after dynos?

 

I tried the Xterra exhaust gaskets and they are not close. For one thing the exhaust ports are circular shaped on the VG33 gasket and the VQ ports are oval. I was lucky to get two VG33 gaskets from the local dealership and lined them up with some old VQ exhaust gasket I have laying around, then I tried lining them up with the Cattman headers. I don't see how the hell they can line up ok without some grinding and then you have to worry about the ports matching up.

The part # is 14036-0w000. I've checked the part # with the FAST CD and on Pinnacle Nissan's part website. This gasket covers all Xterra VG33s since they started making them in 1999 and until 2004. So something you did doesn't follow.

Both exhaust gaskets I have on there are only a year old, so Im gonna chance it and re-use them with the headers. It's too late in the week to order and get them by Saturday anyways.

It's taken a while for anyone to do this. However Im dynoing in another week or so with headers. Provided I can pull a similar A/F curve there will direct before/after dynos for a VQ30DEK with an aftermarket Y-pipe Vs. headers.

IIRC Cattman gained around 20 WHP from a stock Y pipe to headers.

 

Yeah when I first put my headers on a few years back I did it like that with no air tools in the drive way and without removing mounts or cross member. Definitely an exercise in patience on the rear header.

That's the missing link (aftermarket y-pipe to headers). I did dyno my Cattman's at the time but I was coming from stock so the 20 whp was over the stock y-pipe. I can dig up the old posts if anyone wants to see my dyno graph, or just post it again here I suppose...

It's also about area under the curve, the 20 whp is a peak number but the average gains over various rpm ranges were impressive too, I had all that info in an old post somewhere...