has any ported there throttle body.
any vg's???

 

any one? any port there intake manifold be fore the throttle body on the vg? does the v31 na vg have a bigger throttle body or intake manifold??

 

no one I know of.

as for the other question...I take it you've never actually seen a Z31 TB before...

 

Put it this way the maxima makes almost 10lb-ft over the Z31 engine. The only real change is the intake manifold + throttle body.

 

o so the max has higher output than a na vg i see

 

There is no reason that you can't port the TB that you have stock. Just port out as much as you can and keep the stock TB plate. If you touch the metal where the plate sits, then you will have major idling issues and intake leaks.

I really doubt you can find any TB that is bigger than what you have and still be able to bolt up since you have the dual butterflies.

so, if you want to,... port out your stock TB and match the manifold. Nobody I know has done port work to the stock VG TB. But I have friends that are in the process of porting it.

 

Would this be a worthwile mod in terms of power gains? How much could you actually expect to see if you ported the TB including where the plates are and getting new plates. If no one has done any of this on a VG are there numbers from other cars that we could look at for some type of comparison in potential gains?

It seems to me that given a milling machine this wouldn't be that hard of a project. I would think someone would have done it before.

 

the gains will be minimal in my opinion.. yes it would open the flow of air in the intake side. but i dont see ne more than 1 hp or itf that.. and maybe .5 or so torque..

 

Well, someone has dyno proven that a ported VE TB is good for 6hp and 13tq.. I think those numbers are right. But my personal experience, I was only able to see about one tenth shaved off my 1/4. Which is not a noticable mod in the butt dyno. If you are looking to go fast, then do intake and exhaust and then you can look at your options for little things such as a ported TB.

 

lets look at relaity though.....for an NA VG which has the breathing capability of a 400lb out of shape fat man who smokes will it even be worth while?? I can see gains on the better top-breathing VE, but on VG with just bolt-ons, don't see the worth.... call me a skeptic

 

maybe i shouldnt have sent the money for the y pipe..

 

hey 6 hp would be nice

 

i am going to port my TB on my VG.. i would think you coulld see a differences alittle not alot .. i think you could feel a difference. plus more air the better... i will let you know how it goes when i do it..

 

rock on does anyone have any link to how to port write ups

 

Okay after reading some of the other post's I had an eppifany. As someone already pointed out the air we breath is approximatly 14.7psi. If my understanding is correct (and correct me if I'm wrong) almost all cars unless boosted more then 14.7psi are working on a vacuum. That is when the intake valves open the air is being sucked into the cylindar not pushed.

So this is why porting can be so benificial. Going on reccolection of the size of the TB when I was cleaning it(if anyone has the actual measurements please fill in) I would estimate the diameter around the plates to be about an inch. So total area around the two plates is a total of say 6.28in^2.

By porting the area around the plates to a diamter of say 1.125 it would increase the total area around the plates to 7.95in^2 for an increase of 25% more area.

So assuming the area around the TB plates is the most restrictive area of the intake it would seem a 25 percent gain in area could be at least a little benificial.

Any thoughts to where I might be wrong?

 

good info, but even with the VGs un-aggressive and short duration cam profile...I don't see having a bigger TB making any REAL benefit. now if you were going with a more aggressive cam with longer duration or doing a nice N/A setup maybe, but I truly see no worth on a bolt-on VG. just my $.02!

 

so....basically it is not worth it if you dont have time. I think i am gonna do it in my spring break. I am gonna do the TB and upper intake. I will mostly clean and do some porting for better flow.

 

its not about time...its about being worthwhile and not making any significant gains...the VG's breathing capabilities up top are horrible due to the 'weak' cam profile/duration...unless you plan to go with a bigger cam or doing some major mods, this is a waste IMO. I see it as this, now you have a greater capacity due to the porting, but you still have the same weak short, breathing thanks to the stock SOHC cams. of course I'm speaking off speculation, but until someone actually does this and proves otherwise, I'll stick to my speculations.

 

but will this not help with better gas mileage? it isnt always about hp gains

 

I thought there was a set of cams for the VG that went for about 500 bucks. Aside from the amount of work involved 500 bucks doesn't sound like to much if the gains come out reasonable. Does anyone remember who makes the cams and how much they were? Also did they make any difference?

 

yeah, matter of fact there are more than 5(Nismo, MSA, WEB, JWT, etc.) types of cams avaiable for the VG, prices range from $220 for regrinds to $550 for JWT billets...but still $500 for the cams and another $500+ for the install probably. the install ISN'T your average DIY job. maybe more considering you need new gaskets and head resurfacing. before my accident I was in the process of building my spare motor up with Motorsport Auto 270 cams...its no cheap deal...complete engine gasket kit will run around $200, acid bathe the heads, install the cams, gaskets, lifters, new valve stem seals and entire motor was gonna cost me around $400(I got the hook up on that), and I hadn't even gotten to the resurfacing the heads and re-doing the exhaust studs yet. also new lifters still would've costed me another $100-120 and thats a definite when installing new cams into an older head/valvetrain.

the gains are worth it, the cams(the Nismo Euros at least), full bolt-ons, P/P heads make the VG into a whole nother car!