i ALWAYS see people posting up about these, asking every question imaginable.

*edit, sorry for crappy pics. they get the point across, but this camera sucks.


(please, if you quote me, dont quote my WHOLE post, as i dont know how much bandwidth photobucket is actually gonna give me. if someone can host these for me, lemme know)

well, this thread isnt for that. i'm not going to go into the details about how they affect idle, performance, are they worthwhile (imo, yes), or any TECHNICAL data. all i'm going for here, is to show you HOW to do it.

tools you will need:
large air compressor (i use a 26gallon / 8.4SCFM @ 90psi, and running my die grinder continuously @ 50psi, i'd have to stop periodically to let the compressor catch up)

pneumatic die grinder (i use the $15 Husky h*me d***t special, worked great for almost 2 years now, and countless sets of TGVs, manifolds, turbos, etc etc)

carbide burrs (not NEEDED, as this is aluminum, but makes life 100x easier). i did MOST of the work with a single-cut tree-shaped bit. a double-cut or aluminum specific burr would be better (less galling)

can of WD40 (or your preferred cheapo lubricant. WD40 is cheap, and works great, and i had a spare can of it)

flapper wheels: i use 1"x1" 60grit and 80grit. you CAN use 120grit if you REALLY want, but its not necessary). plan on using at LEAST one whole 60grit and one whole 80grit wheel. i DO have a homemade porting tool that cuts down on this, but thats another thread.

time: this will take you a solid 2-3 hours to do correctly.

disclaimer: not my fault if you screw up, blah blah, removing emissions equipment is illegal, blah blah, etc etc, this is a guide only intended for professionals, etc etc.

note: you will have to find your own way of sealing up the holes. you can use a tap, brass plug and JB weld, or you can weld the holes shut (its cast aluminum), use alumaloy *TMS has had great luck with this*, or simply reinsert the rod to avoid that dreaded CEL. if you want more details on these methods, PM me, or SEARCH.




step 1: remove your intake manifold (leaving the TGVs on during this process makes its easier). not gonna explain this one. if you cant remove the manifold, DIY TGV deletes may not be for you.

step 2: remove TGVs from manifold. set one in a vice, as you dont want things jumping around on you.

step 3: remove the stepper motor and sensor. (i suggest sensor first, just because it is rather delicate, you'll need a SMALL phillips head screwdriver for this, and probably some PB Blaster). to remove the stepper motor, it's an 8mm or 10mm (can't recall)

(sensor, removed)


(stepper motor, removed)




step 4: you need to remove the screws holding the flappers in place. this can be tricky. it's IMPOSSIBLE to simply unscrew them. they are peened over at the factory to prevent them from falling out and being ingested into the motor (a la, Nissan Sentra style). you'll need to grind the back of the screws off before you can attempt to do this.

(before)


(after)


now, you MIGHT not be able to actually remove the screws. if thats the case (or you strip it), a 5/32nd's drill bit is nearly the EXACT same size as the screw (just a hair larger), and is perfect to drill them out (in which case, grinding isnt needed).

final goal:



you can now remove the flappers.

now, its time to remove the rod.

step 5: reposition the TGV housing in the vice, with the tab-end of the rob facing up. take a hammer, and give the rod a few gentle taps, then a good whack. it should pop out rather easily (it's pressed in, beware)



step 6: the porting can begin!

now that you've got a clean stripped TGV housing, its time to get started. we want to remove the divider wall, and the lip that the flapper used to stop on. now would be a good time to get those gaskets, and mark out how far you're going to port the TGVs (i typically dont enlarge the housing too much, because unless you're porting the heads too, you end up with a pretty good sized step, and reversion = evil, especially when it's a 1/2" beyond where the fuel injectors are spraying.

wall to remove:


lip to remove:



step 7: the porting actually begins now. to remove the wall, i just used the carbide burr, and cut a slot in the divider wall.



you'll have to flip the TGV housing end over end a few times to accomplish this, but the final product looks something like this






now, if you have an airsaw with a long blade, you can use that too. i just prefer the control of a die grinder over a sawzall or something like it. a mistake with a die grinder doesnt remove a ton of material. a mistake with a sawzall can send ya to the hospital, so be careful.


the rest is rather simple. you take down the lip where the flapper sat, smooth out the ridges you left in removing the dividers, and enlarge the whole housing just a bit.

you then start with a 60grit flapper (or a stone, or a cartridge roll, as another intermediate step, i used a homemade cartridge roll setup), and begin smoothing. your goal is a slightly rough surface. mirror-smooth is actually bad for flow (thermodynamics major, chime in here). your final results are typically quite gratifying

before and afters






a big thanks to TheMadScientist, as he's the one who originally showed me how to do this.

saving space

Nice writeup, Lurch.

niiiiiiiiiiiiiiiiiice.....now if I had tumble valves i would know how to get rid of em

Good write up, hopefully this cuts down on all the questions being asked!

I really need to get around to doing this someday!!! Maybe when I ceramic coat my manifold.

looks good!

lmk if you need webhost space for pics.

and hey, do you have two sets of tgv housings or is your car down for this work?

i should really get around to doing this before i get tuned.

you dont want to use ceramic coating. you want to use a thermal dispersant. check out Techline Coatings. they sell stuff that'd work great for that application. and, you can get the good stuff (some stuff is bulk/shop order only, and cant be shipping to residential addresses.

this was a set of my buddy gary's car (had a couple days downtime, reversed manifold build), so i took pics. Crucial will sometimes have extra stock sets they'll sell for short money (mark got a set after he melted one of his spares with an acetelyne torch, trying to speed up the alumaloy process lol). otherwise, junk yards are your best bet (im actually looking for a spare intake manifold/TGV setup, to port/sandblast/coat for my upcoming build).

not sure if i completely agree with you on this. imo, either material will work. technically with a dispersant you want wind/air to be blowing over it to "take out" the heat....at least that was my understanding of the correct usage of a dispersant. since we are talking tgv's here, there really isnt any air being blown by them since there are sheltered underneath the manifold. my personal tgvs are thermal barrier'd. i use techlines coatings for all the stuff i do.

this has been an issue that i havent completely come up with a resolution that i truly believe in....this is just how i feel so far.

Ok just curious why the smooth surface is a bad thing. I am no thermodynamics major, but I would like to understand the theory behind this. One would think that nice smooth flow would aid in getting the air in there....kinda the whole reason for deleting these right?

So I searched for like 4-5 hours last night and all I could come up with was some theory behind head porting...not so much for intake stuff, but maybe the same. What I found said that for street driving the rough surface on the head makes the stream of af mixture tumble into the cylinder heads making it kinda cloud up the chamber for better combustion, less emissions and better response in lower end and midrange driving. This makes for better, faster burns, low end torque and better streetability. On race applications it is useful to actually have things smooth and it is more like a jet stream going into the cylinder head, thus allowing more to be shot into the chamber. They are more concerned with one particular RPM range and are not concerned about low end torque, just peak numbers and thus want to shoot as much fuel in as possible. This was about all I could find on the subject.

Something about how you don't get laminar flow unless there is at least a little surface roughage. I don't remember exactly.

By doing this mod is there a big difference in low end power and throttle responce. Looks like a sweet mod to do but are the performance benifits alot? Just wondering don't know much about this mod, also was wondering from somebody with it done if it's an awesome improvement.

its hard to explain. ill try my best to explain it, and if i find the diagram i had once upon a time, i'll post it.

with a smooth surface, air is allowed to bounce all over the place. theres nothing thats actually make the air follow the flow of the manifold, except the pressure pushing it. (we're talking a mirror-polished surface here)

with a SLIGHTLY rough surface (we're talking smooth to the touch, you you can see some graining in the metal), the air "sticks" to the rough edges, and acts as sort of a "lubricant", allowing air to flow over it faster. imagine it as pushing a metal block across a smooth concrete floor versus pushing a metal block over a not-as-smooth concrete floor with a light layer of grease filling in the rougher areas.

i'll try to MSPaint/sketch something later tonight, so i can illustrate my point.


there IS science behind it. maybe some Nasioc-thermodynamic engineer will chime in with the technical data.

Good stuff. I follow your explanation. So I guess my next question is which way do you want the grains to go? Will cuts across (perpendicular to the airflow) the flow hurt or help?

Great write-up, thanks Jasper.

Exactly. Thermal dispersant will not help for the IM as there is no where for the heat to go. You would be dispersing heat into heat. Ceramic coating would block the heat from getting to the IM which is much better given the conditions. I would thermal dispersant coat the IC though in a heart beat. Everything else in the engine bay that does not have air flow I would ceramic coat.

Jasper, what did you do about the holes left over from where the rods go through?

personally, i went overboard (bored @ work w/ a Bridgeport), and machined caps that are identical to the TGV stepper motor and sensor, and will use those to cap the holes off in the future)

you could weld em (if you know someone who can weld cast aluminum....which is what i'm doing if i redo these anytime soon....right now, i left the rod in on my own personal car, just because at the time it was convenient (needed the car back together THAT night)

the EASIEST thing to do is drill and tap the outermost holes. brass plugs + JBweld, they'll NEVER come out / leak.

as for the holes between the runners? left em alone. air leaking through that wont make a damned bit of difference.

i understand the reasoning on the thermal dispersant vs. thermal barrier, but with a FMIC, the only thing my scoop does is blow outside air over the top of the motor. i know its not a lot, but i'm sure it helps a bit.


as for the direction of the graining? dont think it matters...as long as theres SOME texture there.

.....

Wow thanks a lot ... a possible next project

So what do you guys think of the final product? I had my intake off and everything but didnt go ahead and do it beacause I brke a bolt holding the TGV's on to the manifold. Anyway I want to do it and leav the rod in to take care of the cel. Just wondering if I will still be able to daily drive the car without getting a tune for them. Please share your input!!!

Thanks

so do u just put the stepped motor and sensor back in wen ur done? and do u plug it back in as well?