timmybighands

Hiya fellas. I'm hoping you can once again save me the trouble of finding out the hard way... I've just recieved my new boost-prepped nikki, turbo manifold and s4 turbo today, so I started ripping into the intake/exhaust to start making things fit.

I'm cleaning up the stock motor and intake parts, and I started thinking when I got to the intake manifold: is it nescissary to have the black plastic intake spacer anymore? I've removed the rats nest, so the vacuum nipples are mostly plugged... so what's the point in keeping it anymore?

The only thing I can think that I'll need is one for my dizzy's vacuum advance. Cant I just pull that from somewhere else, or do I need manifold vacuum to advance it properly? Hell, since I'm going turbo, do I even WANT vacuum advance anymore? Does the spacer itself do anything for the powerband, or is it simply there to act as a port for the vaccum nipples (and possibly a heatshield of sorts from the exhaust)?

I love making the car more 'simple'. So if it's not needed, I'll save myself the extra .28lbs and pitch it. Lol. LMK fellas. And again - thanks for the help. I'm certain I'll be posting with TONS more questions as my project continues.

timmybighands

Also, I'm curious about the butterfly inside the stock manifold. Can I remove that as well, or do I need to keep it for anything at all since emissions are removed?

timmybighands

Where's Scott and Robert hiding at?

inuissus_cendi

yank it and weld (or JB weld) up the holes.

as for the spacer I tried to remove it (new carb had its own vacuum ports) but found that without it the studs coming up from the intake were too long and the carb didnt fit on right. I'm guessing yours is the same way, so unless you can source an earlier intake or cut off the ends of those studs just leave it, or make some other sort of spacer/plate (I'm hoping to switch it with a nitrous plate soon myself )

timmybighands

Cool man, thanks for the info on the butterfly.

The spacer stud issue could easily be fixed with a couple washers on the top side to take up the slack, right?

Does the spacer itself change the powerband at all? And where are you finding a N20 plate at for a stock mani?

Thanks for the feedback bro.

inuissus_cendi

about the studs, no the stud itself bumps into part of the carb. When I was installing the carb I couldnt figure out what was in the way for the longest time.

About the powerband thing, I honestly dont know.

Some guy on the forum was saying he was going to fab up nitrous plates for the stock intake, haven't heard much from him since then. Otherwise nitrous express will make a custom plate for the right price. All you have to do is send them a gasket pattern. Kinda pricey though ($250 if I remember right, its in a recent thread somewhere)

timmybighands

Removed the butterfly already and JB'd up the holes. Modding for moddings' sake, eh? I musta saved another .2lbs.

My carb sits down on the manifold properly with no spacer... which is pretty cool. I guess now I just need to find out if I really do need that or not?

inuissus_cendi

Thats cool, i guess it depends on the year. and yeah by taking out the shutter valve (butterfly thing) you're probably freeing up some serious airflow too.

You know I'm starting to wonder how hard could it be to get one of those little fuel/nitrous rails out of a plate system and get it into the stock plastic spacer?

Oh and by the way mounting your carb straight to the intake, you're gonna want some sort of gasket. The plastic spacer served as the gasket before, but now that you're going metal-on-metal you're going to need something sealing it or you could have a massive vacuum leak on your hands.

timmybighands

I was already thinking on that one too. I think the plastic spacer is too thin to get a nozzle in there... but I'll tinker with it some tomorrow night after work and try to fit mine into it somehow. If it works well, I'll post back.

And I've already been looking for a carb gasket... cant seem to find one anywhere.

inuissus_cendi

you could make one yourself. just buy a sheet of gasket paper and trace the pattern from the spacer. then cut it out with a razor blade or something. let me know how the nitrous in the spacer thing goes.

Tranquil

iTrader: (1)

this thread needs serious bumpage

I'd like to know about the vacuum ports/noozles as well.

trochoid

iTrader: (6)

The carb spacer acts as a thermal break between the engine and carb, I would leave it.

steve84GS TII

Damn,beat me to it!

Ditto,it keeps carb temps down since plastic doesnt conduct heat as well as aluminum.When all intact,the spacer is also a large heat sheild,although often the extremities are broken off and only the core of the spacer block is left.

inuissus_cendi

How important is it really? Plenty of cars just have the carb mounted to the intake.

Tranquil

iTrader: (1)

My question is that is it possible to just replace the phenolic spacer with a nitrous spacer.

What vacuum is neccessary from it?

inuissus_cendi

depends on what you want to keep.

I'd recomment one vacuum port for vacuum advance, and you'll need one to vent the oil filler neck and the carb bowl vent (I think thats all right)

Tranquil

iTrader: (1)

Well I would go out and look at my FB which has the emissions removed, but its been raining for almost 3 weeks straight now.

trochoid

iTrader: (6)

The thermal break that the phenolic spacer provides has 2 major functions. It keeps the fuel in the carb cooler and helps prevent heat sink in the carb after shut down, This makes hot starts easier by reducing fuel percolation in the carb, i.e. vapor lock and flooding by the expanding fuel overflowing into the engine.

If the nitros plate is made of a material that does not tranfer heat easily, it will provide the same function. The plate is more than likely thick enough to tap whatever vacuum ports are needed.

As a side note, removing the spacer reduces the intake tract length, though minimal, it may have a minor affect on low end torque, for those that are trying to squeeze every last 1/2 hp potential out of thier engine.

inuissus_cendi

ok, so i get the heat sink part. but other than that isnt warmer fuel better on account of it atomizes more completely? I've always sort of wondered about that, especially when I saw those little Cryo CO2-cooled fuel bar things (little devices that use a bottle of CO2 to cool your fuel.

I'm probably missing something here, but thats the point. I want to know what.

aussiesmg

iTrader: (1)

The only Vacuum I have is from my intake manifold, not stock, one to vacuum advance, the second to the brake master.

warm fuel is bad, cooler is better due to density.

inuissus_cendi

Density is a factor for a gas (as in vapor, not gasoline gas which I'll call fuel just to avoid confusion) but it doesnt make much difference for a liquid.

Its not like warm fuel is going to displace significantly more volume than cold fuel. Thats the purpose of cold air intakes and such, but thats only with air or other gases.

As far as I can see hot fuel would be better because it will atomize better and make for a more even distribution in the engine, letting everything burn better (instead of having lean spots and rich spots).

Sorry maybe you're right but it doesnt make sense to me. If anyone can explain it please do.

aussiesmg

iTrader: (1)

Density does count, your optimum fuel mix is 14.7 to 1, the denser the air the more fuel, the more heat in the intake the less fuel, heat in the carb affects air density as well as the fuel.

Any increase in intake temp raises the temp and reduces the amount of air and fuel.

Remember the purpose of the carb is to mix fuel and air.

inuissus_cendi

alright that makes sense. I thought you were talking about density of the gas, not the air.

so hot or cold fuel? Doesnt make a difference really? (besides the hot start issues)

Tranquil

iTrader: (1)

cold fuel is best, because if its already hot, then it can burn in the intake
you don't want it to burn in the intake (same theory applies to nitrous)
you want it to burn in the combustion chamber

Anyways, I was just out there and the vacuum that I'm getting off of the carb spacer is for the dizzy, and the oil breather.

The dizzy can be put into the nitrous plate, and I figure the oil breather could be adapted by other means.