Cold air intake for a C3..

[Donbecker]

Last night I completed my DIY cold air intake for my C3.

My case is a little different as I have a C4 intake manifold, but I think it would still work for others that have C3s.

I need to do some cleaning on it and take a test drive, but I have pics and I'll post it on my website later today (I'll post a link later when they're up)

BTW, I got everything I needed at home depot.

"Cold air intakes, you can do it, we can help."

-Don

[Phoenix FRC]

Nice...

Let's see it..

In Grand Prix land I have home made several different versions of cold air intake systems, the cold air box and the FWI, Fender Well Intake systems.

For my Pontiac I removed the drivers side fog light and used areo duct and made a ram air system.

I'm all about do it yourself projects.

Looking forward to seeing the pics..

[Donbecker]

Well, I did the intial test run before lunch.

I was seeing on average 160o to 178o+ on my intake temps.

I have a C4 intake and my temp sensor get a ton of heat soak from the engine which is why the numbers are so high.

The highest it got on the highway was about 130o-135o, which was a pretty big drop.

I've glued some of the pieces, and have screws in a couple more areas.

I need to get one more piece to finish it, the pics/link should be up tonight, along with a parts list and dimensions for everything.

[Donbecker]

See the pics below...

[Eddie44]

The link says I need a password????

Just copy the link and paste them in your post.

[Desertdawg]

Yep password needed......

On the 82 there is a functional cold air duct molded into the hood, but I don't think it would adapt to the TPI.

[Donbecker]

Here is an overall view:

Here is the T pipe, note that eventually I will get another filter for a dual intake

Here you can see the filter thru the front grill:

Ground clearance shot:

Another ground clearance shot:

Top shot:

Down pipe assembly:

Around the sway bar:

[Donbecker]

Ground clearance shot with tape:

Lower pipe assembly:

This is the hole I put in the lower spoiler to pass the pipe thru:

The same hole with the pipe in:

Directly under the headlights/bumper where everything will go:

This is the center of the bumper area where the T will go:

Modified T pipe (needed to cut about 1/2" to 3/4" off one coupling to get it in place):

Completed:

I need to find my list that has all the items and the mods I did, should make it easy to duplicate.

Some parts were glued together, others that needed to be removable have a couple of small wood screws in them.

Let me know if you have any questions.

[Donbecker]

BTW, this sorta requires you to not have a mechanical fan and no shroud. (Kinda obvious... )

[Togo]

cool write up - and cool pics - now that that finished mold and have a 4" stainless mandrel bent tube make for it :D

just curious - is the location of the filters something that might be prone to taking on water?

if NOT - maybe you should opt out of those DUAL filters and the T and use one of these

i seem to recall a guy in a C5 a while back at XTREME that had a "T" setup on his car and it was causing optimum HP numbers on the dyno - once it was removed and replaced with a single element filter, the airflow impoved significantly and of course, HP numbers went back up!

just a 2 cents!

[Donbecker]

Well, I didn't go to deep into what the situation was before, so I'll type up some details here.

First, on a stock 76 (I don't know about the other C3's), the intake going to the air cleaner is this black plastic part that clamps over and under the top of the radiator support frame, directly above the radiator.

So, all the air going into the engine is first running over the top of the radiator and condensor.

Now with my setup, I'm using a C4 intake that has a throttlebody on the front. So at that point I went with a K&N filter that just simply clamps to the front of the throttlebody.

The opening above the radiator was left open (after I removed the old intake) but I knew that I was getting alot of hot air from the engine compartment.

Shortly after putting the filter in, I noticed that the mech. fan was hitting the metal end cap on the filter. It was all a tight fit.

I noticed about that time that my radiator was leaking. So I dropped somewhere around 3k on a new radiator, support frame and dual spals from dewitts.

This helped the temps in the car, and it helped as there wasn't a fan hitting the filter, but I was still sucking hot air in.

I am definately getting much cooler air, my IAT (intake air temp.) sensor is reading around 40o cooler.

I suspect that it will breathe even better when I get the second filter on.

The car feels alot faster and more responsive.

Do they use fans in the front on the dyno? I would definately be willing to try it with and without the intake to get real numbers on the difference.

The way I put everything together, I can tear the whole thing out and have the filter back on the throttlebody in 5 mins with a flatblade and a philips.

Good point about the water, but I have around a foot or so between the filter and the ground...a little water probably wouldn't hurt that much.

The only thing I may do is put some wire behind the grill and in front of the filter to keep the high velocity rocks out...

[Donbecker]

Also,

I had to make a couple of last minute changes to the elbow up top, as well as the length of the down pipe.

I'll take some pics tonight and remeasure the bottom as I think I have more ground clearance.

[Donbecker]

Man, I'm surprised that more haven't been interested.

Anyways, here is my list:

1 - 3" to 4" rubber coupling - no mods (throttlebody to downpipe couple)

1 - 3" pipe - 3" long (downpipe couple to short 90o)

1 - short 3" 90o - cut off have of one couple end (short 90o to downpipe)

1 - 3" pipe - 18 1/2" long (downpipe)

1 - long 3" 90o - no mods (long 90o to forward pipe)

1 - 3" pipe - 8" long (forward pipe to 22 1/2o elbow)

1 - 22 1/2o 3" elbow - no mods (elbow to forward pipe 2)

1 - 3" pipe - 3" long (forward pipe 2 to T)

1 - 3" T pipe - remove half of one of the couples (T to filters)

1 - 3" pipe 6" long (filter pipe)(for each filter)

1 - 3" pipe 3" long and 3" end cap (if needed)

The pics pretty much spell it out.

[Desertdawg]

Probably a few looking, but remember, your the only one here with a TPI C3...

If you used white pipe, you could warm it up and bend (flatten) it where there might be ground clearance problems. but seeing how high yours sits, I bet you never hit it anyway, mine drags on every ramp I see...

You might get some wet filters if you drive in the rain, it will enter through the grill, and it will plug up the filters too...

Other than that, I think you did a great job, nice planning...

[Donbecker]

Yeah that makes sense.

I don't think I'll get much (if any) water as the air takes a 90o turn as soon as it gets past the filter.

Is the black pipe able to bend with heat?

[Desertdawg]

I don't think the black pipe bends but you can always take a scrap piece and try it.

The point I was trying to get across about the rain/water, is that when your air filters get wet, they will not flow any more air, they plug up. I know because my work truck has been in the floods a few times, and if you get water on the filters you have to remove them to get the motor to run.

[Guest Simpson36]

Man, I'm surprised that more haven't been interested.

Hey, I'm interested in any and all fabrication threads . . . . I just don't have TPI on my C3 . . . so I don't have much to contribute. Nice looking job though!

On the other hand, I know of a fellow on the Cross Fire forum who's going to be your best friend if he decides to go ahead with the same conversion.

Is there a thread on your TPI mod?

[Donbecker]

Hiya Simpson...

No, not a thread, but as I went I took detailed notes, and pictures of everything...every part number.

Actually there may be a thread or two, but I've been meaning to get my website up with all the stuff in one place.

I'm home today, maybe I should work on that!

[Desertdawg]

Steve,

Have you seen Noel Carboni's web site, I know it's not a GM TPI but he went through some of the same mods to get it to work... I think he did his about 6 years ago.

http://ncarboni.home.att.net/NC82.html

He took some fantastic pictures of it too...

[Donbecker]

I've seen that before...he didn't provide alot of detail about the air box intake though.