trbob16a

It seems to me like if you own a dremel you could do it yourself. I'd have to take my time, and measure it along the way, but it doesn't seem like it would be hard at all. Most air flow tests show that the air in an intake manifold will flow faster with a slightly rough surface, so it wouldn't have to be polished or anything. Additionally, with forced induction any slight imperfections I may leave wouldn't be too drastic as the turbo is cramming air in there anyway.

So why don't people just do this on their own? It isn't combustion chamber work or anything, what am I missing here?

Spade

http://www.theoldone.com Good advise for your own P&P.

earl

You can do your own manifold matching but not throttle body. That has to be perfectly round and matched to your oversized throttle butterfly plate otherwise the engine won't idle properly. If you port match with the manifold on the car, besure you keep all the filings out of the engine.

trbob16a

Right, but the butterflys can be bought. My intake manifold is at 64.5mm, I'd like to match my throttle body to it. I think I can keep it pretty symettrical by just using sand paper.. any other comments?

I'm pretty sure I'm going to do it this weekend and I'll let everyone know how the car idles after.

Edit: on another note, I don't really care how my car idles. I think that with other adjustments I can get it to the point where it will idle to some extent, and thats all I care about.


[Modified by trbob16a, 4:21 PM 6/21/2002]

dustin

I would listen to earl =P

earl

Where can you buy the butterfly from? How are you going to attach it to the throttle shaft? Please post your results.

int3gra

wouldnt it be a better idea to do it on a decent Drill press with the sanding drum?
center the drum into the throttle body and then do it......that way everything should be even.

Smashback

Yes, a dremel is not in any shape form or fashion the proper tool. It will never be right. Let us know how it comes out though...

X2BOARD

That sounds logical. If you do not get it even, the car will run like ***. Ever had a car w/ a messed up TB ? It sux...

dustin

How are you going to be able to evenly enlarge a throttle body with a sanding drum? It won't be perfectly circular.

That's why they "bore" out throttle bodies

trbob16a

I agree, it will not be perfectly circular, but will it matter? I don't think so. This doesn't have to be perfect. Intake runners and even the insides of throttle bodies are never perfect after 30k+ because they build up all this junk in them. The thought is just to make it bigger so it will flow more. Again, this isn't the combustion chamber, it doesn't have to be perfect. At least thats my thought on the experirement.

I'm about a half hour into this and I'll let you all know the results later tonight or tomorrow. I may end up using a lathe and actually boring it, but first I am going to test this with just sandpaper to see if anyone can do it for $10 worth of stuff.

I will put it back on the car first with the STOCK butterfly and see if I can get it to to idle good by adjusting the throttle cable and idle adjustment screw. If I can't get that close, I will get a new butterfly and post part numbers, etc. I know of a couple of companies that make them, and they go for about $5. Anyway I like to tinker so if I screw this up oh well, time to buy an ITR one.

dustin

But understand that the throttle plate and throttle body DO have to be perfect for the car to idle. It doesn't matter after or before the plate itself. But when the TB plate is shut, no air should be passing it -- the IACV alone should control idle. When you go all crazy ghetto with the grinder, it's not going to match up.

What's next on the list, boring out your own block with a hole saw and a drill?

=P

trbob16a

My thought is that if I can shut the IACV completely off so no air flows, the difference hopefully won't be too much and I can get the car to idle, just higher due to the air flowing around the butterfly.

Oh its ghetto, and I doubt it will work that well, but nothing ventured nothing gained. And b16 throttle bodies are crazy cheap used. Look for a post in classifieds soon: WTB: B16 throttle body ASAP!!!!!!!

dbman96

I think I've got an 84.5mm holesaw when you're ready to move up to some larger pistons.

trbob16a

I've already got 84mm Darton sleeves but thanks for the offer!

Finished it up, going to eat dinner and then put it back on. I'll post in a couple of hours how it works on the car. Pretty simple to do really, just wondering if all of that air that will get in around the butterfly will make my car rev too high. We'll see!

rjardy

if you were to do anything like that at all you would need a machinists lathe. If you know what this is then you know what im talking about (obviously). but still you are not going to increase the mass amount of air / fuel flow while retaining the stock butterfly. And what you said about air running faster over a fast surface may be tru but you would indeed have turbulent airflow and you do not want that. Just save some money and do it right. imho

Rob

earl

LOL

If I could only be there to hear this thing run

PrecisionH23a

$100 bucks says he posts that it runs PERFECT... i honestly wouldnt do this if i were you....