C.A.R

Is there a write up on how to port and polish a throttle body after the "Throttle Body Mod?"

Edit:
Let me clarify... I know nothing about porting and polishing except that you take a dremmel and make holes bigger... I have never one it so I would like to ask for pointers and advice on how to do it, what to look out for, etc.

Please excuse any absent "D's" in my post... The "D" key is next to usless on my keyboard...

Thanks for the help...

jm93rx7

iTrader: (7)

http://www.fc3spro.com/TECH/HOWTO/TBM/tbm.html



http://bdc.cyberosity.com/v/Throttle...bd8ab6a32363f5

NZConvertible

Actually you don't make the holes any bigger. All you're doing it smoothing out the shape of the entry to the throttle bores.

There's really no write-up needed, as it's pretty self-explanatory once you look at it. Here's a couple of photos of what I did to mine, make yours look something like that. Don't expect any noticeable improvement.

https://www.rx7club.com/attachment.p...7&d=1141103624
https://www.rx7club.com/attachment.p...6&d=1141103494

And there is absolutely no point in polishing the inside of a TB. I cannot imagine a bigger waste of time...

C.A.R

I dont expect anything huge... I will just have an extra TB on hand soon and thought I would give it a shot...

Why did you do it then?

Is the TB mod worth it, In your opinion?
(this is not to start a super long discussion on whether the TB mod is worth it... I am only asking on person's opinion on this... Of course if you have an opinion, I cant stop you from expressing it since this is a free country...)

NZConvertible

I didn't, mine isn't polished at all. I used an air-powered die grinder with a carbide bit to do the bulk of the metal removal, and gave it a quick rub with some sandpaper I had lying around just to smooth it out a bit. I only bothered doing this because I had the UIM off for other work, I had the time and the tools, I enjoy doing this sort of stuff, and I know that in theory flow is improved even if I couldn't feel it. No downsides.

If by "TB mod" you mean removing the double-throttle system, then yes for Turbos, not really for NA's. This is because the respective TB's operate differently.

On Turbo TB's the upstream secondary throttles are damped to improve drivability (due to the long intake tract), but this dulls throttle response slightly. Removing them improves this. On NA TB's the upstream secondary throttles are held open all the time once the engine is warm, and so do nothing but add a little restriction. Because the TB is already so big relative to the NA's power, taking the plates out is basically removing a small restriction from a small restriction, which has very little effect.

Removing the cold-idle thermowax is often done as part of the TB mod. I don't recommend this, and it doesn't have to be taken off with the double-throttle system.