Im buying an extra TB off some guy and would like to port and polish mine, but i dont have the tools or expereince to do so. So just wondering what would it cost to have someone here on the forum port and polish my TB. i would need someone pretty expereinced of course.

 

Not worth any gains on an N/A.

 

Someone would probably want more than the cost of tools to do it.

 

^ (C-Squared) Doesn't know what he's talking about.

You can either send it to BDC for something like $150, or try it yourself on your spare TB; if it doesn't work out, buy 3 more. 1 of the 4 should be usable, and you'll learn something new.

 

yeah, thats what you should do, I ported my first one, and it turned out really usable. it's actually great. one tip, take your time, and when you polish it use mothers mag cleaner. One thing for porting it, the dremels a must. thats all I used, I used grinding stone, and stronger dis(get em at home depot) and the dremel comes with little polishing wheels that work great. good luck, I had fun doing it.

 

I agree with c-squared IF the modded throttle body is going on to a basically stock car. In my opinion, the TB mod falls into the catagory of "well, what else can I do?". Until you've made major modifications, messing with the throttle body is essentially pointless.

Also, don't expect amazing results. A little better throttle response, and if ported correctly a small power increase (assuming the rest of the engine needs that much air). The throttle body is not really a restrictions. Keep in mind that MANY people have had major probems with the TB mod. Lots of posts from people who have done this mod and not been able to get back their idle.

 

I have done a TB mod to 3 rotary engines, and all of them idle fine. If you are really concerned leave the BAC on, than you should have no problems assuming you did everything correclty.

Even without the BAC, mycar idles solid at 750(and its ported), it just has to be warm before it will idle.

 

Same with me. My modded TB idles fine too...but there are many that have not had this success.

 

I am guessing that they did something horribly wrong than. Maybe didn't seal the holes left behind from removing the throttle plates? I don't understand though, it is a pretty simple porcedure.

 

COst me about 5 dollars.

Jarrett

 

Yeah he does actually. It's only the Turbos that get improved throttle response from the TB mod, because on the Turbos the opening of the #2 secondary throttles is slowed by a dashpot. Removal of these throttles means the secondary ports receive flow as soon as you put your foot down.

NA's do not have this dashpot, and the #2 secondary throttles open at the same time as the #1 throttles. The only time they're closed is when the engine is cold, otherwise they're fully open, so there's no change in throttle response from removing them. They'll be a minimal reduction in restriction through the TB because of the missing throttles, but unless significant airflow improvements have been made in other areas, it'll be tiny.

I'm not saying don't ever do it. If the UIM's off, and you've got time to kill, knock yourself out. Just don't expect the same gains on an NA that you get with a Turbo. On a Turbo you're removing a feature that isn't there on an NA.

BTW, polishing the inside of the TB is a waste of time. The increase in flow from polishing such a tiny fraction of the complete inlet tract is probably not even measureable. Reshaping and smoothing the insides after doing the TB mod is definitely a good thing, but putting all that extra effort into actually polishing it is nuts...

 

My TII ran like **** when I removed the throttle plates. I could totally feel the primary to secondary injector switch over (switch over is not the right term, but you know what I mean, after all it's 3am), it hessitated bad. Seemed to me my spool up time increased also. I just recently put my plates back in, and it feels 5X smoother from 3k-5k.

Give it a shot, see how you like it, It didn't work well at all on my setup though.

Ahh, one more thing, the TB mod did feel better when I removed my air cleaner entirely. So I assume it was air flow related why it didn't go well for me. Needless to say I wanted my air cleaner on so i put the plates back in.

 

It's got nothing to do with the injectors. I presume you mean the secondary throttle opening.

You must have done something wrong to get those symptoms, but I have no idea what. The TB mod will cause a bit of a stumble if you slam the throttles open, but you quickly learn how to avoid that. It's still better than stock.

It certainly shouldn't have affected turbo spooling, that's for sure.

 

Good god, I swear I spool faster now!

 

I just strapped the secondary throttle open on my TII.
The opening cam was split and would not slide on the dash pot plunger.
It made a huge differance since they had been stuck shut.

 

Hell, I don't know quite why it acted like that for me. I didn't do any other part of the mod except remove the throttle plates. And it was just like day and night worse for me ?? When I think about it I had my car dialed in on a dyno and wide band with the throttle setup normal, then pulled the plates later on. Maybe it affected my fuel ratio enough that I needed to retune it like it, but I never did.

Anyways, Like i said don't take my word for it, try it yourself.. I have heard more good than bad, just somthing with my setup didn't like it.


-Robert

 

can someone link me t pictures of a good tb mod. i would search but TB is too short to put in the search feature. also my car has a half bridgeport, would it be worth it?

 

http://rx7turbo.com/tbmod.htm

Found it by using the search string "Throttle Body Mod". Very difficult....

 

i couldnt remember what tb stood for. so yes difficult.

 

lol!! No problem man, just had to get a dig in!

Jarrett

 

Here's some of the work I do on 13B and 13B-RE TB's:







PM me or email me at bdc196@comcast.net for any other information or questions.

B

 

Ive read alot from the 2nd gen archive that says the TB is a good mod to do on N/A. is there anything to watch out for or mistakes that often people do on the TB?

 

Purty!!! Nice work BDC!