To anybody who doesn't live in an extremely cold climate, you should REALLY think about doing this mod. Throttle response is so much better. I'm not sure if I actually gained any HP but the instant throttle response sure makes my car feel a lot faster. It is much easier to break the tires loose going around corners in 2nd gear because power gets to the rear-wheels faster. The best part is that it makes heel-toe downshifting much faster, as every blip of the throttle makes the rpms jump up a lot faster than before. I recommend this mod to anybody who doesn't need the cold start assist. I live Oregon and it froze the other night, and I had no problems getting my car to start the next morning. I had keep the engine about 1.5k for about 30 seconds or the engine would die, but its no big deal to me at least.

 

Any guess on temp?
Like freezing or what?

 

ok where do i find stuff on doing the tb mod

 

I have just done the next step (FD Mod) i have'nt run it yet as i am Partial Bridging my engine.

So other than cold start have u had any other problems? I was going to do that Mod but i am now running a FMIC so the Fd intake looks better (no IC holes).

So did u take the Cold start Buterflys out of the TB? That will be your proplem, The things u do in the serch for the perfect Seven LOL.

So what mods have u done?


Node u got a car yet? Cold is when the car has'nt run for a long time and is not helped if the temp drops in the night.

 

http://k2rd.freeservers.com/FC3S/TB/tb.html

i found this and i plan on doing the mod this week if not tonight

 

here's a recent thread.

https://www.rx7club.com/forum/showth...&highlight=mod

 

Hear this should be what it looks like Http//:www.geocities.com-rowdy/tbcomparison.jpg Ok.

 

I don't understand your question Node, if you mean how cold did it get the night it froze, well it was 28 degrees when I was starting the car the next morning.

I removed the secondary butterflies, the cold start assist thermowax dealio, and the dashport on the front of thge TB that controlled the secondary throttle plates. I pretty much followed these instructions.http://k2rd.freeservers.com/FC3S/TB/tb.html

 

This is the full gas flowed mod.

 

what is the BAC? and are there any side effects to doing this

 

BAC=Bypass air control valve. Its is used to keep your car idling when using AC, turning your steering, or anything that will drop your idle. It feeds extra air into your engine to keep your engine from dying. If you don't have AC and PS like me, its not a problem. If you do, then raise your idle a bit, and you will probably be fine. There are no gains in HP or throttle response by removing the AC. Just a slightly cleaner engine compartment, and less pesky coolants lines running rampant.

 

Do you think the crisp throttle response is from the elimination of the 2ndary plates? Cause I highly doubt the thermowax would be a factor until the coolant heats up to operating temperature.

 

Who cares.. lets not argue. Whatever he did. It worked. I have to questions.

One is. How did u relocate your coolant hose. I dont understand the pics in the freesever thing??? Or can i tap it and block the flow for a cleaner install?????

The head lights is a load. What will happen if u dont have back???

Third.. I forgot...

 

TB mod makes revving much nicer and quicker, better response and does add about 5hp, for one the throttle plates are removed and let more air in, and then the thermowax **** is gone, that heats up the intake temp, re route your rad hose from the BAC straight from the water pump to the engine, that cools intake temp even more cuz the BAC isnt getting the fluid passed through it, my car starts and idle at 1500rpm's without having to keep it running. if you have a cone filter intake this is a must mod

 

I thought that I read on here a few months back that the TB mod. could cause the mixture to go lean if the throttle was opened too quickly. Anybody know anything about this?

Todd

 

Wow great shot of a ported tb I think thats the first photo I have seen of someone's TB ported out like that. That gives me somehitng to do this weekend.

Any tips I should know about?

 

Yes, the elimination of the 2nd-ary throttle plates is what gives you the throttle response.

 

Well I removed the BAC at the same time, so I just got a coolant hose from schucks and routed it from the nipple coming off the engine block(the one that normally had a hose going to the back of the throttle body)to the nipple coming off the back of the waterpump housing(which normally had a coolant line running into one side of the BAC. If you keep your BAC, just route from the left side of the BAC, to the nipple on the back of the engine block(under the extension/ or VDI manifold)

 

Thnx alot guys. Thats what i needed to know. Very helpful.

 

Sorry if I sounded sceptical, but I only meant to confirm if the removal of the plates were the sole reason for quicker response. I plan to only do whichever the two mods gave the most "gain" for the time and effort invested as I see doing the thermowax takes up a lot more time for probably a lot less of a gain, and more for cosmetic enhancements. The way I see it, our CAI is probably sucking in way more hot air then is produced from the thermowax unit at operating temperature.

 

How well does it run with no BAC valve ?

 

No problems, but I have no AC or PS. Also my idle is set slightly above 1000rpms.

 

Why would you leave the thermowax on? It would be useless once you took the secondary throttle plates out, since thats what they control.

 

From looking at the unit, once I remove the shaft which the two butterflies are attached, I can slide it out from the "front" side of the TB, leaving the thermowax intact on the "back" side. So that would save me the JB weld job on the back side since it's still has the thermowax screwed in with 3 copper philip screws, covering up that hole. Then plug into a rubber cork in the front hole and that should be it. I did not look very carefully at the entire unit in detail so I maybe wrong.

 

You can only pull the shaft out one way, and I don't remember which way it was. One end of the shaft has a plastic piece on the end that prevents the shaft from moving one way. One way to have the 2nd-ary throttle plates always open without doing the TB mod, is to hook up a vaccuum line directly off one of the intake manifold and have it run to the dashpot on the front of TB the one that controls the 2nd-ary throttle plates. Of course the plates and shaft are still in the TB causing turbulence even though they have been removed. Also the coolant running through the TB supposedly heats up the intake charge, which is obviously undesirable, so if I were you, I'd do it right and remove the thermowax.