I was looking for the thread with the steps to do the throttle body mod and i can't seem to find it
i have tried the search
does anyone know where the "how to" thread is?

 

never mind i found a site

 

Wow.. only 5 minutes of searching.... LOL

 

^Thats not nice.

 

dont do it!!

 

Worthless Mod.

If you are talking about porting the TB then you may have a tiny chance of seeing gains from a turbo. If you are n/a, look else where for HP increase. The TB is not the restriction.

Its true though. Searching yeilds faster results.

 

Out side of RX7 club

 

On an NA yes, but on a Turbo the improvement in throttle response (due to the different way the double throttle system works) is worth it.

 

^ Which is why I said you will only see gains on a turbo.

 

Worthless? Could've fooled me. Every single FC I've done this on has had a benefit pretty much across the board. The turbocharged cars gain quite a bit in terms of boost thresshold and torque. Certainly not worthless!

http://bdc.cyberosity.com/v/Throttle+Bodies

B

 

Let me straighten this out. The TB mod every newb thinks about usually consists of removing the 2ndary choke plates and sometimes the thermowax and water ever else usually gets removed that has no benefit.

If you read my entire post, you will see where I said.

 

Your comment specifically mentioned the porting being a benefit on turbos. The main benefit on turbos is the improved throttle response from removing the double throttle system, not any flow increase from porting.

 

So according to you, porting the TB has absolutly no benefit even on a turbo.

 

maybe he meant the TB mod? I wouldn't mind doing it to get rid of all that crap around there.

 

When did I say that?

The word "porting" is misleading anyway, since the "ports" are not changing in diameter. Smoothing out the air path by removing excess metal will make a very small improvement, but realistically for most FC's the stock TB is just not restrictive enough for such a minor improvement to have much effect on the engine's overall performance.

The more power the engine's making, the more effect this will have. That's why it's so pointless on an NA engine, and not worth paying for on a turbo'd engine. I did it because it cost me nothing and it was fun.

 

Your changing the beginning of the TB bore diameter. This is the whole point of "porting" the tb to shape them like velocity stacks. I don't know how else to say that your enlarging the beginning of the TB bores.

I have heard numorous times about this "porting" on turboed engines making a good improvment. Now I never took note on what other modifications had been done to the engine before hand.

 

The only thing you can remove is the 2ndary choke plates, or also called the double throttle system. Thats it.

I removed my 2ndary choke plates because I had to work on the TB and never put them back. I noticed no difference in throttle responce or power on my n/a. I don't know if you have a n/a or turbo. I modified the TB shafts which I knew wouldn't give me really anything but I just felt like doing it. That can be found here
http://howto.globalvicinity.com/gv_w...=313&co=1&vi=1

I also ported the TB elbow on my n/a which also didn't give me anything and that can be found here.
http://howto.globalvicinity.com/gv_w...=308&co=1&vi=1

 

I wouldn't recommend it. The throttle response does improve quite a bit but at the cost of drivability. Try driving around a parking lot in first gear and you'll see what I mean. The transition between open and shut can be harsh, and a certain level of throttle can cause it to bounce between the two. I'd gladly trade my modded TB for another stock one. Port it and block the coolant passage if you want, but I'd leave the secondary butterflies in place.

My car is a stock S4 Turbo, btw.

 

But I bet you've never seen anyone offer actual proof of any improvement. In my experience, on a mildly modded turbo engine the difference is not noticeable.

And nor should you, because the NA TB works differently to the Turbo TB, and there are no throttle response improvements to be made. This has been explained in detail many times...

You must be a very poor driver or have some other problem with your car like a TPS out of spec. The Turbo's double-throttle system is there to prevent stumbling if you open the secondary throttles too quickly at low rpm, which is a bad driving technique anyway and is easy to train yourself to avoid. It has no effect on the opening of the primary throttles, so removing it doesn't effect the transition when opening the throttle from closed. I have no problem driving smoothly around carparks at low speed.

The metal removed when "porting" the TB is where the upstream secondary throttles sit. You can't do anything to the inside of the TB without removing them.

 

I can't say I have.

This is interesting. I spoke to someone about the 2ndary choke plates ( as I call them) and they were telling me it was there to prevent stumble and I disagree'ed only because of how they work on n/a and he would disagree with me. Since I was talking about on a n/a engine and he must have been talking about a turbo engine but we both I guess did not know what engine we were talking about.

Anyways, good to know.

 

The problem definitely isn't my driving. I'll ignore that comment. My TPS is off... when I adjusted it, I found that idle resistance was good, but WOT would jump to 20k-ohms and no amount of adjustment could get it in spec. However, I have no problems under accel... it runs smooth all through the powerband and idle is right where it should be. It does buck a bit off the throttle at low RPM.

My issue is that when I push the gas very slightly, there's no smooth transition. At a certain point, it goes from no throttle to about 5 or 10% instantly. Letting off the gas slighty will cause it to snap shut again. I figured this was just a result of the TB mod, but from what you're saying, I'm having another issue. After fooling with the TB itself, I've noticed that the opening of the plates themselves is just harsh. It will open very slightly to a point and then takes a lot more force. I tried lubricating the springs and such with no result. Any ideas?

 

This has nothing to do with the TB's operation or the TB mod. The throttle is a simple mechanical device that opens as fast or slow as your foot moves.

What you're feeling is the injectors turning on and off when the primary throttle is opened and closed. This is controlled by the ECU based on the TPS's signal. The injectors are only supposed to turn off only when the throttle is fully closed and turn back on as soon as the throttle starts to open. If the TPS isn't set properly the injectors will turn on and off at a greater throttle opening than they should, and the more open it is the stronger the jerk will be when the injectors come on. So setting the TPS is critical for making this happen smoothly. Don't get hung up on the factory numbers. Experiment and find the setting that works best for your car.

Also, use of the clutch at low speed will completely eliminate the jerking, so driving skill/style does come into it a bit...

 

Just a remark about the TPS and bucking at low rpms........Frankly I knew about how when the pedal is lifted when driving, that the TPS would cause the fuel to be cut to the primary injectors. That's mentioned in the online FSM. What I ignored in the past, is that if the pedal is lifted just a touch while driving, that ONLY the front rotors injector has its fuel cut and the rear rotor has it's fuel still being delivered.

If the pedal is completly let off while driving, then BOTH primary injectors have their fuel cut off.

I'd seen comments in the past, about how only the front rotor has fuel cut when the pedal was lifted, and just basically ignored that remark. But recently I challagnged that remark in this thread https://www.rx7club.com/forum/showthread.php?t=686904, and came to the conclusion that I was the one that was wrong about which injectors get fuel cut when the pedal is lifted. I used commone LED lights on the primary injectors (at the ECU) to see which injector gets it's fuel chopped at a given time. Sometimes one injector.....other times both. I think it's both TPS and pressure sensor related in some cases.

This has little to do with the thread owners problem. Just a little FYI as to ONE of the things the TPS does in life. OH........it cuts fuel on one rotor at times as a drivability issue. I.E so the engine won't buck as much during trottle transition ( I assume).

If you have a old swing meter, I'd check the TPS using it as you slowly open/shut the throttle. You'd be looking for a sudden *open* in the reading (meter needle would drop like a rock) as you open/shut the throttle. In your case I'd be looking for that *open* around the lower part of the throttle being open. MIGHT be the cause of ole BUCK. Maybe not.

I mainly wrote this remark to make people aware that in some cases, when you let off the pedal, only one rotor has it's fuel cut. Just a RX-7 trivia thing.

 

I have to lift my my foot almost till the TB closes for the front to cut. It seems when you are at the point where you think both rotors will cut, only front does untill you lift off a touch more and then both get cut. This is what I have experienced.

Next time im driving around when I get a good ECU I will watch the throttle percentage on the SAFC. I can't watch the voltage since im using the full range and not the narrow range. Both of my ECUs are junk, I don't get the nice 1 rotor transition any more after swapping a bad ECU for a bad ECU.

 

I'll try fooling with the TPS again... I adjusted it before the TB mod and got everything running perfect. Must've nudged something during the process is my only guess. If that doesn't work I'll replace it.

Parking lots aren't a problem, I know how to use my clutch and 2nd gear. I'm not retarded. It's 5th gear on the highway that is annoying.