NZConvertible

No, because at light throttle they're supposed to be closed. It would simply be extremely restrictive once you opened the throttle past the point where the secondaries should be opening. Of course it does! Why else would they be there?

600HP CLUB

when you guys mean WOT, do you guys really mean wide open throttle? because i WOT my car all the time even it's cold but always shift at 3k, i WOT so i am able to go up hills.

-mike

NZConvertible

Yes. You shouldn't do that. You shouldn't need full throttle to go up a hill unless your engine's nearly dead.

HAILERS

Its late, about one thirty and I may be wrong, but........I really, really do think some people that have N/A have a misunderstanding about the throttle body mod .

I can almost see doing it on a turboii. Thats because of the dashpot for the number two secondary plates on the TURBOII MODEL ONLY. The n/a does not have this dashpot which slows down the opening rate of the number two secondary plates. The number two plates on a n/a are spring loaded to the open position once the water temp is up.

It seems to me if someone that has a TURBOII and is curious how the THROTTLE BODY MOD would be on his car, then he would just go to that dashpot for the number two plates, and back it off until it does not ride on its plastic cam.

The n/a does not have the dashpot I speak of, nor the plastic cam that rides on it and slows down the opening of the number two plates.

Maybe its just late, but I think there's confusion on the part of people who have n/a's that have never seen a turboii throttle body and the SECOND dashpot that is a part of the turboii throttle body. Key words are: SECOND DASHPOT. They both, n/a and truboii, have one dashpot to slow down the closing of the throttle plates. Only the turboii has the SECOND DASHPOT AND CAM.

Probably just late. It could be me who has no clue. Throttle body mod on a regular ole n/a never made sense to me, being spring loaded open all the time and all(engine warm).

NZConvertible

Hailers, that's even more reason for NA owners to pull the #2 secondary plates out, since most of the time they're doing absolutely nothing. Even open throttles are a restriction. One would hope that any RX-7 owner doing the TB mod whould not be stupid enough to thrash a cold engine.

As a matter of interest, I pulled by UIM today to remove the injectors for cleaning. Since the TB's off I'm pulling the #2 secondary plates, linkages and both dashpots, but leaving the thermowax. I'm expecting a bit more power from this as the #2 plates weren't opening fully even when the #1 plates were.
Also it turns out J-spec TB's don't have the thermovalve that keeps the plates closed when cold. Maybe Mazda trusted Japanese owners more than US ones!

HAILERS

The idea I was trying to get across was that while the turboii has a built in delay with the number two secondaries using the second dashpot, there will be a difference in throttle response once the dashpot is removed(and or whole kit and kaboodle).

But with a n/a, I don't see how you would feel any difference in throttle response since the plates are normally wide open anyway.

Hey! Watch those cracks about Japenese being trusted more than U.S. They probably paid the same price and didn't get all the equipment with their cars. They got short changed!

choritsu-shi

Well actually, I recall back in the early 70's Mazda was forced to do a huge recall here in the states which nearly left them bankrupt. American owners were not prepared to understand the characteristics of a Rotary engine. Most Americans never bothered to read their manuals, let alone even check their oil. If one were to read the owners manual, he would understand that the Rotaries thirst for oil was normal. In the early stages of the Rotary engine design, the oil consumption was pretty healthy, so was the fuel. Consumption varied to driving habits, but 2qts of oil per every 5000 miles seemed to be what I remembered. In short...Mazda was flooded with complaints and blown rotary engines.Everyone was blowing their engine before getting past 10,000 miles! Weird thing was... Mazda did not have these problems with their Rotary cars sold in other countries through out the world, only in America!

Sensei

Pinfield357

very good information and i thank all that replied to this cause i was just pulling off my UIM and TB last night to get at the injectors.

NZConvertible

Yeah, we also missed out on the 3000rpm start-up, EGR valves, shift-up lights and automatic seatbelts. What a rip off!

Jimmy325i

NZ, Your S5's don't have auto seat belts? Lucky bastards!

RX-7Impreza

going WOT on a cold engine isnt the problem, its going over 4K rpm on a cold engine. on acold engine, the bearings dont get any oil, so WOT isnt really as much of a problem as high rpms.

and the secondary TPs can be arrange to openat the same time as the primaries, delayed, or at the same time as stock. you can make arrange all of these so that the plates open "quicker" allowing them to open all the way.

justin

Jimmy325i

"going WOT on a cold engine isnt the problem, its going over 4K rpm on a cold engine. on acold engine, the bearings dont get any oil, so WOT isnt really as much of a problem as high rpms."


Unless you eliminated the thermowax oil pellet...

GLHS

Listen if you feel this is mod is what you want to do. Please test run your car atleast 5 times down the track. Take notes on temp and time and rpm launched and shifted at.

Mod your TB and retest it again, keep notes just for yourself. See what you find out for yourself.

You will find the cars engine will rev faster, but will not pull as hard. The power will not come on as hard, and will result in a slower car due to the fact that you just make the max power band about 500 rpm in lenght, and then its gone.

Every N/A TB modded car I have seen was slower than stock.

NZConvertible

What are you talking about? How is removing two throttle plates that are open anyway going to make the car slower? How is it going to narrow the power band? Please explain... Where's your list of before and after times, temps and revs to prove that?

GLHS

When you remove those plates you effectivly create more area " space for air travel", thus decreasing the velocity that was happening in the TB before.. Do you understand this? The plate take up space.. this increase the velocity... Take them velocity decreases, you may get more flow, but less velocity. so it may even be less CFM overall.


I got my proof.. Matter of fact the people are on this list and part of my car club.. I have the proof, just its their information to share with you, if they feel so.


Do you have any proof, that this mods works? or do you just like it and it feels faster?

Jimmy325i

GLHS, While you're correct in making a stink over intake charge velocity, you are mistaken at which point you should be caring about it. The point at which intake velocity is an issue is at the intake port, not the TB. If you remove those plates you will not significantly change the charge velocity at the port. Removing restrictions from the source of air is going to result in higher flow not reduced cfm. Ever notice that a holley 1000cfm dominator is a lot bigger than a 625 cfm AFB? Going too big will reduce the charge velocity, but removing those butterflies and the bar will not be enough to do it. This is also only a concern at WOT, as the primary butterflies are still restricting the air at any point of lower throttle position.

GLHS

I have to go with my friend who races these cars daily..if he says it loses power, then I trust him fully. He has no reason to lie to me, since I have known him for almost 10 years now...He schools me everytime I go to his shop...


He also said if you do not have custom made headers that have 3" or more of straight piping right from the block, you will never see the power number you think you will get...Not flaming here, just giving out knowledge that has been tested. many times over...

NZConvertible

I don't even know how to reply to this. You have no idea what you're talking about.