I just pulled out the throttle plates in my N/A and it worked BEAUTIFULLY! I was really surprised that it worked so well, the throttle response is like telepathy or something! It's been done for a few months now, and no adverse effects, well except that the car is too touchy for friends who don't know how to drive sports cars...haha

 

The hesitation is due to not having any "damped" secondary tracts anymore.&nbsp The "double throttle" system was designed to keep most of the airflow going through the primary intake runners and slowly open up the secondary runners - this is on full-time!&nbsp The cold-start prevents the damped secondary throttle plates to open fully when cold, therefore running the engine rich (i.e. carb choke) and prevent you from gunning the engine.

The turbo engine has the turbo to "push" air through the intake.&nbsp An NA engine has to "pull" air through the intake.&nbsp The key to the whole system is intake velocity - this is for low RPM power.&nbsp Higher velocity of the intake charge leads to better combustion and power.&nbsp Having the air going through just the primary runners increases velocity - Bernoulli's Theorem.&nbsp By removing the damped secondary throttles, you're "popping" open both the primary and secondary throttle plates at the same time, killing intake charge velocity - this is what causes the low RPM hesitation.&nbsp Thus, a turbo would be less affected due to the turbo "pushing" the intake charge...


-Ted

 

Go away...shoo...
Please take go finish your high school education before posting anymore in here.


-Ted

 

Thanks Ted!! I'm gonna give it a whirl...if I don't like it I'll keep my stock one as a back-up. As an everyday car it's abusive enough to drive as it is (which is all my fault in my mods)... so whats a little more fuel to the fire

 

One last question on this since there seem to be differing opinions...so this is aimed mainly at Ted; the modded TB I have has plugged secondary plate-holes with some kind of epoxy. It's a light gray color and on the inside of the TB the epoxy has been ground down so that everything is flush and even all around. I supposed it's JB weld, right? BUt I have read in searches through the forum that JB weld may warp/fall apart w heat. I DEF. don't wanna throw this TB in if this **** is gonna get sucked into my motor. Should I drill the epoxy out and plug the holes w a couple of bolts and threadlock or am I worrying too much...

 

I always use "metal" epoxys on the engine.&nbsp I'm not a big fan of JB Weld myself. I normally (drill and) tap & plug myself for holes in metal.

For peace of mind, I would punch it out.



-Ted

 

so you would tap & plug or use metal epoxy?

 

and then you port that bitch

http://www.teamfc3s.org/store/images/ThrottleBody1.jpg

 

I searched for a write up on the TB mod and found this but the link is dead. Can anyone direct me to a working link?

- James

 

This doesnt make sense to me, the turbo TB is quite a bit different from the NA TB, the turbo TB has the spring damper on the linkage driving the double throttle, so yes, the turbo TB has 'damped secondary throttle plates', so maybe on the turbo there is a potential for 'hiccup' when you crack the throttle open and now the secondary throttle will crack open without that damping effect from the double throttle caused by that spring in the linkage.

On the NA TB there is no such damping. You simply have the vacuum solenoid present which keeps the double throttle closed until the engine has warmed up (IIRC this is controlled by the thermowax coolant circuit). All this does is prevent airflow through the secondary throttle until the engine has warmed, when you eliminate the double throttle mechanism on the NA TB, you are only elminating the secondary throttle restriction at cold start (so you have to drive nice until it's warmed up, it will let you punch it and get WOT, unlike before). This has some benefit as it removes the restriction which is still pressent even when the double throttle is open @ operating temperature, it's a minor improvement, but surely it will not make your car 'hiccup' when you crack the throttle with the car warmed up, as you're not effecting this transient at operating temp by removing it, just removing a small (constant at operating temp) restriction. The double throttle is not linked to the throttle linkage at all on the NA TB, therefore no secondary throttle damping is there.

Ted, confusing the turbo TB with the NA? I was surprised when I helped a friend with his turbo TB and saw the damper on the double throttle, I suspected there might be some hesitiation if we were to remove the double throttle on his car after seeing that obvious damper put there... so we didnt touch that (yet).

am I totally off here?

 

Still looking for the link??

- James

 

No kidding, is that link forever dead?