Can someone direct me to any thread that explains what the TB mod involves?

I searched for “Throttle Body Mod” but only got a few threads that briefly discussed it’s effects on derivability; but nothing that explained how to do it.


If someone could direct me to any information on the subject, I would appreciate it.

Thanks,
Jason

 

there is a write up on it somewhere, i have done it myself. what you do is take two of the throttle plates out that are not needed once the car is fully warmed up and you plug the holes that the removed plates leave. for a daily driven car or a car that sees alot of traffic time i would not do it, the gains are not really even noticable. so if its a street driven car its my recomendation you find power elsewhere ie porting the intake manifolds will yeild much better results and be as driveable as a stock car.

 

don't do it!

 

On your NA the secondary double throttle is only there to keep you from going WOT on a cold engine.
The TB is so big that removing it makes little difference.

The main reason to simplify the TB is to loose the 3/8" coolant line that can fail without warning.
It comes from a hot space under the UIM where you can't see it bulging or feel if it's hardened

You're in a cold winter area, so you will probably want to keep the thermo-wax ,fast idle cam, & the coolant circuit that works it.

 

TB mod alone didn't do much for me but porting it did. But if you do the TB mod yo0ur ar won't idle cold if you remove the thermowax

 

i did it cuz im moving to fl in a couple days. mwahaha. screw cold weather. HA!

 

if you decide to do it, here's a link

http://fc3spro.com/TECH/HOWTO/TBM/tbm.html

 

There are two distinct parts to the TB mod. One is removing the double throttle system, the other is removing the thermowax. Neither of these affect the other, so you can remove one, the other, or both.

Unless you have a Turbo, there are negligible gains to be had from removing the double throttle system; a couple of hp at best. On a Turbo removing this system results in an improvement in throttle response, because unlike on the NA's, the #2 secondary throttles are damped (i.e. they open slower).

Personally I see no point to removing the thermowax. All you get is a crappy cold idle.

 

True - The thermowax is not a problem, but part of the coolant circuit that works it, hides under the UIM just waiting for an inconvenient time to fail.
In Florida, I consider it one less maintenance item.

 

idle still sux when the engine is cold nbot just the weather. we've had upper 90s here and that wasn't warm enough to make my car wanna idle cold with no thermowax

 

Preventitive maintenence is about replacing things, not removing them. An engine that can't idle cold is considerably more inconvenient than replacing a $5 hose that'll last 15+ years...

 

Hm. All valid points, but I removed my cold start assist stuff to ease troubleshooting with my Haltech system. It could easily go back on if I ever get so inclined, but I don't mind a crappy cold idle if I know that its A) easier on the engine, particularly as it breaks in the new rebuild and B) I know where its target idle speed is and where its heading. With the Haltech still being tuned, having that shitty cold start boost which is hell on a cold engine anyway, just further complicates troubleshooting hard starts and tweaking the starting maps.

Amazingly, once the engine warms up, the idle speed and quality get so much smoother its crazy. And no amount of my adjusting the fuel mixtures or timing seems to have any significant effect on it other than to make it even worse. It must be solely a function of this cold start "feature".

My 0.02 : if your car is stock or runs basically stock systems (ECU, emissions, etc) leave the cold start stuff in place, particularly if you premix and run synthetic in your engine. The synthetic will help protect the cold steel much better than dino oil that's been sitting cold will. But if your car is highly modded like mine, and you don't personally mind a bad *cold* idle and the increase in warm-up time, it removes a LOT of complication around the TB area, not to mention that stupid-*** coolant hose from/to the BAC which bugs the crap out of me every time I have to pull the UIM or throttle. Now I don't have to deal with that. So to me, the maintenance reduction was worth the psychological "loss" of a quality cold idle, which is about all that is really bad about taking the system off. I think theoretically at least, its still better for your engine to not have it, although who knows what a rough cold idle does.

 

Can this cause hard starts..? As I wired mine open and the throttle response and spool of the turbo is great but somtimes I cant get the car started and it ends up flooding. I was not sure if it was this causing the flooding or my 720 injectors in the primaries...? I have had the 720s in for about 2 mos now and this just started but maybe if my plug are getting bad it could cause it to. Anyway just want to know if I can eliminate this as being a starting problem.

 

If you haven't re-tuned the ECU or cheated it with an SAFC to recalibrate for the added fuel, then it could well be the 720s. You're adding 30% more fuel than the engine needs during starting.

If you did tune out the difference somehow, then it could be anything from dirty plugs to leaking injectors (esp. if its harder to start when hot rather than when cold) to any number of other things from low compression to vacuum leaks or a bad/miscalibrated TPS.

 

It sounds to me like you're getting confused with the AWS (accelerated warm-up system) that causes the 3000rpm start. The thermowax has nothing to do with this. When set correctly the thermowax should only increase idle speed to ~1000rpm, which is perfectly fine for any engine new or old.
I've never understood this. Apart from the first time (what hose isn't stubborn after 14 years?), I just don't have a problem with this hose. It takes a bit of fiddling, but personally I think getting this hose on and off is pretty easy.

 

I'm with NZConvertible on this one. I have no clue as to why you would want to pull the thermowax.

 

Ahh yes you are right. Another late night post for me. Ok... I pulled the entire thing on the TB which for whatever reason has coolant running through it. I was under the impression that this was the gizmo responsible for a 3k rpm idle. I did this when I was still running the stock ECU and that 3k rpm idle went away for sure. There was a huge cam, this blocky thing which I believe was thermowax, and a few hoses. I removed all of that. My idle is set to 1500 rpm anyway during break-in . 1500 is fine, 3k is bad though.

Quote:

I've never understood this. Apart from the first time (what hose isn't stubborn after 14 years?), I just don't have a problem with this hose. It takes a bit of fiddling, but personally I think getting this hose on and off is pretty easy.

Its actually not so much the hose, as it is the coolant in the hose. I like a clean engine, and spilling what is to me a significant amount of soon-to-be sticky coolant all over the upper part of my engine bay or having to deal with re-bleeding and topping off the cooling system every time I just want to pull the UIM for something, doesn't make me terribly excited about working on my car. Plus, I think it was stupid to run coolan through a throttle body when the BAC could be used for the same purpose. My Haltech will, if necessary, be programmed to use the BAC for this idle-up "feature".

Hopefully this post (which is, yet again, a late nighter) will not be as full of assumptions and mistakes as many I'm known for. Nevertheless, we're all here to learn, right? Otherwise I wouldn't bother. So please, your comments.

 

To further explain my actions:

http://www.fc3spro.com/TECH/HOWTO/TBM/tbm.html

I did the first part of that (everything short of removing the double throttle plates). As you may be aware, these two mods -- fast idle removal and double throttle plate removal (which are often combined into one) -- are completely independent of each other.

I don't want the double throttle plates gone just yet, but getting rid of the coolant hose was something I just couldn't get done soon enough.

 

wtf?

 

I removed both on my setup.

I at first was going to remove the Thermowax only.

My TB was rusted inside the passages and useless so I ditched it. While I was there I just decided to axe the secondary butterfly.

So far I haven't noticed a big difference but then again.
It's Arizona and it's 110 outside and I have a black car so the engine doesn't stay "cold" for very long.