ok i've done some searching on the TB mod and i want the facts (primarily from people who have done it, Icemark, RETed, etc.) There have been pleanty of posts but they all say the same thing.

first, is this mod any good on an NA? i've heard that it is, but i've also heard that its for turbo's only.

second, are cold starts impossile? heard it both ways.

thanks for your input, i just want to know if the mod is right for my 86 NA. I'm not really into F*%&ing up my car this early.

 

If you remove the thermo wax pellet and disconnect the coolant lines running through it, then it will affect your warmup adversely. It is possible to do throttlebody porting and still retain these but most don't. Don't expect any power gains from doing all of this. It might improve your throttle response though but that's about it. Yes I have done it BTW.

 

thanks for the input. its much appreciated

 

YOU CANT HANDLE THE FACTS!!!!!!!!!!














jk



I never had a problem with it...sometimes I had to turn the AC on to have it hold the idle when it was stone cold. The coldest I started was prob 20F. This was on my 91 TII. Of course it will start no problem...its fuel injected and the tb has nothing to do with starting...its holding the cold idle.

Do the mod...its not gonna kill you . Makes for removing the TB allot easier. And if you car is always being taken apart...you will like the simplicity. I used JB weld on the TB plate holes and it worked just fine. Been holding for 3 years now.

 

Improved throttle response,Quicker rev's. My car has no start issue's so i cant see why it would hurt anything. The main reason why i did it was because i ported my uim and lim and wanted to flow as free as possible no matter how significant it might be.

 

Anyone know where a write-up for this is? I've been looking for one forever! I think I'm just looking in the wrong places!

Of course right after I post this someone is gonna post a link that is perfectly easy to find and I'm gonna feel dumb... Oh well, won't be the first time!

 

Yes, and your right it isn't the first time...I have done it many times


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

 

Thank you very much! I've been on that site many times but never saw that! Sweet! Now I got another little project for this winter.

 

Ive done it, but havnt run it yet. its going in with the rebuild. I did mine, block off the holes, and ported and sanded the whole thing. Ill be upping the idle to 1000 probably becuase the BAC is gone too, I dont see how it wont help with flow.

 

It has little to no effect on NA's. The Turbo's TB has a system to slow the opening of the upsteam secondary throttles to avoid low-rpm jerkiness. Removing this improves throttle response because the secondary ports are effectively opened quicker. NA's do not have this system. The upsteam secondary throttles are held fully open any time the engine is warm. Those open throttles cause a very small restriction, but due to the TB being huge for the NA's output, removing this restriction has no noticable effect. The only way to make gains is if those throttles were not fully opening as they should (easy to check).

In summary, no extra power or throttle response on NA's unless the TB's already broken.

This has no effect on cold starts, only cold idle. If you have a normal 750rpm warm idle, you will have a crap cold idle that'll require you keep your foot on the gas to stop it stalling until the engine warms up a bit.

These two systems (double throttle system and the thermowax for cold idle) are complately seperate and don't effect the other. You don't have to remove both.

 

yep, I agree completely!

The only thing to add is that if you do the throttle body mod, you should also do the E-shaft thermovalve shim or replacement. Part of the purpose of the 2nd set of plates is to help prevent you from whomping on the car while the engine is cold, and oil flow is restricted to help warm up. By shiming or replacing the E shaft thermovalve, you have full oil flow when starting, and do not have to worry about the cold start reduced oil flow.

 

is there a write-up on shimming the thermovalve?

 

Yes, but you shouldn't be whomping on the car when it's cold anyway. :-)

-=Russ=-

 

But your average 16 year old here does not know that.

 

Hrm. True. I keep forgetting the average age/maturity of posters on this forum.

-=Russ=-

 

No YOU'RE immature .

/end Sarcism.

 

i read somewhere that it is not recommened to remove the thermovalve on a motor that is not being rebuilt. When you remove this it is possible that a bearing that is held by the bolt can drop causing damage to your motor on next start up. Ice is this myth busted or plausable?

 

I must have been above average...I bought my seven when I was 16 and babied her Maybe it's because I spend my life savings on it lol

 

I removed my secondary throttle-plates, thermowax, and coolant line. I've driven my car a full auto-x/drag race season with the mod.

I have no idea if it helps on an N/A car.

I did notice that the car seemed to take longer time to warm up. I don't drive my car much in the cold, but even on a hot day it still seems to take a while to get up to operating temp (idling). No complaints otherwise. It really simplified the motor a bunch, and the post-hole for the first set of secondary throttle-plates is the perfect spot in the TB to tap for a Haltech air-temp sensor!

A word to the wise, if you're going to remove the line I suggest you also tap the rear-iron and the water-pump housing and block both locations with a good solid plug. If you just cap them with vaccuum or line caps, the heat from the motor will cook the rubber over time and eventually it will fail. (Heads up, turbo-guys especially) I was lucky and mine broke while the car was just idling.

 

Or run a simple L-shaped coolant line between the two.

-=Russ=-

 

I got my car in question when i was 17. I've always hated rice and how shitty kids treat their cars. I've always taken car of my baby, by spending whatever the cost to fix whatever problem she had, and as you can see, i refer to her as a she. I would like to simplify the intake and remove everything i don't need. here in KC tho its very cold and the cold start is needed (my idle is bad enough from an old fuel filter that i can't get the lines off of, the bracket was easy and what i assume is very bad grounding, (haven't checked with DMM yet)). All i was trying to do is see if the mod fits my needs and wants. Also, i'm intiqued about shimming the oil thermo valve, because i'd rather not skimp on the oil. My question is, is the writeup right about putting the socket on bolt w/ a breaker bar then closing the hood and starting it for a second? (not to belittle anyone RETed i belive). This forum has helped out alot w/ my questions, and thank you for the firm handed justice of not searching.

see? not all us teenagers are stupid and immature

 

Its not necessarily stupid or immature, its more like sex ed.

The stuff you learn from you buddies on the corner is generally wrong.



And they don't teach anything in drivers ed anymore... things like road manners the left lane is for passing, and high speed and the basics like warming up a car or how to even check the fluids, got thrown out the window with budget cuts.

 

agreed. questions answered.

Thread Closed.

Do your magic Icemark