Throttle Body coolant bypass mod instructions??

[broke1]

Finishing up a full 60k and I want to do the coolant bypass mod but the 3 hoses has me confused.....

I'm thinking loop the large coolant line that feeds the TB with the IAC adaptor coolant output that goes to the thermostat housing and just plug the other one???

If anyone has a schematic,I'd be greatful!!! Thanks,

Drew

 

[broke1]

I'm an idiot,I thought the vent on the TB was also a coolant line!!

I went ahead and just ran an air filter on the end of that evap line and blocked it at the TB(I can't stand a dirty intake tract,lol).Plus future removals should be a bit easier.

I also deleted the egr setup and installed a ported mtx intake so the only block off plate I had to fab was for the egr tube on the manifold. Really cleaned up a lot of clutter on an ATX ditching that stuff.....

Under the valve covers was immaculate.....zero crud or buildup. Still had the stock 20 year old plugs and the weren't terrible!!! Still have to install my fuel pump and get it tuned.

I'll post pics of everything when I dyno a whopping 180 whp lol. At least it'll be ready for some real mods!lol

 

[luigisho]

If you're going to drive it in the cooler months, even in Alabama, I would wait until the coldest parts of winter pass before bypassing the tb coolant hose. It's only real purpose is to prevent throttle plate sticking in the cold. I don't think it will make a real difference with it bypassed as far as real world hp either. You really need large scale improvements to get noticeable performance gains from the engine. I would look at handling and braking first if you want to improve driving experience. Actually I would live with the car as is and get a stouter platform to try and make real power

 

[itwonder]

The attached pdf shows how to do it. However, FWIW, there's really nothing to be gained from that mod.

 

[broke1]

Thanks for the PDF.....

I will respectfully disagree with what Luigisho said.....it's not for the TB sticking when cold(ever see the return spring on your TB?). ITS FOR EMISSIONS!!! And eliminating it will help tons with heat soak.....only time it will really make any difference is when it's hot outside and u are in a lot of stop and go traffic. This goes for any car wether it's GM,Ford,etc.....

Just like ridding yourself of PCV from the valve cover and anything else(like egr and fuel evap),it will help with keeping oil out of the intake....that oil/fumes will cause detonation on your relatively high compression SHO. This isn't anything new,it's done on lots of other cars and I found pics of other forum members cars who did these mods although they were way old posts....

And running a breather on the valve cover open to atmosphere will keep the cam seals from blowing hopefully!

All mods so far are mainly for reliability and simplicity.....

 

[luigisho]

Now I'm not an automotive engineer so what I have in the memory banks is that it was supposed to be for icing in the throttle body in cold weather. Mostly when that might happen you would get ice build up and that may or may not be defeated by the return spring. Now that is just from automotive discussions over the years and I never read a definitive reason about the subject from a recognized authoritative source. As far as getting rid of emission stuff that may gunk up the intake I won't argue that it is better to not have that stuff in there

 

[Irish Pride]

From what I remember the coolant line in the throttle body is to keep the throttle plate from sticking in cold weather. That being said, it's also been proven to be a useless feature unless you live in near artic conditions. I've had my throttle body bypassed for several years and have never had an issue in winter. Whether or not it has positive gains in performance I don't know. What I do know is it makes removing the intake all the more easier so it's worth it to me.

 

[broke1]

Would you please explain why you think that could be??? Are u saying the water warms up grease or metal(should stick more the hotter it gets because metal expands)If you have ever taken a TB apart,you would see there is absolutely nothing to stick on the inside unless something wedges on the throttle plate and then u probably have a lot bigger problems.....the TB shaft rides on a seal much like a trans output seal,nothing in there to get stuck.

I'm not trying to argue with any1 because if you have convinced yourself it's for a sticking throttle(again,it's for emissions),I won't be able to make you believe the truth....but I'd really like you to explain to me what you think would stick inside a TB??

I'm no engineer myself but I've done a lot of TB bypass' over the years and taken a lot of throttle body's apart and even my simple mind can see there is NOTHING inside a TB which can stick.

Also,the water going thru on cold start is still cold so it would still stick until it warmed up if indeed the coolant running thru was for a sticky throttle. I've seen bad engineering ideas but this would be the 1st time Id seen a horrible design on every make of car if it were for a sticky throttle.

Not to mention diesels and carbs would have it too if it were for a sticky throttle(they don't)

When I posted this,I thought the crankcase vent to TB was another water line because I've never seen anything like that on the other engines I'm used to working on(sbc/bbc,87-93 5.0's,Buick GN's,LS engines,cummins,and W211 Mercedes)....the SHO engine is def on its own and very over engineered albeit very simple/easy to work on.All the casting ribs in the valve covers and the over use of attachment bolts/points and such really show just how new this design was to the mainstream. And looking at the intake runner on the cylinder head,the casting looks a lot better than anything you'd see out of even Honda(looks very similar to what high end cylinder head manufacturers are just starting to offer with "fast as cast" castings) I'm very impressed at that...I see why ported heads wouldn't be a huge gain.

I'll bet the engine in the SHO was at least 30% of its cost to build......

 

[luigisho]

The metal expansion/contraction is not really the issue. From what I recall it is the issue of icing where condensation quickly freezes and may impede the plate from closing properly. The only car where I really had issues with throttle plate sticking was my GenIII SHO getting gunked up from carbon crap.

 

[pjtoledo]

fyi about "icing."

it does not occur with temps at or below freezing, the moisture is already frozen and does not stick to anything.

it does occur at temps slightly above freezing because as the air is accelerated around the throttle plate (or venturis) it cools enough to freeze the moisture. I never had the chance to look inside and see exactly what is freezing, nor do I want to.
its also dependent on the relative humidity.

being an 'ol guy I've known about carburetor icing since about,, ah,, hmmm, can't seem to recall exactly.

 

[zak]

The coolant flow also helps to warm the throttlebody and keep oil vapors from condensing as they make their way through the PCV system. The PCV system on the SHO is rudimentary to begin with. If the PCV passage clogs your front and rear main seals and spark plug well seals and valve cover bolt seals will all leak oil (from crankcase pressurization), and in the case of the spark plugs the wells fill up with oil and then misfiring will occur. Misfire long enough and the cats will begin to disintegrate. Downshift with disintegrating cats and it will suck the ceramic substrate back into the engine, ruining it.