bypassing intake manifold coolant

[TurboShortBus]

The lightweight flywheel and clutch are a huge free mod advantage to the mod motors

Oh hell, really? I'll have to get on that when I feel like spending big money...but, for now, the stock stuff will have to do. lol

 

Mark

[Cobra4B]

To be fair - some mods do make no difference on some cars and some make a ton. I think this is one of them.

 

what car does it make a difference on?

I'm going to have to say none.... as mentioned above via the uber-technical explanation, the air passes through the TB too quickly to be heated up a meaningful amount. Thus I think it should be a free points mod if it helps simplify the car and remvove un-needed and unwanted bits. Kind of like how we can remove the AIR pump assembly on a C5 and it makes the engine bay much roomier so the car is easier to work on and keep tabs on.

 

In my car I'll just hook mine back up becuae bypassing the TB would requre me to buy a male/male coupler for the tubes or a longer coolant hose to link the radiator to the front coolant crossover pipe then I'd have to zip tie it to the bottom of the TB anyway.

 

You can see the two ends of the pipe in this pic of the front of my motor.... just re-installed the manifold last night so this thread's timing is appropriate.

 

 

-Brian

[Varkwso]

To be fair - some mods do make no difference on some cars and some make a ton. I think this is one of them.

 

what car does it make a difference on?

 

Not any I know of - but I do not know all of them...most of them...but not all of them...

[Varkwso]

The lightweight flywheel and clutch are a huge free mod advantage to the mod motors

Oh hell, really? I'll have to get on that when I feel like spending big money...but, for now, the stock stuff will have to do. lol

 

Mark

 

It will make you grin on corner exit

[Cobra4B]

Not any I know of - but I do not know all of them...most of them...but not all of them...

I'm trying to think of some type of internal combustion engine that could possible benefit from it in a measurable way? I can show you plenty of people who think it's the shit... just look in the C5 general section of CF

[TurboShortBus]

From working on older EFI Fox Mustangs, I am under the impression that the coolant jacket in the EGR spacer serves only to insulate the TPS from the hotter exhaust gases that are flowing through a similar jacket an inch or so away. 200-ish degree water temperatures are nothing compared to the temperature of the exhaust that is being introduced into the intake tract. Maybe there is another reason for the water lines, but I don't see reducing "cold start" or "warm-up" emissions as being one of them.

 

These coolant lines were dropped from the 1994-95 5.0L engines, although they still had a similar EGR setup (although it was external and a little further from the throttle body).

 

Mark

[Cobra4B]

FWIW LSXs in a Corvette don't have an EGR system. The little bit of coolant that flows through the throttle-body is to prevent a potential freeze issue in ultra-cold weather operation. During powertrain validation they have to test the cars in all extremes... i.e. -40 Alaska to 120 Nevada.

 

We do have an AIR system (Air Injection Recirculation) that injects air into the exhaust manifold via a pump in the front bumper area. It's purpose is to feed extra oxygen to the cats to help them "fire off" more quickly during cold starts for better emissions testing. They were able to do away with this for the C6 platform by moving the cats even closer to the end of the manifold.

 

I had to delete all the EGR stuff from the Panoz when we still had EFI on it... was a strange system to look at.

[TurboShortBus]

FWIW LSXs in a Corvette don't have an EGR system. The little bit of coolant that flows through the throttle-body is to prevent a potential freeze issue in ultra-cold weather operation. During powertrain validation they have to test the cars in all extremes... i.e. -40 Alaska to 120 Nevada.

It's apparently not a problem in Dearborn! Not since 1994, anyway.

 

We do have an AIR system (Air Injection Recirculation) that injects air into the exhaust manifold via a pump in the front bumper area. It's purpose is to feed extra oxygen to the cats to help them "fire off" more quickly during cold starts for better emissions testing. They were able to do away with this for the C6 platform by moving the cats even closer to the end of the manifold.

That sounds like the old-school "smog pumps" on 5.0Ls that pumped air into the exhaust system.

 

Mark

[Cobra4B]

If that's what a "smog pump" does then they're one in the same. I always assumed smog pump as a synonym for the EGR system. If my memory serves me correctly some of the early LS1 F-bodys do have an EGR system.

[yakisoba]

The AIR system on an LS1 or 6 engine that is mostly tracked is just wasted weight as it sits. Your tuner can take it out so it never activates again, and the computer will not care. Then, just plug up the holes in the manifolds and take the whole thing out. 10+ pounds easy.

[drivinhardz06]

it's plumbed more like an EGR system though, with small ports on the exhaust manifold, and dumped back into the intake stream. it just has a pump to turn on/off, and like brian said provide cat light off.

[Cobra4B]

The AIR system on an LS1 or 6 engine that is mostly tracked is just wasted weight as it sits. Your tuner can take it out so it never activates again, and the computer will not care. Then, just plug up the holes in the manifolds and take the whole thing out. 10+ pounds easy.

Yep... I removed it from my old yellow 2001 Z that was mostly a street car. Blew an AIR tube off a set of Kooks headers so I repaired it and sold them, and purchased a set from Kooks w/o any AIR tube provisions at all.

 

My current build has them all removed.

 

[Cobra4B]

it's plumbed more like an EGR system though, with small ports on the exhaust manifold, and dumped back into the intake stream. it just has a pump to turn on/off, and like brian said provide cat light off.

Actually it's my understanding that it works reverse from that.... the air pump has a tube connected to the stock airbox to draw in filtered air. At start up the pump runs and sends this air directly into the exhaust stream via the port on each manfiold. This puts extra oxygen in the exhaust and allows the cats to heat up faster. I'm almost positive it doesn't work in the reverse i.e. pulling exhuast gasses forward via the pump and then sending them up into the airbox. I don't think the rubber hoses that make up the bulk of the system and plastic connectors could take fresh exhaust gas heat.

 

EDIT - maybe you just meant that it's design could be easily confused for an EGR setup.

[TurboShortBus]

EGR (exhaust gas recirculation): Post-combustion exhaust gases are directed into the intake tract; in Fords, this is turned off at WOT (engine vacuum opens the EGR valve, and it springs shut with no vacuum), so it is a non-issue for the most part.

 

Secondary air injection, "Smog pump," or AIR (Air Injection Reactor): Fresh air is pumped into the exhaust tract to help preheat the cats.

 

I'm not sure why an AIR system would need to use filtered air, unless the AIR injection locations are close to the EGR outlets and they were worried about some sort of overlap where unfiltered air from the AIR system could possibly carry debris into the intake via the EGR system.

 

Mark

[MSP608]

but I have learned to throw my hands up and walk away

Mark

I feel there is a lot of this.

[sperkins]

Lots of stuff thrown in the mix here, but there has yet to be a good reason why this is a points penalty.

I'm hoping that we don't start penalizing cars based on internet hype, personal opinion and/or speculation.

[Shawn M.]

Lots of stuff thrown in the mix here, but there has yet to be a good reason why this is a points penalty.

I'm hoping that we don't start penalizing cars based on internet hype, personal opinion and/or speculation.

 

 

 

If its not giving any sort of performance gain then why do it at all? If the fear of a coolant leak is why you want to do this mod, then are you disconnecting the heater core too? Its a modification to a part, its that simple.

 

 

So you take:

19) Non-OEM or modified/ported throttle body +2;

and/or, depending on your car:

20) Non-OEM, modified/ported, or deleted intake manifold: 4 cyl. +1, 6cyl. +2, 8 cyl. +3,

12A &13B rotary +2, all other rotary +3

[sperkins]

are you disconnecting the heater core too?

 

Absolutely. You won't find one in my car.

[Cobra4B]

I have the box that used to contain the heater core to retain my defroster.... but the core itself, along with the evap unit, is currently garage floor decoration

 

[drivinhardz06]

So you take:

19) Non-OEM or modified/ported throttle body +2;

and/or, depending on your car:

20) Non-OEM, modified/ported, or deleted intake manifold: 4 cyl. +1, 6cyl. +2, 8 cyl. +3,

12A &13B rotary +2, all other rotary +3

 

so up to 5 pts for a coolant by pass on a V8

 

that may be the absolute worst use of 5 pts in all of history. you could put a coat of wax on the car for aero purposes and it would make more difference

[Varkwso]

So you take:

19) Non-OEM or modified/ported throttle body +2;

and/or, depending on your car:

20) Non-OEM, modified/ported, or deleted intake manifold: 4 cyl. +1, 6cyl. +2, 8 cyl. +3,

12A &13B rotary +2, all other rotary +3

 

so up to 5 pts for a coolant by pass on a V8

 

that may be the absolute worst use of 5 pts in all of history. you could put a coat of wax on the car for aero purposes and it would make more difference

 

 

Yep. What are aftermarket brakes again?

[Aardwolf]

Lots of stuff thrown in the mix here, but there has yet to be a good reason why this is a points penalty.

I'm hoping that we don't start penalizing cars based on internet hype, personal opinion and/or speculation.

 

 

 

If its not giving any sort of performance gain then why do it at all? If the fear of a coolant leak is why you want to do this mod, then are you disconnecting the heater core too? Its a modification to a part, its that simple.

 

 

So you take:

19) Non-OEM or modified/ported throttle body +2;

and/or, depending on your car:

20) Non-OEM, modified/ported, or deleted intake manifold: 4 cyl. +1, 6cyl. +2, 8 cyl. +3,

12A &13B rotary +2, all other rotary +3

 

The coolant flow at the throttle body is disabled on mine. I did this to make the engine easier to work on. Having to drain and then refill coolant every time the throttle body is removed, is tedious! I do still have the heater core, early and late season track events can be cold around here.

[Cobra4B]

The coolant flow at the throttle body is disabled on mine. I did this to make the engine easier to work on. Having to drain and then refill coolant every time the throttle body is removed, is tedious! I do still have the heater core, early and late season track events can be cold around here.

Yeah that's the biggie.... having to deal w/ the cooling system to remove the TB is annoying. As for the heater.... every track car I've ever had is it's own heater

[Aardwolf]

The coolant flow at the throttle body is disabled on mine. I did this to make the engine easier to work on. Having to drain and then refill coolant every time the throttle body is removed, is tedious! I do still have the heater core, early and late season track events can be cold around here.

Yeah that's the biggie.... having to deal w/ the cooling system to remove the TB is annoying. As for the heater.... every track car I've ever had is it's own heater

 

Engine doesn't warm up well early/late season. Seen some snow track days!

[TurboShortBus]

so up to 5 pts for a coolant by pass on a V8

 

that may be the absolute worst use of 5 pts in all of history. you could put a coat of wax on the car for aero purposes and it would make more difference

I'm not going to disagree with you there.

 

But, to avoid those 5 points, you could likely dyno the car, send the results and the weight to Greg, get a new base classification, and see where the final points shake out.

 

Mark