Longtubes on stock motor?

[18mustangs]

it happened to me. that along with decreased gas milage.

Me too, my car pinged like crazy with the milled heads and no EGR. I put EGR back on when I did the fox conversion and ended the pingin and got better mileage.

Tim

 

[Davin]

You will need an adjustable fuel regulator because the O2 sensors will be down stream on the header causing the computer to add more fuel.

Okay Vibe, this is the second time I have heard this...can you explain to me exactly why the computer would add more fuel? The computer doesn't know that the sensors are further and I can't imagine the gas composition changes that much between the stock position and the new position, its not like its on the other side of a cat, its just a tube, so what gives???

 

[VibrantRedGT]

I think its because there is more heat generated closest to the motor (stock O2 location) vs. the O2 being farther away. The computer may sense that the O2 is cooler and add some fuel. I just know from my experience that I've encounter this when I switch from shorties to long tubes. RIO and I did this at the same time and he also had the same thing.

 

[final5-0]

I think its because there is more heat generated closest to the motor (stock O2 location) vs. the O2 being farther away. The computer may sense that the O2 is cooler and add some fuel. I just know from my experience that I've encounter this when I switch from shorties to long tubes. RIO and I did this at the same time and he also had the same thing.

Joe is right on the money here

Some peeps on the self tuning sites have had so much trouble with the O2's cooling off they forced Open Loop idle which allows them to have the control needed to combat this issue.

The guys who had the worst cases of this issue said they could watch their O2's start to cool off during long periods of idle.

As the O2's cooled, the Adaptive Strategy added fuel to compensate to the point where the maximum range was reached.
In some of those cases, the car loaded up with too much fuel and just died.

Funny thing about this strange thing is ................

Some with LT's have issues and others don't. Over the years I have seen it happen with coated and non coated LT's and brand of LT's doesn't seem to matter either.

Grady

 

[Davin]

I know there is a signal wire, a heater wire, a reference wire and a ground. I'm not sure how the O2 sensor would give feedback on its heat...even if it can though, I would think it would be a much bigger change when folks go from cats to off road, romoving the cats makes such a huge change in the temperature of the pipe, you'd think that would be a much bigger difference than just pushing the sensor back 16"///wouldn't you?

 

[final5-0]

I know there is a signal wire, a heater wire, a reference wire and a ground. I'm not sure how the O2 sensor would give feedback on its heat...even if it can though, I would think it would be a much bigger change when folks go from cats to off road, romoving the cats makes such a huge change in the temperature of the pipe, you'd think that would be a much bigger difference than just pushing the sensor back 16"///wouldn't you?

The general thinking about this issue is the placement of the O2's and how it effects the amount of heat they receive.

I have seen some LT peeps solve this issue by moving the O2 to one of the tubes which gets it much closer to the fire.

Moving the O2's to the collectors is a long way down stream from the original mounting locations so you get less heat. This is the main cause one could have this issue with their LT's.

One last thing I think is important to remember about this issue is ......

the amount or severity of O2 cooling is most likely gonna cause the same amount of drivability frustration.

Issues like we now talk about is where having hard data to analyze is invaluable.

No data can cause AND

Grady

 

[DARK-5.0]

Since we're kinda on the topic of dipsticks with longtubes. I bought a new dipstick and tube from summit and it doesn't fit for ****. It only goes in a bit but then where it flares out a bit to fit snug into the block, its too big and doesn't fit. And its not the block. I'm on a new block with is actually a fox block and it still doesn't fit.
Whats the best thing I can do to make it fit. Thanks

Jeremy

 

[final5-0]

Since we're kinda on the topic of dipsticks with longtubes. I bought a new dipstick and tube from summit and it doesn't fit for ****. It only goes in a bit but then where it flares out a bit to fit snug into the block, its too big and doesn't fit. And its not the block. I'm on a new block with is actually a fox block and it still doesn't fit.
Whats the best thing I can do to make it fit. Thanks

Jeremy

How close does your stock tube come to working with everything?

I made only a slight bend to mine and it was fine.

Grady