Project Cool Fuel Take: 1

[Boostwerks.com]

lol @ this thread. I wish everyone owned a dynojet so they can see how futile their hard work really is.

Cool'd fuel does = more power, but will only provide measureable gains when intake temps reach the 150+ range (non IC'd supercharged apps for example). It's more of a factor in those "squeeze all you can" drag car apps where 5hp can = a win. But hey what do I know, I've never done this

IMO. Save the space, time, $, and effort and invest it in something that will be a little more useful (like high pressure meth injection). But hey, thats just me.

Edit: You can build a meth injection system for less than $80 btw.

 

[Hellbent]

i think some people are missing the point. i don't think he ever mentioned trying to create the quickest, cheapest way to make massive hp gains. what's the matter with playing around with something for your own entertainment, and to see what the results are of a particular experiment on a particular vehicle? trying new things and learning from the results are ALWAYS positives in my book.

 

[Milford Cubicle II]

lol @ this thread. I wish everyone owned a dynojet so they can see how futile their hard work really is.

Dude, lose your cocky little attitude and quit acting like a jackass.

Cool'd fuel does = more power, but will only provide measureable gains when intake temps reach the 150+ range (non IC'd supercharged apps for example). It's more of a factor in those "squeeze all you can" drag car apps where 5hp can = a win. But hey what do I know, I've never done this

IAT's DO reach 150+ on XJ's :gee:

That's what happens when you have an intake manifold directly on top of an exhaust manifold on a motor that isn't notorious for running cool.

OBDII won't display HP and torque curves.

Correct. But the softare that analyzes it will.

 

[Talyn]

IAT's DO reach 150+ on XJ's :gee:

They do.

Correct. But the softare that analyzes it will.

I don't think that will be that accurate to show any thing as I doubt that the change was that drastic.

 

[bigdaddyjlove]

I was thinking about wrapping both the exhaust and the fuel rail/injector. Personally, I've never had a problem with exhaust wrap rotting the pipe in a street driven car.

I'm intersted in this, because I'm about to drop a stroker into my '01 DD. I have a Borla exhaust manifold (Stainless) I'd like to install. I'm wondering if I can move the pre cats downstream or eliminate them (add a couple of bungs for the O2 sensors) In reality, they do almost nothing for the emissions. They are just there for "start up" regs.

 

[Talyn]

You would need two O2 sims for the down stream o2 sensors if you remove them. If you remove the precats you must remove them, not hollow them out as hollowing them out will leave a chamber for the exhaust to expand and actually hurt performance. Leave the large main cat in place.

 

[bigdaddyjlove]

I've got a new header to put in place, so no danger of hollowing them out. If I have a regular header in place is this "heat soak" issue going to come up? I'v owned 3 XJs, A TJ and two ZJs and the 2001 is the only one to have this happen.

 

[Boostwerks.com]

Dude, lose your cocky little attitude and quit acting like a jackass.



IAT's DO reach 150+ on XJ's :gee:

That's what happens when you have an intake manifold directly on top of an exhaust manifold on a motor that isn't notorious for running cool.



Correct. But the softare that analyzes it will.

Just trying to slap you back into reality is all. I appologize if I seem "cocky" but I'm only trying to help.

While I'm sure the intake temps reach 150+ with the typical 4.0, all I said was "measureable gains" are seen from this point. In other words you would see 1-5hp depending on the deltaT in the fuel temp in an application that sees temps past this level. Non IC SC and turbo apps typically see IATs in the 250+ range. Obviously in this case the cooler the fuel, the better and the gains would be larger.

My point in all this: meth injection allows you to use a 150psi+ pump. Work out the math on that compared to your sub 50psi system. You can also wire it up with a simple throtal % trigger so it works when you get the most benefit. You can also mount the nozzle farther up stream so there is more time for the atomization affect to cool the charge air. Worried about having to carry a tank of water/meth around? You can actually source directly from your washer fluid tank

There is no benefit for cooler fuel under idle conditions, especially for a stock low compression 4.0l. Any idle symptoms you might have can be remedied by simple ignition adjustments such as advancing the timing, ensuring you have the correct plugs, gapping them correctly, making sure the CPS sensor is picking up a clean signal...etc.

Like I said the first time though... to each their own. I just hate to see people learn the hard way. No offense, but the concept you have is honestly on par with an electric ebay supercharger.

Edit: BTW, what are your coolant temps at idle? The other guys are spot on with the heat soak issues. Wrapping the manifold (AND cats) will solve that problem. The reason the 00/01s have the heat soak issue is due to the dual cats (otherwise known as convection ovens). Simple as that.

But hey, it's all about having fun right? party1:

 

[Milford Cubicle II]

In other words you would see 1-5hp depending on the deltaT in the fuel temp in an application that sees temps past this level. Non IC SC and turbo apps typically see IATs in the 250+ range. Obviously in this case the cooler the fuel, the better and the gains would be larger.

Name one "bolt on" that adds more than ~5hp. Does that mean that they're not worth it?

My point in all this: meth injection allows you to use a 150psi+ pump. Work out the math on that compared to your sub 50psi system. You can also wire it up with a simple throtal % trigger so it works when you get the most benefit. You can also mount the nozzle farther up stream so there is more time for the atomization affect to cool the charge air.

Not to sound snippy but if I wanted meth injection I would've already bought or built it. I don't like the idea of having any other tank to refill besides my gas tank. The same reason I'm not going to install a 100 shot of nitrous on my jeep, I want my power to be repeatable, not to come from a bottle.

There is no benefit for cooler fuel under idle conditions, especially for a stock low compression 4.0l.

Wrong, just like with almost anything else, the more dense something is the easier it is to meter and the more accurate and even amount of fuel is delivered to each cylinder thus, a smoother idle.

No offense, but the concept you have is honestly on par with an electric ebay supercharger.

Then why don't drag cars have ebay electric superchargers on them? Cooled fuel is a PROVEN concept, which is why it is actually used in the real world.

Edit: BTW, what are your coolant temps at idle? The other guys are spot on with the heat soak issues. Wrapping the manifold (AND cats) will solve that problem. The reason the 00/01s have the heat soak issue is due to the dual cats (otherwise known as convection ovens). Simple as that.

I have no overheating issues at all, my coolant temps at idle never exceed 210 @ ~70 ambient. And an easier way to solve the heat soak issues is to do what the factory did, which was simply insulate the fuel rail/injectors from the manifolds, not to go about the pain of wrapping your exhaust manifold. Not to mention, mine and most people's headers explicitly say NOT to wrap them. And no, the dual pre-cats are NOT the reason for the heat soak issue. Simple as that.

 

[wolfpackjeeper]

I did not interpret it that he said cooler fuel was not a good idea, he specifically said otherwise earlier. A dedicated fuel cooler with dry ice will get you super cold fuel temps, far and above what you are gaining by countering heat soak. I think what he meant was that using coolant that flows from around your ac system, to the fuel rail, and back though a pump can be compared to an ebay electric blower.

And if I had to guess, I would say that your idle improved from a heat soaked injector functioning correctly when it was previously malfunctioning. Not from any sort of accuracy enhancement in fuel metering.. Either way you accomplished your goal of running better, just in a more round about way. The 4.0 computer runs from a pretty standard, and broad table at idle. It doesn't really start to get selective until farther up in the RPM range.

 

[Mesh]

It doesn’t matter what these guys think. You had a theory you’re testing it out keep running with it.

 

[Boostwerks.com]

Name one "bolt on" that adds more than ~5hp. Does that mean that they're not worth it?



Not to sound snippy but if I wanted meth injection I would've already bought or built it. I don't like the idea of having any other tank to refill besides my gas tank. The same reason I'm not going to install a 100 shot of nitrous on my jeep, I want my power to be repeatable, not to come from a bottle.



Wrong, just like with almost anything else, the more dense something is the easier it is to meter and the more accurate and even amount of fuel is delivered to each cylinder thus, a smoother idle.


Then why don't drag cars have ebay electric superchargers on them? Cooled fuel is a PROVEN concept, which is why it is actually used in the real world.

Your correct. However, unless you know how effective your method is working (measure the change) you can't say it's doing jack. And your METHOD is what I was comparing to the ebay SC, not the concept.

I have no overheating issues at all, my coolant temps at idle never exceed 210 @ ~70 ambient. And an easier way to solve the heat soak issues is to do what the factory did, which was simply insulate the fuel rail/injectors from the manifolds, not to go about the pain of wrapping your exhaust manifold. Not to mention, mine and most people's headers explicitly say NOT to wrap them. And no, the dual pre-cats are NOT the reason for the heat soak issue. Simple as that.

Did I just read that right?...

Lets take a look at that:

1. They say not to wrap the header because it may void the warranty because it keeps the heat in and may crack the horrible welds that are on there. Containing the source of the heat is the most effective method for controlling it. Buy a quality header, wrap it, and don't worry about it. Mild steel would actually be best due to it's less expansive properties compared to stainless.

2. A precat/cat can typically get hot enough to emit infrared radiation. They are also conveniently located close enough to the motor to be considered in the "engine bay." It doesn't lead to heat soak? :banghead:

3. Please tell me you used a reflective heat wrap on the fuel rail, and not an exhaust wrap?

4. There are so many things wrong with your understanding of fuel "metering" I don't even know where to start.

4. Lastly, did you just say your coolant temps are stable? lol :banghead:

I did not interpret it that he said cooler fuel was not a good idea, he specifically said otherwise earlier. A dedicated fuel cooler with dry ice will get you super cold fuel temps, far and above what you are gaining by countering heat soak. I think what he meant was that using coolant that flows from around your ac system, to the fuel rail, and back though a pump can be compared to an ebay electric blower.

And if I had to guess, I would say that your idle improved from a heat soaked injector functioning correctly when it was previously malfunctioning. Not from any sort of accuracy enhancement in fuel metering.. Either way you accomplished your goal of running better, just in a more round about way. The 4.0 computer runs from a pretty standard, and broad table at idle. It doesn't really start to get selective until farther up in the RPM range.

:thumbup:

Although the computer should not be running from a table at idle, but should be entirely shooting for stoich off the O2. It will have a rich idle during warm up, but past about 180deg it should be 14.7 off the O2. This is yet another reason why his "metering" idea doesn't make sense. The computer doesn't care at all that the fuel is 40deg or 200deg as long as it can hit the 14.7 mark.

The cooler fuel will ONLY affect IATs. This is why I keep mentioning meth injection, because it is much more effective at doing this.

But like Mesh said, you don't have to listen to us. But that isn't going to stop me from sharing my experience. eace:

 

[Milford Cubicle II]

A precat/cat can typically get hot enough to emit infrared radiation. They are also conveniently located close enough to the motor to be considered in the "engine bay." It doesn't lead to heat soak? :banghead:

Yes, it contributes to heat soak but is NOT the cause. Also, the only 00-01's with dual pre-cats are the CA emissions packaged ones iirc. Mine doesn't have any precats at all and guess what... it had the same TSB! Meaning, precats are NOT the cause of the heatsoak.

Lastly, did you just say your coolant temps are stable? lol :banghead:

Have you read ANY of my original post? Where did I EVER say I was doing this for the purpose of lowering my coolant temps??? Give reading another chance man.

Although the computer should not be running from a table at idle, but should be entirely shooting for stoich off the O2. It will have a rich idle during warm up, but past about 180deg it should be 14.7 off the O2. This is yet another reason why his "metering" idea doesn't make sense. The computer doesn't care at all that the fuel is 40deg or 200deg as long as it can hit the 14.7 mark.

There are so many things wrong with your understanding of fuel "metering" I don't even know where to start.

You're missing what I mean by fuel metering. Injectors are imperfect. Doesn't matter what the computer says, if an injector is clogged it's not going to deliver any fuel. Same goes for hot fuel, the only thing the computer knows is the dwell of the injector and the a/f ratio for six cylinders combined. It has no clue how much fuel is actually being delivered by each injector, which is where haveing cooler fuel well help because like I said earlier, cooler more dense fuel can be metered more accurately than hot fuel. If you think a little deeper before you fly into a know-it-all, pretentious tirade then you wouldn't find yourself in this situation.

 

[Vanquish]

Me thinks...

a couple of hood vents > this entire thread.

 

[ColoradoRaptor]

It doesn’t matter what these guys think. You had a theory you’re testing it out keep running with it.

X2 OP, your cooler fuel concept is an old tried and TRUE one!! Keep it up!! :thumbup: Ignore the ignorant bastages giving you a hard time!!

 

[avnsteve]

I'm interested to see this work out. I suspect cooler fuel will prevail, but who knows? Maybe the internet heroes could win!

 

[RedChuck]

here i know this is for a co2 system but if you added it to your system it might cool better.
http://www.designengineering.com/products.asp?m=sp&pid=3

 

[badron]

My goal was to not only solve the infamous heat soak/rough idle issue in the 00'/01' xj's but to actually
=============================================================
When towing hot and heavy I had much the same problems with a hot restart.
Vent the hood and fix a few key off heat soak problems.
Or let it idle for a minute or two out of gear before key off.
Both have worked for me.
((ONE))) of the reason cool cans were used was to try and stabile fuel temp so that jet selecting would be more predictable on carb engine. A vapor/fuel mix is hard to meter well. It may also help on FI systems that don't use a return line as a means of fuel pressure regulating. Like the late model I6 engine do. So you could see a few more HP but do to the injector pumping out fuel only and not a fuel/vapor mix.
YES! this is IMO
Any FI that use a return line (some early models) keep a lot more fuel moving in the system. Keeping fuel and system cooler and ending the vapor lock problem or no cool can needed for them.

 

[Milford Cubicle II]

here i know this is for a co2 system but if you added it to your system it might cool better.
http://www.designengineering.com/products.asp?m=sp&pid=3

I like those products, a lot. Pretty cool stuff. But like I said earlier (over two years ago LOL), I want something permanent that doesn't need to be refilled. Just turn the key and it works, just like the existing A/C system.

I need to know what compressors the 12v fridges such as the ARB fridges use! If I could get my hands on one of those, this thing would be done! However ineffective and useless it would be

 

[Dr. Dyno]

How to keep the fuel in the injector rail cooler and lower the air temp. inside the intake manifold?

Place an insulating barrier on the underside of the intake manifold to shield it from heat radiating from the exhaust manifold:

http://www.angelfire.com/my/fan/manifold.html

It's a simple, cheap solution and trust me, it works.