Project: Hot Rod Cherokee

[John]

Nice work, and a few HP for lower temps under hood. I bet it sounds hungry off idle to a rapidly rolled on WOT. I suspect a little more intake temp drop is possible with insulation?
John

[1bolt]

Yeah, it was an obvious seat of the pants improvement so it must be worth 20hp/ft pounds between the cooler charge and the lower restriction.

The key thing to realize is unlike most mods that give mostly "peak" horse power gains. Cooler intake air gives across the board increases in power, usually expressed as 11* = 1% increase in power. SO the more powerful you build your stroker the more that 6% (roughly) impacts your performance.

It doesn't sound like much, but a 264hp Hesco or Golen stroker times 6% = 279hp, and again that's purely the cooler air, add the lower restrictiveness of smooth intake tubes, and a big high flow filter like the 9" AEM Dryflow and there should be an easy 25 hp gain on a built motor...

Now if you go from sucking 90* to 100* hotter than ambient air from near your header, then we're talking as much as 10% increase in power, that's a big chunk even on a bone stock 4.0, 14hp assuming a normal 144rwhp, on a stroker it's going to be somewhere around 20 to 26 hp ignoring any gains from high flow filters and tubing..

Its hard to say exactly where the 6* above ambient is coming from, I suspect its a combination of heat soak of the intake pipe, and a few degrees of hotter than ambient air getting sucked over from the driver side of the opening. The gauge or sender itself could be off by a couple degrees. At some point I'll have to test it out before startup; see if it agrees with a little wind speed/temperature gadget I have that I'm going to use to test the lastest hood when I get back to it.

Getting John Young's flow bench has pretty much completely side tracked everything else.

[Flash]

You are a lucky man to receive such a gift.
Maybe some day you will be able to finish.........or start were he left off!


so is this just to support the air box................or have you got ideas of feeding it cooler air!........ then out side air????????


You know a nice little vacuum actuated valve, that fell open when your foot was to the floor would work........and my be an acceptable " temporary" noise!


Flash

[John]

"Getting John Young's flow bench has pretty much completely side tracked everything else."

Go for it, I would only get sketchy sleep for a awful long time.

Being within 6* of ambient temp is likely heat soak from the exhaust manifold etc. Nice HP gains for a item overlooked by most. HP gains are not usually found in huge quantities, for singular items, but those are some of the larger economical gains. Too many will spend $$$$ to pull the manifold heated air into their new intake setup.
John

[1bolt]

Flash: yeah I intend to pick up where he left off, there's a huge time investment but I think it's worth wild. That tube is a snorkel for fording water, and it is loud, it is inside the air box, and opening it up (inside the glove box) is a real eye opener, besides being deafeningly loud, it also blasts air into the cabin, proving to me at least (I can't prove it scientifically without some sort of remote fine reading (milibar?) barometer) that the air at the cowl is high enough pressure that it must be having some ram air effect.

John: yeah I have been up nights thinking about all the stuff I want to try. He (NOSIGMA aka John Young) spent the better part of an entire sunday showing me how to use it. It's set up in my humble work shop (a shed) now and I calibrated it last night. First thing I will do is flow a couple things that I have solid CFM numbers for such as 4.0 heads, and a couple SBF intake manifolds to see where its at in relation to known flow bench numbers.

[Flash]

Flash: yeah I intend to pick up where he left off, there's a huge time investment but I think it's worth wild. That tube is a snorkel for fording water, and it is loud, it is inside the air box, and opening it up (inside the glove box) is a real eye opener, besides being deafeningly loud, it also blasts air into the cabin, proving to me at least (I can't prove it scientifically without some sort of remote fine reading (milibar?) barometer) that the air at the cowl is high enough pressure that it must be having some ram air effect.

John: yeah I have been up nights thinking about all the stuff I want to try. He (NOSIGMA aka John Young) spent the better part of an entire sunday showing me how to use it. It's set up in my humble work shop (a shed) now and I calibrated it last night. First thing I will do is flow a couple things that I have solid CFM numbers for such as 4.0 heads, and a couple SBF intake manifolds to see where its at in relation to known flow bench numbers.

Yeah, hadn't thought about the ram air it would create inside the cab........................On vent there should be a equalizing affect as it gets is air of the same wind shield..............the scoop may still have a higher pressure, but you would think with the fan on high.........it would over compensate or cause the air the travel in the opposite direction.......cab to air box

Here is just something to chow on.

an electric motor will work as a generator(low amperage) if it is being spun instead of electricity turning it........ the positive and negative Poles change, depending on which direction you turn it.
Now, if you cold seal a motor/fan inside of that fire wall tube, and hooked a volt meter to it.

Now if is a neg voltage the air travailing one direction, and if it is a pos voltage then the fan is spinning the other way.
I have done this with a small elect motor and a bicycle tire.


Flash

[-XJguy-]

Great job on the hood man. I did the same thing several years ago, but went much bigger to fit an Eaton blower under the hood and to help direct air over the Jeep for improved aerodynamics. But the main difference is you actually finished, and mine is going to be used as a buck to lay down some carbon fiber over.

warriorhood2.jpg

[xsubarudude]

Thanks for sharing this.
Im trying to revive my XJ too ,, same interior colors