Project: Hot Rod Cherokee

[1bolt]

yeah I never noticed any problems and I've got other stuff welded that have paint or powder coating none of them have any issues around the welds... even stuff that is only lightly painted to prevent flash rust.

I did have issues though, But they were my own rookie mistakes, like I should have gusseted the corners of the hump where the profile meets the skin of the hood... Over time slamming the hood the flexation has caused hairline cracks in the filler.

That hood spent about two years on the XJ and then got pulled and put on my MJ before I painted it. At which time I fixed some of my mistakes. But I wanted to make a better version for the XJ. Which is my current project.

[1bolt]

Here's a shot of the hood on the XJ, about this time I got some of the updated 97 and later Cherokee emblems, blacked them out with some textured black paint and replaced the old school ones. I also got some Dodge truck 4x4 emblems blacked those out, and put them on. They are way bigger and chunkier than the stock 4x4 emblems. Guess I've watched too many episodes of Overhaulin' as I was going for some subtle differences, but to date I don't think anyone has ever noticed so maybe subtle on a lifted 4x4 is dumb

here's a side shot


The meat of this hood mod, is coming up. I built a filter box that seals to the cowl opening which resulted in colder air intake and took temps before and after.

BTW if you all haven't found it already, the forum shrinks all images so they fit, this makes things jaggy and less clear. If you click the image it will open it in a larger window and you may still need to click on the image to zoom it to the correct size (firefox does this) The un-resized version is WAY clearer.

[Muad'Dib]

BTW if you all haven't found it already, the forum shrinks all images so they fit, this makes things jaggy and less clear. If you click the image it will open it in a larger window and you may still need to click on the image to zoom it to the correct size (firefox does this) The un-resized version is WAY clearer.

Is the scaling causing a problem? I want to make sure the mod is what you guys want and need!

Would you do hoods for any of us?

[fedrusion]

I might have to head out to the JY and pick up a hood and make a hood like yours. Looks awsome.

[seanyb505]

Very nice work, I would consider it subtlety accomplished!

[Shark]

the hood doesnt look as extreme as i thought it would. i dont think a non-jeeper would even notice.

[1bolt]

wait until you see the next one.

[1bolt]

Is the scaling causing a problem? I want to make sure the mod is what you guys want and need!

Would you do hoods for any of us?

I've thought about building them and offering them for sale. Landscapers need side business' in winter. Unfortunately the paint alone would cost 100 bucks for a pint of decent quality Dupont Chroma base, activators/reducers and a quart of Nassin clear. So add that to the couple days of work (when I got good at doing it quickly which would take a few more hoods for sure) and I'd have to charge more than 600 or 700 bucks painted without shipping. Quadratec sells one for $400-500 unpainted and before shipping.

On the scaling I wouldn't say its causing a problem its either scaling or scroll bars, I just don't know if people realize that they should click the picture to see it without the jagged edges. What size does it scale to? If we could get 800x600 to fit a lot of pics would fit without scaling... On the other hand maybe the aspect ratio that the forum is scaling to is off... if it's not a multiple like 640x480, 800x600 or 1024x768 the scaling will look more jagged. In other words if it's shrunk more in width than height the image will degrade more than if it's shrunk evenly. Like I said it may already be scaling the best it can, I don't know

[Muad'Dib]

Is the scaling causing a problem? I want to make sure the mod is what you guys want and need!

Would you do hoods for any of us?

I've thought about building them and offering them for sale. Landscapers need side business' in winter. Unfortunately the paint alone would cost 100 bucks for a pint of decent quality Dupont Chroma base, activators/reducers and a quart of Nassin clear. So add that to the couple days of work (when I got good at doing it quickly which would take a few more hoods for sure) and I'd have to charge more than 600 or 700 bucks painted without shipping. Quadratec sells one for $400-500 unpainted and before shipping.

On the scaling I wouldn't say its causing a problem its either scaling or scroll bars, I just don't know if people realize that they should click the picture to see it without the jagged edges. What size does it scale to? If we could get 800x600 to fit a lot of pics would fit without scaling... On the other hand maybe the aspect ratio that the forum is scaling to is off... if it's not a multiple like 640x480, 800x600 or 1024x768 the scaling will look more jagged. In other words if it's shrunk more in width than height the image will degrade more than if it's shrunk evenly. Like I said it may already be scaling the best it can, I don't know

I personally wouldnt want one painted, only primered and ready for paint ... what kind of cost are we looking at there?

I give the function a width to scale to (currently 670), and it scales down to that width. It keeps the aspect ratio of the image intact when down-scaling, so calculates the height automatically (or at least that is the way its written to be). It seems its doing the best it can to resize the image IMO. Do you want to try a different width?

[Shark]

i would be interested in one in primer black. how much? i would want a more extreme cowl vent. cant wait to see the "next one". i have seen the one in quadratec. i thought the $ was too much. im hoping yours would be cheaper without paint.

[1bolt]

it would be hard to make it cheaper, the ones from Quadratec are factory stamped, cheap and easy.

I haven't forgotten this thread just busy with work, hopefully do an update this weekend with the custom intake tubing and temperature measurments.

[John]

Please do, interested in reduction of under hood temps. Nice fabricating.
John

[1bolt]

Okay after the hood went on, I fabed up an intake tube that reached over from the TB to the cooler passenger side of the engine compartment, and then tried to figure out how to fit and mount a box in there right against the passenger side of the cowl so that I would simultaneously get cool intake air (by sealing the filter against the opening), and the driver side cowl opening would cool the hot side of the engine bay. I also got a intake temp gauge off Ebay for a steal:



And mounted it in various areas under hood and in my intake pipe right above the throttle body so that I could Geek out even more I taped the cowl opening closed to get a base line of under hood and intake temps.

Base line (no cowl opening)
Intake: 146* to 155*
Under hood 168*

Intake temps was averaged while driving at 55-60MPH, under hood taken with laser thermometer averaged from 6 different locations immediately after stopping, the day was 90* to 92*.

I fab'ed the intake up using some 2.5" mandrel bent tubing, one U bend was plenty, I basically eyeballed it and tack welded it


And after pulling it off and finishing the welds I powder coated it with a good old HF coating gun. I ran with it like this for a while. Before the air box.


Intake temps in this configuration this were much lower than with a cone filter and no cowl opening. and even lower than the filter on the hot side of the engine bay. But still significantly hotter than ambient. which prompted me to make a heat shield, which turned into a completely sealed air box.

Making an air box is not nearly as simple as it sounds at first, you have to fit it in there. It needs to seal against the hood, and it needs to not ruin access to the dip sticks, or grind bare spots on your wires. First I bent the trans dipstick down to the oil


Then moved the washer jug over closer to the fender:


The way I went about getting the right size and shape was mocking it up with a card board box cutting strips where I felt it would touch, I then closed the hood, bending the cardboard which told me how much to trim off until it was in the ball park:



here the basic shape has taken shape, I had some door seal from the rear hatch of a parts Cherokee that would compress against the hood, so I cut the box down until nothing touched, and then cut another inch or so for the rubber seal.
Then I used the box as templates to cut the sheet metal out of; and tacked it together.

Then I spent a few hours mocking it into place and admiring my own handywork and then grinding where I needed clearance.



The weather seal is perfect, it took hours to get everything to fit just right. Not shown is a rubber bumper used to stand it off the valve cover and another one on the little shelf along the firewall to stand off that. I got the rubber parts from a stock Mustang intake's factory vibration stand offs. The hood, the filter, the "snorkle", and the silicone couplers holding the tubing in place were all that was needed to keep it in place. Let me assure you the fit was tight, not perfect but not much underhood air was reaching this filter:



Here's the coated air box:


The proof is in the air temps... After the box they were only 6* degrees warmer than ambient like clockwork, if it was 90* out the intake temps read 96* very steady (plus or minus a degree or two at most). This is approximately 60* cooler than the "best case" underhood intake with the filter on the "cool" side of the compartment with a non-vented hood. Worst case, sucking air from next to the headers by deleting the factory air box and putting a cone filter there would be even more drastic. I'm betting 80 to 100*. The average underhood temps dropped 11* which if you think about it is a lot considering everything is still running at the same temps emitting the same heat levels.

The best benefit was that my mild pinging (on hot days running anything but premium) went away even on the hottest days even with mid grade. The cooler air should be worth from 10 to 15 added hp and torque across the power band. If you went from a paper filter to a K&N style with this setup it should be worth 20hp on a normal 4.0.

The intake also sounded down right cool. Being sealed to outside air means no muffling, and the tube and box resonated nicely when you got into it, sounding quite nice if you like that sort of thing... Let me tell you the Cherokee smoked a late model SS Impala a few days after the mod from light to light, the teenagers in the Impala didn't take it seriously the first light, when I took off at WOT wanting to hear the new sounds. but they still got left behind on the second try. There's nothing like peak torque off idle, especially when it's nearing 300ft pounds, I'm sure they would have caught up in a 1/4 but then that's the beauty of low RPM torque in a street machine it will leave a lot of more powerful cars behind for long enough to have an unashamed smile on your face when they catch up to you

[gradon]

That is so effin bad@$$--excellent job!!! Yesterday I saw a cherokee that looked stock except for the paint matched cowl hood(probably Q-tec). Since I had my radiator out and header panel off(for the stroker install), I cut most of the metal @ the driver's side headlight location so that more air can get to the cone. A few months ago I removed a factory installed plastic cover that should've been off for the stock airbox and cut a little of the fiberglass on the header panel to make it breath more outside air. Again, good job.

[Flash]

That is so effin bad@$$--excellent job!!! Yesterday I saw a cherokee that looked stock except for the paint matched cowl hood(probably Q-tec). Since I had my radiator out and header panel off(for the stroker install), I cut most of the metal @ the driver's side headlight location so that more air can get to the cone. A few months ago I removed a factory installed plastic cover that should've been off for the stock airbox and cut a little of the fiberglass on the header panel to make it breath more outside air. Again, good job.

I will 2nt that.

Whats with the black pipe going thru the fire wall?

Flash.