IMO 15k is not enough. 20ish-k mine did much better, 30k+/- and awesome now.
Bolt on turbo kit (9 Viewers)
- Thread starter scottryana
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
12 to 1 is rich, man. It’s a ratio. 18 to 1 super lean.
alia176
SILVER Star
alia176
SILVER Star
Chris,If that does work, then you know "given enough air flow, the engine will stay cool". How much airflow is the BIG question...
How much air flow are you getting through those louvers in that position? I think raising rear of hood is low cost/low effort project that may help.
I just installed the center louver section from the Trackspec kit, which is right on top of the motor. Since I'm in NorCal, I don't worry about rain () and will make sure sensors on top are adequately waterproofed.
Driving home yesterday outside temps were mid-80s, coolant stayed 190-194 (from OBDII). I don't have a way to measure airflow, but there's a lot of airflow through the louvers, so it seems like it's working.
Show us your Trackspec kit solution pls, I'm intrigued. As far as how much is getting sucked out of the louvers, who knows! The fender skirts are gone so they're helping with heat evac but the 15k CST as, mentioned by others, may be insufficient.
When I go home in the heat of the day today and all uphill (from 5k to 7k elevation), that'll be the big test. Stay tuned......
CJK
SILVER Star
With 30K at full lock-up, it must be like 5hpWow doggy, 30K?
.Installed pics. rear edge of vents on Passenger side are directly above turbo.
I did have to cut through center section of hood support (and partially through the side ones) so I still need to re-bond the hood skin to support as I get a ~3/8” of hood flutter at 75 mph. 3M NVH to the rescue later this week.
Last edited:
CJK
SILVER Star
I can explain my theory more later but…
tldr - I believe we can improve efficiency of cooling system by giving hot air a more efficient path to exit from under the hood.
tldr - I believe we can improve efficiency of cooling system by giving hot air a more efficient path to exit from under the hood.
alia176
SILVER Star
I know, thus the question. The only explanations I can think of for the rich condition are:
- That's the nature of the beast given the limitations of the computer / narrow band o2 sensor
- I have an injector that magically gets stuck open only under certain conditions and it unsticks itself magically thus creating the rich condition
- ?????
- Thread starter
- #5,949
I wrote a lengthy reply (at least for typing on a phone) to your earlier message, It kind of got lost before the cooling posts. It is all normal and that is exactly what it is. The rich condition is called open loop fueling.
Sorry @scottryana , I did miss your reply. Thanks again for dropping wisdom on me!
Just FYI, the placement of your hood vent will not let hot air exit after about 20mph. The cowl area is a positive pressure zone and once you get moving it will push air into the engine compartment. Try the shelby yarn test and drive around a bit, youll see what I mean
I put 2 louvers in near the cowl, one is blowing air where the turbo mounts and one is blowing air on the intake. They made a good difference on trails and the truck cools off really fast when parked now. Helped quite a bit with IAT's too, which is why I installed them.
Last edited:
alia176
SILVER Star
Pics would help!!!
Sorry, something got all screwed up with that post, I meant to quote @CJK and the area by the cowl is a positive pressure area, not negative. I edited the original post.
These are my louvers and they let air out of the engine compartment at slow speeds and and a ton of air in after about 20mph. I did the yarn test and was pretty surprised to find that out. Anything from about 1/3 of the way back from the front of the hood was positive pressure and will push air into the engine compartment at higer speeds.
This video shows what im talking about on a exponentially more aerodynamic vehicle than an 80.
CJK
SILVER Star
Interesting. I will admit that fluid dynamics is not my speciality, but I have a pretty good understanding of physics.
I agree with what you are saying, but if anything it sounds like my hood vent position is better than yours. The rear edge of my vent is forward of the washer fluid nozzles than you installed.
Maybe I'm confused?
I used Race Louvers to understand dynamics and position as well, specifically this pdf:
"Extractor location: This is very important. The main purpose of a hood vent or extractor is cooling, heat exchanger cooling ie rad/oil coolers etc, the secondary purpose is downforce. So to improve cooling one can improve the airflow thru the radiators, this can either be increasing the pressure in front of the radiator (bigger grill opening) or decreasing the pressure behind the radiator (bigger opening behind the rad) to net a larger differential pressure across the radiator core, more differential pressure = more airflow = more cooling. So with regard to vent placement the front should always be behind the radiator with the rear no closer than about 1/3 of the hood length from the windshield. If the vent is forward of the radiator the air exiting the radiator has to do a 180 turn up and forward to the vent and another 180 turn up and out of the vent which is highly inefficient or worse yet a vent forward of the radiator may steal air from the front of the radiator hurting cooling. Why 1/3? With under hood pressure as a reference, generally the front of the hood is a lower pressure zone, the center near zero and the rear a higher pressure then the engine bay. So with no vent the zero differential pressure point on the hoods surface is about 1/3 the way from the glass so say your hood is 48" long then the zero diff press point on the hood is roughly 16" from the glass. Now this high pressure zone on top of the hood is generally in the center, as you approach the A pillars the zero diff press point on the hood is very close to the A pillars, just a few inches, so center vents need to be pretty far from the glass but side vents can be much closer. Vehicle speed generally determines how big the center cowl high press zone is. Now once you add a hood vent everything changes. The first thing is the engine bay pressure gets lowered, this changes the zero diff press point on the hood 1/3 way from the glass to further forward. The better the hood vent or extractor the lower the engine bay pressure the further forward the zero diff press point on the hood is. Next the vent adds pressure to the top cowl area even further moving the zero press point forward. This zero diff pressure point dictates the location of the back of the vent. So our general rule of thumb for Race Louvers is 2" behind the rad to 20" from glass in the center, 15" on the sides and 6" for top mount fender vents give or take and as wide of an extractor(s) as you can get on the hood. This is why our Race Louvers aren't quite as long as some of the other companies."
CJK
SILVER Star
So I agree that I would have better air flow through the radiator if I moved the vents forward. One of the reasons I pushed it a little further back is that it just looked better and I wanted to give heat a place to vacate from the hot side of turbo when the car is moving slow/stopped 
Last edited:
So I agree that I would have better air flow through the radiator if I moved the vents forward. One of the reasons I pushed it a little further back is that it just looked better and I wanted to give heat a place to vacate from the hot side of turbo when the car is moving slow/stopped
View attachment 3065259
In the photo above, everything from about 36" on your tape measure to the base of the windshield is higher pressure than the engine bay at high speeds and will draw air in to the engine compartment.
I did mine to help get heat out of the engine bay on the trail. works as intended for that. I was not expecting the flow to reverse at higher speeds, but it worked out even better that I inteded since the "cool" air blows on the intake and right where the turbo mounts. That helps with heat soak and IAT's on the highway. Yours should work the same, but you can always get some scotch tape and yarn and do your own testing.
Also, once of the worries I had about hood louvers was smells from the engine compartment making it into the cab since the HVAC brings in air from the cowl. With the flow reversal that was a non issue. That is actually why I did the yarn test - to see why my smelly old 80 wasnt stinking up the cab.
CJK
SILVER Star
I'll do a yarn test at the vents because I'm now curious
This was my line of thinking of:
1a) According to Bernoulli's principle (high velocity = low pressure, low velocity = high pressure), as long as air is flowing over the surface of the hood is faster than through the radiator into the engine compartment, the relative pressure will be lower on top of the hood.
1b) The grille + radiator create more restriction (less aerodynamic since perpendicular to direction of air) than the windshield.
1c) Given that, the relative pressure will be lower on top of the hood = lower pressure, thus higher pressure air (engine compartment) will seek lower pressure to equalize pressure.
It is my thinking that the low pressure under the vehicle's engine bay is much greater at speed, which is why you see a reversal in pressure with the hood vents. Hood vents for us being beneficial at a crawl or idle...
