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Renix computer and more air intake (cone filter/maybe bored TB)?

HenryKrinkle

NAXJA Forum User
Location
WI
How does the Renix computer deal with more intake? I understand that this ECU is not really a computer exactly and will not store data, but other than that I have little idea how it works.

I will be putting in a short ram air intake (Rusty's/AEM dryflow) with a homemade heat shield type of thing. Will the computer automatically adjust fuel/air mix settings to deal with this? I know it won't be a huge change, so it should do just fine.

What is the limit of the ECU's ability to adjust the mixture properly? What if you put in a 60mm bored throttle body?

Any insight is greatly appreciated....
 
Goal is to keep up with traffic better until I can figure out my rear axle/gearing. Probably won't go back in to the manifolds right now, maybe in the future.

I'm thinking about that bored out (60mm) throttle body from Leigh Performance to go with my new AEM/Rustys setup.

I guess I don't know how the computer will keep up with the fuel mix without allowing a too-lean situation. Sounds like I won't need to worry about it.

Maybe I'll look into injectors too- I've heard the phrase "Ford 19lb" used a ton around here.

Thanks for the link, Joe - I'll check it out...


ETA: How restrictive is the stock muffler? I've put on a new manifold/downpipe, high-flow cat, and generic stock muffler- maybe that's something I should look into...
 
I have what you're proposing to do, the 60mm TB but not a CAI. Works fine. The computer will adapt to the air flow just fine. While you're at it , move the intake air temp sensor to the air filter and get it out of the hot manifold. You'll feel it..
 
The 4.0 seems to like a little back pressure, so a CAT back system can help quite a bit, that's covered in the 4.0 myths article.

I don't know if the Ford (Bosch) injectors are really a performance upgrade, the 4-hole disc design seems to provide a much improved idle, and the cost compared to stock injectors really is hard to beat. The two-piece body on the early stock injectors will start to leak--right over the hot exhaust manifold. XJ BBQ.

IMHO you will always gain the most from the right gearing--better than engine/intake mods. When you decide on the size tires you want to run, and your type of wheeling, then the gear selection will be easy. Plenty of online ratio calculators to use too.
 
The throttle body give you a quicker throttle response simply because it opens faster than stock. As far as actual power, the only place you would see much of a difference would be at very close to wide open throttle.

I've been building engines for 45+ years. Displacement or cam are the only upgrades that make a marked difference. Everything else gives small increments.
 
Thanks a ton guys. Sounds like I need to focus on gears. I'm glad I didn't dive into this "performance" mod thing without checking here first. Still glad I got the cone filter setup, but I don't know like loud trucks much and was considering doing that for a minor performance increase:dunno: Starting to get carried away I guess.

Anyway, will focus on choosing between 31's and 33's and pick up an 8.25 to build up.

Thanks a bunch!
 
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