Hey guys. I've got a black plastic jlt which is a 123mm I believe. If I swap over to the carbon fiber tube which I believe is a 127mm does the tune need to be adjusted?
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123 vs 127 jlt
- Thread starter CodyK7
- Start date
Yes?
They are virtually the same exact thing and neither flows more than the other. So no, no tune required and why swap? Want the cf look?
Ya I just wanted to change things up. I've heard both ways. But I have heard people say they flow the same so I wasn't sure.
My understanding is that they flow the same as well.
123/127 = 3% difference
If your car was tuned at 11.7 AFR, mathematically it would now be at 12.0 AFR. You would also see a 3% leaner difference in closed loop (closed and part throttle) fuel trims, and a reduction in calculated engine load. The reduced calculated engine load could result in an increase in total spark advance.
If your car was tuned at 11.7 AFR, mathematically it would now be at 12.0 AFR. You would also see a 3% leaner difference in closed loop (closed and part throttle) fuel trims, and a reduction in calculated engine load. The reduced calculated engine load could result in an increase in total spark advance.
They flow the same no retune needed. This has been stated by JLT multiple times.
This is directly from Lund Racing...
"If it's a new JLT 127, yes, the MAF curve is completely different – it will be lean without it. JLT’s latest 127 curve is nowhere close to a 123."
If you have a tune from Lethal/Lund Racing, they will revise your tune at no cost, I can't speak on behalf of others, though. They also went on to say there is no power difference between the two if that is what you are looking for.
"If it's a new JLT 127, yes, the MAF curve is completely different – it will be lean without it. JLT’s latest 127 curve is nowhere close to a 123."
If you have a tune from Lethal/Lund Racing, they will revise your tune at no cost, I can't speak on behalf of others, though. They also went on to say there is no power difference between the two if that is what you are looking for.
The maf can't compensate for a larger maf housing without the tune being adjusted. Anytime the diameter of the maf housing changes, the tune will need to be corrected for it.
It's like this:
Stand next to a doorway (maf housing), hold your arm (maf sensor) in the path of the doorway, and close your eyes (the maf is blind). You've been told (tune) to count 1 for each person you feel pass through the doorway. No problem. Each person that hits your arm is one, no matter how fast they move through, because that's what you were told. Easy enough. Now, without you knowing, I open a second door making the doorway twice as wide, which allows twice as many people through. But you still only feel one person each time, even though two people are passing through at a time. To correct that, I now tell you (retune) the doorway is wider, and two people are passing through each time you feel one person hit your arm.
Hopefully that makes sense. This wasn't necessarily directed towards you, but more for those who aren't quite sure how or why a maf housing can effect how the maf sensor reads.
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makes sense
So what about filters? Some JLT kits have the mesh for smoothing and others don't. Does the 123mm require a meshed filter? I know switching from the meshed to non meshed filter on my 127mm my boost gauge reads higher and reacts quicker now. ( not saying its faster ) I guess just that is messing with my tune.
I would guess Tucker needs to jump in answer this to get a clear answer. My understanding was that the 127 flows the same as the 123 and the only difference was one is plastic and one is CF.
But as I said, Tucker could clean this up rq.
But as I said, Tucker could clean this up rq.
See even this thread is full of both sides. I'm not really looking for a performance gain. I just want some kewl carbon fiber.
....so just your intake tube is going to be carbon fiber, and you are willing to pay that price? Or do you have a CF hood and what not? Otherwise once the hood is popped that CF intake is just...ugly, you can tell it is not "supposed" to be there and was put there, when everything else is flat-black plastic.
Hater in the house. He obviously doesn't have one or he would understand.:rolling:
The point to adding it would be to break up all that flat black plastic. I personally like the way it looks, which is why I'm running one:
Huh. I wondered why my Challenger had an IAT, and my Toyota had the MAF sensor, glad to know we use MAF sensors in these motors. And yeah I can see how that carbon fiber stands out, def does not look bad, just not sure I'd pay the cost for a new CAI just for CF if I was getting pretty much the same results.
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The Mustang has had a MAF every year since 1986.
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