AW4 shifting with big throttle body

Performance mods and Advanced Stroker discussion.
cal
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AW4 shifting with big throttle body

Post by cal »

I just put together a pretty powerful motor and had it tuned by Chris Jensen. Its running very good, but I have an unanticipated drive ability problem.

When cruising between about 40 and 65, I'm using almost no throttle, in OD and locked up after 45. If i want to accelerate, it really really doesn't take very much peddle to do it. In fact, so little, that the trans won't downshift. Unless I *really* get on it. (which means like half peddle, but that's enough to look like I'm trying to race you).

That's not really a problem at highway speeds, but if I'm trying to go around a car that is stopped in traffic waiting to turn or just speed up some, it is awkward. Like trying to drive a manual trans in 5th gear all day.

I suspect part of the problem is the 64mm throttle body. I don't give it enough TPS input for the TCU to want to downshift. I'm thinking I may need step down to a 62mm throttle body? Has anyone else encountered this and am I totally off in my diagnosis?
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Re: AW4 shifting with big throttle body

Post by optmaxx »

You probably need to adjust your TV (Throttle Valve) cable to get your passing gears back; there's probably too much slop.
cal
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Re: AW4 shifting with big throttle body

Post by cal »

There is no slop, it is correctly adjusted.

And the TVP does not dictate downshift RPM's, just how much line pressure is applied to the throttle body while doing the downshift.
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Re: AW4 shifting with big throttle body

Post by Cummins90 »

Interrupt the TC lock up with a push button? 4th gear unlocked.
cal
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Re: AW4 shifting with big throttle body

Post by cal »

They I may as well have bought a 5 speed ;)
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Re: AW4 shifting with big throttle body

Post by Cummins90 »

Purchase an AEM FIC 1913 and use one of the 5v analog signals to intercept the TPS. Then input a percentage into the load map where you are having your issue.

Seems like alot for what a push button will solve.

Chris doesn't have a solution for you?
cal
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Re: AW4 shifting with big throttle body

Post by cal »

He can't do anything for the aw4.

I think if I had deeper gears it wouldn't be manifesting so badly, but I did 4.10's with 33's and a big stroker to see what would happen.

Will check out the AEM module.
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Re: AW4 shifting with big throttle body

Post by Cheromaniac »

Just manually shift down to 3. Problem solved.
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cal
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Re: AW4 shifting with big throttle body

Post by cal »

That's what I am doing right now, but I'm not the least bit satisfied with that as a solution. I'll either end up going to a smaller throttle body or regearing, I think.
Cummins90
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Re: AW4 shifting with big throttle body

Post by Cummins90 »

If you go with an FIC you can add a turbo...just throwing that in the mix. Let me know if you decide to go that route.
cal
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Re: AW4 shifting with big throttle body

Post by cal »

lol. that would be fascinating to watch.

i'm already 11.4:1.
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Re: AW4 shifting with big throttle body

Post by Cummins90 »

Depending on how you set up your stroker it's possible with an efficient turbo and lower boost pressures. If you want pics of my set up PM me.
cal
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Re: AW4 shifting with big throttle body

Post by cal »

My best friend designs turbo systems for a living (he built the 4.0 system for Banks and is currently an engineer at aFe doing similar work). He's been trying to convince me to boost my jeep for years, but I'm really not interested.
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Re: AW4 shifting with big throttle body

Post by Cummins90 »

Yea personal preference. I liked the results when I did mine so I started making some parts to help others that dont have the means to fabricate. My goal is to have a low compression turbo stroker. Did you buy from Russ?
cal
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Re: AW4 shifting with big throttle body

Post by cal »

You could say that. (Russ and I are very close, he put this one together for me while I watched).

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