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Ariel
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810 Posts
Discussion Starter · #1 · (Edited)
Ever since I've boosted my truck Ive had this issue. I thought it might be transmission related but Im not sure. Basically unless i stomp on the pedal for a drag race the low end on this truck sucks. Im usually the last at leaving the light while trying to smoothly ramp up to speed, otherwise the videos below is what its like. So before i drop a lot of money on a 46re swap I need to figure out this issue. What do you guys think?

Video below is leaving from a light trying to ramp up to speed. When the revs go way up i let off a bit then gave it gas to speed up. I pretty much push on the peddle almost to the floor before ti responds.

https://www.youtube.com/watch?v=zT6RoTyCA2Q

On this video i didn't stomp on the gas. I slowly pushed to speed up and it just wants to take off.
https://www.youtube.com/watch?v=AB9SWA5HY8M
 

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Administrator
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17,936 Posts
Ok the second video is that pre boost crap from the load ramp up. That’s tough to get nailed down but we can make it a little better.

The first video not sure it’s almost like your pedal is dead till you get to a certain point
 

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Greg
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20,008 Posts
Not sure what you are trying to demonstrate. You are in drive and I'm sure at part throttle the transmission is shifting to the next higher gear pretty much keeping you from making any boost.
 

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Ariel
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810 Posts
Discussion Starter · #4 ·
Ok the second video is that pre boost crap from the load ramp up. That’s tough to get nailed down but we can make it a little better.

The first video not sure it’s almost like your pedal is dead till you get to a certain point
You think the dead pedal thing is something you can adjust with the tune? Do turbo set ups have the same issue?
 

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Ariel
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810 Posts
Discussion Starter · #5 ·
Not sure what you are trying to demonstrate. You are in drive and I'm sure at part throttle the transmission is shifting to the next higher gear pretty much keeping you from making any boost.

Trying to show normal driving where i cant control acceleration without the truck taking off. When i let go of the gas trying to control my speed then it feels like im on a higher gear where the truck doesn't pull strong just lags. Makes for a crapy ride.
 

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Ariel
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810 Posts
Discussion Starter · #6 ·
Couple weeks back i lost control of the truck in the rain and almost ended up in a ditch trying to get on the highway because of this issue. I havent found alot of boosted guys talk about an issue like mines. Is this a supercharger thing? Would going turbo remedy this?
 

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Greg
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20,008 Posts
Superchargers start making boost around 2800rpm
When boost starts coming in the engine accelerates rapidly.. this is normal. To control this rapid increase in power you need to control what gear you are in. You would see much more control if you manually shift the trans. The easy solution which I don't like is to replace the BOV spring with 1-2psi spring. This will keep you from making boost except when @ WOT. You can put the trans in drive and it will work normally, go wot and it will go boost like throwing a switch. Manually shifting you can hold your gears and have control.. with a 46trans with manual vb you have total control over what gear you are in and can load that gear eliminating the surge of changing gears and rpm jump.
 

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Stu
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21,322 Posts
Do you have the tow/od off? Something seems to be off with the rpm on the second vid. Idling too low. With a 2800 stall tc, it should rev up to 2800 rpm with no problem. It's looks almost like the tc lock up clutch isn't disengaging. Try driving it around with the tow/od off.
 

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Registered
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575 Posts
I was having the same issue as the second video, but with turbos. On top of what you are experiencing, i had the additional problem where i would let off the gas (under boost) and the truck would keep on pulling for 2-5 seconds.
The problem appears to be in the tune. Keith looked into the tune for me, made some changes and so far the problem has gone away.
 

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Stu
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21,322 Posts
In the vids when you let off of the throttle, it looks like it went into over drive (tc clutch lockup). If it does the same thing with the tow/od off. Now, that would be a problem.
 

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Ariel
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810 Posts
Discussion Starter · #11 ·
Do you have the tow/od off? Something seems to be off with the rpm on the second vid. Idling too low. With a 2800 stall tc, it should rev up to 2800 rpm with no problem. It's looks almost like the tc lock up clutch isn't disengaging. Try driving it around with the tow/od off.
On the videos tow/od is on. I usually drive with it off and its a little better but not a whole lot. When it first takes off i let go of the gas and once i try to speed up again its lags.
 

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Stu
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21,322 Posts
Usually turn off the od from cruising when want to accelerate in a lower gear. Never let the 545rfe trans down shift into 2nd prim with the od button on.

Have you tried to reset the running history and re-install the tune? Have you tried a throttle peddle set? Is there a bypass valve on that supercharger?
 

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Mark G Senior Member
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1,976 Posts
I was having a similar issue till I change my Turbo and went to an AR 115 on the hot side. and all of the surging went away. And I always have OverDrive turned off unless I am going faster than 50 mph. I am also running an electronic dual stage boost controller first stage is set for 10 lb but I can flip the switch and go to 15 lb.
 

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Ariel
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810 Posts
Discussion Starter · #14 ·
Usually turn off the od from cruising when want to accelerate in a lower gear. Never let the 545rfe trans down shift into 2nd prim with the od button on.

Have you tried to reset the running history and re-install the tune? Have you tried a throttle peddle set? Is there a bypass valve on that supercharger?

Yeah I've reset it and had the tune taken off and re installed and adjusted but its still doing it. I haven't tried a throttle pedal set, ive never heard of it. I do have a blow off valve
 

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Ariel
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810 Posts
Discussion Starter · #15 ·
I was having a similar issue till I change my Turbo and went to an AR 115 on the hot side. and all of the surging went away. And I always have OverDrive turned off unless I am going faster than 50 mph. I am also running an electronic dual stage boost controller first stage is set for 10 lb but I can flip the switch and go to 15 lb.
Whats an AR 115?
 

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Stu
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21,322 Posts
Yeah I've reset it and had the tune taken off and re installed and adjusted but its still doing it.

Then if everything is working as it should. Get with Keith to check and adjust the tune like he did for Max. Most likely just a minor adjustment. :thumb:
 

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Mark G Senior Member
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1,976 Posts
Are you ready to run it down the track yet? :hide:
I'm only running a single turbo. My truck is drivable but not really track ready. It's been sitting for such a long time in between drives I now need to do some maintenance with the fuel injectors. I believe there's some trash in the injectors from sitting. There are some things I would like to get done but have been unable to do anything. Life has definitely gotten in my way.
 
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