Project Wheels Up

[JoeDaddy]

You can accomplish the same thing with a forward mounting bar with less geometry issues and better control. This is the same thing us pullers have been doing for a very long time.

You can blame me if it doesn't work but.......it HAS worked before.

 

[vanderchevy18]

You can accomplish the same thing with a forward mounting bar with less geometry issues and better control. This is the same thing us pullers have been doing for a very long time.

But if it does work, and I get the better weight transfer, then it's not just a cool looking setup.

 

[Hotrodtractor]

You can blame me if it doesn't work but.......it HAS worked before.

But if it does work, and I get the better weight transfer, then it's not just a cool looking setup.

Let me try a different approach.

How did you determine the link bar placement to determine the instant center of the rear suspension that you have created?

Approximately how much above the anti-squat line is the instant center?

Remember - I am just looking at this through some rough internet pictures - but it looks like your IC is very high and very close to the rear axle. Combine that with a geometry that looks like it has a fair amount of pinion angle change through its motion cycle give me a moment of pause and concern.

You can try all the new ideas you would like - but its still governed by the laws of physics. I would say that this setup would load the rear suspension very hard (taking a good amount of power doing so) and then become unstable and unload and slip as the chassis settles in. Its a fine line to run in any case, but this appears to be extreme.

 

[vanderchevy18]

Instant center moves around doesn't it? I didn't think it was a single position all the time. The track bar is the same length as from the center of the axle to the front spring pivot. At full compression both the track bar and the spring are level. So theoretically the arc is the same size and intersecting at rest. The total movement of axle travel is only about 6 inches. Pinion angle barely moves at all.

 

[Hotrodtractor]

Instant center moves around doesn't it? I didn't think it was a single position all the time. The track bar is the same length as from the center of the axle to the front spring pivot. At full compression both the track bar and the spring are level. So theoretically the arc is the same size and intersecting at rest. The total movement of axle travel is only about 6 inches. Pinion angle barely moves at all.

Yes the instant center does move as the suspension cycles.

That is not a track bar. You might be able to call it a traction bar. A track bar controls side to side motion.

If that bar is the same length as the spring from the axle forward and the spring runs ever so slightly uphill forward of the axle and that bar runs uphill away from the axle reward as it looks in the pictures - that means as it approaches parallel the pinion has to angle further down than at rest.

Small amounts of travel make setups more forgiving.

A picture of this whole setup from the side would help.

 

[vanderchevy18]

Trac bar. Short for traction bar. My phone autocorrected to track.

 

[vanderchevy18]

Yes the instant center does move as the suspension cycles.

That is not a track bar. You might be able to call it a traction bar. A track bar controls side to side motion.

If that bar is the same length as the spring from the axle forward and the spring runs ever so slightly uphill forward of the axle and that bar runs uphill away from the axle reward as it looks in the pictures - that means as it approaches parallel the pinion has to angle further down than at rest.

Small amounts of travel make setups more forgiving.

A picture of this whole setup from the side would help.

And the axle wrapping puts an opposed force on it creating a energy that unloads post launch creating more forward motion. Like I said, this is all something that we decided we wanted to try. If it doesn't work like we're thinking, then that's fine. I'm already set up to run the traditional trac bar. If it does work like we're thinking though, then I should have a truck that launches like a car instead of one that launches like....... Bean's truck. LOL

 

[Hotrodtractor]

The biggest reason for the reverse traction bar set up is so that the force of the axle wrapping is directed to the rear transferring more weight over the rear tires. They are also set to go from perfectly level at full compression to angled upward to the rear so that the force of the wrapping actually lifts the rear causing the wheels to be pushed down even harder giving better traction.

The total movement of axle travel is only about 6 inches. Pinion angle barely moves at all.

And the axle wrapping puts an opposed force on it creating a energy that unloads post launch creating more forward motion. Like I said, this is all something that we decided we wanted to try. If it doesn't work like we're thinking, then that's fine. I'm already set up to run the traditional trac bar. If it does work like we're thinking though, then I should have a truck that launches like a car instead of one that launches like....... Bean's truck. LOL

So - your working theory is that when you launch the suspension in the rear lifts due to your high amount of anti-squat built into the system. As the car settles in (providing it doesn't unload the tires) the suspension will provide a bit more forward force from the axle unwrapping, yet you state that the pinion angle barely moves.....

Why didn't you build in adjustment to fine tune this setup to that theory?

BTW - you can't create energy. That violates the laws of physics. You can transform it all day long, but you can never create or destroy it. All that energy that you are using that is stored up in your suspension came from the engine loading up that suspension at launch. Sometimes that is a good thing, sometimes that is a bad thing. It just all depends on how much power you are making, how hard those turbos hit, etc...

 

[vanderchevy18]

I guess we'll just have to see what happens. Joe hasn't been totally off on everything. LOL


Started the truck today and about crapped my pants. It immediately revved to the limiter so killed it real quick. Next time it started fine till I touch the go peddle and it takes off again. I started it and shut it off a few more times and it either took off right away or did it as soon as I touched the skinny. I guess I'll just have to track down the chafed wire. Might swap the IVS real quick first though.

 

[lincolnlocker]

Oh sh!t prolly came to mind?

live life full throttle

 

[vanderchevy18]

Oh a little. I'm sure it's a chafed wire somewhere. That wiring harness has been dragged through hell and back being pulled from one truck and shoved into another that it wasn't designed for. Either that or the idle validation switch needs replaced.

 

[lincolnlocker]

Lol.. hope that's all it is.

live life full throttle

 

[vanderchevy18]

There's really nothing else it should be. The engine and electronics were all in the white truck and ran to perfection with the same tuning.

 

[vanderchevy18]

Trans adapter is on its way and will be here tuesday. That will take care of that huge problem. The roll cage is getting welded in today so there's that problem taken care of too. This throttle issue is all that's left and it'll be race time!!

 

[strokin'_tatsch]

What's the return voltage from the TPS with the pedal in the idle position?

Sent from my SAMSUNG-SGH-I337

 

[vanderchevy18]

Gonna find out in a few hours. AE shows 11% tps at idle.

 

[vanderchevy18]

OK so idle voltage is .11v. Wot is .46v if I remember right. IVS is working properly as well. I am however getting a little bit of continuity from vref to ground. I pulled the pcm plug and did continuity checks to ground and and almost every sensor input has a bit of continuity to ground. Not quite enough to make the dvom beep, but there is still continuity. The only thing I can think of is there is a vref wire somewhere touching ground.
Also the left turn signal arrow on the cluster stays lit.
I tried to hook AE up to it again and now it won't connect. Fuse is fine. Just won't connect. It did the day before.
While messing with it the relays for the fuel pump and pcm relay started buzzing so I checked voltage on the pcm relay and the constant hot showed 11.9 volts like it should. The keyed power showed 2v while off and 9.5v with the key on. WTF? So now I have to go through and check all my battery connections.

This damn thing is starting to give me nightmares. I couldn't find a single bare wire anywhere. The tough part is I tried to leave every wire and plug from the stock wiring harness in tact but tucked away out of sight so that maybe in the future I can make it a street rod. I may end up spending a few hours trimming the fat though.

 

[lincolnlocker]

You have a power wire grounding out somewhere.

live life full throttle

 

[vanderchevy18]

I know I do. I just need to start pulling fuses now and see if it goes away. If it does I'll run the wire down and see where it is.

 

[lincolnlocker]

Cant imagine the blinker drawing enough to make it drop that far but thats where I would start.. is that on all the time or only at key on?

live life full throttle