Limit Straps at the Track

[SRT82ECOBOOST]

I came across these while researching methods of launching FWD vehicles:
http://www.racereadyproducts.com/limit-straps/dirt-bagz-limit-straps/
I think they are kind of ghetto on a $50,000 car, but I would venture to guess that these would reduce the transfer of weight to the rear that lightens up the front end on launch. I know some guys launching the Dodge Magnum R/T AWD used these as well for the best times out of the hole. May be worth looking into to drop those 60' times.

 

[QwikEVO]

we have AWD.  This is completely unnecessary.

 

[SRT82ECOBOOST]

we have AWD.  This is completely unnecessary.

Now isn't the greater majority of guys at the track spinning the front tires due to the power distribution of the AWD system and weight shift to the rear as the suspension is loaded. Limit straps combined with very stiff shocks/coilovers have worked on other platforms that are AWD that are rear wheel biased, so I am sure it applies here even more with a front wheel biased AWD system. Correct me if I am wrong.

 

[QwikEVO]

we have AWD.  This is completely unnecessary.

Now isn't the greater majority of guys at the track spinning the front tires due to the power distribution of the AWD system and weight shift to the rear as the suspension is loaded. Limit straps combined with very stiff shocks/coilovers have worked on other platforms that are AWD that are rear wheel biased, so I am sure it applies here even more with a front wheel biased AWD system. Correct me if I am wrong.

You're not spinning the tires all the way through the 60' like you would in a FWD. As soon as the system senses slip, the AWD system engages.  All the weight would shift to the back, where your rear wheels grip anyway.

 

[SRT82ECOBOOST]

The goal is ultimately to remove any spinning at launch regardless of the number of driven wheels. The method of limit straps and a stiff rear suspension pushes the vehicle to maintain optimal weight distribution on launch. Which it would seem on this platform is very crucial due to the FWD bias. I will wait for others to chime in.

 

[JMR76]

From what I understand the AWD system doesn't necessary wait until slip to engage the rear wheels.  It is definitely front wheel bias, but even without slip, I could be wrong but I believe it's torque management, meaning on hard acceleration even without slip the rear wheels will power up to 50%, probably to help torque steer.

Still IMHO it would benefit take off to have have the weight shift to the rear minimized as much as possible.  I look at it like if you have 50/50 power to front and rear wheels on take off, (100% overall) but are spinning the front a little, you just lost some of that front 50% power meaning your not getting all 100% overall potential on the ground.

 

[SRT82ECOBOOST]

From what I understand the AWD system doesn't necessary wait until slip to engage the rear wheels.  It is definitely front wheel bias, but even without slip, I could be wrong but I believe it's torque management, meaning on hard acceleration even without slip the rear wheels will power up to 50%, probably to help torque steer.

Still IMHO it would benefit take off to have have the weight shift to the rear minimized as much as possible.  I look at it like if you have 50/50 power to front and rear wheels on take off, (100% overall) but are spinning the front a little, you just lost some of that front 50% power meaning your not getting all 100% overall potential on the ground.

I actually think that only 150 ft/lbs of torque can go to the rear, so the effect us even more exaggerated.

 

[QwikEVO]

So get better suspension or tires if you're worried about weight shifting and tire spin.  Not some gimmicky ratchet strap.

Have you seen the rake on our cars?  The weight distribution would probably help level it out lol

 

[05yellowgt]

I wouldn't call limiter straps gimmicky. A much different application, But they are used on rwd drag cars as well. You want to have weight transfer to the rear wheels in this case, but in a controlled manner. The limiters restrict how high the front end can lift and helps to use that energy to drive the car forward and not upward.

The same principles work here, but we are more concerned with preventing front wheel spin to exceed rear wheel spin, which triggers the ECU to do its thing and shut power down till traction is gained.

 

[CooperS7777]

So get better suspension or tires if you're worried about weight shifting and tire spin.  Not some gimmicky ratchet strap.

Have you seen the rake on our cars?  The weight distribution would probably help level it out lol

Better suspension and tires is probably the best answer for most on here - but limiting straps are anything but gimmicky.  I ran them on my diesel and run them on the SS.  If you watch just about any vehicle with decent power launch hard youll see the front, rear, or both ends of the vehicle lift as it takes off (often people say the car "squats" when in reality, its picking up the front end).  Any thing you can do to convert this upward motion to forward motion will help get you down the track faster.

 

[EcoBrick Bob]

we have AWD.  This is completely unnecessary.

Now isn't the greater majority of guys at the track spinning the front tires due to the power distribution of the AWD system and weight shift to the rear as the suspension is loaded. Limit straps combined with very stiff shocks/coilovers have worked on other platforms that are AWD that are rear wheel biased, so I am sure it applies here even more with a front wheel biased AWD system. Correct me if I am wrong.

You're not spinning the tires all the way through the 60' like you would in a FWD. As soon as the system senses slip, the AWD system engages.  All the weight would shift to the back, where your rear wheels grip anyway.

I was at the strip tonite with my Flex.  I was HOPPING with only Torrie's 93 tune. No 3 bar and no W/M...Front tire pressure was 24 PSI, which is the lowest I have ever run. It was around 75 deg, and I was running my Pilot Super Sports.  AWD is limited by the limits of the amount of torque the rear can handle.  Our EB cars are basically FWD with some limited AWD provisions.

Don't know if these things work, but I sure needed something.

 

[EcoBrick Bob]

And... for the record, I have H & R's.  My son's said that my fronts were spinning around at least 4 times before the rears started moving.  I also have Firestone Air Bags in the rear.

 

[crash712us]

1st-Sho has limiting straps on his car. But since he installed the Megan coil overs they are not needed anymore.