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Discussion Starter #1
So my following mods for my 2016 scat pack shaker 8 speed are an 87mm throttle body, hellcat inlet, R2C air filter, BMR lower trailing arms, Pettys garage front strut tower bar and rear static tower X bar, a differential brace, catch can, 275 Nitto 555 G2 in the front and 555R in the rear also 275/40/20. With a 220 person in the car I was pulling consistent 4.3 0-60 runs shortly after he got out I pulled a 4.2 and today I launched it at 1500 RPMs and pulled a 4.1 (also pulled fuse 31) after consistent 4.2 0-60 runs in 1000 Das. I've been doing all my launches in sport mode with traction control on, I was wondering if there is a more efficient way to launch it, also I was looking at getting tazer for track mode but was curious if I could put the trans into track mode but keep my traction control on or if turning traction control off would really make it faster, my front tires were also at 36-37 PSI and my rears at 29-30 no burnouts. any helpful tips are appreciated. I'm also only at 2,600 miles is it true as the engine break in more I'll run slightly better times?
 

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So my following mods for my 2016 scat pack shaker 8 speed are an 87mm throttle body, hellcat inlet, R2C air filter, BMR lower trailing arms, Pettys garage front strut tower bar and rear static tower X bar, a differential brace, catch can, 275 Nitto 555 G2 in the front and 555R in the rear also 275/40/20. With a 220 person in the car I was pulling consistent 4.3 0-60 runs shortly after he got out I pulled a 4.2 and today I launched it at 1500 RPMs and pulled a 4.1 (also pulled fuse 31) after consistent 4.2 0-60 runs in 1000 Das. I've been doing all my launches in sport mode with traction control on, I was wondering if there is a more efficient way to launch it, also I was looking at getting tazer for track mode but was curious if I could put the trans into track mode but keep my traction control on or if turning traction control off would really make it faster, my front tires were also at 36-37 PSI and my rears at 29-30 no burnouts. any helpful tips are appreciated. I'm also only at 2,600 miles is it true as the engine break in more I'll run slightly better times?
Are you able to heat the tires up and simply floor the car at idle to launch and have it dead-hook?

I was able to get an occasional 4.3 on the factory tires on a "stock" car in good weather on the street.

Definitely try it with traction & stability control off.
 

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My technique for factory tires (RSA-2) is to put the car in track mode (or sport if you don't have track) and turn traction and stability OFF by holding the button down.

Scrub tires to clean and slightly warm them in 2nd gear. Too much heat will make them feel "greasy", you only want a little heat. Not much smoke.

Use the left paddle to put the car in 1st, but leave shifter in D. This lets you modulate throttle and prevents the trans from upshifting early. It will upshift on it's own at redline in this "semi-automatic" mode.

Roll into the throttle while feeling, listening and watching the tach. You will get a feel for how much to give it how quickly after a couple of tries.

It's not too hard to get a 4.5. The 4.3's require a little luck.

With your 555R's you should be able to do a more aggressive burnout and hit the tires harder initially. The harder you can hit them at first, the better it will hook as the rpms climb.
 

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Discussion Starter #4
Update

So just today no launch control I pulled a 4.0 0-60 in 1500 Das, I guess it's true as your engine breaks in they get faster :)
 

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Discussion Starter #5
Update 2

1000 Da might not be right because it was kinda humid but I pulled a 3.9 0-60 no new mods launched from 1500
 

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DA is much more a function of temperature than humidity. It goes temperature, pressure and then humidity for influencing factors.

I do agree that our cars get a little quicker over time. It was the case with my old 300C SRT8 and now my Scat Pack...however my manual '12 SRT8 got a little slower, however there could have been other factors with that car.
 

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I pulled a 3.6 on the Mickey Thompson ET street R's in like 50*. No burnout, just stabbing it from idle in sport mode. It just plain hooked. I was shocked. I backed it up with a 3.7. Car is a 2017 A8 SCAT with about 17k miles on it at the time. They do seem to get faster with more miles.
 

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I pulled a 3.6 on the Mickey Thompson ET street R's in like 50*. No burnout, just stabbing it from idle in sport mode. It just plain hooked. I was shocked. I backed it up with a 3.7. Car is a 2017 A8 SCAT with about 17k miles on it at the time. They do seem to get faster with more miles.

That's cookin'! Great job! :thumbsup:
 

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Great to see what others are pulling down gives me some guidance on what it takes to run those numbers, I'm stuck right now at 4.3 on stock size 275 tires with 500 tread wear rating on my stock engine 2015 SRT. no matter what I do, 4.3 is all I can get, try to push a little harder on launch and tires slip to much and I just go slower. But I can run a 4.3 like clock work- thanks to some easy suspension changes.

Time for tires see what I can do with 295 tires with a 460 tread wear. I'm going to cut another 1/2 coil too to bring the back down to at least level with the front to help with weight transfer. like to see 4.1 out of those bigger tires and coil cut.
 

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Great to see what others are pulling down gives me some guidance on what it takes to run those numbers, I'm stuck right now at 4.3 on stock size 275 tires with 500 tread wear rating on my stock engine 2015 SRT. no matter what I do, 4.3 is all I can get, try to push a little harder on launch and tires slip to much and I just go slower. But I can run a 4.3 like clock work- thanks to some easy suspension changes.

Time for tires see what I can do with 295 tires with a 460 tread wear. I'm going to cut another 1/2 coil too to bring the back down to at least level with the front to help with weight transfer. like to see 4.1 out of those bigger tires and coil cut.
I'd like to see if cutting the coil will help or hurt your time. This is just me kind of thinking out loud, but maybe cutting the coil might actually hurt your weight transfer because it might make the spring rate higher. When a progressive spring that's softer at the beginning of travel gets shortened, it no longer has that softness and has to go right into the heaviest part of the spring (which has a higher spring rate). It could hurt weight transfer if the spring can't compress quick enough. If that makes any sense. It did in my head, but sometimes I lose things in translation from the brain to the fingers.

I've gotten as low as 4.2 seconds with the stock 275 Pirelli's, but can't do any better than that. I rev it to about 1500-1600 rpm's and then let off the brake and quickly roll into the gas (listening to how much or little the tires spin and determining how much gas to give her).

I'll give Dodge credit, the 392 makes some torque!

Please let us know how your experiment works out.
 

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I'd like to see if cutting the coil will help or hurt your time. This is just me kind of thinking out loud, but maybe cutting the coil might actually hurt your weight transfer because it might make the spring rate higher. When a progressive spring that's softer at the beginning of travel gets shortened, it no longer has that softness and has to go right into the heaviest part of the spring (which has a higher spring rate). It could hurt weight transfer if the spring can't compress quick enough. If that makes any sense. It did in my head, but sometimes I lose things in translation from the brain to the fingers.

I've gotten as low as 4.2 seconds with the stock 275 Pirelli's, but can't do any better than that. I rev it to about 1500-1600 rpm's and then let off the brake and quickly roll into the gas (listening to how much or little the tires spin and determining how much gas to give her).

I'll give Dodge credit, the 392 makes some torque!

Please let us know how your experiment works out.


Those 275 Pirelli's are what 200 tread wear rating tires? Softer compound to hook up better. I know I can go straight to drag radials, but the tinkering in me likes to experiment and try to utilize other areas to help.

The stock suspension allowed a massive amount of wheel hop, I hit 4.4 one time and that run just shook the car to death and I never could repeat that run again no matter what i tried, so I had several runs 4.7- 5.0 and worse and all with wheel hop. It was tuff to nail down a consistent 0-60 run. but I did have my hero run as a bench mark.

I put v6 springs up front from a 2010 v6 challenger and removed the front sway bar. Tried more runs but nothing really changed, lots of wheel hop, 0-60 not any quicker, never hit a 4.4

But I could tell the front end came up pretty high, but only when the car hooked ( like rolling hits), if I can't hook I really can't utilize the springs up front on a launch. Driving around and doing some rolling throttle smashes, the front end came up very quick and high.

So went to work on the rear end, cut the rear coils 1/2 coil which lowered the car 1/2"- the idea was to help put move more static weight over the rear tires and to increase the spring rate to help drive the tires into the ground and to help resist wheel hop, make it harder for the tires to bounce. I installed camber bushings to straighten up tires for more contact patch, then built my own hop not kit and made the rear cradle solid with the body. I also installed BMR lower trailing arms.

All that netted me consistent 4.3 and 4.4 runs, I no longer had wheel hop and my launches really became uneventful, I practice with different launch rpm and different rates of throttle feed, just kept running 4.3 over and over again, and if I just added a slight more foot feed on launch tires would spin and I would run 4.4 or 4.5 or worse if I screwed up real bad.

I did have some chatter in the azz end, still felt like the rear differential was bouncing in the cradle, so I bought a diff brace and that feeling went away. didn't help in my 0-60 runs.


So my 295 tires are taller which raised up the rear of my car 1/4" or better ( so that moves some static weight to the front not good) and my camber is .1 positive- I went a little to far on my bushing- opps, so cutting another 1/2 coil should put my camber at zero or just slightly neg. plus it should bring my car down 1/2" anyways as well which in turn will move static weight back to the rear tires and a little more than before because my car did have a 1/4" rake before tire change ( 1/2" now with bigger tires), so my car will sit level or slightly down on the rear, stiffen up the spring rate some more to help drive the tires into the ground.

So cutting a 1/2 coil brings many benefits- more static weight over the rear tires than before, stiffer springs to drive the tires into the ground harder, help correct my camber.

Many of the sites i visited and researched folks tightened up the irs, get away from the car squatting, IRS seems to take some work to get them to hook well. I know some folks will argue just putting on drag radials cars hook and run what ever 60ft number, to me what if those folks did more work on the IRS other than drag radials and saw even more return and drop say another .10 in 60ft. That's me, I want to go beyond just bolting on a drag radial, I want to dig for more.

I did show the suspension work I did on my srt made it more consistent and I even got .10 quicker 0-60 running the same tires. So to me that's a win and proof there is more than just drag radials as a cure all. All the little details add up. for some maybe it's not worth the work for them.

I will post up see if those last two changes will help my 0-60 mph times.
 

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Wow...I don’t wanna throw shade but you should have just threw some drag radials on your car and left it stock.....I dunno. Good luck and prove me wrong! :)
 

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Wow...I don’t wanna throw shade but you should have just threw some drag radials on your car and left it stock.....I dunno. Good luck and prove me wrong! :)

Ya, that's not me, I got that a lot when i worked on my 2013 SXT V6, folks thought what I was doing was waste of time and it wouldn't help, but as far as I knew, I was the only one who had a v6 that ran 13's over 100 mph naturally aspirated.All by paying attention to details and I'm just getting started on the 392, it's all stock (50K miles)except for the suspension changes, car makes good power at the moment, no sense in making more power if I can't apply the power I have now. I would like to do everything I can to the suspension to be able to launch with full throttle. I can feel what I did helped. It shows as well. Once I feel I can not do anymore with the suspension, then I will put the best tires on it ( drag radials) and accept what it gives. Then start making more power and digging into the intake and exhaust side.

Has anyone run a 3.9 on regular street tires? I know folks run in the 3's with drag radials, but what about just on run of the mill regular street tires? My 4.3 which is repeatable come from 500 treadwear rating 150 dollar tire. Far from a performance tire. My new tires I'm going to play with while sorting out the suspension cost me 130 bucks for a 460 treadwear- not any better really, they are taller at 295 40 20. these should get me 4.1 or 4.2 I would like to think, just because the bigger foot print alone.

I'll keep tinkering. heading to track friday to run some 1/8 mile at a new race track near me 20 minutes away that just opened. See what kind of 60ft times I can pull down. folks say stock ( tires) pull down high 1.8's and 1.9's I hoping to really smash those times maybe see some 1.70's with my cheapo tires and suspension changes.
 

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Those 275 Pirelli's are what 200 tread wear rating tires? Softer compound to hook up better. I know I can go straight to drag radials, but the tinkering in me likes to experiment and try to utilize other areas to help.

The stock suspension allowed a massive amount of wheel hop, I hit 4.4 one time and that run just shook the car to death and I never could repeat that run again no matter what i tried, so I had several runs 4.7- 5.0 and worse and all with wheel hop. It was tuff to nail down a consistent 0-60 run. but I did have my hero run as a bench mark.

I put v6 springs up front from a 2010 v6 challenger and removed the front sway bar. Tried more runs but nothing really changed, lots of wheel hop, 0-60 not any quicker, never hit a 4.4

But I could tell the front end came up pretty high, but only when the car hooked ( like rolling hits), if I can't hook I really can't utilize the springs up front on a launch. Driving around and doing some rolling throttle smashes, the front end came up very quick and high.

So went to work on the rear end, cut the rear coils 1/2 coil which lowered the car 1/2"- the idea was to help put move more static weight over the rear tires and to increase the spring rate to help drive the tires into the ground and to help resist wheel hop, make it harder for the tires to bounce. I installed camber bushings to straighten up tires for more contact patch, then built my own hop not kit and made the rear cradle solid with the body. I also installed BMR lower trailing arms.

All that netted me consistent 4.3 and 4.4 runs, I no longer had wheel hop and my launches really became uneventful, I practice with different launch rpm and different rates of throttle feed, just kept running 4.3 over and over again, and if I just added a slight more foot feed on launch tires would spin and I would run 4.4 or 4.5 or worse if I screwed up real bad.

I did have some chatter in the azz end, still felt like the rear differential was bouncing in the cradle, so I bought a diff brace and that feeling went away. didn't help in my 0-60 runs.


So my 295 tires are taller which raised up the rear of my car 1/4" or better ( so that moves some static weight to the front not good) and my camber is .1 positive- I went a little to far on my bushing- opps, so cutting another 1/2 coil should put my camber at zero or just slightly neg. plus it should bring my car down 1/2" anyways as well which in turn will move static weight back to the rear tires and a little more than before because my car did have a 1/4" rake before tire change ( 1/2" now with bigger tires), so my car will sit level or slightly down on the rear, stiffen up the spring rate some more to help drive the tires into the ground.

So cutting a 1/2 coil brings many benefits- more static weight over the rear tires than before, stiffer springs to drive the tires into the ground harder, help correct my camber.

Many of the sites i visited and researched folks tightened up the irs, get away from the car squatting, IRS seems to take some work to get them to hook well. I know some folks will argue just putting on drag radials cars hook and run what ever 60ft number, to me what if those folks did more work on the IRS other than drag radials and saw even more return and drop say another .10 in 60ft. That's me, I want to go beyond just bolting on a drag radial, I want to dig for more.

I did show the suspension work I did on my srt made it more consistent and I even got .10 quicker 0-60 running the same tires. So to me that's a win and proof there is more than just drag radials as a cure all. All the little details add up. for some maybe it's not worth the work for them.

I will post up see if those last two changes will help my 0-60 mph times.
The stock Pirelli P Zero's on the SRT 392's are a 400AA rating, so they aren't great by any means (according to The Tire Rack).

I don't understand why you don't want to bolt on a drag radial and get the easy gains first and then go hunting for more. The reason that I say this is because you could do all that work (not too mention money spent) to get your gains on the street tires and then bolt on a drag radial and it doesn't work as well because your car was set up for a tire that wasn't optimal in the first place.

As far as putting the different coil springs up front, I don't think that it's the coils that help with weight transfer as much as the shocks do. You want a shock that will extend quickly and settle down in a reasonable amount of time (like the old 90/10 shocks that worked well on the strip, but weren't a lot of fun for street driving) and something in the back that would compress at a relatively quick rate to allow for that sudden transfer of weight.

That's what used to work "Back in the day" and it's basically science to get the car moving. The parts used might be different, but the theory is the same.

I'm not saying that you're on the wrong track because I certainly don't know every way to make a car faster, but it has worked in the past for me.

In closing, you sound like you have a plan and I'm curious and looking forward to see how it turns out. Please share your results when you get them.

Thanks in advance and Good luck. :cheers:
 

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The stock Pirelli P Zero's on the SRT 392's are a 400AA rating, so they aren't great by any means (according to The Tire Rack).

I don't understand why you don't want to bolt on a drag radial and get the easy gains first and then go hunting for more. The reason that I say this is because you could do all that work (not too mention money spent) to get your gains on the street tires and then bolt on a drag radial and it doesn't work as well because your car was set up for a tire that wasn't optimal in the first place.

As far as putting the different coil springs up front, I don't think that it's the coils that help with weight transfer as much as the shocks do. You want a shock that will extend quickly and settle down in a reasonable amount of time (like the old 90/10 shocks that worked well on the strip, but weren't a lot of fun for street driving) and something in the back that would compress at a relatively quick rate to allow for that sudden transfer of weight.

That's what used to work "Back in the day" and it's basically science to get the car moving. The parts used might be different, but the theory is the same.

I'm not saying that you're on the wrong track because I certainly don't know every way to make a car faster, but it has worked in the past for me.

In closing, you sound like you have a plan and I'm curious and looking forward to see how it turns out. Please share your results when you get them.

Thanks in advance and Good luck. :cheers:
I Know the changes that I make will work great with any tire, like the front coils, more coils hold more energy for lift, street tire or slick this helps with weight transfer, so there no down side. Removing sway bar same thing street tire or slick or drag radials no down side removing it for weight transfer.

Since my SRT has the active suspension I don't get to put on 90/10 struts, so I have to live with just putting them on soft setting and let them be. Not to much I can do to the front other than maybe some day add skinny's. So those changes all help with traction no matter the tire.

On the back, camber bushings is a given to help traction, this straightens up the tires for better contact patch, so no matter the tire this helps, no down side at all for launch.

Making the cradle solid with body, this is given as well to help with traction, whether 1/4 mile or road course, this should be done if anyone does any performance style racing, so no down side for me to stiffen the cradle to the body.

BMR lower trailing arms, this is a plus for anyone in any performance style racing, no down side to this change for any tire to be used.

Cutting springs, benefits- it lowers the rear of car to move static weight over tires, so that's a plus, it stiffens the springs not allowing the suspension to compress, when the suspension compresses it cause neg camber reducing tire patch, stiffer spring rate also helps to reduce wheel hop. The stiffer spring rate helps in reducing squat on launch which forces the other rear suspension parts to take on the weight of the car which helps to plant the tires harder.

I can't do nothing with shocks but another IRS guy used bushings on the chrome rod - he stacked several bushing to keep the shock from compressing during launch, a live axle you set up different like you was saying, but IRS takes a different path. Many just stiffen it all around so there is no compression.

The rear differential brace just helps the diff to live and helps take some of the slop out of the rear components.

So all the changes are good for what I'm doing no matter the tire, it does show working the suspension helps no matter the tire. I see it already in my 0-60 mph runs, I know it's not as dramatic as sticky tires, but the car is better even with crap tires.

Drag radials are a given, anyone knows they help, most folks stop there, I know there is more than just bolting on drag radials, I want to take advantage of those small changes. I would rather burn down a set of cheap tires than 750 dollars worth of drag radials while I practice launching and monitoring the changes. Plus I have proof making changes stopped wheel hop all together on my car using the same tire, I got to see how the car settled down on launch and I can run back to back 0-60 runs with the same e.t., I know I'm tire limited now, so testing a bigger tire with about same treadwear I can see what a bigger tire will do if anything.

Because you know folks argue, you put a bigger tire on a wheel you don't get more traction, just because your tire is wider, it don't mean nothing, you have the look of a wide tire and it gives nothing more when mounted on a narrow wheel. So I get to test a 295 tire on a 9.5" wheel, which it looks real good. If my traction improves and my e.t. comes down then I know it's worth some e.t., if not then maybe I can just go with 275 drag radials. So in a sense I'm testing width on the same wheel, this could help me pick the right drag radial width.



So for me it's tinkering and doing my own trial and errors, it's what I do. I just report my findings good or bad.
 
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I Know the changes that I make will work great with any tire, like the front coils, more coils hold more energy for lift, street tire or slick this helps with weight transfer, so there no down side. Removing sway bar same thing street tire or slick or drag radials no down side removing it for weight transfer.

Since my SRT has the active suspension I don't get to put on 90/10 struts, so I have to live with just putting them on soft setting and let them be. Not to much I can do to the front other than maybe some day add skinny's. So those changes all help with traction no matter the tire.

On the back, camber bushings is a given to help traction, this straightens up the tires for better contact patch, so no matter the tire this helps, no down side at all for launch.

Making the cradle solid with body, this is given as well to help with traction, whether 1/4 mile or road course, this should be done if anyone does any performance style racing, so no down side for me to stiffen the cradle to the body.

BMR lower trailing arms, this is a plus for anyone in any performance style racing, no down side to this change for any tire to be used.

Cutting springs, benefits- it lowers the rear of car to move static weight over tires, so that's a plus, it stiffens the springs not allowing the suspension to compress, when the suspension compresses it cause neg camber reducing tire patch, stiffer spring rate also helps to reduce wheel hop. The stiffer spring rate helps in reducing squat on launch which forces the other rear suspension parts to take on the weight of the car which helps to plant the tires harder.

I can't do nothing with shocks but another IRS guy used bushings on the chrome rod - he stacked several bushing to keep the shock from compressing during launch, a live axle you set up different like you was saying, but IRS takes a different path. Many just stiffen it all around so there is no compression.

The rear differential brace just helps the diff to live and helps take some of the slop out of the rear components.

So all the changes are good for what I'm doing no matter the tire, it does show working the suspension helps no matter the tire. I see it already in my 0-60 mph runs, I know it's not as dramatic as sticky tires, but the car is better even with crap tires.

Drag radials are a given, anyone knows they help, most folks stop there, I know there is more than just bolting on drag radials, I want to take advantage of those small changes. I would rather burn down a set of cheap tires than 750 dollars worth of drag radials while I practice launching and monitoring the changes. Plus I have proof making changes stopped wheel hop all together on my car using the same tire, I got to see how the car settled down on launch and I can run back to back 0-60 runs with the same e.t., I know I'm tire limited now, so testing a bigger tire with about same treadwear I can see what a bigger tire will do if anything.

Because you know folks argue, you put a bigger tire on a wheel you don't get more traction, just because your tire is wider, it don't mean nothing, you have the look of a wide tire and it gives nothing more when mounted on a narrow wheel. So I get to test a 295 tire on a 9.5" wheel, which it looks real good. If my traction improves and my e.t. comes down then I know it's worth some e.t., if not then maybe I can just go with 275 drag radials. So in a sense I'm testing width on the same wheel, this could help me pick the right drag radial width.

So for me it's tinkering and doing my own trial and errors, it's what I do. I just report my findings good or bad.

Thank you for the explanations. I'm looking forward to seeing your results. :cheers:
 

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Thank you for the explanations. I'm looking forward to seeing your results. :cheers:
Got the springs cut again tonight, so just in case some are wondering they are stock rear coil springs on a 2015 srt 392, they are .625" wire diameter, looks like about 2.75" inside diameter and a 4" outside diameter and stock has 7.5 turns on coils.

Cutting the first 1/2 coil lowered the car 1/2" cutting another 1/2 coil lowers the car 3/4", as far as I could figure stock spring is about 600 lbs/inch and cutting 1 coil makes them 745 lbs/inch rate. I used an online spring rate calculator to come up with those numbers. free coils being 4.5 and 5.5 since the spring sits in rubber pockets top and bottom and the calculators say not to count and spring that touches something.

So now my car sit 1/8" lower on the rear. So pretty much level now, so I'm happy with the stance.

Car back together took it out with the new tires the 295 40 20 tires I bought- 460 tread wear, with 33 psi hot, the tires only gave 8" of rubber on width. The tires are greasy for sure. The 275 tires was pretty dry, these tires are wet with grease/oil- wow, so don't want to do much of a burn out with them. I did to see where my tire width was at with 33psi hot.

Best I could do was 4.7 0-60 runs, so I need to lower tire pressure because the 275 tires I had 9.25" of tread width to the ground, so right now I'm 1.25" short in contact patch. I must let some air out and work down the air pressure til i can get all the tire I can to the ground and see if the 0-60 runs come down.

Tinker tomorrow evening and see what I come up with.
 
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Got the springs cut again tonight, so just in case some are wondering they are stock rear coil springs on a 2015 srt 392, they are .625" wire diameter, looks like about 2.75" inside diameter and a 4" outside diameter and stock has 7.5 turns on coils.

Cutting the first 1/2 coil lowered the car 1/2" cutting another 1/2 coil lowers the car 3/4", as far as I could figure stock spring is about 600 lbs/inch and cutting 1 coil makes them 745 lbs/inch rate. I used an online spring rate calculator to come up with those numbers. free coils being 4.5 and 5.5 since the spring sits in rubber pockets top and bottom and the calculators say not to count and spring that touches something.

So now my car sit 1/8" lower on the rear. So pretty much level now, so I'm happy with the stance.

Car back together took it out with the new tires the 295 40 20 tires I bought- 460 tread wear, with 33 psi hot, the tires only gave 8" of rubber on width. The tires are greasy for sure. The 275 tires was pretty dry, these tires are wet with grease/oil- wow, so don't want to do much of a burn out with them. I did to see where my tire width was at with 33psi hot.

Best I could do was 4.7 0-60 runs, so I need to lower tire pressure because the 275 tires I had 9.25" of tread width to the ground, so right now I'm 1.25" short in contact patch. I must let some air out and work down the air pressure til i can get all the tire I can to the ground and see if the 0-60 runs come down.

Tinker tomorrow evening and see what I come up with.

Is the ride firmer with the cut coils in back?
 

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Is the ride firmer with the cut coils in back?
Oh ya, I can feel the difference, not awful, feels good to me, I'm not complaining.

Took 5 psi cold out of my tires, when they warmed up during my runs they was at 29 Hot. I'm at 8.5" of tread width to the ground, So dropping from 33 psi hot to 29 psi hot gave me 1/2" more tread to the ground. still short.

So i will take 4 more psi out tomorrow and see where that puts me. right now it's not looking good at all. I may have to go back to a 275 tire these 295 tires are not doing it for me. I don't think there is enough side wall to allow the difference in widths. I had 18" on my last challenger and going from a 245 to 275 worked very well on a 9" wheel. got more rubber to the ground and dead hooked launches.

I got to do what i can, going to the drag strip friday.

I looked at B manson videos on youtube '16 392, he tried 5 different tires over the years, the two stock size 275 street tires pirelli's and atturo, he never ever did better than 4.2 even with all his extra engine/exhaust/tune mods, no matter the power he couldn't do better than this 4.2 even with the power to run mid 11's, street tires he couldn't run no better than 4.2 on the street

thinking I'm 100% stock engine and killing a 4.3 like clock work with my old tires, I should feel pretty good about that.

His Drag radials on the street both 275 and 305, mt and nitto he never did better than a 3.8 which was his hero run really, mostly 3.9 to 4.1 runs normally , so drag radials even with extra power you doing well to run a 3.9 /4.0.


His final tires was his drag pack, he ran 3.1 seconds 0-60 mph on the street. Before this his best race track 0-60 mph run was 3.2 on a very well prep track on 305 nittos on his 20" wheels. which those same tires could only do a best of 3.8 on the street.

So all the power he was making 20" tires will not allow you to hook it up no matter what, not on the street.

So it looks like i can dink around with crap tires or just start making plans on 18 and 17" wheels and go straight to dead hooking up. Following his testing the best anyone can hope for is 3.8 0-60 using drag radials either 275 or 305 on the 20" wheel. Others might claim slightly quicker but I don't think it will ever be a 3.1 on the street.

I may change directions here, find a real good cheap 275 40 20 tire with something like a 200-300 treadwear rating and use that as my driving tires and not expect much out of them. Start digging for some 17x10 wheels and get some drag radials, get some matching wheels for the front in 18" to clear brembos.
 
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