Dodge Challenger Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
123 Posts
Discussion Starter #1
I have a 5.7 6 speed with an stp. Currently running 295/45/20’s on the rear. Running a 125 to 150 spray.

What additional mods can I be looking at to increase power delivery to the rear wheels? Not looking to do much of any cornering, this would be for point and shoot or rolling start applications.


Sent from my iPhone using Tapatalk
 

·
Registered
2013 Challenger SXT
Joined
·
1,221 Posts
You can do some normal drag race changes that's been done for many decades to get power to the ground, you can start with the front to get better weight transfer, 6 cylinder springs- which can add 1 or 2 extra coils for more lift, I just did this on my srt 392, 90/10 drag shocks/struts, remove front sway bar, lighter wheels or tires- anything to shed weight off the tires or wheels so the front reacts quicker to weight transfer.

For the rear bigger tires and softer compound, stiffer rear springs, 50/50 shocks, air bags, solid bushings in cradle or something similar to a hop not kit, take out the neg. camber and get the tires straight up and down to zero camber, replace rear bushing where you can to a harder bushings to control slop in the suspension, rear shock tower brace.

I'm sure there is more, I'm working on my 2015 srt 392 in getting the power I have planted to the rear before I start to find more power, so far i have v6 springs installed in the front and got my front end lowered a little - to make room for cutting the rear coils to increase spring rate which will drop the rear down some. Removed my front sway bar and I'm looking at lighter weight front tires- shave a few lbs on the front so it reacts quicker. I have 295 tires for the rear, lower bmr trailing arms to get installed, I will be making my own hop not kit to keep the rear cradle from moving around. Soon as I'm done on the rear I will post up my results. I'm sure i will do more than this but I got to get done what i have already ordered before moving on to some more changes.

Hope some of this helps.
 

·
Registered
Joined
·
123 Posts
Discussion Starter #3
That is some good info. Will the v6 springs in the front make the care sit taller? Not sure if I want hat or not looks wise.


Sent from my iPhone using Tapatalk
 

·
Registered
2013 Challenger SXT
Joined
·
1,221 Posts
That is some good info. Will the v6 springs in the front make the care sit taller? Not sure if I want hat or not looks wise.


Sent from my iPhone using Tapatalk

I did a write up on the install, the short of it I bought 2010 challenger v6 springs that had thinner wire (.520") and 7.5 coils vs the srt 392 coils that have thicker wire (.590") and 5.5 coils. I installed the v6 springs and that raised my car 1/2" over stock ride height, I removed the v6 springs and cut them down to 6.5 coils and that lowered my car 3/4", so I had lowered the car 1/4" from stock ride height. I now I have one extra coil to help with lift, the more coils the more energy can be released to raise the car on launch.

The car jumps up now when I get on it much more than it did before. I could not use 90/10 drag race struts since the srt 392 has the active suspension. So I have to make do with the stock struts for now. There could be some Moroso trick springs available from vendors that do the same thing with out having to cut down v6 springs. That would be something to look into. Back in the 80's and 90's I use to use moroso trick springs in the more popular camaro's that provided more lift on launch along with 90/10 drag race shocks. I also used small block chevy springs in the front of my big block chevy cars as a cheap alternative since this was next to free to do before I started spending money for purpose built springs.

Hope this helps
 

·
Registered
2013 Challenger SXT
Joined
·
1,221 Posts
Your tires are 2" taller than the stock height.

That isn't helping.
Who's tires tires are 2" taller?, My 2015 srt 392 has 275 40 20 tires in all 4 corners which are 28.7" tall, before anything was done to the stock ride height it measured 29 1/2" from ground to middle of fender well, installing v6 springs in the front with 7.5 coils raised the front to 30" then cutting one coil brought it down to 29 1/4" inch. So end result is 1/4" lower than stock.

Don't matter what tire you run on your car if you start off , if you change to v6 springs with 6.5 coils you wil lower the car 1/4" from where you started.



I have 295 tires for the rear but they are not installed yet, still working on the rear of the car.


Does this clear things up?
 

·
Registered
2013 Challenger SXT
Joined
·
1,221 Posts
I think I might have misunderstood the 2" statement - meaning the back tires are 2" taller causing a rake making the front of the car way lower than the rear making it hard to transfer weight. Larger tire helps with traction in the rear giving a larger foot print for forward traction, this is a good thing. As far as the rear being higher because of the larger tires, 275 4020 tires are 28.7 inches tall going to a 295 40 20 tire is 29.3" tall so your only talking .30" taller overall.

This assumes the OP tires was 28.7 to start with- I'm not aware what factory size was for bigred61.

Never the less, if you have a bunch of rear rake, cutting some of the rear coil down can adjust ride height, at least on my v6 when I did this, 1/2 a coil was good for 3/4 of an inch drop in the rear and a full coil was good for 1.5" or so. Cutting the rear coil will increase spring rate. Which will help to apply more pressure to the tires for more traction during launch.

My srt 392 at factory ride height was 29 1/2" in the front and 30" in the rear. Knowing I was going to cut a rear coil to increase spring rate, I needed to get the front end dropped a little to make room for at least a 1/2 coil cut on the rear, I'm assuming cutting a 1/2 coil on the rear of my srt will drop it 3/4"- so if I would have left the front alone my azz end would have been 1/4 inch lower than the front.

So since I got the front lowered a little with v6 springs, I can now cut the rear coil at least 1/2 coil and I should be close to 29 1/4" on the rear, so my car will be level, adding the 295 40 tires will raise the rear 1/4" or so just because the tires are taller.

Now if I cut a 1/2 coil on the rear and it drops more than 3/4" that's cool too, because I will get a little rake back with the bigger tires and my car might end up being level.

I know some might call this anal or waste of time, some might not understand, but all these small changes will add up to better traction, that is a given.

As far as the hop not kit, I watched some youtube videos of before and after install of the hop not kit and the kit pretty much made the cradle one with the body of the car and took out all movement that I could see in the video. The video was located under the car while under hard launches so you see first hand of what the cradle is not doing now.

So the hop not kit works on taking the movement out of the cradle, you still have other work to do to eliminate wheel hop, other parts have to be addressed, but it's in the right direction to cure wheel hop and to gain traction using the hop not kit
 

·
Registered
Joined
·
123 Posts
Discussion Starter #10
I think I might have misunderstood the 2" statement - meaning the back tires are 2" taller causing a rake making the front of the car way lower than the rear making it hard to transfer weight. Larger tire helps with traction in the rear giving a larger foot print for forward traction, this is a good thing. As far as the rear being higher because of the larger tires, 275 4020 tires are 28.7 inches tall going to a 295 40 20 tire is 29.3" tall so your only talking .30" taller overall.

This assumes the OP tires was 28.7 to start with- I'm not aware what factory size was for bigred61.

Never the less, if you have a bunch of rear rake, cutting some of the rear coil down can adjust ride height, at least on my v6 when I did this, 1/2 a coil was good for 3/4 of an inch drop in the rear and a full coil was good for 1.5" or so. Cutting the rear coil will increase spring rate. Which will help to apply more pressure to the tires for more traction during launch.

My srt 392 at factory ride height was 29 1/2" in the front and 30" in the rear. Knowing I was going to cut a rear coil to increase spring rate, I needed to get the front end dropped a little to make room for at least a 1/2 coil cut on the rear, I'm assuming cutting a 1/2 coil on the rear of my srt will drop it 3/4"- so if I would have left the front alone my azz end would have been 1/4 inch lower than the front.

So since I got the front lowered a little with v6 springs, I can now cut the rear coil at least 1/2 coil and I should be close to 29 1/4" on the rear, so my car will be level, adding the 295 40 tires will raise the rear 1/4" or so just because the tires are taller.

Now if I cut a 1/2 coil on the rear and it drops more than 3/4" that's cool too, because I will get a little rake back with the bigger tires and my car might end up being level.

I know some might call this anal or waste of time, some might not understand, but all these small changes will add up to better traction, that is a given.

As far as the hop not kit, I watched some youtube videos of before and after install of the hop not kit and the kit pretty much made the cradle one with the body of the car and took out all movement that I could see in the video. The video was located under the car while under hard launches so you see first hand of what the cradle is not doing now.

So the hop not kit works on taking the movement out of the cradle, you still have other work to do to eliminate wheel hop, other parts have to be addressed, but it's in the right direction to cure wheel hop and to gain traction using the hop not kit


Again ddeennis, great info. Do you have a link to the write up you did? Also, what is the drivability of the car with the cut v6 springs like? Is it a tougher ride, poor handling?


Sent from my iPhone using Tapatalk
 

·
Registered
2013 Challenger SXT
Joined
·
1,221 Posts
Again ddeennis, great info. Do you have a link to the write up you did? Also, what is the drivability of the car with the cut v6 springs like? Is it a tougher ride, poor handling?


Sent from my iPhone using Tapatalk
Link below with pictures! LOL even with "only" 6.5 coils look at how much longer the spring is, this is packing some energy to help raise the car, wish I could have done it with 7.5 coils, but it would require going a different route in modifications to make it work. I'll take the one extra coil, and smaller diameter wire, it helps.

http://www.challengertalk.com/forums/f18/anyone-do-v6-srt-392-front-coil-swap-646066/

The front is softer like having 90/10 drag shocks and moroso trick springs, it raises up so much easier even under light throttle, don't feel so stiff, I'm happy with it. I don't do any cornering at high speed, not what I do. I do have my active suspension set on the softest setting. I drove it today for several hours an even hit 156 mph on the open road and car felt fine.
 

·
Registered
2013 Challenger SXT
Joined
·
1,221 Posts
My post about a 2" taller tire has absolutely nothing to do with ride height.

What else happens when you increase tire height?
Your not helping at all with the OP question on getting more traction- since I am assuming he's looking for traction. If your taking his question about more power delivery literally then you need to lighten things up with lighter wheels and lighter tires, just lighter rotating mass to put more power to the ground.

So i guess we can play your game of what's on your mind. Increase tire height you normally gain tire weight which takes away from available power, increased tire height will reduce your gear ratio which is normally ok if your already overpowering your car and can't hook up anyways- the increased height provides a little more traction, increased tire height raises the rear of the car which makes it harder to transfer weight, increased tire height on these cars can increase camber which doesn't help-but having more sidewall will soften the launches allowing for better traction, increased tire height makes the brakes work harder..........so what are you getting at, let's read what's on your mind, why you think his taller tires are not helping.

Do you have anything to say to help or just statements that provide no help and everyone has to guess what you trying to get at.
 

·
Registered
Joined
·
123 Posts
Discussion Starter #14
Ddeennis, I just got back from dinner with the fam for my daughters birthday. Give me a day or two to digest all this info, will probably pm you with some more questions. Thanks for the help so far.

A.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
964 Posts
Your not helping at all with the OP question on getting more traction- since I am assuming he's looking for traction. If your taking his question about more power delivery literally then you need to lighten things up with lighter wheels and lighter tires, just lighter rotating mass to put more power to the ground.

So i guess we can play your game of what's on your mind. Increase tire height you normally gain tire weight which takes away from available power, increased tire height will reduce your gear ratio which is normally ok if your already overpowering your car and can't hook up anyways- the increased height provides a little more traction, increased tire height raises the rear of the car which makes it harder to transfer weight, increased tire height on these cars can increase camber which doesn't help-but having more sidewall will soften the launches allowing for better traction, increased tire height makes the brakes work harder..........so what are you getting at, let's read what's on your mind, why you think his taller tires are not helping.

Do you have anything to say to help or just statements that provide no help and everyone has to guess what you trying to get at.

Glad you agree that taller tires aren't helping.
 

·
Registered
Joined
·
3,501 Posts
If you can go wider tire try a nitto 555r drag radial 305/35 or 315/35
I did them and cradle bushings in the rear and all new bmr control arms upset and lower and it is a amazing difference in traction, feel, and no wheel hop


Sent from my iPhone using Tapatalk
 

·
Registered
2013 Challenger SXT
Joined
·
1,221 Posts
Glad you agree that taller tires aren't helping.
Nope don't agree with you at all to make it perfectly clear!, your just another person on the internet that provides no help to anyone and should remain silent unless you have something useful to say.
 
1 - 17 of 17 Posts
Top