Suspension Upgrade for Challenger
#1880674
07/29/15 12:38 PM
07/29/15 12:38 PM
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Joined: Jul 2015
Posts: 163 Florida
Spartan040
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I'm planning out a 1970 Challenger build with a 440/512 EFI stroker, and a GV 727 auto. I wanted to know what suspension upgrade system would work best. Whatever system I go with, I know I will be going with a US Car Tool chassis stiffening kit.
This is my current (possible) list of upgrade parts:
Borgeson P/S Conversion Box 1-1/8" Sector Shaft Firm Feel E-Body 1.18 Dia Torsion Bars w/ dust boots and adjustors Hotchkis Geometry Corrected Tubular Upper A-arms w/ protective boot kit Hotchkis Sport Sway Bar set Hotchkis Geometry Corrected Sport Leaf Springs Hotchkis Tuned 1.5 Adjustable shocks Hotchkis Adjustable Steering Rod Kit Hotchkis Adjustable Strut Rods Firm Feel Fast Ratio Steering Arms Hotchkis Pivot Shaft & Bushing Kit Doctor Diff. Strange S60 Rear End w/ 35 spline axles, TrueTrac Carrier, 3.23 gears, 1350 large aftermarket yoke Baer Front and Rear Pro + Brake Kit
It's either all this, or an RMS AlterKtion front end and Street Lynx rear. My goal is to make this handle as close to a modern car as possible, like a 2015 Challenger (they recently did many suspension upgrades), so that it can keep up with (or at least come as close as possible to) modern cars on a track or the street. Money isn't my main concern here, I just want to know what system will give me the best performance. What has the best turning radius, the best stability, the least body roll, and which can handle at speed the best.
Also, is there anything here I should add or discard? Anything that might work better?
Last edited by Spartan040; 07/29/15 12:39 PM.
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Re: Suspension Upgrade for Challenger
[Re: Spartan040]
#1880734
07/29/15 01:50 PM
07/29/15 01:50 PM
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Joined: Jan 2003
Posts: 27,480 So Cal
autoxcuda
Too Many Posts
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Fast ratio arms AND a borgenson box will make for some serious fast ratio steering. Faster than current production cars I believe.
Borgenson is roughly 14:1 Fast ratio arms make a 16:1 stock ratio 12.7:1.
Im going to take a wild guess estimate without calc'ing anything out that you'll get 10:1 or something steering. Is there some modern car you've driven with that ratio to compare to?
Why 3.23 gear ratio with Gear Vendors? That would seem like really lugging the motor on the highway.
What tire size you running back and front?
Last edited by autoxcuda; 07/29/15 02:27 PM.
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Re: Suspension Upgrade for Challenger
[Re: Spartan040]
#1880753
07/29/15 02:21 PM
07/29/15 02:21 PM
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Joined: Dec 2003
Posts: 22,732 Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,732
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Make it a trifecta, LCA stiffening plates, 11/16" TR, 4 link triangulated rear suspension and US frame connectors, wait that's four stellar solutions, Oh well. Not. You have your mind made up, go for it, the vendors need the cash flow.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Suspension Upgrade for Challenger
[Re: jcc]
#1880833
07/29/15 03:30 PM
07/29/15 03:30 PM
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Joined: Jul 2015
Posts: 163 Florida
Spartan040
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Make it a trifecta, LCA stiffening plates, 11/16" TR, 4 link triangulated rear suspension and US frame connectors, wait that's four stellar solutions, Oh well. Not. You have your mind made up, go for it, the vendors need the cash flow. I'm sorry, I don't know what you mean by trifecta, LCA stiffening plates or 11/16" TR, would you please elaborate?
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Re: Suspension Upgrade for Challenger
[Re: Spartan040]
#1880874
07/29/15 04:00 PM
07/29/15 04:00 PM
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Joined: Jan 2003
Posts: 27,480 So Cal
autoxcuda
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So Cal
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I drove a 2015 Challenger R/T Scat Pack, I believe it has a 12.3:1 ratio, and even that was very nice. I wonder if 10:1 may be too fast...? Does it make the car harder to turn if it has a higher ratio (may be a stupid question but I'm new to suspension and steering)?
As for the gears, what ratio would be better for a GV?
I haven't decided on the tires, I don't even have the car yet. I'm in the process of building up the cash to buy the car, and I'm planning out the build in advance so that I know exactly what to do and what to buy once I have it. What size tires would be ideal for a good mix of speed and handling, and to accomodate 17" or 18" wheels? Probably 18" rims since high level performance DOT wide 17" tires are disappearing. Think 275 wide in the front as a starting point. In the rear, I don't know what people can fit in there with a low stance. I'm sure 275's will fit. I'm thinking 295's with fender lip and offset hangers?? And I you mini tube and relocate springs you can get much wider. Steering ratio does not make the car go faster or slower. It's the driver's preference and whether he can make the car go faster or slower with certain ratios.
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Re: Suspension Upgrade for Challenger
[Re: Spartan040]
#1880888
07/29/15 04:14 PM
07/29/15 04:14 PM
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Joined: Feb 2011
Posts: 4,302 Nebraska
72Swinger
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master
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I have a 14:1 box with a 13.5" wheel and I like it, I just need to work on NOT driving one handed all the time.
Mopar to the bone!!!
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Re: Suspension Upgrade for Challenger
[Re: autoxcuda]
#1880889
07/29/15 04:15 PM
07/29/15 04:15 PM
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Joined: Jul 2015
Posts: 163 Florida
Spartan040
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Joined: Jul 2015
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I drove a 2015 Challenger R/T Scat Pack, I believe it has a 12.3:1 ratio, and even that was very nice. I wonder if 10:1 may be too fast...? Does it make the car harder to turn if it has a higher ratio (may be a stupid question but I'm new to suspension and steering)?
As for the gears, what ratio would be better for a GV?
I haven't decided on the tires, I don't even have the car yet. I'm in the process of building up the cash to buy the car, and I'm planning out the build in advance so that I know exactly what to do and what to buy once I have it. What size tires would be ideal for a good mix of speed and handling, and to accomodate 17" or 18" wheels? Probably 18" rims since high level performance DOT wide 17" tires are disappearing. Think 275 wide in the front as a starting point. In the rear, I don't know what people can fit in there with a low stance. I'm sure 275's will fit. I'm thinking 295's with fender lip and offset hangers?? And I you mini tube and relocate springs you can get much wider. Steering ratio does not make the car go faster or slower. It's the driver's preference and whether he can make the car go faster or slower with certain ratios. Good info, thanks. And I know it won't make it go faster or slower, I just want to know if it'd be harder to steer with a 10:1 ratio vs a 12.7:1
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Re: Suspension Upgrade for Challenger
[Re: Spartan040]
#1880927
07/29/15 05:39 PM
07/29/15 05:39 PM
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Joined: Dec 2003
Posts: 22,732 Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,732
Bitopia
|
Make it a trifecta, LCA stiffening plates, 11/16" TR, 4 link triangulated rear suspension and US frame connectors, wait that's four stellar solutions, Oh well. Not. You have your mind made up, go for it, the vendors need the cash flow. I'm sorry, I don't know what you mean by trifecta, LCA stiffening plates or 11/16" TR, would you please elaborate? It was a bland way of saying you don't have a nice plan going. The 4 items I mentioned are what the novices normally list in their goal to achieve "modern handling" and my disdain for all of them, cited here many times, in length. Your request is common. A little research here would make you painfully aware of that initial goal and my position. Very few in one sitting make the changes you are contemplating, and those that actually do, years later the cars are still on jackstands. If you are contracting the work, they should be making the suggestions to you. My suggestion is, your car is probably in really good shape with only a few of the long list upgrades. You need to do a bit(?) more research here, narrow down your goals, tweak the car as you go, and learn the process. And I seldom follow the herd.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: Suspension Upgrade for Challenger
[Re: buconine]
#1881419
07/30/15 11:33 AM
07/30/15 11:33 AM
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Joined: Jul 2015
Posts: 163 Florida
Spartan040
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The new challengers have electric power steering with a couple different modes to change the driving feel. Be hard to simulate that with a normal steering box, i would think.
too bad you are so far away Dan, I'd love to get whooped by your challenger! True, but I wasn't planning on trying to replicate it exactly
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Re: Suspension Upgrade for Challenger
[Re: Spartan040]
#1881499
07/30/15 01:53 PM
07/30/15 01:53 PM
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Joined: Jan 2003
Posts: 5,394 Pikes Peak Country
TC@HP2
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Good info, thanks. And I know it won't make it go faster or slower, I just want to know if it'd be harder to steer with a 10:1 ratio vs a 12.7:1
Harder to steer, if you are using power assist, no. However, what fast ratio steering does is make a car feel "twitchy" and very sensitive to inputs at higher speeds. At 75 mph highway speeds, it may feel like you can change lanes by flicking your wrist. Generally speaking, the higher the speeds the car is used at, the slower the steering speeds tend to be. Uber fast steering ratios are great for autocross, disasterous for top speed events.
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Re: Suspension Upgrade for Challenger
[Re: TC@HP2]
#1881587
07/30/15 04:06 PM
07/30/15 04:06 PM
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Joined: Jul 2015
Posts: 163 Florida
Spartan040
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Good info, thanks. And I know it won't make it go faster or slower, I just want to know if it'd be harder to steer with a 10:1 ratio vs a 12.7:1
Harder to steer, if you are using power assist, no. However, what fast ratio steering does is make a car feel "twitchy" and very sensitive to inputs at higher speeds. At 75 mph highway speeds, it may feel like you can change lanes by flicking your wrist. Generally speaking, the higher the speeds the car is used at, the slower the steering speeds tend to be. Uber fast steering ratios are great for autocross, disasterous for top speed events. In that case, I may want to just go 12:1
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Re: Suspension Upgrade for Challenger
[Re: Spartan040]
#1883360
08/02/15 09:22 AM
08/02/15 09:22 AM
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Joined: Jan 2007
Posts: 7,664 IN
ahy
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I'll share a few comments based on running a similar car (Challenger, 496 EFI, 5 speed/20% OD, 3.23 rear) on the road and HSAX course a little bit. In terms of stiffening, the frame connectors are a start. There is benefit in reinforcing and stiffening the K frame also. Firm feel did mine with gussets, plates in failure prone strut and LCA mounts and full welding. Torque boxes help and also believe plating the LCA's helps. The 3 speed auto + GV + 3.23 should put the gear ratios about where you want them as long as your cam is not too wild (what cam?). The ~20% overdrive will be a "top speed" gear or close. For cruising you could handle more OD with the stroker or lower numerical axle ratio. For sustained hard running (road race, Silver State classic ect.) you will need a low slip converter and good cooler to keep transmission temps reasonable and keep the transmission alive. It will be a seriously fast car. I would not personally want super fast steering in that application. The stock ratio with a smaller steering wheel would be my choice. Also the fast ratio arms limit header choice. Brakes sound good. I run a Cobra based kit with 13" in front and 11.7" in the rear. I started with Bear front only and drums in the back. Not the best. Hard to balance and I burnt up the drums at a track day. I installed the Dr Diff rear disc kit and a huge improvement. With the brakes you choose, need to check piston area, especially on the front. The Cobra based kit has smaller piston area vs stock Mopar and needs more hydraulic pressure. I wound up changing to a 15/16" master + dual 8" booster to get my setup to 100%. Hydroboost is another option. Good luck!
Last edited by ahy; 08/02/15 09:34 AM.
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Re: Suspension Upgrade for Challenger
[Re: ahy]
#1883541
08/02/15 02:42 PM
08/02/15 02:42 PM
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Joined: Jul 2015
Posts: 163 Florida
Spartan040
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Joined: Jul 2015
Posts: 163
Florida
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I'll share a few comments based on running a similar car (Challenger, 496 EFI, 5 speed/20% OD, 3.23 rear) on the road and HSAX course a little bit. In terms of stiffening, the frame connectors are a start. There is benefit in reinforcing and stiffening the K frame also. Firm feel did mine with gussets, plates in failure prone strut and LCA mounts and full welding. Torque boxes help and also believe plating the LCA's helps. The 3 speed auto + GV + 3.23 should put the gear ratios about where you want them as long as your cam is not too wild (what cam?). The ~20% overdrive will be a "top speed" gear or close. For cruising you could handle more OD with the stroker or lower numerical axle ratio. For sustained hard running (road race, Silver State classic ect.) you will need a low slip converter and good cooler to keep transmission temps reasonable and keep the transmission alive. It will be a seriously fast car. I would not personally want super fast steering in that application. The stock ratio with a smaller steering wheel would be my choice. Also the fast ratio arms limit header choice. Brakes sound good. I run a Cobra based kit with 13" in front and 11.7" in the rear. I started with Bear front only and drums in the back. Not the best. Hard to balance and I burnt up the drums at a track day. I installed the Dr Diff rear disc kit and a huge improvement. With the brakes you choose, need to check piston area, especially on the front. The Cobra based kit has smaller piston area vs stock Mopar and needs more hydraulic pressure. I wound up changing to a 15/16" master + dual 8" booster to get my setup to 100%. Hydroboost is another option. Good luck! Your car sounds pretty great too! If I may ask, what EFI system did you go with? As for the cam, I'm not sure yet. I know I want to build this engine and car so that it is possible to get 20 mpg on the highway, and Chryco Psycho over on cuda-challenger.com said he could design me a cam grind that would work for that. I solved the fast ratio arm and header problem, I found headers that will clear them. Thanks for the advice!
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Re: Suspension Upgrade for Challenger
[Re: Spartan040]
#1883859
08/02/15 10:38 PM
08/02/15 10:38 PM
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Joined: Jan 2003
Posts: 27,480 So Cal
autoxcuda
Too Many Posts
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Too Many Posts
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...snip...
I solved the fast ratio arm and header problem, I found headers that will clear them.
Thanks for the advice! Which headers are those? Are they big enough to not hinder a 512 cubic inch motor?
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Re: Suspension Upgrade for Challenger
[Re: autoxcuda]
#1884034
08/03/15 01:31 AM
08/03/15 01:31 AM
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Joined: Jul 2015
Posts: 163 Florida
Spartan040
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...snip...
I solved the fast ratio arm and header problem, I found headers that will clear them.
Thanks for the advice! Which headers are those? Are they big enough to not hinder a 512 cubic inch motor? They're TTI 2" headers with 3.5" collectors, and I was planning on using 3" reducers to hook up to the 3" TTI exhaust I selected. They're rated up to around 600 horsepower
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Re: Suspension Upgrade for Challenger
[Re: autoxcuda]
#1884217
08/03/15 12:33 PM
08/03/15 12:33 PM
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Joined: Sep 2006
Posts: 221 Portland, OR
shawge
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Portland, OR
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Probably 18" rims since high level performance DOT wide 17" tires are disappearing.
Think 275 wide in the front as a starting point. In the rear, I don't know what people can fit in there with a low stance. I'm sure 275's will fit. I'm thinking 295's with fender lip and offset hangers?? And I you mini tube and relocate springs you can get much wider.
Steering ratio does not make the car go faster or slower. It's the driver's preference and whether he can make the car go faster or slower with certain ratios.
I've got 285-40-18s on 10" w/ 5.5" BS for the back of my Challenger w/ stock spring locations and rolled lips, so 275 would definitely fit. I _think_ 295s would fit but I would 3x check the BS measurements as it will be tight. They would for sure fit with the offset hangers and rolled lips.
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