IRS under 68 Newport

tbad

New Member
Joined
Sep 8, 2018
Messages
37
Reaction score
12
Location
new york
Happy Thanksgiving everyone!
Started trying to install a Hellcat rear in my 68 Newport. (Why not?) Any chance someone could send me measurements from the back door sill and from the top of the wheel opening (without skirts on) to the rear wheel center? Didn't take those measurements before I pulled the old axle and I need a reference to get a location for the new rear.
Any help is appreciated, thanks.
 
I can tell you its 25" from front leaf eye to axle center and 37 from the rear eye to center....if that helps.
 
Thanks for the replies. All the old suspension is gone, I can only use the body for reference.
Haven't killed anyone yet with this thing. It might kill me though!
 
The mounts for the Hellcat rear sit just outside the frame rails, which will have to be notched. I will have to add back some support on the inside. There is room under the rear seat to add material to the other side of the frame rails to get the full strength back. It's involved but I am hoping it will be worth it. Just have to find out where the rear has to sit relative to the body.

rear 1.jpg


rear 2.jpg
 
After this upgrade are you gonna do the rest of the engine and drive train?
 
Yes, most likely a whole new driveline out of something new.
 
What about the front end? You could end up with a car that handles like a modern car in the rear and a 50 year old car in front. I see these pro touring builders tear out the stock subframe and put in a new set-up with coil overs and rack & pinion, and it’s pricey.
 
Honestly I was always going to do a modern drive line, wanted it to be relatively reliable. Got into pricing all the parts to beef up the original rear. Going with the IRS was actually cheaper. Much more involved, but that is the fun of this. Still newgoing to get new torsion bars, sway bar and bigger wheel/tire combo. Hoping it all works out.
 
Cheaper? What did that drop out cost? I would have thought a wrecked chally or charger 392 would have been a more affordable way if you planned on using modern susp and drivetrain?
 
Hello everyone. About 90% finished with the IRS install on my 68 Newport convertible. Lots of cutting and fab. Been at if for months. Seems to be in straight and square. Car will probably snap in half, but it is different. Had to make rear mounts from scratch, and cut off the ones Mopar gave it. Been cutting the crap out of the frame. Still have to make a pocket for some sort of shock/spring combo. Added some frame support behind the back seat right over where most of the cutting happened. Hoping by putting back what I took out I got enough strength back. Instead of welding tried solid rivets and automotive structural adhesive. Supposed to be stronger than welding. That's a good thing since my welding is an ongoing lesson. Rear has it's own frame which also should help with the strength. I'm not a structural engineer so just been going with the, "adding more, thicker metal".
Working on subframe connectors now. More, thicker metal, anywhere I can add it. I'll add more pictures once I have these monsters done.

IRS 1.jpg


IRS 2.jpg


IRS 3.jpg


IRS 4.jpg


IRS 5.jpg


IRS 6.jpg
 
I gave you a like but then took it back when I had a closer look at this. Your fab skills look great and I will give you the like back when you show me where you moved the support that used to be there.
29FC2710-F793-4B9F-94E8-F404B301E8BC.png
 
First, thank you for the, "fab skills look great" comment. Never did this before. I only removed what was in the way. I even left the shock support crossmember that runs from one frame rail to the other. I am paranoid that the whole car is going to fold in half after all this work! The only thing I remember removing was the pad where the rubber bump stock was. It was interfering with the upper control arm. That wasn't structural. The last two pictures are the pieces I made to get the strength back to the frame where I removed the metal. Each one is over the same area where I cut metal out. The added metal is thicker than the frame material and the same dimension I cut out. If I took out 2 inches there is 2 inches back on the other side of the frame. The rivets go through where the folded frame is spot welded to the floor (thickest spot) and the whole piece is glued. That is the snotty looking stuff in the second to last picture. Couldn't think of a stronger way to join it to the car. Welding would just be around the edges on thin metal and I'm not a welder. Each rivet is supposed to be rated up to 1500 lbs of sheer and there are over 20 on each side. I actually called 3M to ask them about the glue. Sent me a bunch of technical info, but found video's of guys testing stuff like this compared to riveting and welding. Believe it or not the glue won!
Going to drive around with my family in this, not going to kill people because I didn't do my homework!
 
First, thank you for the, "fab skills look great" comment. Never did this before. I only removed what was in the way. I even left the shock support crossmember that runs from one frame rail to the other. I am paranoid that the whole car is going to fold in half after all this work! The only thing I remember removing was the pad where the rubber bump stock was. It was interfering with the upper control arm. That wasn't structural. The last two pictures are the pieces I made to get the strength back to the frame where I removed the metal. Each one is over the same area where I cut metal out. The added metal is thicker than the frame material and the same dimension I cut out. If I took out 2 inches there is 2 inches back on the other side of the frame. The rivets go through where the folded frame is spot welded to the floor (thickest spot) and the whole piece is glued. That is the snotty looking stuff in the second to last picture. Couldn't think of a stronger way to join it to the car. Welding would just be around the edges on thin metal and I'm not a welder. Each rivet is supposed to be rated up to 1500 lbs of sheer and there are over 20 on each side. I actually called 3M to ask them about the glue. Sent me a bunch of technical info, but found video's of guys testing stuff like this compared to riveting and welding. Believe it or not the glue won!
Going to drive around with my family in this, not going to kill people because I didn't do my homework!
Ok, I gave it back, nice work!:thumbsup:
Now how far away are you from putting wheels on it and some power to it?
 
That is the other problem, getting wheels to fit. We'll cross that bridge soon. Years, 2-3, best guess. Thanks for the compliment
 
One of the neatest things I've in in sometime.
Best of luck, I hope you keep it all Mopar.
 
Back
Top