The Rodding Roundtable
Motorhead Message Central => Rodder's Roundtable => Topic started by: chevy 47 coupe on October 09, 2007, 09:55:42 PM
H i all.I have a 47 chevy stylemaster cp.and i was thinking of doing a frame swap with a g-body chassis(monte carlo,olds cutlass etc).I was told not a good swap by some members .he gave me some ideas as how to go about useing that frame.might be too much of a hassel?? is there another vechicles frame besides the toyota truck frame.or would it be easier to use a nova,camaro subframe and weld to existing 47 frame.i would like to use as many existing parts from the donor vechicle as posible(engine,sterring, rear, poss electric).if i use the subframe any help as to go about doing this would help a lot.as where to cut frame.measurements etc thanx
A quality MII front suspension kit is probably the easiest. There are some bolt on units available...Chassis Engineering if I remember correctly. A sub will work but it's a lot more work if you've never done one before...and the hat style frame on the Chevy isn't as easy to attach a sub to. Can be done but takes a bit of experience.
Charlie
Quote from: "chevy 47 coupe"H i all.I have a 47 chevy stylemaster cp.and i was thinking of doing a frame swap with a g-body chassis(monte carlo,olds cutlass etc).I was told not a good swap by some members .he gave me some ideas as how to go about useing that frame.might be too much of a hassel?? is there another vechicles frame besides the toyota truck frame.or would it be easier to use a nova,camaro subframe and weld to existing 47 frame.i would like to use as many existing parts from the donor vechicle as posible(engine,sterring, rear, poss electric).if i use the subframe any help as to go about doing this would help a lot.as where to cut frame.measurements etc thanx
You could not pay me to install another G-Body clip into a 46-48 Chevy. They are not the easiest of swaps. As Charlie Says the easoest solution would be a Mustang II based suspension. That is what I am installing in my own 48 Sedan.
I was staying away from the bolt o weld on kits that are avalible(price) if i did go that way what else would be needed (sterring col.etc??) or if i went with the sub frame what would be the way to start this?matting subframe to 47 frame,im up to the challenge 8) enjo suggested a extended cab toyota pickup which he said was almost a perfect fit but the frame has to be stretched 4" then id have to mount a 350 to that and need a rear also. my mind is going in so many places so thats why all the ????? your input is so helpfull thanx
Since $$$$ are important here are a couple of $$$$ issues to think about.
A GM clip will be old and almost certainly road weary. Plan on (budget) for rebuilding or replacing every wear component; bushings, ball joints, shocks, brakes, etc.
In the end, I think you will find that upgrading to a Mustang II front suspension will not cost much more than doing a clip.
And in today's market a clip will detract from sale value while a well executed Mustang II suspension will add to value. No matter what you do to your car; paint, interior, drive train, it will always be a clipped ride.
ok so if i go the mustang suspention ,which is the better way to go bolt on or weld on i have seen both.after that suspention is in what is the next thing that has to be done ,bought etc? and another ? i need to get a rear also what do you suggest-mustang camaro or nova rear or?
Functionally, there is no difference between a bolt on and a weld on crossmember. If you are a competent fabricator and welder you can save a couple of hundred bucks using a weld in over a bolt in crossmember. So the decision is based on your skill level.
And, if you are a very capable welder and fabricator you can save another couple of hundred bucks using a kit from these guys: http://www.welderseries.com/
Most of the bone yard around here have been picked clean of Mustang II and Pinto/Bobcat front suspension parts. But if you are lucky you may be able to score a complete front end with rebuildable arms and spindles and a core R&P. You can save some big bucks going this way. But I do recommend upgrading the brakes. The stock ones are not suitable for the vehicles they came on, much less a full sized sedan.
it has all been covered but do yourself a favor and do the mustang two and you will be happy with it bottom line. it is worth more drives great and everything fits back on it way better. get your self a speedway catalog and or go on line and check out out alol of the mustang two stuff they have as it is pretty easy to know what to buy and it is very reasonably priced there.... good luck
I would avoid the clip route. Too much engineering for most people to get it done right - and looking right.
Having said that, I would prefer using an S-10/15 chassis/clip over the G-body chassis/clip.
While the front-end components are interchangeable, the S-10/15 front crossmember is mounted differently - which gives the truck a slightly (one-inch) higher roll center.
This higher roll center works well with the earlier cars that had such high Center of Gravity - especially when compared to the G-body.
The other thing is that the G-body is a perimeter frame - which often makes it too wide resulting in the need to fabricate straight rails....and it comes in one flavor - 108"....meaning it will, most likely, need to be stretched.
The S-10/15 is a ladder-style chassis which comes in wheelbases running from 100" to 123", and is quite easy to shorten at the factory weld where the front clip attaches. There is a 117" version that fits MANY late '40s and early '50s cars.
B.P.
If you are really comfortable with your fabricating skills, and want to save the maximum amout of $$$ check out the H.A.M.B. archives for the plans for a MII crossmember. Remember, this is coming from a guy that used the G body crossmember in my Olds. However, I only used the crossmember and built my own frame rails. Biggest issues with the G bodies and S10/15 is the big steering box out on the front. It will just hide behind the grill on my Olds.
Doug
Quote from: "chevy 47 coupe"H i all.I have a 47 chevy stylemaster cp.and i was thinking of doing a frame swap with a g-body chassis(monte carlo,olds cutlass etc).
I have a post-war Chevy sedan that I put a G-body clip in. As the guys here can tell you, I have had plenty of trouble doing it. Mainly due to my screwing it up. Would I do it again? Too early to tell. I have not driven it yet.
I made my clip decision based on many factors, cost being one of them. I put a Fatman MII kit in m y '39 and I am not at all happy with it. I don't like the way it handles, and I don't like the brake kit (ECI) that I used. It is a big mis-mash of parts. I am building this car with a goal of my wife being able to drive it anywhere, and get it fixed if it breaks down. If something happens on the front, all she has to tell the garage is that the front is '87 Grand Prix. Not "I think the rotors are Granada, the calipers are Camaro, the bearings are MII..."
I also talked to MANY guys at shows. I did not talk to anybody with a clip on their car who regretted it. I talked to a couple who took off their MII and went to a clip.
A clip is much more work. If you are a good fabricator and have lots of time, that is a plus for the clip. You will have to modify all of the inner fenders, the bumper mounts, etc.
I got my clip for free, and it was in nice shape. I am going to replace all of the bushings, etc,. just because I want everything new.
I wish I knew that the S10 would work better when I did mine. I would have went with that. I have seen swaps that used the entire frame, and if your floorboards are gone I would say give that a go. My car was solid so I just did the clip.
If you need more info or have more questions please feel free to PM. I have plenty of pics and made enough mistakes so maybe I can help in some way.
Walt
I'm in the process of putting an S10 (S15) frame under a '48 Willys Jeepster and there are some problems you might have to deal with. The rear axel is only 53" axel end to axel end which is a bit narrow for my use and I imagine it would be way to narrow for your Chevy. The fix that some people are using is an S10 4X4 rear end that is 58" and bolts right in. This would take care of the rear but you will also be dealin with the 53" on the front. Some people are using 2 1/2" wheel spacers on the hubs which will run you $50.00 or so. If you think a 4X4 frame would be better that is not the case because from the side view they are flatter/higher and not very conducive to body changes because of that. The '78 to '87 Metric frames have an even wider (63"?) tread width and you might end up running neg. off-set wheels to get the tires in the fenders. Another thing is the engine will probably sit in the wrong place on the stock mounts with a new body around it. If you can deal with those 2 items add to that list that the S10 is a pick up or SUV frame and the rise in the frame for rear axel clearance and the gas tank starts behind the front seat. All of this can be engineered around but if you want to drive this thing soon then I would use someone elses engineering and Mustang II it. Now, I haven't talked myself out of doing mine that way BUT!. Fat Cat plans on driving his by April and he's only had it a month. It has been my experience that SE Ohio climate is not easy on frames. My Jeepster had (has) a "Top Hat frame and I had a '53 Chevy that did to. People talk about road salt but the reality is with the high humidity and dirt/mud the frame actually rust from the inside/out. Pa. is not that far from here, if you still have a frame I'd use it. That way your body would already be mounted, so would your radiator. inner fender panels, bumpers and gas tank. We're just trying to help you make an informed decission. GPster
The metric frames are 58" wide, mounting face to mounting face on the discs. In my case, I think I am going to have to space the front wheels out a bit (3/4" or so each side).
Doug
Hi guys
I just wanted to say thanks for the link. This looks like a great forum - I'm enjoying going through the tech articles!
DW Horton
Welder Series Inc.
Quote from: "sirstude"The metric frames are 58" wide, mounting face to mounting face on the discs. In my case, I think I am going to have to space the front wheels out a bit (3/4" or so each side).
Doug
For my rear, I am using the Z28 Posi rear from my donor. It was too wide, so I took the axles to the salvage yard and did some caparison. As it turned out, S10 Axles (can't remember if it was 2 or 4-wheel drive) are the same size except they are a little shorter. I had the housing narrowed and with the S10 Axles I ended up with a 59" width. I may need to use a ½" spacer, but I am going to trim the side of the frame at the wheel opening and see if I can get by.
You could cut all the coil spring stuff off and use leafs, but I like a coil spring ride, so I fabricated brackets for the trailing arms and panhard bar and upper spring and shock mounts. I hope it works!
Walt
Like 48 BUILDER, I chose to go with the clip. It is great to go to a parts store, ask for stock parts and walk out with exactly what you need. Too many people that I have known and talked to have found the Mustang unit is not heavy enough for big cars, but perfect for lighter units. Most people I have talked to that recommend the clip got the "caster" right, by removing the front shocks before dissassembling the donor car and locking the suspension at ride height using threaded rod. They also used an Inclinometer on the sub frame to match the sub-frame angles before and after. This is my Winter project on a 1947 Chev Aerosedan using a 1981 Z28 Camero as the donor car. This car will be a trailer puller so I feel the heavier the components are in the suspension, the better.
Fred Drew
I have put several MII front ends from Fatman on cars with no problems. My 54 Chevy has their Stage 3 and I really like it. The only thing I might change is to go to manual steering instead of the power rack. I went with the power because of backing a trailer in a campground would be easier with it. I have over 10,000 miles on it in the last year. If I did another one, I'd use the same one. The stage 3 has shims like a GM frontend.
All good suggestions for both clips and MII kits. My vote is for MII for the cleaner end result on hat section frames (Chevy). As for the beefiness issue on MII's I would not use the sheet metal crossmember from an MII donor car though. I have done numerous installations of both as have others here.
I have a Heidts MII crossmember kit under my '40 Chevy convert. I used the bent tubular strut arms and also boxed my stock lower a-arms. I also used Pro-Shock coil overs which went about 17 years before they need rebuilding. I left the upper a-arms alone and used the stock t-bolts. Hasn't moved alignment over the past almost 20 years and 70K+ miles.
My car weighs in at about 3700 pounds, maybe a bit less. I guess I look at the MII kit as being derived from the Mustang, not necessarily keeping the light weight nature of it by improvement provided in the cross member kit.
On the other hand, the driving feel of a Nova, Chevelle, G-body sub euipped car is awfully hard to beat. At the end of the day it boils down to preferences and abilities.
Charlie
Quote from: "Charlie Chops 1940"..............On the other hand, the driving feel of a Nova, Chevelle, G-body sub equipped car is awfully hard to beat. At the end of the day it boils down to preferences and abilities...Charlie
I'm not saying a clip is for everyone, but I love mine. It wasn't that hard to install. The time came in widening the front fenders 1 1/2 inches on each side for tire clearance.
I've driven in cars and driven cars with MII front-ends and none have been bad, but I haven't been in one yet that I think handles as good as mine in the turns or has a just good feel going down the road. I'd be interested in trading rides someday with someone who thinks they have a really great MII for a comparison. I tend to like to drive a little faster than some, so this is probably not a big deal with most people.
One thing I did though is run Camaro springs in the back and set them up with the same geometry as in the Camaro. I also shortened the wheelbase to the same as the Camaro, so basically the truck thinks it is a Camaro.
c ya,
Sum
thanks for all this information,which is helpful.i saw a Heidts superide 2 kit $2,599 (street rod headquaters) which i think is a little steep!!dont know if its weld on or bolt on?it seems to have all the componets that are needed. any one here used this setup? remember this car will be driven alot and i need it reliable and easy to get parts also.im still not sure which way to go,nova clip form donor car (which i can also use the motor,trans,rear,poss interior,steering column etc.)Ive restored some cars in the past but never started a rod project like this so bear with what seems like the same ???over and over.just trying to find the best way without over spending on a driver on a limited budget :roll:
The Super Ride is a weld in with all proprietary Heidts parts...which means replacements are sorta kept a secret. With a MII kit you are using MII a-arms, shock, spings or someones coilovers and an MII rack and pinion, so replacements aren't a complete mystery. You should be able to do a MII kit and p[arts, and big brakes in the $1500 area - all new parts.
However, I have installed a couple Super Rides and found them to be very good front ends. Recently though, I have heard of some issues with their rack and pinion which is a lFaming River unit. I don't know if the issues are resolved or not.
Charlie
Quote from: "chevy 47 coupe"................im still not sure which way to go,nova clip form donor car (which i can also use the motor,trans,rear,poss interior,steering column etc.)............
That is the way I went with a Camaro donor I got for $700 and was on the road for less than $5000. Of course that was before paint, upholstery, and later a rebuilt motor. I completly rebuilt the front with J.C. Whitney parts except for the bushing kit that I got from someone else.
Just make sure the width is not going to be an issue, probably not with the nova, but then be sure and factor in a disc brake conversion. You want disks,
Sum
MII KITS who sells these? any pointers on doing the clip?how you did it would be great. pm me with info thanx. more ideas and comments are needed 8) I might go either way more research and info needed. im glad you guys can help me otherwise id proably still be scratching my head :?
Quote from: "chevy 47 coupe"MII KITS who sells these? any pointers on doing the clip?how you did it would be great. pm me with info thanx. more ideas and comments are needed 8) I might go either way more research and info needed. im glad you guys can help me otherwise id proably still be scratching my head :?
Look at chassisengineeringinc.com, scroll down to their 41-48 Chevy Pinto kit. I think this is one of the simplest ways to go as it utilizes original suspension mounting holes.
Google Mustang II suspension kits. There are gobs of makers.
Charlie
If you decide to do a clip, and have the skill, look at a 67 to 69 Camaro or Firebird, or 68 to 74 Nova and clones(X body). These are rear steer, and dont have the issues with the drille, radiator, and steering interfering with each other. There are new problems, but they are easier to solve. :lol:
Here is an article on clipping a frame I did some years ago http://enjenjo.com/frameclip.html
It's a chevy truck, but most of the steps are the same.
just a thought about later model camaro subframes as donars.. 76 through 79 sevilles use an almost identical sub frame except for the frame horns wich were set up for big bumper shocks. and they are much more common in the junk yards out here in socal....
Well ive decided to go with the mustangII IFS kit. ive found a kit from speedway motors.mustangII tubular control arm ifs .for $1379 within my budget. it has different options which i need some opinions and guideance.
1.shocks or coilovers?
2.bolt pattern 5x4-1/2" or 5x4-3/4" ?
3.standard or 2"dropped spindles(id like the car to have a low rake)?
another thing they ask is what spring weight i need and i dont know.it has to do with what motor i use correct? if i use a 350 for example.they have for coil overs-700lb-600lb-500lb+350lbs. for spring with shock 500lb-425lb+350lbs. i dont know very new to me :?
you can also get the kit with 1" narrower tubular control arms???
1.shocks or coilovers?
You can do it either way. Springs and shocks are somewhat cheaper, but both work good. On my own cars, I run shock and springs.
2.bolt pattern 5x4-1/2" or 5x4-3/4" ?
It depends on what you are using for a rear end. Match the bolt pattern of the rear you are using.
3.standard or 2"dropped spindles(id like the car to have a low rake)?
On a 48, you will be plenty low without dropped spindles. The stockers will work fine.
springs
On my 47, I used 500 lb springs, they worked good.
thanx enjenjo for the info. when i weld this kit is it has to be in the same spot as the oringinal center to center 116" also do i need to remove the steering box or can i adapt it to this kit.or do i have to get a new steering box? I would like to use the oringial column and steering wheel if i can.if thats to difficult ill use one from the donor car i get
The new suspension will have rack and pinion steering, which replaces the original box. You can use the original column, but you have to fabricate a bushing at the bottom to support the shaft, also a mount where it goes through the floor. You would then connect it to the rack with a couple U joints, and an intermediate shaft.
When you get the kit, there will be instructions on locating the crossmember on the original centerline. I usually cheat it ahead a bit, because it looks better on a lowered car. Usually 1/2" to 3/4".
The radiator support is part of the front crossmember, you new kit may, or may not have one. Measure the location of the original, so you know where to put the new one.
When I put kits in, I use tape on the floor and a plumb bob to mark important items such as axle centerline, radiator support holes, and a few other points so I can make sure the frame hasn't moved as you work on it. I take heights at those points also. When you put the new one in, it gives you a few reference points for mounting things in addition to measuring to points on the frame. If you end up not needing them, no harm. But if you need some additional reference, you have the measurements.
ok here are other ??? before i order the mustang11 kit .when i weld this kit on is it going to be lower in the front than it is now stock?
also they said on there site when installing the front spring crossmember (is this the top pieces ,upper control arm area or the lower control arm area or i assume they mean the whole kit top and bottom pieces of the crossmember?) take into account the final front axle caster settings.car at normal ride height will be 5-7degrees positive(tipped back at top) :? whats tipped back at top?? normal chassis rake approx.3-5 degrees.(how is this done? ) if you install the front crossmember square with the chassis you will lose some castor angle.they suggest you tip crossmember back 7-10 degrees.so that final front end alignment can be made without binding up the spring and shackles. do i need to worry about this? opinions and suggestions.they also have pivoting spring perches for adjustment if you welded crossmember flat. ( little confused i looked at them and cant figure out what they do and where they go)
This is a symplified answer, so take that into account.
Yes it will lower the front of the car, by several inches usually. If you get a universal kit, instead of one designed for your chevy, you can mount it so the car sets somewhat higher in front if that's what you want.
The right way to set up a new front suaspension, is to set the car on stands, so it is at the height you want front and rear. This will give you frame height and angle where the crossmember mounts. you can use this to figure the crossmember angle before installing it.
This is not a hard thing to install, thousands have done it. But getting it right so the car handles well involves figuring in a lot of things like caster, camber, strut rod angle, steering clearance, antidive.ect. Assemble it first, tack welded in, set ride height with a strut instead of springs, and check all the alignment before welding it in place.
If you don't understand, ask more questions, we will be glad to help.
That's what we always tell our customers too... get the car at ride height (where you want it to sit going down the road) and put the wheels and tires you'll be using in the wheel wells. Take a walk across the road, turn around and see how the car looks. Try moving the wheels around in the wells until they're exactly where they look best.
We've got an assembly video of the Mustang II crossmember on our website.
Look for "Mustang II".
If you stick with Heidts, Fatman, or the WS kit, you'll be happy. There are lots of resources here to tap in to.
dw
sorry still a little bit confused :? (thats why we are here i hope) if i set the frame where i want it with the rake how does it affect where i weld the crossmember. i dont want to sound like an idoit ,but i want to do this the correct way.I dont have the rear yet and dont know what wheels and rubber i'll be useing. should i wait till i get the rear then go from there? or should i just weld the kit square to the frame? remember this is my first project with frame and suspention work and want to learn all that i can so this car will be driveable and enjoyable
You have to have the frame set at the attitude you want in the running condition so the crossmember can be set level and the spindles set at the proper caster. If the whole thing is put in relative to the frame and the final ride angle is different, you may not be able to get the proper front end alignment, the lower control arms in the wrong angle, or the wrong anti-dive. If you don't have the frame at the final ride angle, it can't be aligned when the pieces are tacked in. You have to look at the alignment when it is assembled as well as when it is done. If you don't understand caster, camber, etc. find a shop that is willing to show you and use that info to set your components up when tacking everything in. Double check the settings before welding everything solid.
Quote from: "wayne petty"just a thought about later model camaro subframes as donars.. 76 through 79 sevilles use an almost identical sub frame except for the frame horns wich were set up for big bumper shocks. and they are much more common in the junk yards out here in socal....
hey wayne, the one i had was a bit wider, don't remember how much but it was enough to cut up and send to the scrap.....
Quote from: "chevy 47 coupe"sorry still a little bit confused :? (thats why we are here i hope) if i set the frame where i want it with the rake how does it affect where i weld the crossmember. i dont want to sound like an idoit ,but i want to do this the correct way.I dont have the rear yet and dont know what wheels and rubber i'll be useing. should i wait till i get the rear then go from there? or should i just weld the kit square to the frame? remember this is my first project with frame and suspention work and want to learn all that i can so this car will be driveable and enjoyable
I'd recommend getting the rear end and wheels/tires before you start on the front end.
If the frame was horizontal with the ground, welding the crossmember square to the frame would work great. But, to get a desired "rake", the frame will end up lower to the ground at the front than the rear. You have to take this angle into consideration when you're installing the crossmember. The angle itself isn't important - it could be 5* or 15* - but you have to remember that the frame is on an angle. Because our crossmember is "trim-to-fit", the actual angle of the frame is inconsequential. Again, there are installation and assembly instructions on our website. It's a weekend job for a novice if you read the instructions...
Please give myself, Heidt's, or Fatman a call if you have any questions. We're all here to make sure your front end gets installed correctly, safely, and simply.
We all tell someone doing this to get the frame at ride height, but fail to tell them that this can be difficult to do.
The front isn't so hard knowing that the bottom a-arms should end up parallel to the ground. Put the tires/wheels on and use all thread in place of the shocks/springs and get the a-arm parallel to the ground and you will know where the frame will be there.
Now if the car/truck is all together from the cowl back you can put a rear under it and springs and see where the back sits with the normal weight on it.
The problem arises, at least it did for me, was putting the front end in when you are dealing with a bare frame without the body on it. Now how far is the back going to go down?? I piled a bunch of weight on my frame as I had the cab on it ,but no interior, no motor/transmission weight (yes that will transfer to the back also), no bed, etc.. I then located the rear shackle bracket for the rear spring only to find out I needed to move it further rearward later when all the weight was there. So I had the frame rake somewhat wrong, but it all seemed to turn out fine as the truck aligns fine and so forth.
(http://purplesagetradingpost.com/sumner/underconstruction/framerear.jpg)
In the picture you can see that the rear shackle is pointed the wrong way with no weight, yet it is 45 deg. the other way with weight. This is where it had to be after I fixed it. More pictures here:
http://purplesagetradingpost.com/sumner/underconstruction/underconstruction2.html
So how do you guys set the rear frame height if you are working with a bare frame??
I run air shocks in the back and that really helps to keep the rear the same height under different loads. If I did it again I would run shocks and separate air bags along with the leaf springs.
c ya,
Sum
Quote from: "1FATGMC"
So how do you guys set the rear frame height if you are working with a bare frame??
On the Packard I'm running a 4 link with air springs so setting the final ride height is a matter of adjusting the air. On the 54 I had all the dimensions before I tore the body off the frame (had a spare frame I was welding on) so I could compare "old" to "new". On most that I've done I end up with a few degrees rear up at final ride height, but the wagon ended up almost level to the ground. All depends on the look you want. With the wagon, I got new springs for it and the guy that built them (from RB's) talked to me and I gave him dimensions of what I wanted. After about 100 miles, the new springs settled in and were at the exact height that we planned.
Leaf springs are difficult to set up, since they don't have a designed ride height. With coilovers or even air springs, you will know where the car will sit because they both have a designed ride height. A typical rear coilover will have a 13" or 14" center-to-center dimension (measured at the mounting bolts). All you have to do is drill 5/8" holes 13" or 14" (depending on your coilover) apart in a 1" square tube, and use that in place of your coilovers when you're setting up the ride height. Leaf springs are definitely more difficult to know where they're going to end up.
It's totally correct that the lower arms should be horizontal at ride height, but that's hard to do if your crossmember isn't installed yet. On the Welder Series kit, there is a notch in the crossmember where spindle centerline at ride height will be. To be 100% sure of where the car sits, you really should have the fenders in place to accurately mark spindle centerline on the frame front-to-back. An alternative is to measure someone else's car (whose wheels are nicely centered in the fenders) at a show. It's so important to measure because although the center of the wheel (spindle centerline) will stay the same, it's where the centerline ends up on the frame that will change.
Please read the installation instructions on our website all the way through... they explain it well.
To figure ride height on leaf springs, here's a quick and dirty way to do it. If you are using new springs, you more than likely know the spring rate. That is the amount of weight needed to move the spring one inch. Take that figure, lets say 150 lb. Then take the weight of the rear of the car, for our purposes 1500 lbs. Take a straight edge, and measure the arch of the spring, from the spring eyes, with the spring out of the car, in this case we will use 7". Divide the weight of the car, by 1/2 to get the weight on one spring. Then divide that weight by the spring rate. So take 1500lbs divided by 2 equals 750lb. 750 divided by 150 equals 5. So the spring arch will decrease by 5" when installed. You can use that figure to get the center of the rear axle loaded. this will get you real close.
If using a used spring with an unknown rate, set the spring with the eyes on a flat surface, and measure to the center of the spring. Add 100 lbs of weight in the center of the spring, and measure the deflection. Then do the same with 200 lbs, and 300 lbs. lets say the spring deflects 2" with 300 lbs, this gives you a rate if 150 lbs per inch, you can plug this into the equation, and figure it like a new spring.
Quote from: "enjenjo"........................... Then take the weight of the rear of the car, for our purposes 1500 lbs...................
Good post Frank, using the spring rate is a good idea.
Hopefully you know ahead of time what the vehicle is going to weigh and how much of that weight is on the back. I didn't have a clue when I started with my truck. Now with the internet it is probably easier for someone to find the weight from someone with a similar vehicle.
My truck at 4000-4100 lbs. (loaded and in travel trim) came in higher than I would have ever guessed in the first place.
As usual you came through :D ,
Sum
Boy ....that Frank guy is one smart cookie... :shock: Can we save this spring info to the "Tech" section??? 8)
I always set the rear suspension first. BUY the Chassis Eng bolt on rear kit and it will center your rear wheels PERFECTLY. The ride height will give you the rake you are after. I use P235/70 or similar size tires and they will fill up the rear fender opening. Now to the front. BUY the Chassis Eng bolt on front crossmember and guess what = it will center your front wheels in the wheel opening PERFECTLY. The ride height is adjustable - about 2 1/2 inches. THis will enable you to fine tune ride height and level the car from side to side. You said this is your first street rod build and thes kits will be perfect for you. YES they cost aliitle more but they are worth it, reguardless of your abilities and the end result,time saved,and added value will always be there. PLUS they are foolproof !!
I think i might as well go with the( chassis engin) bolt on kit.so i dont have to worry about any mistakes with the weld in kit.thanks for all the help so far from all of you.i'm sure i will have more questions down the road.till then im going to concentrate on some of the metal work and the start on the frame and order the ifs kit 8)
You'll like the CE kit.