# Anti - Hop



## dcoydad (Sep 27, 2017)

Running a Kauffman 463 stroker in my 68 goat with MY6 tranny. It has an 8.5 BOP diff with Eaton true trac posi. Lots of wheel hop when lighting it up. Added poly upper/lower arm with adjustable uppers, adjusted pinion angle and installed QA1 adjustable rear shocks - not much difference, dribbled like a basketball. After research I found lots of folks were happy with the QA1 or Edelbrock anti-hop brackets. Found some NOS Edelbrocks and they rock. I already had poly lower arms and adjustable upper arms. The install was straight forward, you do have to grind off some lumps of the diff case, but not a big deal. Now the car breaks loose at command without any hop. These are a good fix.


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## Baaad65 (Aug 29, 2019)

I had those on my '67 back in '84, this time I went with South Side Machine lift bars. No wheel hop but still can fry the 10" drag radials anytime in first gear with my 461.


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## armyadarkness (Dec 7, 2020)

I also run the BOP rear with a posi, and I get no hop.


UMI factor height coils
Bilstein shocks
Global West Upper and Lower control arms.
Global West Frame Supports.


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## 67lemans (Oct 30, 2009)

I would like to see a picture of those anti hop brackets on the car. I'm having a hard time envisioning how they work.


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## PontiacJim (Dec 29, 2012)

67lemans said:


> I would like to see a picture of those anti hop brackets on the car. I'm having a hard time envisioning how they work.


Here is the set I fabricated for my Ford 9" rear. The purpose of the "no-hop" bars is to change/correct the upper control arm geometry. In my case, raising the body stance up required the use of a 3" lift under the springs. What this does is put the upper control arms at an extremely steep angle coming off the front control arm mount/crossmember to the rear control arm mount/rear end. Not a good thing at all and you also no longer have much/any movement of the upper control arms.

The "no-hop" bars are designed to raise the control arm at the back bolted to the rear axle. As you can see, this gets the upper control arm in a more straight line pull coming off the crossmember that it is attached to at the front - and not the wicked angle without them.

The "no-hop" bars are available for the GM rear ends, and the only option for the Ford 9" is a set of weld-on extensions that raise the mounting point of the back of the control arm to provide a better angle on the control arm. Since I am using a 3" lift under my springs, and I did not want to weld-on an extension that would have been too short anyway, I fabricated my own - whether they work out or not is yet to be seen. I added several holes so they are made adjustable where I can move the upper control arm rear mount down a hole or two if I need to play around with getting the tires to bite.

This was no easy job for the inexperienced as I had to make a number of alterations to include fabricating my own front mounts on the upper tubular control arms to make things work. A factory sway bar will not fit the Ford 9", so another fab job, BUT, you can buy a kit that will work - I just skipped doing that because I had purchased the new rear sway bar and just had to make it work 'cause I could.

Pic #1 shows an extreme angle on the stock/factory upper control arm - no extra lift under the springs. The 3" lifts makes this even worse and pins the control arms up against the crossmember leaving no movement - not good at all.
Pic #2 is my fabricated "no-hop" bar for the Ford 9"
Pic #3 is the bars bolted in place on the 9"
Pic #4 shows the upper control arms I modified and how straight the angle is - so it will pull straight from the crossmember, and not at an angle.


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## GTO Yeah (Dec 6, 2021)

PontiacJim, I always look forward to your posts. Those look great!

Did you use anything to template a starting point for fabrication?


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## Baaad65 (Aug 29, 2019)

I've read some things that you have to be careful with the anti hop bars that they're not to high and hit the body on big bumps but maybe that was with Elcaminos that have the flat bed. If the wheel hop is a common problem as they put these big horsepower motors in, then why didn't GM make the upper arms mount higher or I guess the bias ply skinnys didn't hook so it wasn't much of a problem. I read up on traction fixes in a good article I will post here that focuses more on center of lift which is way in front of the car with the stock lower arms, so that's why I went with the SSM lift bars which lowers the rear of the arm putting the lift point in the middle/front of the car thus putting a lot of weight to the rear planting the tires. And they weren't to conspicuous either.


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## Baaad65 (Aug 29, 2019)

Drag Racing Traction: Rear Suspension: Coil Springs and Four-Link


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## 67lemans (Oct 30, 2009)

Thanks Baaad65 and PontiacJim. It sounds like the issue is the angle of the upper control arms for some reason. Here is a video I found when looking around for a picture, it's poor picture quality but good at describing the process and view of the final result. 
QA-1 NO HOP BARS INSTALLATION - Bing video


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## armyadarkness (Dec 7, 2020)

Did you install spherical bushings on any of the arms? They drastically reduce bind


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## 67ventwindow (Mar 3, 2020)

Alternatively you can install an adjustable upper mount.

https://wildridesracecars.com/product/a-body-upper-control-arm-mount/

From what I have read the G-Body kits can be used with minor changes.









G-Body torque box


G-Body upper and lower torque box set. Spacers included for 3/4 rod ends



merillatracingllc.com







https://doubleaaperformance.com/products/g-body-mat


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## PontiacJim (Dec 29, 2012)

GTO Yeah said:


> PontiacJim, I always look forward to your posts. Those look great!
> 
> Did you use anything to template a starting point for fabrication?



Sure did. I always make/use templates if/when I need to fabricate anything that is not straight forward in easy measuring. So I use a manila file folder/thin cardboard for a lot of things as it is easy to cut out with scissors and shape/modify as needed. I sometimes use a little heavier box cardboard, but harder to cut with scissors so an exacto knife or retractable blade is used and I may cut curves with the scissors.

For the no-hop bars, I began with box cardboard because it is stiffer than the manila file and I needed the rigidity when fitting it to the actual control arms and rear axle. Once I had that about correct, I went to Hobby Lobby and purchased a blue poster board which is 3/16" thick and like a cardboard box material, but more rigid and the color helps when drawing your dimensions on it.

Pic #1 is the first piece in a template - goes from the upper control arm to the top of the rear axle, following the slant on the "pumpkin" section of the rear end. The lower bolt goes through the bar and through the ear on the rear end at the attachment point for the upper control arm. I made the template so as to have the control arm horizontal to the frame at its highest point and then drilled my bolt hole.

Pic #2 I wanted a little extra holding means for the no-hops other than the single lower bolt to the rear end, so I made a template that followed the front lines of the rear end housing and joined it to the previous template. You can see the brown cardboard section used as a template - looks like a dog leg of sorts. I then added the short blue rectangular to extend that dog leg down the front of the rear end case. Keep in mind that there are 2 of these parts for each no-hop, so 1 template is used to make a left/right outer piece.

Pic #3 Here is a finished template with all my dimensions/hole centerline and positions. I made another flat template for the inner plate of the no-hops. You cannot use a matching dog leg piece because of the gear housing in the front of the rear end. The outer panels are outside of the gear housing/center section - so no interference from the housing. The inner template mirrors the hole positions in the dog leg side and is the other side that goes on the ear of the rear end and gets the bolt at the bottom.

Pic #4. I took the templates to a local machine shop and they made my pieces - 2 outer dog leg piece and 2 inner flat pieces. Here is the finished parts.

Pic #5 I bolted my 2 halves to the rear end housing to check for fit. Perfect. But, not done. To make the 2 halves more rigid, I cut/welded a plate across the back of the pieces. Here was one of the reasons I added the dog leg extension. I welded metal tabs (1" x 1" cut square tubing I fitted & drilled) on the dog leg so that I could use a 3" muffler clamp to secure/hold the no-hops in place to prevent any movement of them. The way the base of the no-hop sections sit on top of the rear axle housing prevent any movement by design, but the u-bolt was what I felt as a little extra security in clamping additionally. I cut/welded on my rear plate. Then positioned/tack welded the metal tabs using the u-bolt clamp to locate them, then welded everything up.

Pic #6 Here is one of the no-hop bars all welded together, cleaned-up. and painted. 

The previous photos show the finished product. I can additionally weld the no-hops to the rear end housing, but at this time, I have not gotten all things secured or torqued down until I get the full weight of the body/engine/trans on the suspension and know if I need to make any final adjustments.

With regrads to the note about the no-hop bars hitting the bottom of the floor/trunk, I can only see an issue if you were to drop the suspension down and put the body lower over the rear axle. In that case, my guess is that you would not need the no-hops as you are altering the angle of the upper control arms upward - the same thing the no-hop bars do. The no-hops are probably best used when raising the rear ride height of the car with taller rear springs to get that "look" of the late1960's & 70's. Good springs and shocks are also important and can sometimes in themselves cure the wheel hop problem and then no need for the no-hop bars.


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## GTO Yeah (Dec 6, 2021)

Very nice! It's always good to see how things like this come together. The write-up is very much appreciated! I plan on having my rear an inch or two higher than the front, so I'm sure I'll be referring back to this post at some point to make my own.


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## PontiacJim (Dec 29, 2012)

GTO Yeah said:


> Very nice! It's always good to see how things like this come together. The write-up is very much appreciated! I plan on having my rear an inch or two higher than the front, so I'm sure I'll be referring back to this post at some point to make my own.


I should also add that pinion angle is very important and can be cause for wheel hop. Adjustable upper control arms may be in order, but measuring pinion angle woud be the first thing to do. I have the adjustable uppers, and lowers, so anothe reason I have not gotten all my rear suspension locked down until I make my measurements and check pinion/driveshaft angles.

QA1 has them for the GM cars - which are the same style I see for the GM rear ends. You can see the lower hole below the bushing which bolts to the rear end's bushing ear and then you bolt the upper control arms to that upper control arm bushing of the no-hops. The dog leg fits in front of the rear end's gear case and you have to drill holes in the support ribs and bolt it - same idea I used with my set-up, but used the brackets/u-bolts.






Anti-Hop Bars | QA1


QA1 Rear Anti-Hop Bars relocate the upper trailing arms to change the instant center of the rear suspension, improving chassis reaction and increasing forward bite and traction.




www.qa1.net





Dick Miller does offer the weld-on extensions for the Ford 9" that will raise the upper control arms if you have a 9" under the car.

Here is a really good article that shows the good/bad no-hop bars and the Dick Miller weld-on ears.









Drag Racing Traction: Rear Suspension: Coil Springs and Four-Link


This chapter looks at muscle cars with rear suspension systems using coil springs with two upper and two lower control arms. These cars include GM intermediates built in 1964–1977 (A-Bodies), 1978–1988 (G-Bodies), 1994–1996 Impala SS cars (B-Bodies), and 1979–2004 Ford Mustangs (Fox-Bodies)...




www.musclecardiy.com





Some also have good luck with the Air Lift Drag Bags that go inside the coil springs. They don't require much air pressure and you want them even for the street, and can jack up the right side a little more for racing at the track to give better traction. I do have a set of these on hand I can install just to test if I have any issues. Never used them, but purchased them just to have an maybe play with. They are not "lifting" air bags.






Air Lift 60750: Drag Bag Kits 1964-1966 Skylark All Models - JEGS High Performance


Chevy 1964-66 Chevelle & El Camino Pontiac 1964-66 (including wagon) Tempest & GTO Buick 1964-66 Skylark, Custom, Deluxe, Sport Wagon Oldsmobile 1964-66 Cutlass & Vista Cruiser




www.jegs.com


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## Noangelbuddy (Dec 6, 2017)

PontiacJim said:


> I should also add that pinion angle is very important and can be cause for wheel hop. Adjustable upper control arms may be in order, but measuring pinion angle woud be the first thing to do. I have the adjustable uppers, and lowers, so anothe reason I have not gotten all my rear suspension locked down until I make my measurements and check pinion/driveshaft angles.
> 
> QA1 has them for the GM cars - which are the same style I see for the GM rear ends. You can see the lower hole below the bushing which bolts to the rear end's bushing ear and then you bolt the upper control arms to that upper control arm bushing of the no-hops. The dog leg fits in front of the rear end's gear case and you have to drill holes in the support ribs and bolt it - same idea I used with my set-up, but used the brackets/u-bolts.
> 
> ...


Pontiac Jim,
You said this changes the geometry wrt upper trailing arm and the rear. Did you notice a stiffer, harsher ride due to the no-hop brackets? Please advise.


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## PontiacJim (Dec 29, 2012)

Noangelbuddy said:


> Pontiac Jim,
> You said this changes the geometry wrt upper trailing arm and the rear. Did you notice a stiffer, harsher ride due to the no-hop brackets? Please advise.


I cannot comment on the ride as the car isn't anywhere near completed - just the chassis is done and body set back down on it.

I can't see how that would affect the ride as it is the springs/shocks/bushings/sway bar that would affect the ride. The ride should be the same as the control arms still move up/down. It is the way the control arms "pull" on the crossmember that is affected - which changes the way the car reacts going forward. I do not know how the handling will be affected, but that should be an action of the stiffness of the suspension in general. I have the spherical ball joint ends on the control arms, 3-position adjustable rear shocks, and my sway bar is connected to the frame which will also keep the rear end centered (but could add a Watts crossbar if needed), and is not like the lower control arm attached sway bar like factory. The rear should react independent of the body. Rear springs are stock and kept it this way to hopefully give a good ride. BUT, I may be cursing the car once I take it for a "hard" ride to see how it reacts to a good clutch dump and tight cornering. Then if any issues, I will adjust as needed.

I am no suspension engineer by any means! LOL Just incorporated those things that improve traction and handling as a package - with the aim to plant the rear tires firmly over a corner cutter. Could turn out badly and all my efforts were in vain. But in any case, with the big 3" rear end lift to get my mid 1970's look, I had to move the upper control arms upward. I also drilled new holes in the lower brackets on the rear axle to move the lower control arms up a bit.


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## Noangelbuddy (Dec 6, 2017)

PJ

I am far (very far) from being a suspension expert. I doubt you will be kicking yourself for your work. If it stops wheel hop with negligible ride difference; That would be a good trade off. 

I get your point about the bracket changing the geometry between the real and the trailing arm. My assumption with the QA1 kit is that it puts more force down vertically on the rear; helping to keep the wheels on the ground. However, I would expect that to make for a stiff ride. Just my assumption.

Please provide an update after you get back on the road. I may be looking to copy what you have done. Have not broken my engine in yet, but expect wheel hop in my future.

NoAngelBuddy


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## PontiacJim (Dec 29, 2012)

Noangelbuddy said:


> PJ
> 
> I am far (very far) from being a suspension expert. I doubt you will be kicking yourself for your work. If it stops wheel hop with negligible ride difference; That would be a good trade off.
> 
> ...


Well, I am still a couple years out on my car. Got tied up rebuilding a '48 International box truck which I hope to finally have completed this Spring. Doing body repairs/paint, but cold weather stops all my work as I work in the elements outside. Once done, its back on the Lemans. 

Here is a snipet I pulled from the internet with regards to a 4-link set-up which can be somewhat applied to the rear suspension on most coil spring cars,

"The angle of the top bar (control arm) is the final ingredient to determining how much bite the tire will have, and for how long. _The flatter the top bar, the easier it is to use its pull on the chassis to plant the tire._ It makes sense, since this is the bar that also dictates the Instant Center once the rest of the parameters are set flatter is longer, and longer is associated with greater hook. _The more angular the bar,_ the greater the ‘snapping' force (anti squat) it will apply to the sidewall at the hit, and since it is at a mechanical disadvantage to pull on the chassis, it will generate less load as Instant Center theory dictates."


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## Baaad65 (Aug 29, 2019)

Just ordered the Hook and Launch book today, was searching for some type of brackets like you made to raise the upper control arms without using anti hop bars but haven't seen any. Hoping to get mine to the track this year but I know I won't have the traction popping the clutch with my torque and 9.5" wide tires.


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## PontiacJim (Dec 29, 2012)

Baaad65 said:


> Just ordered the Hook and Launch book today, was searching for some type of brackets like you made to raise the upper control arms without using anti hop bars but haven't seen any. Hoping to get mine to the track this year but I know I won't have the traction popping the clutch with my torque and 9.5" wide tires.


You will like the book as it is pretty good at explaining things and covers the different suspension types. You can use the "old school" ladder bars which also work. The problem with these is that they will put a lot of force at the front of the bars where they mount and that force is trying to lift the car by the frame. My brother had a set on his 67 GTO when we were young and the bars cracked his frame (not sure where) and he had to get the cracks welded up and then removed the bars. The control arm braces may have prevented this (?) as his car was originally an automatic and converted to a 4-speed so it would have not had the factory control arm braces - nor we would have known anything about them back then. So just throwing this out there.

The book will give you some good info and then go from there.


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## Noangelbuddy (Dec 6, 2017)

PontiacJim said:


> Well, I am still a couple years out on my car. Got tied up rebuilding a '48 International box truck which I hope to finally have completed this Spring. Doing body repairs/paint, but cold weather stops all my work as I work in the elements outside. Once done, its back on the Lemans.
> 
> Here is a snipet I pulled from the internet with regards to a 4-link set-up which can be somewhat applied to the rear suspension on most coil spring cars,
> 
> "The angle of the top bar (control arm) is the final ingredient to determining how much bite the tire will have, and for how long. _The flatter the top bar, the easier it is to use its pull on the chassis to plant the tire._ It makes sense, since this is the bar that also dictates the Instant Center once the rest of the parameters are set flatter is longer, and longer is associated with greater hook. _The more angular the bar,_ the greater the ‘snapping' force (anti squat) it will apply to the sidewall at the hit, and since it is at a mechanical disadvantage to pull on the chassis, it will generate less load as Instant Center theory dictates."


Working in the elements. Brrrrrr. I remember those days. You make me feel guilty about complaining about my cramped and cold garage. When will you take a break from helping forum members, pick up some tools and build your own garage?


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## PontiacJim (Dec 29, 2012)

Noangelbuddy said:


> Working in the elements. Brrrrrr. I remember those days. You make me feel guilty about complaining about my cramped and cold garage. When will you take a break from helping forum members, pick up some tools and build your own garage?


Yep, it sucks - rain & cold. I have an odd piece of property which used to be a Boy Scout meeting hall/club house and was not build as a home - block building, cement floor, open truss ceiling, big fireplace, well, septic tank, 1 acre lot with woods. One big open room like a cabin and one reason I purchased it. The house is set back from the road about 100' so people could park in front on the gravel drive. I had inquired many years ago about putting up a garage in front, off to the side of my property. The town people said I could not put a garage in the front of my house - I could attach it to the front and incorporate it into the home, but not free standing in front. I could make it free standing at the back.

My property is narrow, but goes long. I have BIG oaks on the side of my house, chain link fence on the other, septic tank at the rear, and my land has a really noticeable slope as I am kinda on a small mountain top. So the only possible place would be the front EXCEPT my land dips down going from my gravel driveway to the house and I would either have to fill, putting the side of my house under dirt, or dig down where I have gas lines running under ground. So the garage is out.

Town said I could have a 12' x 12' storage shed up front of the house. So I boxed in a 12' x 12' area and had a cement poured. I made it level when it was poured. So I had a nice flat level slab up off the dirt to work on. Several years ago I made an A-frame type awning on top of the slab using free materials from work. Keeps the sun off me in summer and can work in the rain. I could put tarp sides on it, but it really is not large enough to work in with sides. Still not winter friendly, but winters here do not last long.

Until I get my brother's '48 International done, I won't jump back on my Lemans because once I start, I want to keep on rolling with it. Have a ton of parts just waiting to be installed once I get going on the body - which needs it's share of major work. So still a couple yeas out, unfortunately. There is land behind my house being developed - 530 homes on a 52' x 52' lot going for 350K-450K. The entrance runs along the side of my property. My home value just shot up and would not be surprised if some day I get a big offer for my place at which point I may accept it with my goal set on relocating to Florida at some point. Have family already there, BUT, I gotta take all my cars and "stuff" with me so it'll be a small inexpensive place with land and a garage/shop to continue the car hobby.

Here is a pic of the '48 as it sits right now which doesn't look like I have done much but it has been almost 5 years in the rebuild/refurb process and now tackling body repairs/paint which is another major undertaking (7 layers of paint on the box body that have to come off before priming!), and today's view of my '68 Lemans as sad as it may look. Chassis/suspension done and body back on the frame and my 455/TKO keep whispering, "when is it our turn?". And a pic of the huge development right behind my house. My wooded area actually hides it and can't be seen - nor they see me!


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## lust4speed (Jul 5, 2019)

FWIW the '67 and earlier A-bodies are usually good up to about 2" lift before hop shows up while the '68 and newer will run into problems at about 1-1/2". Never figured out why the later cars would wheel hop at a lower height. Always exceptions to this, but seems to hold true for most cars.

I currently run a set of air bags in my '67 street car but solely for carting around extra weight. The compliance of the air bag sucks and they simply work too good in keeping the rear end up. Hitting dips at speeds faster than I'll admit to going has the front nicely compressing and rebounding while the rear with only 12 psi basically feels like a 3/4 ton truck suspension. Will be going to air shocks when the bags finally wear out. I have friends racing with the bags and they drop the passenger side down to 5 psi and take the valve stem out of the driver's side fill. When I was drag racing the car in the late 1980's & 90's I had spacers under the stock rear springs and simply used a somewhat taller spacer on the passenger side and the softest set of shocks I could find. The rear suspension had the same spring rate as stock with the spacers under them and would settle down nicely on acceleration. I had the front raised about an inch over stock so the car would sit about level.


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## armyadarkness (Dec 7, 2020)

Noangelbuddy said:


> Working in the elements. Brrrrrr. I remember those days. You make me feel guilty about complaining about my cramped and cold garage. When will you take a break from helping forum members, pick up some tools and build your own garage?


Yeah... my brakes, front and back upper and lower control arms, coils, and shocks, were all done outside, in the dark, 7 degrees. Of course, in the summer, it's too hot.


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## armyadarkness (Dec 7, 2020)

PontiacJim said:


> Yep, it sucks - rain & cold. I have an odd piece of property which used to be a Boy Scout meeting hall/club house and was not build as a home - block building, cement floor, open truss ceiling, big fireplace, well, septic tank, 1 acre lot with woods. One big open room like a cabin and one reason I purchased it. The house is set back from the road about 100' so people could park in front on the gravel drive. I had inquired many years ago about putting up a garage in front, off to the side of my property. The town people said I could not put a garage in the front of my house - I could attach it to the front and incorporate it into the home, but not free standing in front. I could make it free standing at the back.
> 
> My property is narrow, but goes long. I have BIG oaks on the side of my house, chain link fence on the other, septic tank at the rear, and my land has a really noticeable slope as I am kinda on a small mountain top. So the only possible place would be the front EXCEPT my land dips down going from my gravel driveway to the house and I would either have to fill, putting the side of my house under dirt, or dig down where I have gas lines running under ground. So the garage is out.
> 
> ...


Don't know if you could get away with this, but I put wood chips down, and then a portable garage from tractor supply. Town cant say anything because it's not permanent. It was $500, plus I waited until it was on sale and I had a coupon... took us two hours to build and it has a front and back roll up door. It fits my GTO with a ton of room to spare for tools, jacks, and heavy equipment. Best of all, it stays 10-20 degrees warmer than outside. Works like a green house, and the wood chips insulate the ground.

If you want, I'll send pics.


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## PontiacJim (Dec 29, 2012)

armyadarkness said:


> Don't know if you could get away with this, but I put wood chips down, and then a portable garage from tractor supply. Town cant say anything because it's not permanent. It was $500, plus I waited until it was on sale and I had a coupon... took us two hours to build and it has a front and back roll up door. It fits my GTO with a ton of room to spare for tools, jacks, and heavy equipment. Best of all, it stays 10-20 degrees warmer than outside. Works like a green house, and the wood chips insulate the ground.
> 
> If you want, I'll send pics.


I know what it is. That is exactly my plan when I get the car together to a point I can start it up and move it. I will use what is called "crush & run" which is a gravel like material that when wetted sets up like cement for the floor.

I could extend the sides out, lean-to style, and use tarps as there is a tarp store in Charlotte I have been to. They supply tarps for big rigs and/or any other use in various sizes. This would close it in. I could get a kerosene "salamander" heater as I have used these in the past to heat a garage. But, I just don't have enough time to justify the added expenses as I have way too many projects and when it is cold outsided, I simply move over to another "winter" hobby and get a few of my other things knocked out. I just don't have enough hours in the day and really need to clone about 3 more of myself - except they can't have vocal chords as I don't need to put up with my own sarcasm and bitchin' from a single one of them - 1 of me is enough in that area!


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