Rears Anyone????

[pontiacgp]

Maybe I'm wrong, but that just makes no sense to me. So what you are saying is that the weight of parts that are not being supported by the springs will affect the spring rate? I agree that it might affect the handing a bit because of the weight. But our cars have a lot more weight up front than in the back. And for handling, isn't the '50/50' balance what everyone wants to achieve? And then then adding more wight to the rear help this?

I don't know, I'm not an expert in any way. And I'm not arguing with you. I am just trying to learn as much about suspension as I can.

I know your not arguing and neither am I...50/50 is what you want but with a metric (G body) circle track we never could never get close to a 50/50 even with all the tin we got rid of. We could achieve 50/50 with the lead we put in to increase the back end weight but then the car would be too heavy. We could load up our street cars to achieve a 50/50 but you'll probably have to add about 400 pounds in the back end to get close and then handling won't be a concern cause you won't get enough speed to worry about it....lol

We ran a 7.5 rear end because we had to run what the car came with. We could have if we found one used a 8.5 Grand National rear end but we never had the need for it. We never has any issues with the rear end in the metric and we ran a 7.5 for years. We now run a1980 camaro in the Nascar Whelan super stock series which has the 8.5 rear end and we have broken the flange off of two right hand axles due to the stress of left hand turns so we have a set of strange axles now...I don't know how stock 7.5 axles would have handled the stress since at this tack we are hitting highers speeds than the speed we hit at our old track. There are some metrics at this new track but they all run strange axles

and I just saw your post about the weight of the rear ends...I'll see what I can dig up...

 

[will6318]

pontiac I am curious if you experience is with circle track or drag racing. there is a difference in the rear setups. I want a much stronger rear in drag racing because of the initial hook. unlike circle track racing you are putting enough torque to the rear end in drag racing and hooking so hard that you are lifting the nose of the car. In my honest opinion to build a 7.5" rear is like putting a silk hat on a pig. its a time bomb. 500 to build a 7.5 that is a ? when for 1300-1500 you can have a rear that can take whatver is thrown its way and never have a worry. plus with a third member the ease of gear swapping is a welcome side effect. lol. :lol:

 

[pontiacgp]

will...it's circle track and I agree that a 7.5 won't last too long if your pounding the rear end from a dead stop. What I am saying about a 7.5 is that they are alot tougher than most give them credit for. A ford 9" is strong but it's main advantage is the quick change gears but it is heavier then an 8.5 that's used in Grand Nationals and there are GN's out there doing real quick 1/4 miles with the 8.5

 

[turbo78]

i always answer this question the same way" would you sleep with a hot girl even if she had aids? then why run a 7.5?" being careful might work, but for how long? spending a little at a time and putting together a bitchen rearend may take a bit, but once its done and in, you wont have to worry about it 😀
now i know i probably just started a war with someone that has ran 10.0's or whatever on a 7.5, but theeir luck will eventually run out. reguardless, anything can be broken, just let me try, but if you do it right the first time, you wont be sorry. 😀

 

[pontiacgp]

i always answer this question the same way" would you sleep with a hot girl even if she had aids? then why run a 7.5?"

 

[Bonnewagon]

I'll add that the 7.5 is much stronger than most think. I had one in my Malibu wagon with a 70' Pontiac GTO 400, fourspeed manual trans, 3:23 rear gears. I was not racing but I was not easy on it either. Your rear gear ratio will go a long way to taking the strain off it. With dead 2 series gears, it'll break faster. As allways, fit the punishment to the crime. For a daily driver, it'll last. As you start to pound it, well, you know the rest.

 

[pontiacgp]

G bodies were mass produced from 78 to 88 and most were built with a 7.5. I can not find any recalls or owner complaints about the 7.5 rear end....it is what it is....

 

[Oldsmoletick]

Except for the bolts breaking, causing the rear end to fall out .

 

[pontiacgp]

what bolts are you talking about?

 

[Oldsmoletick]

Control arm bolts, 78-80 and early 81 had a recall on them, built in certain plants and such.