Wouldn't that depend on how much movement the axle had? I am thinking it will be VERY stiff and there will not be all that much vertical movement.

Dep

 

Place the axle at the same ride height as stock and you will find that the pumpkin on the live axle sits lower than the stock differential, think about it, with the stock setup and the halfshafts sticking out straight, the ride height you'd get then would almost be max. droop w/ a live axle and an unmodified frame, there's just no room under the pinion.

 

I wish we had a better view of the underneath of that red Vette with the leaf springs. Doesn't look like he did much cutting under there at all.

Dep

 

Unless I'm mistaken (..... and it won't be the FIRST time..... ), isn't this very similar to what guys ran 25-30 years ago, with those 'budget', solid-mount ladder-bars set-ups with leaf-springs?

I'd think that, as the leaaf expanded/compressed, it would allow the axle C/L to move up/down in a straight-line, where-as the soild-mount ladder bar allowed the axle C/L to swing on an 'arch', based on the front-mount point, meaning it would 'bind-up':
is my thinking correct?

 

Glen, I think the way his is setup it would act a little like both.

The rigid link on the top would cause the the axle to try to arch, but with no connector on the bottom it will try to go down in a straight line.

If enough power is applied with either alot of motor or enough "hook" the spring will load and form an s shape instead of and arch and bind causing wheel hop when it goes thru the cycle of "S"ing and straightening. The only way to control it would be with tire pressure and allowing the rear to spin some off the line.

I'm not knocking his setup, I think it's very innovative considering this is a solid axle in a vette. I remember reading he put this rearend in a long time back and that was probably the suspension technology back then. We are talking about fine tuning the suspension to get the most out it.

 

The only cutting I saw was the rear crossmember in the center and an extended driveshaft loop welded in to compensate for rearend travel.

 

Eddie: Would a set of Lakewood traction bars on that Vette cure any wheel hop? Just thinking it would eliminate spring wrap up.

Dep

 

Dep, I don't know exactly what would work on his setup the way the lower mount is made. Like TT said a few posts back it looks like the rear was setup for a 4 link and he converted it to this.

I don't see anyway to put standard traction bars on it. I can't really tell how much room is under the lower spring plate but he might could weld a connector to it to accept the end of a CE Slide-a Link traction bar.

Personally... I would change the way it mounts to the spring and use a lower connector too and a floater for the axle. Kind of like a modified ladderbar/4-link setup. With enough adjustment on the heim ends and the front mounts strategicaly placed or adjustable, it could be used to set the IC of the car and transfer more weight to the rear for a harder launch and the floater would stop the binding. If the motor he has in it runs as good as it looks it would NEED wheelie bars with this setup.

 

Dep what did Alston Racing have to say about your little project? surely they have answered by now.

Why don't you just carry it to them and let them back-halve this car and be done with it? That way if you do hit the lottery and can afford the aluminum big block the platform will be waiting on it.

Cut the frame right in front of the rear crossmember and let them have at it. Then there will be no working around anything or excuse to do the process anyway but correctly.

I see no need to save any of the rear frame section or the rear compartments / floor. Remember you have already ripped the heater/ AC box out, sold the original engine and transmission and thrown everything else overboard and committed the Vette to drag car only so what's the big deal?

I think the labor cost of trying to work around the obstacles is more costly than buying a complete back half that all you have to do is weld it to the frame rails. I support you in your solid axel decision, but your direction of it being bolt-in has no merit.

The roll bar needs to be a part of the chassis not just a safety bar behind the seat. The chassis will also function much better with an integral roll cage than a simple roof crush safety roll bar welded on top of a stock frame rail. You can get a structural strength in your chassis that will firm up your launch capabilities, especially needed with the four speed you have planed.

I can't see you finding a bolt in rear axel assembly anywhere, you will have to get one fabricated. So while you are at it have it done to work with a real suspension in the back-halved fame. Same cost either way.

If you want to budget something the rear wheel wells and floor can be partitioned at the rear window. Just use a simple sheet of metal from the bottom of the window to the floor just behind the roll bar.This would save some money and possibly weight.

Build your chassis properly to do the work it is intended to do and quit worrying about bolting something inadequate into your car. Do this right and there is a good chance the 302 will be competitive, do it halfazzed and well, it will only be halfast.

As we continue to discuss the merits of a good drag car suspension the main one is good 60 feet times. They don't come from a good engine, they come from a finely tuned chassis.

The car discussed above with the solid axel was put in years ago and technology has evolved greatly since then. That is a nice looking car but is antiquated by todays standards.

It has been 20 years since I ran a drag car and everything has changed greatly. But I can still see that the way to go is not a bolt-in solid axel. Do it right DEP, and have a competitive car. I can't see putting good money into an antiquated system to race. jim

 

Jim, I agree with you on how to do it to be competitive, but for the ones of us that don't want to cut up the back of our cars... the solid axle on springs is a good "halfway" point. It requires only minuimal welding skills and only a basic understanding of tuning a suspension. A person wouldn't have to learn about setting up IC's and setting up preload on a ladder or 4-link. It would be more about bolting on parts and having fun at the strip(not being competative and becoming the next John Force of your local track) with a rearend in the car that you wouldn't have to worry so much about breaking.

Actually most of the parts to do this kind of conversion can be found on the cheap at a local wrecking yard. The axleshafts and axle tubes would have to be cut and some steel stock bought but it could really be done cheap if you do all the work yourself.

If we're talking about a strictly race car and someone who wants to win... then you are entirely correct, but for a dual purpose car and just racing to have a little fun and some excitement in our lives...this is a good alternative

 

When you start to back half a car you damn well better know what you are doing if you plan to actually use it.Yes you need to cut it in half since you will be fully caging it to react with what you are doing. Everyone thinks it is only 60 ft times but that is not correct, It is an integral part of the car all the way down the track and very important how it is set up when you lay on the brakes and chute, everything you set up to launch has to respond well when you are stopping. If it is not right you will have your hands full.If you are going to the trouble and expense to back it Iam assuming you plan on running singles,otherwise whats the point.If you just want to look cool then you can hodgepodge it together and wow them at the cruise,otherwise do it right or leave it alone .I have seen many back cars that are terrible.Now a days it is easier to make hp than hook it. Many cars have a 100 thousand dollar chassis and 20 thousand dollar engine.If anyone wants to know exactly how to do it , be certified to 7.50 and run dead straight everytime I will outline what you need to do and send it to you. Dep I think you have the longest post I have ever seen .Lets clear the air here ,if you wont be running singles dont bother backhalving,

 

on both points!

 

EDDIEJ82, I agree with you, but Dep is looking to hook with a 10k launch using a 302, he needs all of the chassis he can get. If Alston builds it, it will hook. DEP has also thrown the baby out with the bath water, he has gutted the car, It is no longer a cruise car.

As for there being an area for the bolt-in solid axel I agree with you. I stated earlier that there is a need for a solid axel in a C-3 if done correctly and with in reason of need. If I had a double digit automatic bracket car I could see a four link with coil overs slipped into the back of a C-3 using a good set of small slicks to do bracket runs. I can't see using leaf springs though.

Big632, all good points. Yes it is especially needed on single digits, but I see a lot of 12 second cars that need more suspension just as badly and for the safety issue if nothing else.

I also stand by my 60 foot comment being the most important to a good time. You are correct, a tuned chassis is needed all of the way down the lane, and again if for no other reason than safety. You are also correct on the chassis being done correctly and a back-half car or full frame/ cage being done by a professional or knowledgeable chassis builder. That is why I asked about Alston's response to DEP.

It looks like I'm out of this debate now, I can not add any information on DEP's initial request of How to bolt in a solid axel. I'd back-halve it if it were mine and then I would know that I had the chassis I needed to move on up as when I needed it. IMHO jim

 

If you look back a ways at Glensgages post, my car will be basically built the same as his. I am NOT looking for an NHRA record holder. I am NOT racing ET bracket. I am NOT interested in 60foot, 1/8th mile or any other time except 1/4 mile. I am NOT going to be competing for $$$. It will be more a fun thing to do on Sunday afternoon...just like Glen. Heads up trophy racing...it's a hobby...NOT a JOB.

My car is NOT "gutted" in the sense I have removed everything but the
frame, body and driveline. I have removed a lot of weight as far as pollution crap, AC, heater, wipers, etc. I still have a full interior and would like to keep it (minus a heater and AC). I am NOT worried about being streetable, but I also do NOT want a duplicate of a Funny Car.

The launch will be in the 7500 area..not 10,000. Remember, I CAN'T get the parts for a 302, so it will be more like a hot 350-355 LT-1. This whole weight transfer/needing chassis movement thing is overemphasized because the weight will be considerably less than stock, and the suspension is going to be VERY stiff, no matter how it is built. There will be NO "Corvette squat". I don't expect the rear end to move much at all. I have run cars with similar, nearly rigid suspension, and they performed quite well. Wrinkle wall slicks can make up for a lot of the lack of movement in suspension.

Alstons response to me was "bring it in". Unfortunately, that is not an option right now. I have seen Vettes built for S/S class that have had a solid axle installed WITHOUT major surgery to the car. I think that is the route I need to follow.

I apprecaite ALL the suggestionsd made by guys in this thread. They have given me much to consider and have helped my decisions on a number of things.

Dep

 

Dep:

I'm not taking 'my' project THAT lightly.....


My 'plan' is to win as many rounds of competition in the Florida Corvette Challenges Series (along with other bracket races ) as I can when I reloacte there, and 'my' thinking is this:

a vast-majority of the Corvette Challenge Series racers have C4/C5/C6 cars with rear-suspensions NOT designed for drag-racing, build 500+ HP into them while running ET Streets or BFG Drag-Radials, then 'wonder' why their cars can't hook with such little sidewalls, resulting in inconsistent ETs and dial-ins
(remember, all C4-up cars have 16"-or larger wheels, meaning they probably have less than 5" sidewall per-side, and NOBODY makes a 'true' 16" or larger drag-racing slick, either ).....

'MY' thinking is if I run a pump-gas, 400-425 HP 355" SBC, yet put 32"-tall by 14"-wide (on 15" wheels, which is the 'standard' wheel-size for 'true' slicks ) slicks hung from a 9" Ford, under a C3, with a chassis/suspension built with one goal in-mind:
to plant thoses slicks each-and-every run, no-matter if the hot Florida sun draws the oils to the surface of the asphalt.....

it'll be deadly-consistent in 60', 660', and 1/4-mile ET, resulting in a better chance of winning at bracket racing.

Will it be relatively-slow, compared to the competition?
Of-COURSE.....

Will it be over-kill to the maximum degree?
Yes.....

Will it provide bullet-proof durability (i.e. NO-breakage )?
Probably.....

Will it give me the best chances of winning?
BET YOUR AZZ!!!!!


Besides, when I become an 'old-fart' (oldER fart? ), I can use this car to terrorize the NCRS-guys at car-cruises and Corvette Shows.....

 

Glen I went to the Corvette Chalenge Nationals in Akin, SC last year and there were some fast cars there that were hooking very well of the C4-5 variety. Yes, alot of them were running 16" DR's and ET's... those tires hook alot better than you would think (practicly dead) and a good number of the field was deadly consistent. They can even stuff more meat under the rear wells than we can. The fastest car there was a C4 with a straght axle. Watch Em, there wasn't many push overs in the group I saw.

I like the terrorizing thing... That's funny

 

EJ82:

Ain't taking, nor did I mean to take, anybody as a 'push-over' on the race-track.....

Gotten my pee-pee whacked TOO-many times by guys who didn't 'look' like they could've beaten me for that.....


Even if they (C4-up racers ) put 12"-wide DRs and ETs under those cars, I'd guess they'd have a foot-print 10" long by 12" wide, for a total of 120 square inches:
the 32" x 14" slicks have a foot-print of approx (front-to-rear weight and PSI will determine the exact sizes ) 14"-wide by 12" long (front-to-back ), for an area of 168 square inches.....
that's 40%-more foot-print!!!!!

At-best, a C4-up car most-likely has 6" of sidewall (if he runs 28" tires on 16" rims) per-side:
I'd have 8"+ per-side (32-15=17 div/by 2= 8.5) to 'wind-up', then spring the car forward, cushioning the initial 'hit'.....

They'll have a highly-advanced sports-car type suspension, while I'd have a purpose-built, 4-link suspension.....

"Most" of those guys worry about the all-mighty ET first, last, always and only:
I sit in my car, wearing a helmet and belts, practicing my Reaction Times on a 'practice tree' device several times a week, in the pits on race-day, and in the staging lanes before each run.....

If I can consistently cut .015-.030 Reaction Times and run with-in .02 of my dial-in (remember, with tires THIS big, and power THAT-small, 60' times 'should-be' VERY consistent ), the guy who runs .05 slower than his dial-in CAN'T hit the stripe before me without breaking-out (running quicker than his dial-in ):
in-effect, he'd be 'locked-out' of winning that round of competition.

This is just 'MY' thinking on the subject.....

 

Glen: Oopsy...forgot you were running ET
But I feel the same way about NOT back-halving and spending a zillion dollars for a car that WON'T be running in competition that needs that level of modification. Like you, I want "bullet-proof durability" in the rear end. Not necessarily a rear end/chassis setup that will turn 9's. No way I'll ever come close to that. Just something that won't leave me worrying if u-joints and axle stubs are going to ream out my a-hole

Dep

 

He Glen will have to back half if he wants 14inch x slicks under it. I think his plan is very sound and he will have a great back end to handle more down the road if he feels the need.

 

Mike: You are right!!! I thought he was talking about running 9-10 inch slicks in back previously. WTF.....14 inch....NO WAY HOESAY!!!

Dep