Hooking up an A Body Mopar

[bill dedman]

My bracket car needs help, but I'm not sure which way to go with rear suspension mods, and since the Stock Eliminator '67-76 A bodies with small blocks are very similar to what I run, power-wise, I thought I'd ask for some advice on making this thing hook.

Here's the car's specs: 904 Torqueflite-equipped 1972 Plymouth Valiant 4-door (just 14 pounds heavier than a '72 Duster, so should be very similar chassis dynamics; same 108" wheelbase, etc.) Race weight with heavy-*** driver 3,600. Engine is a near-stock, Vortech supercharged 360 Magnum running 10 pounds of boost; chassis dyno says 445 RWHP at about 5,500 rpm and and 470 RW torque. Redline is 6,000 for reasons of longivity. Best 1,000-ft. e.t. was 9.74 @106 mph. Best 1.8th-mile (same pass) was 7.59 @94. Those were with minimal bite (1.81 60-ft. time) No quarter-mile times available, but that equates to approximately 11.85 and 116mph, 1/4-mile.

The rear is an 8.75" Auburn Sure Grip, (new.), and the ring and pinion I have for it is a 4.10 ratio (will be installed, soon.) The times I gave you were done with a 3.55.1. The 4.10 will go in as soon as the Moser axles get here. No spool, just a NEW limited-sliip.

New slicks will be probably 28" tall. That will put me at the finish line of the 1,000-foot strip I run, just under the redline with the 4.10 gear. The tires I had when I ran it with the 3.55 were 26"-tall, B.F. Goodrich T/A Drag Radials. No burnout. No traction, either. It spun all the way through 1st gear, no matter what, but it was only 48 degrees... so, maybe that was why the VHT didn't seem to work.

Anyway, the 1.81 60-foot times I turned won't get it. Wheelspin is my enemy, so I need some advice as to which way to go with the mods.

What I have in use, currently insofar as "traction aids" are: stock, 5-leaf rear springs with three clamps each side, on the front section; pre-load air bag on right rear; adjustable pinion snubber, 1/2" gap; 90-10 shocks up front with stock torsion bars. KYB Gas-Filled shocks in back, non-adjustable. 8" wide BFG T/A drag radials at 16-pounds, on 7"-wide, 15"-diameter Centerlines. Spin city...

I know the tires have to go, and I am not averse to buying REAL drag slicks from Hoosier, or M/T... or, whoever, but this car has very limited lateral wheel-well dimensions (not like a Duster, which has more room), so they can't be 10.5's... those would hit everywhere, I'm afraid. They DO need to be 15"-wheel size and 28"-tall... no exception, because of the wheels I have and the gears I'll be running. Other than that, manufacturer and width can be anything, within the "fit" parameters, width-wise.

What I REALLY need to know is this: Is it possible to get this car to hook WELL, with "old-technology" super stock springs, or do I really need to bite the bullet and buy a set of Cal-Tracs or Slide-a-Link bars? This engine pulls really hard at low rpm's and will generate some reasonable (1,60?) foot times IF I can get it to hook.

I'd prefer NOT to have to put Cal-Tracs (or, the others) on it if I can get by with just the S/S springs as it's a street driven car and I really don't want all that hardware hanging down in view unless it's totally necessary. But, I WILL go that route if I have to. Also, will Cal-Tracs work with my stock springs (if I have to go that route), or should I use Cal-Tracs AND S/S springs??? I'm pretty ignorant about this stuff, as to what to use.

Can some of you A-Body Stocker gurus tell me which route to take with this thing? I'm lusting after a launch like the A-Body cars that run well in F, G, and H/SA bring to the strip, and am willing to spend a few bucks to get it. It's just a bracket car, so it will end up with a fiberglass hood, bumper, etc., and already has two big batteries in the trunk; none up front (the blower occupies the old battery space.)

It's a shame to have the power to go low-to-mid 11's in the quarter and barely be able to break 12-flat because of traction problems.

Any help on this issue would be greatly appreciated.

Recommendations, please.... ????????????????

Bill

[herbjr]

Quit screwing around and put the Calvert, mono leaf, rancho shocks and bars on. We did that on our car,

3800 LBS
12.05 108.00 1.52 in 60 foot first time out. Made 8 runs within .003 in 60 foot. My first set of mono leaf cal tracks set and I love them.

Its a Dodge Coronet Wagon. Or Ill sell you my SS springs off our duster so I can put the Mono's on that car.

Its a stock crate motor 360, 5.13 gear dana.
Herb Jr

[George Mirza]

Some of us are still using SS springs, but the Cal tracs are the way to go on an all out race car. For a few hundred bucks you can try 3200# or 3400# SS spring, Mancini Racing has a good selection. Make sure you get the aluminum front eye bushings and lube them up well so they pivot easily on the hanger bolt. Get some 2 and 4 degree pinion shims and try them to see what works best. These go between the spring perches on the rear end and the springs. Most guys are using the Rancho 9 way adjustable shocks, get the ones for a Dodge truck, or you can use a stock shock with a shock extension on it. Make sure the shock has enough travel and does not limit the amount the rear can drop. Simple way to check this is to put the car on jack stands under the frame and disconnect the shocks and let the rear end drop as low as it can go, then see if the shocks extend past the lower shock mount. Throw the pinion snubber away, if the springs work it will never touch the floor.

Now that the rear is right it's time for the front, I won't get into it, but 6cyl torsion bars or the Mopar drag bars are a good choice. V8 bars have to much spring and will unload the back tires and cause spin after the launch.

Good luck, let us know how it works out.

George Mirza 1236 E/SA '71 Duster

[Jeff Teuton]

Send me the chineese ss springs. My anchors have been eaten away by the salt water for my boat. Get the Cal Tracs;, mono leafs, shocks, and go fishing. 1.81. That's really bad.

[bill dedman]

Thanks guys.... Cal Tracs/mono-leafs it is... I won't waste my time with the "old" technology this time.

John Calvert is a genius, I guess....

For right now, I'll leave the front torsion bars in; that'll be a project for next winter. I think they're the 340 bars because this car was originally a 318 with factory air. I think they put the 340 bars in those cars.

I have them "unwound" to the extent that the rubber bumpers are just touching (set very low.)

Any suggestions on tires? I need something S-T-I-C-K-Y.... I'm tired of these turbo Buicks eating my lunch...

Thanks again to all of you for all the good advice!!!

Bill

[Qwik426]

"I won't waste my time with the "old" technology this time.

John Calvert is a genius, I guess...."

John's "new" technology ain't exactly new. It's been around a while. But I do get your point.

[bill dedman]

Well, I think it's newer than the S/S springs... lol! That's all I meant.

Now, I need some 28"-tall, 9"-wide, 15" wheel-diameter slicks that are really sticky...

Got any ideas?

Anybody??


Bill

[X-TECH MAN]

Originally Posted by bill dedman

Well, I think it's newer than the S/S springs... lol! That's all I meant.

Now, I need some 28"-tall, 9"-wide, 15" wheel-diameter slicks that are really sticky...

Got any ideas?

Anybody??


Bill

Bill....We always had great life (over 100 runs) and luck with 9 inch "WHOS-YER-DADDYS" . They were 92 and sometimes 94 inch radials on 8 1/2 inch wide rim. 1965 Plymouth IHRA crate motor car. 3730 lbs with driver and a 116 inch wheel base. 2.75 low gear 904 trans.(found that Turbo Action trans and converter was about a 10th better than all the others tried) 4.88 rear and S/S springs. cheap no name rear shocks. NEVER spun a tire. wt distribution 49/51. car ran as fast as 11.38 in K/CM. Ran 11.60's and 70's in bracket mode every where. 6700 RPM shift points. Stock V8 torsion bars in the front. Got tired of readjusting the bars when we ran the 6 cyl versions. Never used a 2-step. Always foot braked.

[bill dedman]

Terry,

Thanks for all that GREAT information!!!

As you may, or may not know, A-Body sedans have smallish wheel well rear wells, and my Valiant is no exception. I really don't want to have to mini-tub this old crate; I think I can get by without that aggravation by running a 28"-tall, 9-inch-wide tire if I can find one with the right compound. The tires you were running won't fit this thing. I'd like to know what compound you had on those Hoosiers. I'd buy a pair of Hoosiers in a minute if they had a set 28"-tall I could use. That's an 88" rollout.

My setup is rpm-limited; the chassis dyno showed that power falls off really rapidly after 5,600.... I think the engine is outrunning the blower about then, and boost goes from 10 pounds down to about 6 as it approached 6 grand, so I'm gearing it accordingly. That's okay; it'll live longer that way, and this is my daily driver.

Thanks again for all the tire and suspension info. I think before I spend a bunch of $$$ on Cal Tracs, after thinking it over, I'm gonna put some really good tires on it and see how it hooks. If it still spins, then I'll attack the rear suspension with a vengeance...

Bill

[X-TECH MAN]

Originally Posted by bill dedman

Terry,

Thanks for all that GREAT information!!!

As you may, or may not know, A-Body sedans have smallish wheel well rear wells, and my Valiant is no exception. I really don't want to have to mini-tub this old crate; I think I can get by without that aggravation by running a 28"-tall, 9-inch-wide tire if I can find one with the right compound. The tires you were running won't fit this thing. I'd like to know what compound you had on those Hoosiers. I'd buy a pair of Hoosiers in a minute if they had a set 28"-tall I could use. That's an 88" rollout.

My setup is rpm-limited; the chassis dyno showed that power falls off really rapidly after 5,600.... I think the engine is outrunning the blower about then, and boost goes from 10 pounds down to about 6 as it approached 6 grand, so I'm gearing it accordingly. That's okay; it'll live longer that way, and this is my daily driver.

Thanks again for all the tire and suspension info. I think before I spend a bunch of $$$ on Cal Tracs, after thinking it over, I'm gonna put some really good tires on it and see how it hooks. If it still spins, then I'll attack the rear suspension with a vengeance...

Bill

Sorry Bill....I forgot the dart/valiant had the small wheel wells for a moment. If the 88 roll out 28X9's will fit go with that. The smaller the diameter (roll out) of the tire the less traction you will have with a given tire width. The best we had used with an automatic was the Hooziers. I will check the compound (I forgot) when I get the chance to look. Maybe tomorrow evening? As far as the PSI on the blower it sounds like your heads need some work or the cam is way to short (wrong overlap, Duration). The blower will calm down the cam. Most street boosts on pump gas are around 5-7 lbs depending on compression like on the B&M 6-71 style blowers when using PUMP gas. . Are you using a "Blower" style cam? There is a difference. Ive only played and built some MARINE blower application engines (Not drag race) several years ago and had comp cams (talk to Chris Pagent) grind me some hydraulic roller cams for lower RPM use for the thunder boats (5200 RPM).They were 502's and made 753 HP on one engine and 752 HP on the other engine on the dyno with marine exhaust maifolds at 5250. 8. 8 compression, 5.3 lbs of boost, no intercoolers, pump gas, ported heads (square ports-Ive preped cylinder heads since 1969). Ran 107 MPH in a 1994 (non stepped botom) 42 ft Fountian boat (10,000 lbs plus-lots of beer on board) on the river. What Im trying to say is you need to have the right heads and cam to use the full benifit of a blower. Hope this helps in some way. Terry