Author Topic: rear suspension drag racing  (Read 27610 times)

Offline csajerreb

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rear suspension drag racing
« on: November 14, 2009, 05:52:20 pm »
hi i have a 77 shortbed, with a pretty stout small block to much to list. i haven't dynoed it yet but i should be in the 400 to 425 hp range. the truck has a worked 400 turbo,3500 stall converter, 373 locked rearend. it is lowered 4". it has 265 60 15 tires and a stock rear springs. i have removed the twin tanks and replaced them with a fuel cell in the rear of the bed. i have also relocated The battery to the bed as well. i have removed at least another 300 lbs off of the truck.
my 60 ft times are horrible due to no traction. i roast the tires clean into 2nd gear without trying hard, no matter what i try. once i hook it up it flys. i was only able to get a 14.1 out of it. i am sure i can do better. i know i need a set of cal tracs, some 90/10 front shocks, and a set of slicks or street radials. 2 questions. has anyone had any luck removing all the spring leafs except 1 instead of replacing them with a new race spring? i would sure like to get some weight transfer going. also anyone with a similar setup have you found a tire height that works good in the 1/4 mile?i think a taller tire would help. mine are 10 wide x 25 tall.

thanks jerry

Offline VileZambonie

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Re: rear suspension drag racing
« Reply #1 on: November 14, 2009, 06:14:53 pm »
Actually, I did the exact opposite with my leaf system. I beefed it up with new leaves and flipped the axle. I'm putting the Caltracs but removing leaves will only hurt imo. Your next best bet is a link system. The reason I didn't go that route is bc down the road I am building a custom frame/chasis and just plopping the body on it. So for now the leaves work and don't interfere with the way I ran my exhaust. I have a posi and drag radials and hooking up is hard to do with the bb
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Offline csajerreb

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Re: rear suspension drag racing
« Reply #2 on: November 16, 2009, 06:34:32 pm »
That one surprisws me, i figured weakening the springs would help drop the ass end for some weight transfer when i launch.all my cars before were coil springs, leaf springs are a new animal for me. sure wish i could aford to narrow the rear and put a 4 link in! thanks for the info.



jerry

Offline campcrf

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Re: rear suspension drag racing
« Reply #3 on: November 16, 2009, 10:35:01 pm »
csa.... I am so glad you asked that question because I am haveing the same problem (500hp 383 and the best i did was 13:7). My truck still has the just the lowering leaf springs and belltech shocks.  I just bought some competition engineering (morosso) cal-tracs (slide-a-links), but havent installed them yet.  Please let me know what you end up doing and I will let you know what these bars do aswell....  hopefully some more ideas get posted.....   cant afford a 4 link yet.
-smile-... Just because its contageous

Offline SUX2BU99

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Re: rear suspension drag racing
« Reply #4 on: November 17, 2009, 10:09:28 am »
In my opinion, removing leafs is a bad idea too since you are also promoting a situation for more spring wrap. Your wheelspin might turn into serious wheel hop and you could start busting things. HAULIN IT on here built is own Cal-tracs. He posted a thread on it somewhere. Maybe look for his rear end thread.
85 Chevy Silverado C10 short, wide, yellow, 2wd. Lowered, 60-over 350 with Dart Iron Eagle heads and Comp Cams XE268 cam, TH350 w/ shift kit, 3.40 Gov-lok 12 bolt.

Offline HAULIN IT

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Re: rear suspension drag racing
« Reply #5 on: November 17, 2009, 06:12:36 pm »
Guys, Your biggest factor is tires! Good sticky tires are a must...Not to bust on you Jer, but a 25" tire? There are several good tires to pick from, but ET Street Radials are what many guys are using (me included) with good results. As for the spring thing...You want the front stiff & the back soft. Calvert makes what is called "Split leaves" (the front is heavier than the back, they over-lap under the U-bolts & are held by the center pin & extra band type clamps.
 For what it sound like you guys got going, stock springs should work fine.
 The original rear set-up I had (stock springs w/over-load removed & one, simple clamp, old-used Monroe shocks) was good for mid-high 1.60's 60'.  At one track in particular it would wheel-hop some which led to the newer set-up. Still stock springs with homemade traction bars...Good for a 1.52 & 1.53 60' last weekend. These trucks can hook, it just takes a little effort.
 The post Sux was referring to is in the "Members Projects" section.
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Offline campcrf

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Re: rear suspension drag racing
« Reply #6 on: November 17, 2009, 08:02:51 pm »
csa...  dont mean to jump int your thread, but we both have the same problem. thank in advance...lol
  Haulin...  thanks for the info.. I am running a 295/50/15 cheap tires, so i guess I'll put some street slicks on and the comp eng. cal tracs and hope for the best...
  csa... what are you planning on doing now?
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Offline oldredtruck

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Re: rear suspension drag racing
« Reply #7 on: November 24, 2009, 11:01:30 am »
 glad I found this thread -
same probs here - that little ramjet motor boils my tires ( 29 x 12.5 Hoosier pro streets - not a drag tire by any means) no prob - if I could get her to plant I know she'd squirt ahead alot quicker and quit roasting the tires...
I remember when I was building the truck that Alston or someone had a "Pro-Street" 4 link back half for the 73-87's - but I can't seem to remember where I saw it...If I can find one, it's goin in! -all the power in the world but no way to get it down is useless.
85 shortbed...She digs it...

Offline team39763

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Re: rear suspension drag racing
« Reply #8 on: November 26, 2009, 04:41:48 pm »
There's a guy down here in Texas that has the Alston Ladder bar setup in his squarebody truck.  If I remember correctly, that truck hooked pretty good.  Last I seen he was running a 454LSX with nitrous and it was running in the 10's.  It must work good to hook that kind of power.
  If you're looking to keep it simple, cal-tracs seem to work pretty good.  But like they said, you need some sticky tires.

Offline csajerreb

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Re: rear suspension drag racing
« Reply #9 on: November 28, 2009, 02:23:35 pm »
  hey guys thanks for the advice!! after looking at my options i figure i don't have enough motor or money to make the investment in a 4 link setup. i will keep it simple go ahead and get a set of slicks for the track. my tires are actually 28" tall they are the same setup i bought the truck with. (before i got it, it was all show no go). i have improved everything except the rear suspension. looks like i can find allot of 10.5 slicks and rims pretty reasonable for now. remove the overload spring,add cal tracs and 90/10 shocks.that should get me started. if i can get it to hook up from a 2.3 to a 1.5 / 1.6 with this setup i will be a happy man. then i will look and see about a set of split leaf springs ( if needed). maybe a different set of wider/taller rims and tires. it looks like i can get at a 12" wide tire no problem. with the correct backspace i may be able to squeeze in a 14" without tubs. by the looks of haulinit's picture its hooking up pretty Dang good on stock springs and what look like maybe 10" tires.

thanks again, jerry

Offline oldredtruck

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Re: rear suspension drag racing
« Reply #10 on: November 30, 2009, 09:35:42 am »
 cal tracs and mono leaf  after looking seems like a great option...I'll let ya'll know...
great thread!!!!
85 shortbed...She digs it...

Offline team39763

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Re: rear suspension drag racing
« Reply #11 on: November 30, 2009, 10:12:13 am »
About how much would that split leaf setup cost?  Anybody know?

Offline Captkaos

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Re: rear suspension drag racing
« Reply #12 on: November 30, 2009, 11:35:37 am »
the split mono leafs are $338 + shipping.