Opinions on what to buy to lower ET...

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flyfish

flyfish

C8H18+N2O = :-D
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I have some money earmarked for the car and I can’t decide what to do with it. Currently the car runs fine and hooks hard and pretty consistent. Current times are in sig. Here is the combo:

410 small block, 10.8:1, pump gas, ported Eddys, small solid roller (248/254 duration @ 0.05 with 0.576/0.582 lift)
Victor intake, 750dp, 727, 8” converter, 4.10 gear, 3200#’s, stock suspension with drag shocks and a snubber.

I was thinking of doing one of these, but I only have money for 1…not both.
1. Buy new 950 carb to replace the current carb (650dp with a 750 Proform main body, so basically a 750dp).
2. Get full Caltrac setup with mono springs.

IDK, I think the car would benefit from both, but there is only money for one at the moment. Any help would be appreciated.
 
SS springs + hangers or sliders ... snubber if it's a stick. probably cheaper than caltrac
auto you probably dont need the snubber

not a fan of the caltracs, according to Ma par the springs are supposed to wind up a bit absorbing the shock of the launch so that the axle tubes do not twist/stress crack; the snubber limits the travel. if you put spring clamps/ladder bars/etc that prevents the spring from twisting at all it puts all the stress to the axle tubes.

the SS springs and hangers are like $250 + $100 something. caltrac kit is $340 and the springs are another $380

that being said the 8.75 will probably handle it if you go caltrac, i'm guessing you are at about 550hp

on the carb upgrade, maybe there is a way to get 800-850cfm a bit cheaper if some others want to chime in.

that way you could do both upgrades. fresh SS springs + fresh carb
 
I have a 850 on my 10.0-1 pump gas motor and it seems happy. Will turn 7K which I am now finding out can be a bit hard on the valves / guides / seals. That 1.49 looks pretty good to me with those smallish tires. Work on the top end MPH = HP.
 
Holley "flat top" 830 NASCAR carb. The 340 had the same carb but a 750. Both work great.
 
In the 1/4 mile its running 122+ MPH on a regular basis. Tires are 28x11.5 Hoosier QTP.
 
the 950 holley really only flows around 800-830 cfm...and your proform main body is pretty close to that..


I would spend the money on the cal tracs....
 
I'd put caltracs on it. Been involved with a bunch of cars, going from ss springs to tracs and only one didn't improve (wasn't the caltarcs IMO, it was the owner refusal to change front end settings). My friends 10.50-10.60's Cuda went from 1.43 to 1.39 60's with better consistency and flatter/level front attitude on launch. No more twisting up as with the ss springs.

Look through the Stock Elim mopar cars, you won't see many ss spring cars anymore.

Anything that absorbs or softens the stress on axle tube twist is wasted motion. Anyone that's run SS springs successfully will tell you that a snubber can go over to hold the door open, clamp the crap out of the front segments to get rid of wrap up, the opposite of what some references say. Along with aluminum front eye bushings, again more solid transfer of energy.

Will and can SS springs work OK, sure they can. Are they my preference, nope.

The carb, can you borrow a 950hp to try? The 950hp is an AWESOME WOT carb. Seen 10+ HP increases with an OOTB jetted 950hp over custom prepped 950hp carbs. They work real well. If you drive it around town or cruise, they are silly rich on cruise.
 
crackedback said:
I'd put caltracs on it. Been involved with a bunch of cars, going from ss springs to tracs and only one didn't improve (wasn't the caltarcs IMO, it was the owner refusal to change front end settings). My friends 10.50-10.60's Cuda went from 1.43 to 1.39 60's with better consistency and flatter/level front attitude on launch. No more twisting up as with the ss springs.

Look through the Stock Elim mopar cars, you won't see many ss spring cars anymore.

Anything that absorbs or softens the stress on axle tube twist is wasted motion. Anyone that's run SS springs successfully will tell you that a snubber can go over to hold the door open, clamp the crap out of the front segments to get rid of wrap up, the opposite of what some references say. Along with aluminum front eye bushings, again more solid transfer of energy.

Will and can SS springs work OK, sure they can. Are they my preference, nope.

The carb, can you borrow a 950hp to try? The 950hp is an AWESOME WOT carb. Seen 10+ HP increases with an OOTB jetted 950hp over custom prepped 950hp carbs. They work real well. If you drive it around town or cruise, they are silly rich on cruise.
Click to expand...

Yes, this is one of the things I thought the Caltracs would help with. Currently, my car twists up on the launch with the driver side front tire WAY higher off the ground...but it hooks hard. I was hoping that by getting rid of the wasted twisting motion it would 60' better.

I have no desire to try SS springs, I like my car low, in the weeds. My current springs are VERY old stock springs that are pretty much flat as a pancake.
 
What do you average for 60' time now?

The front end is important too. Do you have the travel to take advantage of cal-tracs? What are you using for shocks in the front?

My car runs very consistent low 7.50s, and 60' averages 1.54 with the cal-tracs, springs, and their shocks. I have tweaked on it a fair bit, but I am sure there is more in it. Kind of lost incentive to find it since I run 12.00 and 7.50 index and the car seems to run that all the time.
 
crackedback said:
Anyone that's run SS springs successfully will tell you that a snubber can go over to hold the door open, clamp the crap out of the front segments to get rid of wrap up, the opposite of what some references say. Along with aluminum front eye bushings, again more solid transfer of energy.
Click to expand...

Would it be possible for you to put this a different way? I'm not disputing this or criticizing, I just don't understand what you are saying here and would like to.
 
No problem Steve.

Snubbers are not required on well set up SS spring cars. They clamp the crap out of the front segments to get rid of wrap. Snubbers are a band aid. The first thing I do is tear snubbers off serious race cars, clamps control that stuff. I also don't generally subscribe to the rt/lt spring set ups. I HATE the lean. I've run two left springs on a car (common) and had one with two rights at one time.

Think of the front spring segment, axle center to spring eye bushing, as a lever arm. Basically want the lever arm to be like a solid bar. Wrapping springs, a bowing right behind the front spring eye, takes rotational energy, energy that could be used to plant tire, classic Mopar chassis separation. The pinion wanting to climb up is the force that's being applied. Rubber front eye bushing will have the same effect, it crushes, energy taken to crush the bushing, isn't transferred to the tire or chassis. I've had ss spring cars require as much as 10* down pinion to get them to hook, that's a LOT of slop... Solid good SS spring cars maybe 6* down, cal trac cars 3* ( easier on u-joints too)

Don't get me wrong, I don't mind SS spring, would run them if given to me, but won't spend much money on them.

The other factor in all this is shocks. People cheap out on shocks. IMO, shocks, like converters in auto cars, are one of the single most important items you can apply to a drag car.

I don't want to hijack Flyfish's deal here. Front end is just as important as what's out back.
 
LXguy said:
What do you average for 60' time now?

The front end is important too. Do you have the travel to take advantage of cal-tracs? What are you using for shocks in the front?

My car runs very consistent low 7.50s, and 60' averages 1.54 with the cal-tracs, springs, and their shocks. I have tweaked on it a fair bit, but I am sure there is more in it. Kind of lost incentive to find it since I run 12.00 and 7.50 index and the car seems to run that all the time.
Click to expand...

In the summer on an average day, it runs 6.93 with 1.50-1.51 60' with dead hook. This puts the driver side tire a little over a foot off the ground and the passenger side about 3-5 inches off the ground. The car always goes strait as an arrow, but it looks funny on the launch. Front shock are comp engineering 90/10, and I have LOTS of front end travel.
 
You wanna buy a 830 double pumper Holley with choke tower but never had a choke? I'll sell it to a fellow fishdriver for $200 plus the ride. Can get numbers tonight if you are interested. It came with the Demon I just got and that's all I know about it.
 
Wow.

I'd say the car could definitely benefit from the Cal-tracs, and if ET is your benchmark for a decision, I'm pretty certain that your car would go quicker/faster by adding the Cal-trac vs. the carburetor. I would not be shocked to see your 60' improve by .4 - .5 after some tweaking - certainly you're making the power for it.

How much it will help with the twisting is hard to say. My car leaves with the drivers side very slightly higher than the passenger side. When I was only pulling the driver wheel about an inch or two the passenger side was barely on the ground still, but I'm not making close to the torque you are, and I only have subframes/no bar. Could I tune that out a little messing with the preload? Maybe?

I assume you've got a roll bar and subframes and all that?
 
LXguy said:
............

I assume you've got a roll bar and subframes and all that?
Click to expand...

Yes.


Airwoofer -- Thanks for the offer, but I have a specific carb in mind if I go that route.
 
-I would say before you spend on anything else, get the bdy to stop twisting that much. If it doesnt come up eventhat's one thing, but if there's really a foot difference between the two front tires, fix that. Then work on tightening the rear suspension, and you'll see more overall benefit in terms of ET drop and consistency from a set of top of the line adjustable shocks than a carb.
 
Solid bushings in front spring eyes?

There are cars running almost .1 faster in 60's that are the same or slightly slower et. Low 1.40's, 1.40-1.43. There's a bunch of time in that window alone. Brian's Duster went 1.43 60's with that magazine 480hp/510tq 410 stroker, a cheap shelf Hughes 10" 3500 converter (pushed through at 3200), 4.56's on about the same tire as you and around 3350#, 6.93 at 96ish.

Whether the converter is right is only something you can dicker with. It's a bit of a crapshoot. It wasn't uncommon for us to got through 4-5 converters getting it right.

I wouldn't be surprised if the car picked up .05 in 60's with a better rear set up under it.
 
We'll find out how much the rear end matters in the 60 when I get my stroker in the Demon. It is a stripped down coilover ladder bar car. Has a 4.10 spool which isn't much different than the 3.91 SG, and I will be putting my 275 DRs on the Demon's 10" wheels.

Yeah, I can see getting 0.05 better with setup. His 1.49 creams my fish's 1.65 but it had a 2500-2800 converter.
 
I have almost the same engine(410)just different cam,carb,rear setup.Lastyear I switched to CalTracs,mono-leafs(with solid spring eye).My cars 60ft dropped from 1.50 to 1.44,runs 6.71@102mph in the 1/8 and [email protected] in the 1/4.My car also used to lift the drivers tire more than the pass,but both lift the same now.I also run QA-1 12 way adjustable on all 4 corners.Buy the Caltracs,mono-leafs this year,save for a new carb nextyear.My AED 850dp flows 930cfm.:D
 
pettybludart said:
I have almost the same engine(410)just different cam,carb,rear setup.Lastyear I switched to CalTracs,mono-leafs(with solid spring eye).My cars 60ft dropped from 1.50 to 1.44,runs 6.71@102mph in the 1/8 and [email protected] in the 1/4.My car also used to lift the drivers tire more than the pass,but both lift the same now.I also run QA-1 12 way adjustable on all 4 corners.Buy the Caltracs,mono-leafs this year,save for a new carb nextyear.My AED 850dp flows 930cfm.:D
Click to expand...

Hey Pettybludart, Yes your car has a little bigger cam, a little more gear, a bigger carb, and a 904 trans....I wish I had a 904 (jealous), but that's a whole other thread topic.

Nice gain on the CalTracs! This is the kind of gain I'm hoping for (about 0.05 ish). I have a friend at my local track with a Charger that will 60' in the 1.47's in the heat of the summer (when my car is doing 1.51)...We have almost the same dial in most of the time (mine is a few hundredths quicker usually) and when we race each other he always kills me out of the hole. I real him in down track, and usually about a 4 MPH difference...but if I could just get my junk to 60' better I would probably have him covered by a tenth or more.
 
If you set the CalTracs correctly, your car will leave evenly. We had the same problem with the LF wheel coming up higher than the RF and by setting the preload of the CalTracs we eliminated that and improved our 60' times from high 1.5's to low 1.5's and have even dipped into the high 1.4's.
 
Thanks for all the input guys, Caltrac's are ordered and on the way :cheers:. I'll post results in a few weeks after the first race of the year.
 
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