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Front spoiler for 70 Duster drag car (130mph)

Posted By: 440Brian

Front spoiler for 70 Duster drag car (130mph) - 03/22/14 12:12 AM

I'm looking for more front end stability at the top end (130mph). Based on what I've read, I think I should try a front spoiler. I contacted Spoilers by Randy, but he doesn't think it will hold up at that speed. Has anyone tried that one at this speed?
Is there a stronger pre-made one out there or does everybody build their own?

Attached picture 8083083-DSC00006(1)(640x422).jpg
Posted By: SpareParts

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 12:30 AM

Have you tried looking other places in the front end to gain stability? Not to destroy your thread but I don't think 130 should be too loose and require a spoiler. I think maybe there is a bigger hidden issue here. My stock front end is fine at those kind of speeds.
Posted By: 412 SB Duster

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 12:45 AM

May want to look at your alignment, I've been 137 with no issues with stock setup. And
Know a lot of others that have been faster.
Posted By: Locomotion

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 12:46 AM

Do you have clearance to lower the front any? Proper front end alignment can also affect/help top end stability.

Something integrated into the bumper, straight down with a small lip facing out would help, but would involve a lot of fabricating and take away from the classic Duster look.

I built a simple, angled and reinforced aluminum plate front spoiler on my old street challenger. But that was before I ever went to the drag strip or went that fast.
It can get complicated and if it forces too much air under the hood, you could have problems keeping it on.
Posted By: pittsburghracer

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 01:51 AM

Check the play in the steering box
Check the welds on the steering box
check toe in with a floor jack for improper changes.
check for play in front suspension parts
Make sure front and rear tires are proper for each other.
If the front is to high try lowering but if you do so with the torsion bars check alignment again.
35 plus pounds in front tires.
Posted By: MR_P_BODY

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 02:01 AM

Quote:

I'm looking for more front end stability at the top end (130mph). Based on what I've read, I think I should try a front spoiler. I contacted Spoilers by Randy, but he doesn't think it will hold up at that speed. Has anyone tried that one at this speed?
Is there a stronger pre-made one out there or does everybody build their own?



It looks like you could lower the front 2"(re-align
after but use racing specs)
Posted By: dezduster

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 05:31 AM

That hood catches a lot of air that is pushed into the engine bay and that ads to air under the car also.
Posted By: MR_P_BODY

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 05:39 AM

Quote:

That hood catches a lot of air that is pushed into the engine bay and that ads to air under the car also.



That scoop doesnt catch that much but the grill
opening sure does.. for racing you can close the
whole grill off... it should pick up ET and MPH
Posted By: rebel

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 07:03 AM

Quote:



That scoop doesnt catch that much but the grill
opening sure does.. for racing you can close the
whole grill off... it should pick up ET and MPH




i agree. when i fitted my cowl & blocked off my grill i picked up both et & mph with no engine work. but back to the subject, i fitted this front spoiler which definately helped pull the front down at speed, so much so that the rear was becoming twitchy at the top end. i had to fit a rear wing to control that & now my car pushes down hard & is real stable even on a slipery track.

Attached picture 8083707-555899_472773859456309_1654093299_n.jpg
Posted By: Tig

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 12:07 PM

Apologies to OP about the thread hi-jack.
Rebel, closing the grill off, how did that effect engine temps?
Posted By: Dragula

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 01:25 PM

Quote:

I'm looking for more front end stability at the top end (130mph). Based on what I've read, I think I should try a front spoiler. I contacted Spoilers by Randy, but he doesn't think it will hold up at that speed. Has anyone tried that one at this speed?
Is there a stronger pre-made one out there or does everybody build their own?



We started having trouble with ours over +125...Found some issues with the front steering and tie rods...Actually had a weld 85% torn on one side that holds one of the pivot arms on...Then found the bolt that holds the linkage to the pivot was the wrong diameter and replace a couple of worn out ball cups...Now +135 and its not to bad..I would be looking at anything that allows too much movement in the linkage and the items the linkage is bolted too...
Posted By: MR_P_BODY

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 01:35 PM

If ALL of the front end parts are right and tight I
might think about the rear of the car... the front
doesnt tend to lift(areo wise) with a heavy engine
sitting in front at those speeds... what some guys
think is the front moving can be the back.. if you
get the front end shudder its loose or bad parts
EDIT
If the car starts to dart back and forth its normally
a toe OUT issue at some point in the travel
Posted By: Quicktree

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 02:09 PM

yea the thing is setting way high in the front, do you have a full view pic? Like Locomotion said lower the front and possibly the whole car some.
Posted By: SpareParts

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 06:03 PM

What's the rear tire pressure? That can make the car loose if it's too low, it can give the feel that the front end is loose
Posted By: jim sciortino

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 06:38 PM

Your car appears to sit a little high in the pic you posted.....

We had a 69' Barracuda in the early 90s with a 68' SS/AH scoop, all brand new stock front suspension pieces and steering box, with a set of Koni shocks and that car was pretty stable at 155.80 without any body modifications, spoilers, grille blocks, etc.....

Try lowering front, then check the alignment and all front end/steering components. I wouldn't think there'd be an issue at in the 130 range, but if there's a component problem somewhere, you'll feel it.
Posted By: pittsburghracer

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 07:14 PM

Lots of guys suggested the ride height being to high and its hard to tell from your picture but it very well could be an issue. I changed out a set of super stock springs years ago on my 9 second 74 Duster as the other set had LOTS of runs on them. Well the car sat a little higher and that car was terrible to drive. I removed them that week and took them to a spring shop and had them de-arched some and the car worked great. If possible post some better side, front and rear pictures and the guys on this site will get you straightened out.
Posted By: OUTLAWD

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 09:28 PM

My dart used to get a light feeling above 120, and it helped alot to lower the front, I also added a spoiler from a 69 camaro. The lower valance on the dart made this easy. The duster isn't the same, so the spoiler might not work.

The spoiler I used was ABS plastic, pretty flimsy itself, but I fastened the top to the valance, then ran tube supports to the bottom edge. I could putt the car forward from the spoiler, there was no deflection at high speed.
Posted By: rebel

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 10:06 PM

Quote:

Apologies to OP about the thread hi-jack.
Rebel, closing the grill off, how did that effect engine temps?



it didn't change it at all. my electric fan pulls sh!tloads of air thru my radiator & i can drive back to my pit after a run with ease.
Posted By: gregsdart

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 10:23 PM

Check bump steer also. It looks like the front would run through the lights very high, and might be WAY off on alignment. That would cost you handling, and a chunk of ET and MPH. stock A bodys with good alignment and components are good to 130 at least. Also check caster, to see if you have any. You want all you can get.
Posted By: deaks

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 10:29 PM

I went from 29.5 tyres to 31" and if the car got a bit of line it was quite unnerving. I fitted 1-1/2" lowering blocks and it was fine after that.
Mick
Posted By: 72Swinger

Re: Front spoiler for 70 Duster drag car (130mph) - 03/22/14 11:35 PM

A problem alot of cars have is to much rake which also has the side effect of giving you way less caster. Caster is probably the largest contributor to high speed stability out of all alignment settings. Lowering the front will not help this condition whatsoever.
Posted By: 440Brian

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 12:10 AM

Thanks for all the responses. I think I'll try lowering the front end and checking the alignment/steering linkage first.
The car is back halved so I can adjust the rear height easily. I run 8 psi in the slicks. The front suspension has been updated to disc brakes by swapping everything over from a 73 A body.
It does seem like the front end is sitting high as I go down the track.
I didn't know it was possible to block off the grille and still keep it cool.
I added a whole car pic so you can see how it sits.

Attached picture 8084498-DSC00006(1)(640x271).jpg
Posted By: rebel

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 12:20 AM

when you block off your grille, make sure it is flush with the front edge of your car. this leaves a large area for the radiator fan to pull air from behind the new grille panel, as well as improving aerodynamics. my car also uses drop spindles on the front & at speed the car really hunkers down onto the track. the front spoiler in my pic is actually off a Ford but i cut & modified it to fit my car.

Attached picture 8084508-DSC08349.jpg
Posted By: pittsburghracer

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 12:41 AM

Quote:

Thanks for all the responses. I think I'll try lowering the front end and checking the alignment/steering linkage first.
The car is back halved so I can adjust the rear height easily. I run 8 psi in the slicks. The front suspension has been updated to disc brakes by swapping everything over from a 73 A body.
It does seem like the front end is sitting high as I go down the track.
I didn't know it was possible to block off the grille and still keep it cool.
I added a whole car pic so you can see how it sits.





Look at your front tire height and look at mine. I'm running exactly 130mph right now and should be a hair over 150 next year and still don't think I will need a front spoiler. Also I'm running 14-32 around 10.5 pounds. At 8 it didn't hook or handle as well.

Posted By: Quicktree

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 12:47 AM

Quote:

Thanks for all the responses. I think I'll try lowering the front end and checking the alignment/steering linkage first.
The car is back halved so I can adjust the rear height easily. I run 8 psi in the slicks. The front suspension has been updated to disc brakes by swapping everything over from a 73 A body.
It does seem like the front end is sitting high as I go down the track.
I didn't know it was possible to block off the grille and still keep it cool.
I added a whole car pic so you can see how it sits.

theres your problem, the rear is setting lower that the front. looks like the front is at least 5" to high. looks like the wheel is leaning in at the top just setting there. lower that thing and reset the alignment. and you don't need to block off the grill
Posted By: CHAPPER

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 02:39 AM

Quote:

Thanks for all the responses. I think I'll try lowering the front end and checking the alignment/steering linkage first.
The car is back halved so I can adjust the rear height easily. I run 8 psi in the slicks. The front suspension has been updated to disc brakes by swapping everything over from a 73 A body.
It does seem like the front end is sitting high as I go down the track.
I didn't know it was possible to block off the grille and still keep it cool.
I added a whole car pic so you can see how it sits.



That doesn't happen to be a radial tire on the front with a bias ply slick on the rear...? My A-body didn't drive good with a radial/bias ply combination. Others have had no problems, but I sure did. I would have to agree with some of the others, the front looks high to me too.
Side pic of mine for comparison.

Attached picture 8084642-freddy'stoy005.jpg
Posted By: Cab_Burge

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 03:12 AM

My 1971 Duster had issues when I mixed radials and bias plys at first, I ended up finding that I had a bad idler arm, new out of the box My car ran 134+ mph in the 1/4 a bunch of times, no issues with a good alignment and tight steering components. Low rear tire pressures can and will make your butt cheeks pucker when you let off or try to steer it when it is wondering around in high gear I like to run, find, the highest amount of air pressure in the rear tires I can run without spinning them on the starting line for that very reason A freind of mine has added a partial spoiler to his 170 BB Duster, he ran it the width of the front sub frames only in front of the radiator to block air going into the front suspension and K member. He picked up almost a tenth in the 1/4 and some MPH He runs low tens and high nines also with no issues on steerng it on the other end in the 1/4 mile He runs ladder bars on leaf springs with sliders, mine was ladder bars and coil overs with a diagonal link I hope you find out what is causing it , let us know what you find
Posted By: bigtimeauto

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 03:12 AM

if your ladder bars are to high in the front that will make the car unstable also. My car has a open grille and I have been faster than 175 with no issues at all. I have recently added a 1969 Camaro front spoiler to help hide the belly pan and blower and saw no difference.
Posted By: ProStock1320

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 03:28 AM

Quote:

I have recently added a 1969 Camaro front spoiler to help hide the belly pan and blower



Pics?
Posted By: bigtimeauto

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 03:30 AM

Quote:

Quote:

I have recently added a 1969 Camaro front spoiler to help hide the belly pan and blower



Pics?



Posted By: rebel

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 05:04 AM

Quote:

Quote:

Quote:

I have recently added a 1969 Camaro front spoiler to help hide the belly pan and blower



Pics?







not much gain with only a couple of inches, maybe a few more might make a difference.
Posted By: bigtimeauto

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 05:08 AM

Quote:

Quote:

Quote:

Quote:

I have recently added a 1969 Camaro front spoiler to help hide the belly pan and blower



Pics?







not much gain with only a couple of inches, maybe a few more might make a difference.




really no need, no more quarter for this car and its runs 155 in the 1/8th
Posted By: B3422W5

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 05:23 AM

Quote:

Thanks for all the responses. I think I'll try lowering the front end and checking the alignment/steering linkage first.
The car is back halved so I can adjust the rear height easily. I run 8 psi in the slicks. The front suspension has been updated to disc brakes by swapping everything over from a 73 A body.
It does seem like the front end is sitting high as I go down the track.
I didn't know it was possible to block off the grille and still keep it cool.
I added a whole car pic so you can see how it sits.



I would put some air in your near flat rear tires. A tubbed car with big tires going 130 mph should hook easily with WAY more air in the rears. Dragging anything down the track with flat tires will result in ill handling. I would sort out why you can't/ don't run more air before I did anything else.
Posted By: Sport440

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 06:39 AM

Its not a spoiler issue for sure. Your rear slick psi 8# is way to low and your front end is set to high not helping things.

Get your psi up to 12+ or so and lower that front end. Realign and see how it handles. Also check your front end componets for slop.
Posted By: rebel

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 09:18 AM

i don't consider 8 psi as low. over the years of using the same sized slick, (32x14 with stiff sidewall), i found 8-8.5 optimum pressure for my car, (2959lbs with my fat ass in the chair). i was running 12 psi when i started but found i was running the middle of the slick bald before the sides were loosing all their depth dots. i went lower over the next few seasons settling into the 8's with no adverse affect in top end handling, if fact my 60's improved. when you change to new slicks, cut your old ones open & measure the thickness across the middle, you could be quite surprised.
Posted By: Dragula

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 04:19 PM

Quote:

Quote:

Quote:

I have recently added a 1969 Camaro front spoiler to help hide the belly pan and blower



Pics?







Am I the only idiot that noticed your blower isn't a side slinger anymore like all the pics you normally post? You owe me a reply on the other site you know....
Posted By: Quicktree

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 04:26 PM

thats not a blower it's a pic of one on his front tag plate
Posted By: 70satelliteguy

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 04:28 PM

"I don't consider 8 psi as low" Rebel at 2900 race weight that may be true but I know that my car at 3600 race weight is all over the track on top end at 8 psi. I don't think we know what his car weighs going down the track at 130 440 Brian how much does it weigh with you in it???
Posted By: MR_P_BODY

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 04:42 PM

Quote:

"I don't consider 8 psi as low" Rebel at 2900 race weight that may be true but I know that my car at 3600 race weight is all over the track on top end at 8 psi. I don't think we know what his car weighs going down the track at 130 440 Brian how much does it weigh with you in it???



Very true... its about the weight.... I run 7 psi on
my car but at 2400# and its totally fine.. but a car
at 3600 would be squirming all over on top end.. but
I dont know his race weight.... weight VS tire size
makes a BIG difference
Posted By: bigtimeauto

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 07:01 PM

Quote:

Quote:

Quote:

Quote:

I have recently added a 1969 Camaro front spoiler to help hide the belly pan and blower



Pics?







Am I the only idiot that noticed your blower isn't a side slinger anymore like all the pics you normally post? You owe me a reply on the other site you know....



I made a bunch of new stuff for a customer so I make changes to my car so theirs can be plug and play.
I still run the front license plate when I drive it around the street, pits and to the lanes just take it off when we make a pass.

Reply?
Posted By: moparniac

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 07:11 PM

Still a F2 bob?
Posted By: bigtimeauto

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 07:55 PM

Quote:

Still a F2 bob?



same blower, different location
Posted By: 70dusterjohn

Re: Front spoiler for 70 Duster drag car (130mph) - 03/23/14 08:27 PM

I would start with 8 psi ! That's way to low for that big a tire ! I agree that the front end is to high, I had an old DC spoiler on our Duster, It was always stable on the top end ! But when the car was on the edge of a 9 second pass I just couldn't get it there, my pops suggested taking it off ! I didn't really want to, I thought I would upset the car, but did ! Next pass the car went 9.93 with no other changes ? Where running 10.05 10.06 and 10.04 ! The car drove the same as it did with it so I stuck it up in the barn and haven't had it on since !
Posted By: 1967dartgt

Re: Front spoiler for 70 Duster drag car (130mph) - 03/24/14 02:29 AM

Quote:

Quote:

Still a F2 bob?



same blower, different location



You had it at Josh's last race in the front. I guess they just don't look in person.
Posted By: gregsdart

Re: Front spoiler for 70 Duster drag car (130mph) - 03/24/14 02:31 PM

Quote:

if your ladder bars are to high in the front that will make the car unstable also. My car has a open grille and I have been faster than 175 with no issues at all. I have recently added a 1969 Camaro front spoiler to help hide the belly pan and blower and saw no difference.


Sounded like the right move, but they must not work as well as one at minimum height of 3 inch?
Posted By: 440Brian

Re: Front spoiler for 70 Duster drag car (130mph) - 03/24/14 04:29 PM

Quote:

"I don't consider 8 psi as low" Rebel at 2900 race weight that may be true but I know that my car at 3600 race weight is all over the track on top end at 8 psi. I don't think we know what his car weighs going down the track at 130 440 Brian how much does it weigh with you in it???



It weighs 2950 lbs. with me. I'll try a higher rear tire pressure next time at the track.

I checked the steering linkage and didn't find any play. It did seem like I had just a little in the front right wheel bearing. They look allright so I'll re-pack them. The front shock bushings look like they are falling apart, so it's probably high time I replaced them with a racing part. Any suggestions?

I ordered an algnment check tool kit, so I'll be taking a close look at the toe.
Posted By: PolyDart

Re: Front spoiler for 70 Duster drag car (130mph) - 03/24/14 04:40 PM

I have used one of Randy's spoilers on my '70 Dart. No problems with it holding up what so ever. I couldn't tell you if it helped with stability, since the car has had it since I began racing it.
Posted By: Sport440

Re: Front spoiler for 70 Duster drag car (130mph) - 03/24/14 04:42 PM

My car weighs the same as yours and it will get drifty on the top end with only 8# and my tires dont look as big as yours.

Your front still should come down some IMO. Also dont forget to look at your Lower inner control arm bushings. If they havent been changed by somebody they are probably shot. They were on my car. The rubber part of the passenger side bushing was halfway out when I checked it.
Posted By: MR_P_BODY

Re: Front spoiler for 70 Duster drag car (130mph) - 03/24/14 04:53 PM

Quote:

Quote:

"I don't consider 8 psi as low" Rebel at 2900 race weight that may be true but I know that my car at 3600 race weight is all over the track on top end at 8 psi. I don't think we know what his car weighs going down the track at 130 440 Brian how much does it weigh with you in it???



It weighs 2950 lbs. with me. I'll try a higher rear tire pressure next time at the track.

I checked the steering linkage and didn't find any play. It did seem like I had just a little in the front right wheel bearing. They look allright so I'll re-pack them. The front shock bushings look like they are falling apart, so it's probably high time I replaced them with a racing part. Any suggestions?

I ordered an algnment check tool kit, so I'll be taking a close look at the toe.



Have you moved the body height ever without having
the front end aligned afterwords... that will kill
your alignment... if you check the toe curve(in the
MP chassis book) and it toes out at all during the
travel it will cause the car to dart around and with
low rear tire pressure it WILL get real scary... so
you may have multiple things that are wrong/bad
Posted By: Slingshot383

Re: Front spoiler for 70 Duster drag car (130mph) - 03/24/14 06:03 PM

In addition to blocking off the grill, fabricating a belly pan from the core support to the firewall would help a lot.
Posted By: Cab_Burge

Re: Front spoiler for 70 Duster drag car (130mph) - 03/24/14 07:21 PM

When you align the front end rasie it up one inch to simulate the ride hieght at WOT, set the toe in to zero to 1/16 toe in, try to get zero camber on both sides and as much positive caster, upper ball joint to the rear of the lower ball joint, as you can
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