Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Drag Racing Forum

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 09-25-2000, 05:25 AM
340king 340king is offline
Registered User
 
Join Date: Oct 1999
Location: Fort Pierre, SD
Age: 61
Posts: 2,233
Post

After reading the thread on the First Pass with the 572, I started thinking about a course of action that is being contemplated for the future. I help a friend with a '70 Duster, 360 engine, 904 with brake, 8.75" rear end, 9" slicks and 3050lbs measured with driver.

The car has Superstock springs with a snubber. My question is what is the limiting factor for the stock style rear supension? Is there an E.T. limit or is it a horsepower limit? The car runs very consistent with 11.65 sec passes, varying less than .05 sec, even from week to week.

The rearend is modified with a full spool and either Moser or Dutchman cut down axles. The car lifts the front end about 12-14" on launch and carries it for about 7-10 feet. One reason for the question is that we have not seen a reduction in 60 foot times with the brake, but it is more consistent.

The contemplated course is aluminum heads with some porting. Will this exceed the capablity of the stock suspension? Obviously, we will not be breaking many parts here, but are we sacrificing some performance with stock parts and are we going to make it worse by adding more power?
Reply With Quote
  #2  
Old 09-25-2000, 06:26 AM
MD MD is offline
Inactive User
 
Join Date: Jun 2000
Location: MT
Posts: 212
Post

I ran a BB Dart deep in the ten's with a stock type suspension, and I doubt that you would see any major problems by adding some power. I think that when you reach the limits you'll know, the car will simply not be consistant and may "waste" some power by not running as quick as possible. Probably somewhere in the mid tens and quicker is where a back half job starts to become justified, if the extra performance seems worth the cost. At the level we are talking about here, you may only gain a tenth or so for a couple of thousand dollars worth of suspension parts and labor. The stock type Mopar suspension is a good one in my opinion, compared to the other brands.

If the subframes aren't connected yet you may wish to consider doing that.
Reply With Quote
  #3  
Old 09-25-2000, 11:23 PM
Leigh's Avatar
Leigh Leigh is offline
Inactive User
 
Join Date: May 2000
Location: Andover, Mn
Posts: 435
Post

Seems like each converter has a major impact on the workability of leaf springs. I went from a fairly loose (5200) TA 4400 to a pretty efficient Dynamic and lost the leaf spring combo completely. I finally went the ladder bar route. Everyone always wants to go faster, but why? A 11.60 car can be a killer racing fast door cars and diggers. Practically zero maintainence too. I can't fault you for wanting to faster though, we all do!
Reply With Quote
  #4  
Old 09-25-2000, 11:28 PM
Stan Cameron Stan Cameron is offline
Inactive User
 
Join Date: Feb 2000
Location: Bakersfield, CA, USA
Posts: 113
Post

8.75 don't like trans brakes. When the rear end breaks it usually takes trans with it.

We ran a 8.75 for 3 years foot brake only. Changed gears every year. Ran 11.0s with 3300# road runner.


------------------
Cameron's Racing
Division of GOT NUTZ?
MotorSportz
66 Belv 440 auto 10.76 @ 125
69 Road Runner 426 wedge auto 9.74 @ 138
99 Dakota Pro Stock type
truck (under construction)
79 Lil Red Express Truck
96 2500 Ram 5.9
99 Durango 5.9
Reply With Quote
  #5  
Old 09-25-2000, 11:37 PM
Christopher's Avatar
Christopher Christopher is offline
Inactive User
 
Join Date: Mar 1999
Location: fl
Posts: 2,018
Post

I'd say as you aproach the 9.80 bracket in the 1/4,you MAY want to consider a ladder bar or 4 link setup,but it really depends.I look at it this way.....The Mopar Pro Stockers in the early 70's used the S/S springs(as did Jenkins and Dyno Don!!)and they were in the 9.80-9.90 bracket then.Also the current stock eliminator Mopars that are in the higher classes are using the S/S springs or the ones from Tri-City and they are almost in the 9 second bracket as well(A/S and A/SA) and they use a 9" tire,so obviously they do work.Subframe connectors are a must.I like the fact with the S/S leaf spring suspension,there really isn't any "tuning" to be done,save for maybe a pinion snubber height adustment occasionaly.Both our cars with the S/S suspension never had a 60ft time lower than 1.55,and we never played with the snubber either,just left it 1" below the floor pan.I'm also surprised about the trans brake not improving the 60ft time,but I haven't installed mine yet either,so I cant say for sure if it would improve the 60ft time.
Reply With Quote
  #6  
Old 09-26-2000, 12:47 AM
Comp Chassis Comp Chassis is offline
Inactive User
 
Join Date: Apr 2000
Location: Glendale, AZ
Posts: 155
Post

For bracket racing or super class racing, I wouldnt pay much attention to stock eliminator cars, they are forced to run stock suspension. Look as the super stock cars, I would bet that every record holding super stock is a 4 link coil over car.

I ran a 72 Dart with 340 for almost 10 years. With SS springs and 9" slicks it was very consistent all the way to 11.60s, as soon as we stepped up a little more, the consistency went away. If track was perfect we were ok, but if it wasnt, we were dead.

If this is a serious bracket car and you ever plan on stepping up and going faster, I would recomend a ladder bar and coil over setup. It is fairly easy to put in a A body mopar and later on if you take out the stock wheel houses and put in tubs, you can fit a 12" slick without moving the frame rails.

A little planning ahead now will save you bundles of money in the long run.
Reply With Quote
  #7  
Old 09-26-2000, 03:24 AM
fast68plymouth fast68plymouth is offline
Inactive User
 
Join Date: Aug 2000
Location: so burlington,vt usa
Posts: 111
Post

i agree with compchassis. although im not a chassis guy, i do know what its like to run a relatively fast S/S sprung car.(10.60's @3650lbs). when the bite is good its consistent, when the bite is marginal, im hoping ill line up next to someone else in my shoes to help even up my chances.
i also dont think comparing a bracket car to an NHRA stocker is good either. when you compete in Stock, all of your competitors are also running stock type suspension and 9" tires. with a bracket car you may have to run a guy with an 11.50 car that has 14X32's that wouldnt spin in a grease pit. you should look to level the playing field by putting in a suspension that you can tune for varying track conditions.
as far as the transbrake goes, i ran a friends Camaro S/G car for a awhile. it went the same with or without the brake. it would lift the wheels with the brake, but didnt go any quicker.
Reply With Quote
  #8  
Old 09-26-2000, 04:06 AM
Christopher's Avatar
Christopher Christopher is offline
Inactive User
 
Join Date: Mar 1999
Location: fl
Posts: 2,018
Post

It to me doesn't matter what size tire you have.My Dart has the S/S springs,with a 13x31 tire and it hooks well-best 60ft is 1.48.My car has run 11.20's. The Road Runner had the same setup and ran consistent 1.51 60ft times until the rear tires started to go away,then would drop to 1.55.My comparison between a bracket car and a stocker was for a Mopar only..chassis wise the cars are the same as most average bracket cars.As far as tire size goes,most cars have too much tire.(mine included)I look at it this way,the S/S spring setup worked well in the 70's, works well now.Even the older KOS cars used it and they were running 9's.Just my opinion.
Reply With Quote
  #9  
Old 09-26-2000, 07:21 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Post

Doesn't Bucky Hess's SS/AA 'Cuda use leaf springs?
Reply With Quote
  #10  
Old 09-26-2000, 02:53 PM
Comp Chassis Comp Chassis is offline
Inactive User
 
Join Date: Apr 2000
Location: Glendale, AZ
Posts: 155
Post

Im not familiar with all the super stock cars but I do know that some of them do have leaf springs. But, all the leaf springs do is hold the car off the ground. The cars are 4 link cars and use floaters on the springs. That is a completely different story than actually using them to launch the car.
Reply With Quote
  #11  
Old 09-26-2000, 11:39 PM
Leigh's Avatar
Leigh Leigh is offline
Inactive User
 
Join Date: May 2000
Location: Andover, Mn
Posts: 435
Post

Comp Chassis, you're right on. Plus, most stock eliminator events are run on well groomed tracks. I was in love with the purists leaf spring idea for many years....until I bolted in 535 ft. lbs. Then I had daydreams on how I would mutilate them.
Reply With Quote
  #12  
Old 09-27-2000, 02:32 AM
Christopher's Avatar
Christopher Christopher is offline
Inactive User
 
Join Date: Mar 1999
Location: fl
Posts: 2,018
Post

I dont agree with the "well groomed" track theory.Gainesville and Atlanta turn the same et's before and after a major event.
Reply With Quote
  #13  
Old 09-27-2000, 04:26 AM
fast68plymouth fast68plymouth is offline
Inactive User
 
Join Date: Aug 2000
Location: so burlington,vt usa
Posts: 111
Post

well, i cant speak for the conditions at the tracks down south, but i can tell you here in NE, the track conditions vary greatly. my frien runs a GTO in stock with a stick. during divisional events he usually 60's better than he does at the same tracks during regular(bracket) events. typically the track champs at these tracks have cars that wouldbe good 9.90 cars and have 450hp motors in them. they dont have enough power to spin.
im not saying this to rag on your car, but 1.50 60' times arent really enough to put a suspension system to the test. my car will 60' 1.46 on a good run, and maybe 3 or 4 runs later will go a 1.52. meanwhile my friend in his ladder bar equipped 9.30 S/G car will be raving about the great bite and rip off a string of 1.34's and 1.35's.
and looking at stockers performance levels attained at national or divisional events just isnt relative to weekly bracket racing. a good running low 11 sec stocker will 60' in the mid to low 1.40's. and a low 10 sec stocker will 60' high 1.30's. you just dont typically see that kind of performance from an average bracket car with leaf springs and 9" tires. one more thing to remember about guys running stock, you cant believe ANYTHING they tell you. dont believe for a second that a guy running mid to low tens with a stocker is leaving it in the trailer between events.
take advantage of what the rules will allow, and run the best rear suspension you can afford that fits your racing program.
Reply With Quote
  #14  
Old 09-27-2000, 06:01 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Post

There are competitive SS cars that do not use four links, and I think Bucky Hess's 'Cuda is one of them but I'm not really sure about it. I remember him saying that the car ET's as well with the leafs as a four link, but doesn't go as straight. John Calvert races his Mustang with leafs and Cal-Tracs and so on. I think that with any suspension type, the most important thing is htat the suspension works. Ladders or four links are not a magic word that will make your car launch like a Pro Stocker. You still have to pay attention to the adjustments, spring rates, shocks and the build up and angles in the first place. I thi nk that people who go in to using ladders or four links are more likely those who pay more attention to things than an average leaf spring racer. That's part of the reason why they work so well. Pay the same amount of attention to leaf spring suspension that is needed to dial in a four link, and you have a suspension that can handle some serious ET's. I have seen a lot of ladder and four link suspensions that do not work at all, and in the case of four link there are pretty many possibilities to go wrong. On my experience, the leaf springs work pretty well just the way they are.
Reply With Quote
  #15  
Old 09-27-2000, 05:27 PM
etracer etracer is offline
S/SS Member
 
Join Date: Sep 2000
Location: Western PA.
Age: 64
Posts: 28
Post

There are A LOT of 10 second Chrysler stockers running SS springs. I'm running low 11's with 1.52-1.53 60ft. times and 20lbs-21.5lbs of air in the slicks. The car is super consistent,it's a shame the driver isn't!!
Reply With Quote
  #16  
Old 09-28-2000, 12:31 AM
Leigh's Avatar
Leigh Leigh is offline
Inactive User
 
Join Date: May 2000
Location: Andover, Mn
Posts: 435
Post

I don't buy that theory, Christopher. I think you're benefiting from the unordinary situation of a track owner who really gives a damm about his tracks hook. All divisional and national events are sprayed multiple times, scrapped each night, and have clean rubber layed down. I don't recall the operator of the local track I race at do ANY of those. He does not have to...theres no place else within 300 miles. Thats my point, I don't EVER see any of the stock - superstock guys at this place, and its owned by a heavy hitter stock eliminator racer. The cars are either slow with stock type suspensions, fast stock type with throttle stops, or fast with ladder bars and 4 links. To each their own. I enjoy seeing the win light come on rather than spinning running 10.30's.
Reply With Quote
  #17  
Old 09-28-2000, 01:31 AM
fast68plymouth fast68plymouth is offline
Inactive User
 
Join Date: Aug 2000
Location: so burlington,vt usa
Posts: 111
Post

dart66, i dont know about your car, but there isnt anything i can easily adjust at the track on my leaf spring car, other than tire pressure. if the bite is marginal on a given day, im screwed.
i dont know what the typical car count for an average sunday is there, but two of the tracks i frequent will typically have 250-300 cars every weekend. when you are trying to make your car faster, and track conditions are not the best, you will probably have a better shot at the winners circle if you have a suspension thats more than up to the task of your combination.
etracer, i know several people with 10 sec mopar stockers, and none of them actually use mopar SS springs, although im sure they tell everyone they do.
one other point im suprised Comp Chassis didnt bring up is that when you work a leaf spring hard it loses some of its shape on every run. so the performance of the rear suspension deteriorates over time. my SS equipped car has sunk several inches since their installation, and the car doesnt work as well either. so although the initial cost of the SS spings is less, they are a continual expense, needing replacement every year to keep the car sharp.
Reply With Quote
  #18  
Old 09-28-2000, 02:27 AM
Maxwedge Maxwedge is offline
Moderator and HEMI FIEND
 
Join Date: Aug 1999
Location: Redondo Beach California
Age: 24
Posts: 2,608
Post

I believe, and I could be wrong, but the IHRA SS cars are limited to mechanicals that the factory offered..like bore/stroke/cfm and type of carbs and suspension...at least I think so..oh and if that is true then bucky Hess has run a best of 8.72 this year in his SS/barracuda prepped by Ray Barton
Maxwedge
Reply With Quote
  #19  
Old 09-28-2000, 03:41 AM
fast68plymouth fast68plymouth is offline
Inactive User
 
Join Date: Aug 2000
Location: so burlington,vt usa
Posts: 111
Post

you DO NOT need to use the stock rear suspension in super stock. BASICALLY, you can run any 4 link or ladder bar set you want as long as it fits under the oem trunk and floor(im looking at the NHRA rule book now). if buckey Hess' car has leaf springs, they are only there to hold up the back of the car. the power is not transmitted through them, but rather the 4 link or ladder bars(which ever his car has.)
im sure that as weight conscience as SS car owners are that his car has coil springs(and most liklely a 4 link). ill see if i can find out.
Reply With Quote
  #20  
Old 09-28-2000, 04:28 AM
Christopher's Avatar
Christopher Christopher is offline
Inactive User
 
Join Date: Mar 1999
Location: fl
Posts: 2,018
Post

There is a lot of differences of opinion about the S/S springs in what I call "losing their arch",and I think that is what fast 68 is describing.The S/S springs on my Road Runner were installed in 1972 and they still hook great.Dave Morgans chassis manual says the Mopar springs lose the ability to hook as well after a period of time.I haven't found this to be the case with my cars,but I also run a heavier spring.The Dart has the 3400lb springs on it and the 'Bird has the 3800lb springs.I know most A-body cars with either 340 or 383/440 use the "002-003" springs that were originally designed for the factory 68 Hemi cars.I don't use them as my car with the 440 weighs in at 3300,not counting me in the car.The 'Runner weighs 3670 w/o driver.I tried to match the actual weight when I installed the springs.As far as track surface grooming,they don't do it here.We have a few Stock and S/S guys that run here plus alot of the S/G cars that run nationally and they say the same thing.The track does get greasy at times,but it's not sprayed.But I also would like to know what 340King's friend's car 60ft's at as well.
Reply With Quote
  #21  
Old 09-28-2000, 04:47 AM
Comp Chassis Comp Chassis is offline
Inactive User
 
Join Date: Apr 2000
Location: Glendale, AZ
Posts: 155
Post

My point here was that you dont necessarily want to look at stock eliminator cars when comparing suspensions for bracket racing. Stock eliminators are forced to run that suspension by the rules. Believe me, if they changed the rules tomorrow to allow ladder bars and 4 links in stock, I would almost bet that 90% of the cars would be in a chassis shop the day after.

Leaf springs can and do work in some cases, but take a lot of tuning and maintenance. Ladder bars are a set and forget suspension. They can pretty much be set on a set of scales and go racing. 4 links are a little more involved, but once you have a basic understanding of how they work, they are very easy to set.

Personally, I will never build for myself another car for the track with leaf springs. I have learned many lessons over the years and I like to keep my headaches to a minimum. For street/strip is a different matter, but race only I wont use them.
Reply With Quote
  #22  
Old 09-28-2000, 06:56 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Post

Fast, I do not have any adjustments, and my leaf springs do not work too well, I think. I've got one old right side Hemi SS spring, and one partially self made left side. Currently I have removed two leafs from each side and added Cal-Tracs style bars, and my 60 ft times are usually in the 1.5's, which is not very quick for a low 10 sec car. The tires are 13.5/30/15 M/T ET Streets. But if I had a four link, I would have no idea what to do with it. I have seen many cars that do everythign but go straight and quick with a four link. I think these people are like me, they would be quicker even with not so well set up leaf springs. Of course this is just my opinion, I'll stick to the leaf springs in the future too (not because i believe it's superior, but because of other technical things), but try to get the max out of that suspension. I may remember the Bucky Hess thing wrong, but I remember reading that he used a true leaf spring suspension in his 'Cuda when he drove the first 8's. If he were using links or ladders, there would be no sense in keeping the heavy leafs hanging out there, would there? And I remember him saying that the car doesn't go as straight as the cars with the links, but it's as quick. Hope someone can confirm this.
Reply With Quote
  #23  
Old 09-28-2000, 02:36 PM
fast68plymouth fast68plymouth is offline
Inactive User
 
Join Date: Aug 2000
Location: so burlington,vt usa
Posts: 111
Post

dart, to my way of thinking you arent running a true leaf spring set up. having cal-tracs is a modified leaf spring suspension, and you do have adjustments. you can preload one side,and adjust the "hit", both of which cant be done with a traditional leaf spring suspension(not easily anyway). also you may be able to improve those 60' times by removing the SS springs, and getting something more compatible with the cal-tracs, and letting them do all the work.
Reply With Quote
  #24  
Old 09-28-2000, 03:21 PM
Maxwedge Maxwedge is offline
Moderator and HEMI FIEND
 
Join Date: Aug 1999
Location: Redondo Beach California
Age: 24
Posts: 2,608
Post

Fast68Plymouth..
Bucky Hess runs IHRA not NHRA, dont know if it matters or not..in so far as the rules go.
But just thought I might add my .02 to the fire..
Maxwedge

[This message has been edited by Maxwedge (edited September 28, 2000).]
Reply With Quote
  #25  
Old 09-28-2000, 11:37 PM
340king 340king is offline
Registered User
 
Join Date: Oct 1999
Location: Fort Pierre, SD
Age: 61
Posts: 2,233
Post

Thank you all for replying to my query. It is as I thought it would be, a very interesting and somewhat controversial subject.

Christopher, the car runs 1.55-1.56 60 foot times. The track was paved this year and they are trying to keep it consistent with good grooming. They periodically have pro-mod cars practicing there running in the low 7's.

As for the alchohol carb, it can make a difference, depending on the application. We are putting up consistency numbers that would make some alchy running guys envious. The car will run 11.65 sec from 65° to 95° without changing jets or lifting the hood other than to cool down.

My concern is that we may reduce this consitency by adding HP to the mix. The closest track is 200+ miles from here and we don't compete on a regular basis and tuning something difficult might be an impossiblity based on our current schedule.

I gotta now, thanks for all the info, there is a fire in the National Grasslands and it sounds like they are needing help. Its these damn 96° days in Sept. after no rain for 60 da
Reply With Quote
  #26  
Old 09-29-2000, 01:41 AM
fast68plymouth fast68plymouth is offline
Inactive User
 
Join Date: Aug 2000
Location: so burlington,vt usa
Posts: 111
Post

Max Wedge, Buckey Hess is the current(at least as of 9/15/00) NHRA record holder in SS/AA. i dont know if he runs IHRA or not, but the first time the SS/AA cars went into the 8's was during an NHRA event.
Reply With Quote
  #27  
Old 09-29-2000, 01:53 AM
Comp Chassis Comp Chassis is offline
Inactive User
 
Join Date: Apr 2000
Location: Glendale, AZ
Posts: 155
Post

I am sitting here looking at an article on Bucky Hess's car. Yes, it has leaf springs, but all it does is sit on them. The car is a 4 link car. If he dumped the leafs and put in good coil overs, the car would probably be a few hundreths faster due to the weight reduction. That is unless he is running some kind of fiberglass spring or something. The article doesnt say and there are no pictures of the rear suspension.
Reply With Quote
  #28  
Old 09-29-2000, 02:30 AM
Clonestocker Clonestocker is offline
Inactive User
 
Join Date: May 2000
Location: Tucson, AZ
Posts: 9
Post

I like Christophers version. I use the 3400lbs body springs on my A-body. Mild 360 goes 11.60s, w/1.56 60ft times. By the way they were used when I put them on. I've used the 002-003 springs on an E-body. Wasn't impressed, I think DC descriptions of springs for applications leaves something to be desired. I'm putting a home made set of springs on my K/SA wagon. I'll let the board know how they work.
Reply With Quote
  #29  
Old 09-29-2000, 02:58 AM
Christopher's Avatar
Christopher Christopher is offline
Inactive User
 
Join Date: Mar 1999
Location: fl
Posts: 2,018
Post

I guess my main concern is cost.I'm not trying to sound "cheap",but I cannot see spending money to change over to ladder bars or a 4-link unless I'm going to get some guaranteed results.If my car were to go into the 9.80 zone and I wanted it to go faster,and I knew my 60ft time would drop dramatically,then I'd go for the ladder bars.But the way the 340King's buddy Duster sounds as if it pretty much a stock bodied chassis,and with a 11 second or even a 10.90 motor,I still think the S/S spring setup is all he needs.This has become a very interesting topic,and I hope it will continue. Be careful with those fires King.
Reply With Quote
  #30  
Old 09-29-2000, 03:33 AM
fast68plymouth fast68plymouth is offline
Inactive User
 
Join Date: Aug 2000
Location: so burlington,vt usa
Posts: 111
Post

a pair of SS springs is about $200. a ladder bar kit with floaters is less than $500. anyone who can weld decently can put one in. all the ladder bar has to do is get you one win where you would have runnered-up, and the ladder bars would have paid for them self. i guarantee thats happened more than once.
the point to remember is not that his current set up works, its how well will it work with a substantial hp increase. most of the replies are from guys running 60' times nearly the same as he's running now, so you dont have first hand experience as to how well the SS springs will repeat when mid 1.40's are in order. also id be interested to know what the typical car count is at the track he's running.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Kevco Stock chassis oil pan ? MOD 50 Circle Track Chat 2 01-26-2011 10:20 AM
Hobby Stock Chassis bmoddan Circle Track Chat 7 10-20-2006 05:48 PM
Stock car chassis bmoddan Circle Track Chat 10 08-30-2005 11:41 PM
HP limits rb77413 Performance Talk 2 05-03-2002 12:55 AM
indy sr/stock chassis headers moeflo Performance Talk 4 06-26-2001 08:04 PM




All times are GMT -4. The time now is 09:59 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .