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Author Topic:   Leaf spring modified
rnoswal53
Dirt Maniac

Total posts: 120
posted January 15, 2005 12:45 AM  
I am almost being handed a later modified. All I have to do is put the drive train together (rebuild the engine). That is the only money out pretty much. I will race the car no matter what rear setup it has, but it happens to have a leaf spring setup. I understand they work pretty well in a tacky stituation, but can they be made competitive on a dry slick surface?

I have searched the forums and found that some still race a leaf car, but an FR-1 of something like that. This is not one of those. But other than the usual, "I can only get 4 or five races out of leaf springs" comments, this is what I have and would like to know some of the spring hook ups and setups that might work on a fairly flat track that turns black after a short while.

Thanks
Russ

tilley88
Dirt Forum Champ
Total posts: 879
posted January 15, 2005 04:17 AM  
Go to the mod tech section on www.4m.net , and look up any thread on the "fastboys" setup. I'm building a leaf spring e-mod using stack leafs, and I'll try to post pics as the build goes on.

orange2mod
Dirt Maniac

Total posts: 113
posted January 15, 2005 07:44 AM  
We run the leaf setup and won't go back to bars. Go to the 4M.net site and the tech thread for fastboys and read all 7 pages. Direct your questions to scooter40 or dirtrace21 and you'll get all you need. The archives are also full of info. Do this in the modified section.

mdsteacher
Dirt Maniac

Total posts: 145
posted January 15, 2005 09:38 AM  
I run leafs without the Fastboys set up. Too me, it is too much hassle. I do fine with LR stack and RR mono with coil slider. For hard slick tracks, float the RR. I believe randys-racemart (the FR1 maker) sells a floater kit for a decent price. Check it out. I have it on our mod and am faster than ALL bar cars on hard slick track. If I was just a better driver, I'd win more races?????
And yes, you will replace the mono-leaf every 4-6 race nights. A stack should last entire season.

rnoswal53
Dirt Maniac

Total posts: 120
posted January 15, 2005 11:01 AM  
WOW! Thanks for the replies. I will go to the site you all talked about. After being so successful with the mini stock I drove for so long, I don't really want to ride in the back all year and it sounds like I don't have to.

Thanks again.

Russ

Xtrem4U
Dirt Maniac

Total posts: 144
posted January 15, 2005 02:40 PM  
What about side bite on a leaf car?

FASTLAP
Dirt Maniac

Total posts: 171
posted January 16, 2005 05:38 AM  
quote:
Originally posted by mdsteacher:
I run leafs without the Fastboys set up. Too me, it is too much hassle. I do fine with LR stack and RR mono with coil slider. For hard slick tracks, float the RR. I believe randys-racemart (the FR1 maker) sells a floater kit for a decent price. Check it out. I have it on our mod and am faster than ALL bar cars on hard slick track. If I was just a better driver, I'd win more races?????
And yes, you will replace the mono-leaf every 4-6 race nights. A stack should last entire season.

mdsteacher, what do you do to adjust the sidebite? Just curious since you are beating bar cars (which isn't supposed to happen! LOL) Thanks.

[This message has been edited by FASTLAP (edited January 16, 2005).]

mdsteacher
Dirt Maniac

Total posts: 145
posted January 16, 2005 08:05 AM  
When you float the RR with the mono it seems to bite good. Sometimes we'll do that and lighten the coil spring on the RR to about 125#. Again the trick is getting it into the corner (I guess, that is the trick with all cars) where the car will set itself up with a tap on the brakes. We never touch the LR. I have good bite all the way around the track. The chassis builder did his homework on his chassis' (he builds both bar and leaf cars)

OK, we all exaggerate, but maybe there are a few bar cars (especially the 3-link racers) that kick everyone's @ss on hard slick.

[This message has been edited by mdsteacher (edited January 16, 2005).]

rnoswal53
Dirt Maniac

Total posts: 120
posted January 16, 2005 08:37 AM  
I really don't understand what you mean by floating the rr with the mono leaf! What spring weight is the mono and what spring weight is the rr coil spring? Seems like the 125 lb spring is almost all you would want total on the rr...HELP!!

Russ

orange2mod
Dirt Maniac

Total posts: 113
posted January 16, 2005 08:57 AM  
Floating the right rear is a bird cage. Randys race mart sells a very nice piece that will mount your mono up. On my car the r.r. mono is a 65# and the coil is a 150. The stack on the l.r. is a 175. don't worry about adding the rates up for the coil and mono as the coil does all the work. Sidebite? the car rolls hard onto the r.r. and you all but can't break the rear loose. I'm not real good at explaining things so go to the 4m site for the finer details.

zeroracing
Dirt Forum Champ
Total posts: 1875
posted January 16, 2005 09:26 AM  
if the 3 links and the leafs are the fastest on slick then the 4 bar and swing arms need to stop slacking. leafs and 3's should be able to run with a good 4 bar or swing arm, but properly set up a good 4 bar should have a HUGE advantage over the leaf car.

orange2mod
Dirt Maniac

Total posts: 113
posted January 16, 2005 09:33 AM  
Could be true. Who ever is on top of their game that night.

mdsteacher
Dirt Maniac

Total posts: 145
posted January 16, 2005 10:16 AM  
orang2mod is right. I don't explain things well either when it comes to racing. It is a birdcage shackled to the rear and one or two bolts are removed to float the RR. Like I said, only unbolt it when track is dry and slick. I run a 142lb. stack leaf on LR and a 47lb. mono on the RR along with a 150 or 125 coil spring. The coil spring must be mounted to the rear-end. Again www.randys-racemart makes a nice set-up for all this, though my stuff came from my chassis builder. I actually ordered the 8" arch stack spring from randys racemart. Going to see if this adds any advantage.

Zero is also right. A 4 bar, Z-link set up is unbeatable IF set up perfectly. I'd say 1 out of 25 get it right. But also, drivers do make a difference. I'm still learning.

mdsteacher
Dirt Maniac

Total posts: 145
posted January 16, 2005 10:24 AM  
There's a 2001 leaf spring Buzzard chassis for sale in "for sale" section. Same chassis as mine. Buzzard made out of Indiana. Look for them in Florida in the next few weeks. I believe he'll be running the house bar car though.

mudd on the tires
Dirt Full Roller

Total posts: 42
posted January 16, 2005 10:28 AM  
what about the composite leaf springs? would they help or work?

orange2mod
Dirt Maniac

Total posts: 113
posted January 16, 2005 10:32 AM  
From what I get off the 4m site and talking to others that they cost more than they are worth. In some classes (e-mods) I don't think they are legal.

mdsteacher
Dirt Maniac

Total posts: 145
posted January 16, 2005 01:09 PM  
I'm sticking with Afco steel springs. Haven't had problems, why change.

orange2mod
Dirt Maniac

Total posts: 113
posted January 16, 2005 03:15 PM  
We are leaving Oregon on Fri. the 21st for Memphis, Mo. to pick up our new fr1 chassis. Are there any good shops to stop and check out on the way? Will be going I-80 going out and coming back on I-70.

[This message has been edited by orange2mod (edited January 16, 2005).]

rnoswal53
Dirt Maniac

Total posts: 120
posted January 16, 2005 05:29 PM  
quote:
Originally posted by mdsteacher:
orang2mod is right. I don't explain things well either when it comes to racing. It is a birdcage shackled to the rear and one or two bolts are removed to float the RR. Like I said, only unbolt it when track is dry and slick. I run a 142lb. stack leaf on LR and a 47lb. mono on the RR along with a 150 or 125 coil spring. The coil spring must be mounted to the rear-end. Again www.randys-racemart makes a nice set-up for all this, though my stuff came from my chassis builder. I actually ordered the 8" arch stack spring from randys racemart. Going to see if this adds any advantage.

Zero is also right. A 4 bar, Z-link set up is unbeatable IF set up perfectly. I'd say 1 out of 25 get it right. But also, drivers do make a difference. I'm still learning.


Ok I went to randys racemart and saw the leaf floater for a mono leaf. It takes the place of a leaf perch and 1 1/2 in lowering block. I also saw the HD steel birdcage retainer. Other than the coil spring mount, is that all I need for the rr leaf spring? I am not sure about the birdcage part. I see different types and I don't see what they are for on a leaf spring setup. I have also heard mention of a slider for the rear of the leaf. I have also heard of an adjustable, up and down mount for the rear mount. What about these pieces.

Sorry to ask so many questiions, I hope you don't mind going over them with me and anyone else who is not sure about this type of setup.

Thanks
Russ


orange2mod
Dirt Maniac

Total posts: 113
posted January 16, 2005 05:54 PM  
The r.r. floater is the birdcage. All that is happening here with the floater(birdcage) is the monoleaf is basically a locator. The r.r. will work off of the coil spring. The slider that we're talking about is a coil spring eliminator to be mounted behind the rearend housing. This last year we ran the coil on top of the housing but going to change to a slider this year. Mount your shock in front of the rear end and your coil either on top with a weight jack or behind on a coil slider.

rnoswal53
Dirt Maniac

Total posts: 120
posted January 16, 2005 06:30 PM  
quote:
Originally posted by orange2mod:
The r.r. floater is the birdcage. All that is happening here with the floater(birdcage) is the monoleaf is basically a locator. The r.r. will work off of the coil spring. The slider that we're talking about is a coil spring eliminator to be mounted behind the rearend housing. This last year we ran the coil on top of the housing but going to change to a slider this year. Mount your shock in front of the rear end and your coil either on top with a weight jack or behind on a coil slider.

Do you find one slider better than the other? Randys racemart has 2 to choose from. One holds an 11 or 13 in coil and the other holds a 13 to 16 in coil. Both 5 in dia. One, the one I like costs 79 and the other costs 129. I like cheaper.

Russ


orange2mod
Dirt Maniac

Total posts: 113
posted January 16, 2005 07:26 PM  
I use the 11'-13'' because I like cheaper too.

mdsteacher
Dirt Maniac

Total posts: 145
posted January 16, 2005 10:10 PM  
You can also mount the coil slider with coil spring in the front of the rear end. It is attached to the rear by the leaf perch mount. I haven't tried any other way. Also, shock in front on both RR and LR.
I also use 11-13" gaerte eliminator, but have used other brands and all seem to work the same.

I also recommend using spring shackles versus the leaf sliders (this might be what you thought we were talking about) on the rear mount. I've only heard that leaf sliders bind up. Plus, the chassis has to have the set up for leaf sliders. Also, the RR front leaf mount should be bolted extremely tight. Do not let it move around or it will make the hole oblong . . . bad.

[This message has been edited by mdsteacher (edited January 16, 2005).]

rnoswal53
Dirt Maniac

Total posts: 120
posted January 17, 2005 12:15 AM  
OK, how about the shocks themselves. Which type would be best. Do I particularly want a soft compression on the rr and just the opposite on the lr or keep them the same? And is it just a matter of preference as to being in front or in back mounting of the shock on the rear end or is there a genuine reason for doing one or the other?

mod4racer
Dirt Newbie

Total posts: 2
posted January 17, 2005 07:13 AM  
What length shackles are you using? Also, what height lowering blocks do you use? Thanks.

mdsteacher
Dirt Maniac

Total posts: 145
posted January 17, 2005 10:44 AM  
Shocks, lowering blocks, shackles, etc. depends on the ride heighth you are looking for on the RR. Again, I don't worry too much about the LR. Ride heighth RR is around 6.75 to 7 inches.

Shocks we use are Carrera LR - 94 and RR - 95; the 31 series. We use normal spring shackles. The lowering block I believe is 2 inches total on the RR. The rear damper shock is set at 8 degrees upward angle.

My guess is the shocks being mounted in the front of the rear help the car settle when off the gas. I bought the car this way and was told to leave it that way. So I did.

This is about all I know.

tilley88
Dirt Forum Champ
Total posts: 879
posted January 17, 2005 02:48 PM  
Shocks in front help keep the rear of the leafs freed up.

mdsteacher
Dirt Maniac

Total posts: 145
posted January 17, 2005 06:46 PM  
Thanks Tilley88.

orange2mod
Dirt Maniac

Total posts: 113
posted January 17, 2005 07:05 PM  
I'd rather see the coil slider mounted to the rear because when you are on the gas and the pinion is coming up the coil on the rear with the weight it is getting helps that pinion raise. Remember the mono on the right is floated.

tilley88
Dirt Forum Champ
Total posts: 879
posted January 17, 2005 10:42 PM  
Yeah, definitely put the eliminator behind the rear on the right side, and remember to lock the floater when runnin' on tacky.

rnoswal53
Dirt Maniac

Total posts: 120
posted January 18, 2005 04:59 AM  
Never having seen the floater system for the right rear, but I am getting a better picture. If you loosen the pinch bolt to allow it to float, doesn't a lot of wear occur between the leaf mount and the rear end? In order to keep it tight for a tacky track and floating for a slick track, does all that tightening and loosening of that single bolt cause any problems with keeping it tight when you need it to be tight? Since thelr never need to be loosened is it better to tack weld it or does the bolt hold it well enough for it no to slip. All I noticed when looking at the spring perches was that they were a single bolt design and worried about strength and longevity.

Thanks
Russ

tilley88
Dirt Forum Champ
Total posts: 879
posted January 18, 2005 01:27 PM  
Apparently, you were looking at the wrong floater assy. The correct one has (4) bolts that look like they clamp on, but in reality probably have .040"-.060" clearance between the floater and the housing. You keep the floater greased to eliminate most wear on the housing. You also have a bolt-on or weld-on retainer on each side of the floater, which in turn have (1) or (2) short tubes that line up with (1) or (2) tubes on the floater assy. in which the locking bolt/bolts will pass thru. You will have to add these yourself. Also, do not mount the coil-over eliminator or shock to the housing on the RR, mount them on the shock plate above or below the leaf. The whole idea behind floating the RR spring is to allow the housing to rotate inside the floater, allowing the LR to gain more bite. I'm still working on gettin' some pics. Racemart has a pic of the correct floater. I'll try to get a part number for ya. Southwest Speed also sells this piece, along with the guys mentioned from www.4m.net .

tilley88
Dirt Forum Champ
Total posts: 879
posted January 18, 2005 01:37 PM  
OK, my bad. The one that Racemart sells is for floater rearends, where the assy. slides onto the housing. Won't work with a standard 9". The one Southwest Speed sells you can "clamp" on. The Racemart piece is nice, tho.

rnoswal53
Dirt Maniac

Total posts: 120
posted January 18, 2005 02:35 PM  
Ohhhhhhhhhhhhhhhhh I think I see what you are talking about. Thanks for the patience. I will get there eventually. And yes I would still appreciate it if you did get those part numbers.

Thanks again

Russ

A&M Motorsports
Dirt Maniac

Total posts: 117
posted January 19, 2005 06:54 AM  
You guys really got my pea brain working now. If this leaf set up works as well as you guys say it sounds like the way to go.

------------------
Artie Perilloux
A & M Motorsports

rnoswal53
Dirt Maniac

Total posts: 120
posted January 22, 2005 09:17 AM  
Finally got the car over at my house. Not bad, but every corner needs to be brought up to date. The front tires are standing straight up. The rear leafs are four leaf truck leafs almost, very stiff. I am very excited to get to work on it though. With all the information and advice you all have given me in these posting I should have a pretty nice car.

I will keep this posting going with updates and see how all this stuff goes together. Thanks again everyone.

Russ

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