Tech Talk

I have not tried a big front spring split yet. I presume this would reduce body roll. I know I'm getting soft on the springs so maybe I should keep the LF at 800 and go 1000 at the RF? I have a 1025 spring in my collection.

I could reduce body roll by moving the moment center more to the right too. Right now its around 6" right and stays in that general vicinity in dive and roll. I need better data on the dive and roll to really know whats happening. What I learned with my video of the LR those shock travel indicators are showing max travel over bumps and not whats happening in a turn.

I'm not low on the frame heights. The LF is at 7" and I pitch up a bit to the other corners. Lots of dive with 20 degree banking.

Hope I'm not boring folks with this thread. There is oodles of info here in old posts but none of them ever get closed out with what ended up working. I'm gonna document my struggles here till I get it right or quit. I know these metric cars work somehow. I get passed by them all the time.

Quote posted by timmj:I have not tried a big front spring split yet. I presume this would reduce body roll. I know I'm getting soft on the springs so maybe I should keep the LF at 800 and go 1000 at the RF? I have a 1025 spring in my collection.

I could reduce body roll by moving the moment center more to the right too. Right now its around 6" right and stays in that general vicinity in dive and roll. I need better data on the dive and roll to really know whats happening. What I learned with my video of the LR those shock travel indicators are showing max travel over bumps and not whats happening in a turn.

I'm not low on the frame heights. The LF is at 7" and I pitch up a bit to the other corners. Lots of dive with 20 degree banking.

Hope I'm not boring folks with this thread. There is oodles of info here in old posts but none of them ever get closed out with what ended up working. I'm gonna document my struggles here till I get it right or quit. I know these metric cars work somehow. I get passed by them all the time.

First fix the RF camber / caster,....tell you see 10* across the RF tire..!!!

you need weight and heat transferred to the LR...!!!
the Big RF @ 900, will do that...!!

and the softer 650 in the LF ,
...will allow more left side weight transfer back to the left rear ..tire...!!
and it will take heat and weight off the RR...

btw- i think your RR spring is too soft..try even across the rear.., or no more then a 50lb split...



Bar controls body role...

i run as much as a 1400 lb RF spring on pavement..

to send as much weight as i can to the LR...

my springs are...: 650 LF 1400 RF
..................: 250LR ..225 RR

your temps say your getting closer ..!!
don't quit quite yet...


this is aq little over do ... But what is your shock setup...???

I've set the RF camber as far as it will go without cutting the frame and remounting the shock. Gonna need a few days of vacation to tackle that. The upper arm hits the shock in dive the way it stands now.

Sooo many things I want to try. Missed practice tonight - had to take dear old Mom to the airport. I tend to make small (no very bold) changes on race nights. Fearfull of wreslting a really bad car through a 25 lap feature.

So maybe for Saturday I go up on the RF? I have a 900, 950, and 1050 on the shelf. Going back over my notes the 800LF and 900 RF combo was great for a few laps and then pushed bad with only 56% cross. Front tire temps were 20F greater than the rear tire temps. Kinda why I went down on the spring rates......

Shocks are:
LF=5 RF=6
LR=4-6 RR=4

On the shelf I have a 5, 6, 6-3, and 3-5.

trim the a arm , dent the header.,.. or what ever you need to do to increase the camber / caster too the right front...
that's most of the problem...!

the rear shocks are ok...
id use split shocks on the fronts ..!!!
like a 3/7 lf ,..and a 7/3 on the rf


seeing what you have ,
id put the 3/5 on the LF , and the 6/3 ,on the RF.
go with the 650 to 700 , on the LF,...and a 900 or more on the RF..
the bigger split will load more weight/heat to the LR..

go up on the RR spring,.
or use a rubber....that will add heat to the LF.

and,...TAKE tire TEPS...!!!

if it's tight in the middle ,...use less sway bar ....
ether a smaller bar , or less pre load... !

or get creative and fab something to git you some adjustable slack , on the LF up link..!!

if it feels tight in the rear ,
add rear stagger by dropping the tire Psi in the LR only..!

the big picture is the RF tire,....like it is , it's rolling the RF edge under,...witch lifts the middle of the tire... decreeing the effectiveness of the RF contact patch..., and when you get a balance, it will be at a lower % until you fix the RF...
and it will continue to push ,
tell you address the camber / caster issue in the RF..!!!!

Had a terrible run Sat night. Car had a comical lack of bite off the corners, got spun out, finished dead last. In retrospect a few good things came out of it.

#1: Found $20 bill on the ground.
#2: Got 183/179/176 on the RF without denting the shock. (165/154/154 in heat)
#3: Convinced myself the principal issue is rear suspension sticking or rolling too much and not recovering quick enough.

Here's what I thinking:

Increase RF spring from 850 to 950. I'll have 800#LF and 950#LF
Increase both rear springs 25# to 200#LR and 150#RR.
Swap the shocks from 5LF 6RF 4-6LR 4RR to 4-6LF 6-4RF 6LR 4RR.

Quote posted by timmj:Had a terrible run Sat night. Car had a comical lack of bite off the corners, got spun out, finished dead last. In retrospect a few good things came out of it.

#1: Found $20 bill on the ground.
#2: Got 183/179/176 on the RF without denting the shock. (165/154/154 in heat)
#3: Convinced myself the principal issue is rear suspension sticking or rolling too much and not recovering quick enough.

Here's what I thinking:

Increase RF spring from 850 to 950. I'll have 800#LF and 950#LF
Increase both rear springs 25# to 200#LR and 150#RR.
Swap the shocks from 5LF 6RF 4-6LR 4RR to 4-6LF 6-4RF 6LR 4RR.



well you found loose....lol
you fixed the front end ,... and now...
it will balance out , with much more cross...!

is this a 108" metric..??

if so a 650 lf... and more kike a 1200+ RF..

250 lr .......RR 200. too 300.., depending on LF tire temp..

your shocks are ok... find a 4/4,..to 4/3 ,.... for the LR..

Timmj,

I have watched this thread from the beginning. I haven't wanted to chime in much about the advice you're being given by racer270, but please do report back if you try it. I don't want to come across as argumentative because just about any setup can me made to work decent enough. I have just never tried the drastic front sprint split and high cross he's recommending. If fact, I've found a great deal of success with much smaller front spring splits with much lower cross weight numbers. Some folks have even had great luck running heavier on the LF spring than the RF with metric cars depending on the track type. Best of luck, and please do report back.

Crewchief99... please feel free...

i should have asked if it was a 108" car.... from the first questions ...

i ran this spring package ....on my metric 108" car...

but my shocks were more aggressive....on the front...!!
with as much as60% cross..

and 1.5 in, of rear stagger...

with out even 10 laps on the car,....i Qed in Q3....
finished 3ed in the main also..only to discover my Buddy's that helped me scale the car , had added a Extra 100lb...lol

the car needed to be 3200,...after the race,...
with just a little help from my friends...
it crossed the scales @ 3340...lb...

the main point here was the camber & caster were reducing total front grip..
for him...
he went from a push , to loose as hell... from mostly just correcting the front contact patches...ability too stick... ...


and that's why i told him to get the front tires working , before he tried for a grater balanced car...

i take no o fence ,
...and im not past the point of learning ...so jump it...!!..

I appreciate all advice. It gets me thinking about whats going on. I can also use it to provoke my fellow racers into interesting discussions. I got a whole different set of filters for listening to them!

I will continue to chronicle my efforts.

I bought a RePlay HD camera to see whats happening on each corner. I learned alot filming the LR with my old 8mm.

Yes its grampa's old 108" go to church car.

Quote posted by timmj:I appreciate all advice. It gets me thinking about whats going on. I can also use it to provoke my fellow racers into interesting discussions. I got a whole different set of filters for listening to them!

I will continue to chronicle my efforts.

I bought a RePlay HD camera to see whats happening on each corner. I learned alot filming the LR with my old 8mm.

Yes its grampa's old 108" go to church car.




a video will help you a bunch... ,..play it in slow motion,..forward and reverse..!!!

your going to end up about 60% cross.. to get the crazy loose out of it..now..!
with the front tires working...now.. \~~\ it won't push..any more..

So I did my video's of each corner (thumbs up for the RePlay XD) and found some interesting stuff going on in the rear. As expected the RR compresses in turn 1 to the apex. The LR extends. I wasnt really expecting this on the 22 banked track. From the apex off under power the RR compresses further and the LR extends a little more. The LR does not return to ride height until just before the next turn entry. So in effect the body roll reaches a set static position at the apex and then continues to roll under acceleration, releasing the LR.

Also the two 'soft' rubber bushings I have in the front upper links of the rear are allow the rear end to twist ALOT. Rotates down in deccel and up in accel. I already changed the right side to a poly bushing. Past track champion said he had poly bushings everywhere and didnt have any bind issues.

My camera experiment opened several good discussions and I've been told to stiffen the shocks all around. Going to put AFCO 7's in the front. REportedly the AFCO's dyno consistently and are stiffer that the PRO's which reportedly never dyno consistently. Advice is from the top two competitors from last year, who moved up to late models. Going to use my front PROs in the rear.

Tim,
run split shocks ... 3/7 in the LF , and a 7/3 in the RF..
the direction i suggested for the springs..
ie. the huge RF spring will plant the LR...on these metrics..

the stock bushings are junk.. the poly bushings ,.. are best for the rear..
but make sure to use steal for all the front A-arms..

and post temps..!!

as far as your camera experiment opened several good discussions...?

why are you tell people your racing..against, what your finding..

The AFCO 7's in the front made a huge difference. The front end feels much more stable and rolls less and helped alot with traction center off (even thought the tire temps dont show it). I put old old front PRO's in the rear. Will be buying new 5 and 3 AFCO's for the rear.

Springs were 800 LF, 900 RF, 225 LR, 175 RR. Cross was 56.4%. Bar just snug.

Tire temps were:
169/179/169LF 215/216/186RF
172LF Ave 206RF Ave

156/164/160LR 192/201/207RR
160LR Ave 200RR Ave

My tire pressure maintenance was sloppy I know. Left the laser in the sun before practice and its brains scrambled. Long tech line after the heat race so no temps to tune off of for the feature.

Still need more bite. We'll see what the rear shock change does.

So in my mind the big mystery of my loose off is coming to a close. Went up and down and sideways on spring combo's when the cure was to be found in shocks. The $80 non rebuildable shock rule does not take shocks out of the setup equation. Still important. Maybe critical.

the LF still needs camber , if you can get it...!
that will add more total front grip..and the balance will again loosen up..

the psi in the LF FR , and LR...are all to hi..!!

try LF 9 to 10 psi..
RF 26 to 27 psi..
LR... drop by 1 psi..
fwi-
your average tire temp should also be the same as the middle tire temp..
adjust the psi.... to cool the middle of the LF, RF , and LR..

your cross is a touch low now..! , it will need to go up ,
when you fix the LF camber...setting..!!

the LR is cold , compared to the other 3 tires..!
you need to go up...on the RF spring ,
to put more heat in the LR tire..& take some heat out of the RF tire.....!!
and shocks are a big tuning deal.. change the rears....asap..

when you get this adjusted right, your cross will need to jump up to about 60%..

Quote posted by crewchief99:Timmj,

I have watched this thread from the beginning. I haven't wanted to chime in much about the advice you're being given by racer270, but please do report back if you try it. I don't want to come across as argumentative because just about any setup can me made to work decent enough. I have just never tried the drastic front sprint split and high cross he's recommending. If fact, I've found a great deal of success with much smaller front spring splits with much lower cross weight numbers. Some folks have even had great luck running heavier on the LF spring than the RF with metric cars depending on the track type. Best of luck, and please do report back.

I agree.
I run a metric, and although my rules put more restrictions on what i can do to my car vs what you can do, i found a perfect balance from 47.8% to 48.2% cross depending on time of year/track conditions.
I do a lot of reading about setups, and found some qualified opinions in a couple articles that stated a car that has a lower rear percentage (stock car, hobby stock, street stock) will usually find a better balance with negative static cross weight.
Notice 'static'. i don't have the expensive pull down machines, but you can put a softer RR spring or stiffer LF and still put car at negative cross with adjusters.
My car is a Pontiac LeMans, and won championship in 2011, and is consistent top 3 against Camaros.
just my 2 bits.
I can share more details if you have email.

Quote posted by RacerX1622:Quote posted by crewchief99:Timmj,

I have watched this thread from the beginning. I haven't wanted to chime in much about the advice you're being given by racer270, but please do report back if you try it. I don't want to come across as argumentative because just about any setup can me made to work decent enough. I have just never tried the drastic front sprint split and high cross he's recommending. If fact, I've found a great deal of success with much smaller front spring splits with much lower cross weight numbers. Some folks have even had great luck running heavier on the LF spring than the RF with metric cars depending on the track type. Best of luck, and please do report back.

I agree.
I run a metric, and although my rules put more restrictions on what i can do to my car vs what you can do, i found a perfect balance from 47.8% to 48.2% cross depending on time of year/track conditions.
I do a lot of reading about setups, and found some qualified opinions in a couple articles that stated a car that has a lower rear percentage (stock car, hobby stock, street stock) will usually find a better balance with negative static cross weight.
Notice 'static'. i don't have the expensive pull down machines, but you can put a softer RR spring or stiffer LF and still put car at negative cross with adjusters.
My car is a Pontiac LeMans, and won championship in 2011, and is consistent top 3 against Camaros.
just my 2 bits.
I can share more details if you have email.

I have read alot of Bob Bolles and have been thinking about testing with a low cross. I even had it jacked it into my car once but practice got cancelled that week. I emailed Bob about my cold LR but he has yet to reply(lol). At this point it seems counter-intuative to take weight off the LR when I'm fighting to get it there off the corner. I pit next to the former Sportsman track champion and qualifying record holder. He only drives his late model now so he's been slowly revealing his old setups. He ran 54% cross and 2.5 turns on the bar. I think once a get this 'conventional' setup working I will experiment with the low cross setup. Maybe I'll even hear back from Bolles.

Congrats on the championship. Thats alot of hard work and alittle luck. My email is tmj@grummanbutkus.com

I take what Bob writes with a little salt.
He talks most to east coast tracks.
And they seem to maintain the 'stiffer is better' philosophy.

We don't run suspensions nearly as stiff.
For example, a new guy last year called a shock/spring company for setup info on his '82 Monte, and they told him 800/1000 in the front.
And he wondered why his car pushed the asphalt right out of the corner.

maybe i'm wrong, but we have a 1/2 mile slightly banked track and we are in the 23 seconds in Pure Stocks and 22 seconds Hobby Stocks.
(late models in 18's, Streets in 20's)
Bob knows a lot, but there are SO many variables.

I also run a Camaro Street Stock, and one thing i learned, was if you are running the 'ladder bar' shackles (for adjustment) get rid of them.
We found (at least for high speed corner track) the torque put on them as you go down increased so much, that it put the bushings in a bind, and springs (rated) did not act consistent, if at all. I actually went back to stock, some guys use the sliders, some with shorter than stock, and change lowering blocks.
Anyway, The front stiffness depend on speed of car, banking, length of corner (which all equals g-force, roll couple, etc.) and although all these guys have good advice, it usually pertains to their specific track, and may throw you completely off. (lesson learned)
Tire temps, and I use a zip tie on the shocks to measure travel, I let other drivers drive my car, and use all three to make adjustments.
Keep on it.

I meant to say when you go into the corner, not "go down".

Has anyone tried bumpstops on the front of a 108" Metric?

first of all a 108" metric.. is nothing like a Camaro,
,..it's a 4 link , not a leaf spring car..

there set up's are not even close..to the same..as far as springs...

there 3" narrower , 3" shorter..,& 3 " higher ,

the spoon on the clip...is most of the front end height problem !
along with the A-arms..
there 6" frame height cars.., unless you use 2" drop spindles...or ,*&^%$$%

as far as a RF bumpstops , i came close with a 1400lb RF spring..lol

because there short , narrow , and high...//
you need a big RF spring..and lots of cross%... to get them to work..

or bumpstops...???

Quote posted by racer270:first of all a 108" metric.. is nothing like a Camaro,
,..it's a 4 link , not a leaf spring car..

there set up's are not even close..to the same..as far as springs...

there 3" narrower , 3" shorter..,& 3 " higher ,

the spoon on the clip...is most of the front end height problem !
along with the A-arms..
there 6" frame height cars.., unless you use 2" drop spindles...or ,*&^%$$%

as far as a RF bumpstops , i came close with a 1400lb RF spring..lol

because there short , narrow , and high...//
you need a big RF spring..and lots of cross%... to get them to work..

or bumpstops...???
camaro wheel base is 107, and is wider than an a body, not even close to 3 in higher. and 1400 spring is nothing like a bump stop! are you high?
my experience is mainly with camaros, and have run springs from 10000 to 400 in the front, I prefer the softer front springs. i do know racers that run the metric chassis, and also run verry soft up front. 500 to 550
most setups take alot of time and work to get right. test and tune but if you are giong to try someones set up and only go half way, don't expect it to work. All drivers, and i mean All drivers. like somthing different. and nobody knows what that is but him.

oops 1000 lb spring not 10000

front springs getting softer. just came in the mail. sub 400. hope it works?next is new shocks.

Quote posted by racer270:first of all a 108" metric.. is nothing like a Camaro,
,..it's a 4 link , not a leaf spring car..

there set up's are not even close..to the same..as far as springs...

there 3" narrower , 3" shorter..,& 3 " higher ,

the spoon on the clip...is most of the front end height problem !
along with the A-arms..
there 6" frame height cars.., unless you use 2" drop spindles...or ,*&^%$$%

as far as a RF bumpstops , i came close with a 1400lb RF spring..lol

because there short , narrow , and high...//
you need a big RF spring..and lots of cross%... to get them to work..

or bumpstops...???
I'm getting ready to turn my old Metric F8 car into a street stock, but last time I ran the oval it was crazy loose at entry, middle, and exit but was turning good lap times (5th fast).
I didn't change anything from the F8 setup except to dial in about 52.5% cross.


3150# total w/driver
53% left
48.2% rear?
Springs
1400LF-1400RF
145LR-145RR
Carrera 4/6LF & RF
NoName very soft rear shocks
Camber -4.25deg L & R
Caster 2.5deg L 3deg R
Ride Height 4" (Using tall monoballs to eliminate bind and bottoming)
Rubber bushings all around and stock mounting points

I was getting some hop on deceleration, but there was no sign of bottoming on the RR.

From what I've seen on here, I should just start over.

Quote posted by redneckracer:Quote posted by racer270:first of all a 108" metric.. is nothing like a Camaro,
,..it's a 4 link , not a leaf spring car..

there set up's are not even close..to the same..as far as springs...

there 3" narrower , 3" shorter..,& 3 " higher ,

the spoon on the clip...is most of the front end height problem !
along with the A-arms..
there 6" frame height cars.., unless you use 2" drop spindles...or ,*&^%$$%

as far as a RF bumpstops , i came close with a 1400lb RF spring..lol

because there short , narrow , and high...//
you need a big RF spring..and lots of cross%... to get them to work..

or bumpstops...???
camaro wheel base is 107, and is wider than an a body, not even close to 3 in higher. and 1400 spring is nothing like a bump stop! are you high?
my experience is mainly with camaros, and have run springs from 10000 to 400 in the front, I prefer the softer front springs. i do know racers that run the metric chassis, and also run verry soft up front. 500 to 550
most setups take alot of time and work to get right. test and tune but if you are giong to try someones set up and only go half way, don't expect it to work. All drivers, and i mean All drivers. like somthing different. and nobody knows what that is but him.


im sure your a legend in your own mind redneck....lol

most tracks have rules against camaro's even competing.

widest A-body is a big car..impala..ect...
your camaro.. is not as wide.

ive run a 108" metric for 12 years... so please tell me more..lol
TRY TO GET ONE BELOW 6" FRAME HEIGHT....LOL

the close to a bump stop ,
was tongue in cheek..with a 1400lb..RF spring..

all drivers like a car that works....!!

is your still changing springs at this point in a session....??
YOUR LOST...LOL

REMEMBER THERE IS no such thing as a car that pushes on entry.. ,
just grow some balls....son. and drive.....