97pontta

iTrader: (10)

Well I just finished my first track day (track orientation) at Raceway Park of the Midlands http://www.midamericamotorplex.com/site/about

I had an absolute blast and cannot wait to go back again to begin honing my driving skills, but would like a few suggestions from experienced F-body guys as there was no one driving a f-body at the track for me to ask questions.

A little info on the car, it has changed over the years from drag race minded to turning corners. I was getting bored with the car back in 06 and the stock suspension was getting high on miles and wanted to upgrade with a focus on braking and handling. I installed the parts below over the following couple of years.

-Toyo Proxy T1R 265/40/17 front and Toyo Proxy T1R 295/35/18 Rear

-Strano springs with Koni SA 4/4 shocks

-Strano front and rear sway bars

-Upgraded to LS1 brakes front and rear along with a new LS1 master cylinder, with a fresh bleed of DOT 3 fluid the day before the track event.

-ATE rotors and Hawk HPS pads on all 4 corners

-9" rear end with a Wavetrac diff.

-Removed ABS and installed a proportioning valve.

-LCA relocation brackets

-UMI Roto joint LCA's

-BMR full length Torque Arm with trans relocation

-adjustable pan hard bar

The biggest problem I had at the event was brake hop which I have never experienced on the street as I have never driven the car this aggressively. I adjusted the prop valve for more front bias and softened up the rear shocks to about 1-1/2 turns down from full hard to soften up the rear a little. I also was running 30 psi in the front and rear tires and I went down to 28 in the rears which seemed to improve a little but I could still feel the car trying to start brake hopping so I was a bit nervous. These changes also seemed to help with over steer as well.

All I have ever done with the car was run in a straight line and that is how the torque arm and rear LCA's are setup, with accel traction in mind. I'm running the rear LCA's so the axle side is about 3/4" lower than the chassis side. The torque arm is setup on the trans relocation mount with the lower bolt 4 holes up from the bottom which is just above the half way point on the mounting hole choices. I'm looking for input on the LCA and torque arm setup and if it will help eliminate the brake hop. I know that my driving technique also will play a big role but I just want to make sure my suspension is setup somewhat correctly first.

M4N14C

iTrader: (3)

Keep the hawk pads on the front but get some cheap autozone ones in the rear. That should help a lot with your brake hop.

Also try running the LCA a bit higher on the axle side and see what that does.

JD_AMG

Probably a combination of things, the torque arm , relocation brackets and rear pads.
I would'nt replace the rear pads yet, work with what you have for free first.
Try messing with the torque arm mount, or removing it all together. And same with the relocation brackets, make the LCA's flat or angle them down toward the car (opposite of how you have them now).
Is that diff a locking diff?
One more thing, unrelated, the staggered wheel/tire setup is not helping you handling.

97pontta

iTrader: (10)

Thanks for the input guys. My LCA relocation mounts are welded on so I cannot remove them. I will move the axle side of the LCA up two holes and see what that does for the car. On the torque arm mount/trans crossmember, I don't have a stock one as I swapped the T56 into the car and that is what I purchased for a trans crossmember at the time. I will change the LCA position and try that before I mess with the torque arm.

The diff is an open differential and seemed to do a really nice job with transferring power from what I could tell with my limited track experience thus far.

I had read that the staggered wheel setup wasn't the best for handling. I purchased these wheels and tires back in 07 and was mostly for looks. The tires are also down to about 40% tread so they will be needing replaced soon. I'm hoping that I have a chance to do at least 2-3 more track days this year before the end of the season so I can find out what I like and what works. If I continue to run at the road course I would like to get a set of wheels for the track. My current wheels are the OE Wheels C5 Deep Dish style and are ridiculously heavy. I know this is down the road but I'm leaning towards 17's all around.

beach cruiser

iTrader: (1)

I would soften up the rear shocks to two clicks from full soft. I run HP+ pads in the front and cheap autozone pads in the rear, but I don't have a prop valve. I have pretty much the same setup as you other than the torque arm. I also run 315's on all four corners.

97pontta

iTrader: (10)

I made a few adjustments and tried the car out again. I moved the rear link of my LCA up one hole which puts the front and rear parallel right with the ground now. I also softened up the rear shocks to one turn from full soft. The car seems to brake hop a little less but still does it but the problem is still there. I did a few test starting at 40 mph and worked my way up to check for brake hop. It seems like the brake hop really doesn't show up until about 60+ mph when stopping hard. It seems like the longer the braking period the more likely it brake hops which makes me wonder about the Haw HPS pads in the rear. Is it possible that when they get warmed up from a longer brake slow down they are biting harder which is causing the brake hop?

I think I'm going to try and raise the axle side of the LCA one more hole which will put the axle side a little higher than the chassis side of the LCA and try again.

79_T/A

iTrader: (1)

You need better front brake pads.

gscherer78ta

iTrader: (1)

Try some Hawk pads on the front, HPS+ or better. In addition to that, I think your first post suggested that you had DOT 3 fluid. You need a higher boiling point fluid for these big cars- DOT 4 at least or DOT 5 if you want to flush your system and go with something that you should be able to boil.

Congrats on your first Autocross! They are so addictive!

Midnight02

iTrader: (8)

As noted above, I'd throw more pad on the front to see if it helps. The HP+ is one option, however I prefer the DTC-30s and DTC-60's over those. If you are running dedicated track pads, I would go with the DTC-60's on track. If you're looking for a mixed use pad (street and track), I would go with the DTC-30's.

Also, one trick I learned from others on here to help with pad knockback is to lightly press the brake in the straight as you are getting ready to enter the braking zone. I played around with different pad combos and started doing this and don't have nearly the brake hop issues I was having before.

From a tires and wheels standpoint, if you want to start spending more time on track, it might make sense to get a dedicated set of 18" track wheels. Better tire selection and availability and a little more flexibility if you look to upgrade the front brakes down the road.

The OEM C5 Z06 Speedlines and Alcoas make great budget-friendly track wheels. The standard set is staggered, however many just run the rears (18" x 10.5") all around.

97pontta

iTrader: (10)

Thanks for the input guys. I will look into new front brake pads, the HPS pads I have now are getting down to about 30% and need replaced. Can I use the same rotors if I go with different pad? My ATE rotors are in really good shape and can be reused if the pad will allow. I see recommendations to run DOT4 or DOT5 brake fluid. Is that compatible with my stock brake system? Is there a specific brand that I should lean towards? Also my car isn't daily driven at all, street driven on the weekends and then to track evens or 1/8th mile drag. The car hasn't seen over 5k miles in a year for a long time.

I'm going to strongly look into a dedicated track rim and tire if I can get to the track often enough to make good use of them. My current Toyo tires are needing replaced and don't want to have to compromise with a tire for both the street and track.

One more thing, I see a few replies saying they have similar setups for springs, sway bars, shocks. What setting are you guys running your front Koni shocks at? I installed them years ago and cannot remember where they are set and would like a base line to start from for track use.

brigade24

DOT4 is compatible with DOT3...but DOT5 is NOT!!! ATE brake fluid (DOT4) should be sufficient for your purposes...

many ppl run separate pads and rotors for the track and street particularly the more advanced drivers which i agree with. you don't have too...but it is better, considering the bedding of the brake pad material on the rotors. there are different thoughts so mine is simply an opinion.

you will have more options in the cheater tire segment if you go to 18"...RS3, Rival, direzza Z2, etc...but for R-Comps there are still more options in the 17". In your particular case, i reco going with an 18x9.5 corvette wheel...the max width you can get in an 18" RS3 is 285 and i believe that's the same for the Z2...the rival is available in wider sizes however that may be overkill.

97pontta

iTrader: (10)

I will plan to switch to ATE DOT4 fluid, as well as some new brake pads at the end of the year as mine are getting low on material.

Another question, I had my car aligned by a local Tires Plus years ago and I question the accuracy of the alignment and think they may have done a "toe and go" on it. I've found a different shop that has a good reputation and plan to take the car there to have the alignment checked as I swear I can see "toe in" just by looking at the front of the car, not to mention irregular wear on the tires. What alignment specs should I ask to hit? As much negative camber as possible? Straight toe? What about Caster?

Back to tires, my street tires are going to need replaced at the end of the year. I've seen some good recommendations for a track tire which I strongly consider to get once I have more driving experience. Is there a street tire that is somewhere in between that I can use until I decide on a dedicated track setup? My car isn't daily driven at all, weekend and "fun" driving is all I do with the car and don't plant to change that.

Thanks again for the info, I'm trying to learn as much as I can.

brigade24

I got fed up with the alignment shops so i just do my own. Because the adjustments for caster, camber and toe are all on the lower control arms, they must be done in order: 1.caster 2.camber 3.toe. I run max positive caster since it is what the subframe will allow...that brings me to about 4.75 - 5.25 deg. I run max negative camber...again here i am limited by the subframe so i am sitting 2.0 - 2.1 deg...this camber setting is ok for autox but you would not need that much for lapping. keep in mind, tire width plays a role...for example, the wider the tire, the less camber would be required.

I set toe at a 1/16th inward...i know lots of autoxers/lappers say that toe out is ideal for quicker turn in and that is true by all accounts however toe-out will make quick work...very quick work of the inside of your tires so since i am cambered in, i toe-in to preserve rubber.

when i load the front suspension (nose dive) the tires will briefly toe-out so in an attempt to have the biggest contact patch (flattening the tire so to speak) i am toed-in to compensate for that in the hopes of maximizing cornering grip.

suspension is never done...Amen.

hard to reco multi-purpose tires when you are not running a square setup so i will share what i did...i used the BFGood. Comp2 on my 17x9 factory wheels. i used these for lapping/street duty last year...they are still on my car right now. IMO, they represented good value as they held their own on track, very consistent high performance tire..when they heat up they were a touch greasy but still performed...

97pontta

iTrader: (10)

I like the idea of doing an alignment myself. Is there a specific set of tools that can be purchased? Seems doing the alignment yourself would allow an individual to fine tune things much easier than going to the alignment shop each time.

FASTFATBOY

iTrader: (23)

Put a DTC 60 or so on the front, leave the HPS on the rear, these cars teach you to be smooooth on brake application...or your teeth will fall out. Brake hop tears up stuff, breaks welds and bends things in the rear.


Leave the rear control arms flat with the ground.


Tap the brake with your left foot on the straight prior to the brake zone, don't drag your foot on it. I am in a Vette now and I STILL do it . This will push the rear pads back out and give you a firm consistent pedal in the brake zone.

Start braking a tad earlier, ease down on the pedal, as the weight rotates to the front squeeeeeze it down. I got pretty good at this once I replaced some bent parts on my rear end.

That tire setup will make the car push, if you want to run it you need more rear bar.

Get all your braking done in a straight line, off the brake and turn in.

These cars are naturally "*** happy", the tire setup you have may help this, depends on your style.

I had Porsche guys ride with me that got sick, my old car scooted and skipped all over the place. When the rear feels like it wants to come around...crack open the gas and it will settle itself down.

If you want to get good at this .Put a GOOD seat in the car, there is no substitute for this. And by good seat I mean a Kirkey or fixed back fiber seat.

The best mods I made to my old Mullet were:
Kirkey seat, roll bar and belts: Should have been the very first thing I did.

Slotting the front lower control arm slots for more camber: With -2.3 camber the push came out of the car and made my tire wear perfect.

Lowering the rear panhard bar, put a bigger rear bar on(22 solid I think) and 200lb rear springs: This gave huge confidence and was worth at least 1 second on track, the rear end felt almost glued down. I never really explored this mod to it's full potential.

97pontta

iTrader: (10)

Thanks for the pointers, a seat is definitely on my list. My stock 110K leather seat has seen better days as far as looks and doesn't do much to hold my butt in place. It looks like I will be ordering a set of pads for the front before my next track outing.

Can someone explain why lowering the panhard bar helps? With the car setting on the ground the chassis side of the panhard bar is about 1" higher than the axle side of the bar. Is level with the ground ideal?

79_T/A

iTrader: (1)

The advice from Fastfatboy is fantastic.

Regarding the panhard: no need to have it level. What we are talking about is installing brackets to lower BOTH sides of the panhard (not the panhard relocation kits you see people using). Lowering the panhard lowers the rear suspensions roll center. It makes the car far more stable, increases traction out of corners, and allows the user to add more rear spring rate, better balancing the car in my opinion. The same can be accomplished with a watts link by adjusting the propeller down, and adding stiffer rear springs. My car was much faster around the track after lowering the roll center (I have a watts link) and adding stiffer springs.

For your next track day, I would start by upgrading the front pads to track ones like the suggested hawk DTC, and flushing with a high temp fluid like ATE or Motul RBF600. Try and find a good alignment shop to verify your alignment is good. I would shoot for zero toe, and as much caster and negative camber you can get with your current suspension. Another great mod is a supportive seat. Then just go out and get as much seat time as possible. Worry about tires once you completely wear them out, then consider getting a square set (same size front and rear).

brigade24

There are several ways to do it. youtube is your friend...i use a smart camber/caster gauge since it has a setting to level the surface you are working on. if your axle is centered which would be an anomaly for our cars, you can use the rear axle to set your toe even though the track width front and rear is not exactly the same.

for camber and caster, a straight edge (steel square tubing works great), tape measure or caliper, a level and a scientific calculator so that you can convert inches to degrees are what you need to take the measurements.

for toe, i have used jack stands, string and a tape measure but the challenge is to account for the off-centre axle and the difference in the track width making it difficult to establish equal reference points on both sides of the car. so i started using toe plates...i don't like them but the methodology is functional.

to level a work surface, i use a bucket water, clear tubing (10'-15'), a level with a ruler built into it, hydraulic jack, some duct tape, salt, and some 1/8" 12x12 tiles (i needed approx. 20 tiles)...

i should probably do a video on this...

brigade24

agreed. i got the seat...just need the roll bar and belts.

FASTFATBOY

iTrader: (23)

To do the alignments.

You need the camber caster tool, I bought one but dont remember where. It's a big horseshoe looking deal that hooks into the lower control arm and the frame with a turnbuckle kinda deal in the middle.

To make cheap turntables to sit the front tires on, get two pieces of old plastic floor tile and put sand in between them.

http://www.tooltopia.com/otc-tools-7...FZE6gQodVQcHmg