AT THE TRACK: Need more front grip

[|Drew|]

Pretty steady understeer all the way in, through, and out of the turns. I'm thinking about lowering the rear just a tad, I'm not sure if this car is weighted or not.

Suggestions?

Also, what's a good hot pressure range for the Pirelli D3s?

[panozracing]

hot ideal is 32psi

if your car isnt corner balanced its very tough to recommend adjustments. ride height would be my last change. how are the tire temps across each tire? what springs are you running, where are the sway bars.....

[Blue Streak 21]

How many temp cycles are on your tires, or is the under steer condition present regardless of tire condition? With the suspension and ride height set up per the manual, and after a good corner balance, I've found the car to be most sensitive to tire condition.

My car goes to an under steer condition the older the tires get. When I'm on new tires, it is very neutral. It also goes to under steer when I've over heated the tires during a run. I run Hoosier Cups, not Pirelli's.

As for lowering the rear of the car, like Brian says, mess with that adjustment last. I'd not go that direction at all. If anything you want more weight on the front, not less. The front goes to under steer when the weight doesn't transfer properly to the front tires. Either the weight moves to fast to the front (and overwhelms the front tires), or not enough weight gets to the front tires (and they don't have the necessary loading to stick). After checking and setting the static parameters (ride height, corner balance, etc.) check bar settings, and shock settings. Those are the components that effect the dynamics most greatly.

[panozracing]

make sure you have the right springs in the car too....

[eric1h]

Originally Posted by |Drew|

Pretty steady understeer all the way in, through, and out of the turns. I'm thinking about lowering the rear just a tad, I'm not sure if this car is weighted or not.

Suggestions?

Also, what's a good hot pressure range for the Pirelli D3s?

Easiest way to correct corner understeer....

trail brake into it, or throttle out of it!

these cars modulate rotation VERY well IMHO, trail brake get the car to start to rotate and then just stay on the gas!


The other suggestions are good too, soften front sway, take out some air pressure in the front tires, or add some depending on where they are at.

[NZGTRA17]

Could also be a front shock issue, may be worth dynoing the shocks if you dont resolve with the adjustments suggested.

I have also found that if you go in to hot you can cause this problem. I have had a couple of off track excursions from simply trying to turn the car in to hard with our highly assisted power steering. Pulling off a little more speed prior to entry and getting on the throttle earlier worked well for me on slow corners.

[carhauler]

In like a Lamb...out like a Lion! Don't forget you need to rotate the car thru the corner.

[Dawgfan]

Carhauler, well said. I can only speak for my car but I think our car LOVES new tires as much as anything. I too am running the new Hoosiers and love them. A lot of grip and if that falls you can always juice them. Works every time.

[P_Mac]

I've found that the steering is the cause for me. With it being so boosted, and having a pretty quick ratio, it tends to dive for the corner before the weight transfers fully, and I plow my way around. The easy things to try are:

1) Trail-brake just a tad more
2) Focus on turning the wheel as slowly as you can get away with. The first 10-15 degrees of wheel input are critical
3) Drop a PSI or two from the fronts (or nudge up the rears)

If that doesn't work, tires, then suspension last...

[boothkc]

My guess is that most of the school cars were set up with understeer to reduce spins and make them easier to drive for clients. As you gain speed and experaince this becomes limiting and there is a need to loosen up the rear end etc.

If you havent had your car aligned yet take it to a "race shop" that can do a proper corner weight alignment and have them set specs and ride height to the GTS numbers. Also install the GTS springs (550# and 300# I think) and you will have a good place to start. This is very worth the initial investment and will give you a good index to make later adjustments.

Properly set up these cars have great turn in, easy throttle stear and are alot more fun when they aren't pushing there way around the track.

Kevin
GTS & GTRA

[Panoz Paul]

For springs I run 550's front / 350's rear .... 5.4 degree caster ; 1.8 negative camber & just a bit of toe w/ BFG R-1s ... I'm going to 750's & moving the 550's to the rear ; this was after Tommey Archer / Mr. Viper showed me what these car can really do !!! By the way ; He teaming w/ BIR for advanced racing school ... Heat cycles are a real issue !!! I've never worn a set of tires out , always had them turn to "wood" from heat & dooooo they push ; I get about 10 track days per set & after the off season of sitting in the garage , you may as well throw them away !!! ... As earlier stated , you must keep the chassis loaded to keep the tires planted ... Google the "BFG R-1 Owners Manual" ; about 8 pages ; they have a chart on how pressure stagger can impact the push / loose play ... I also run a right turn high speed dominate track ,& start w/ 28#s cold & run the left front + 1.5 #s & + 2.5#s left rear ... Got that insight from BIR Instructor Herm Johnson / Retired Indy Driver w/ many top 10's ...

Hope this Helps / Paul M. Winship

[panozracing]

I dont think 750 and 550's is the way to go. I have been racing HARD 2 GTS's since 2004 and we have tried lots of springs....It does depend on the track but I would be surprised to see that much spring on either end.

[eric1h]

I have been running 750/550 for most of the time I have had the Panoz, I think its a GREAT setup. I also pulled the rear sway which also made a huge difference IMHO.

Devin was running a 900/750 setup and it was definetly WAYYYYYYYY too much spring, the car was twitchy and unstable, but with the 750/550 my car has grip out the wazzoo and never feels like its going to break loose.

And yes I am driving it hard enough to know the differnce!, My first time at VIR N in the car i broke the FFR Challenge car record time from 2008 and was 2nd FTD out of 44 cars, it was just in the THSCC TT series, but it still counts in my book.

now for a bumpy track like Sebring it may be too much, but for the tracks I run, RA, VIR, CMP, Roebling, its the best setup Ihave driven so far in this car.

[eric1h]

Originally Posted by panozracing

I dont think 750 and 550's is the way to go. I have been racing HARD 2 GTS's since 2004 and we have tried lots of springs....It does depend on the track but I would be surprised to see that much spring on either end.

And I don't mean to contradict what yore saying, you certainly know your stuff! but for me, the 750/550 is a great setup.

Not bumpy or twitchy at all, and turns well throughout the corner. But like you said, its track dependent too.

[panozracing]

honestly, without a huge crew, how can we really know the right setup for each track. I have been to Barber, RA, Homestead, Daytona, Sebring, Moroso (old track), and Mid-O we hardly had the ability to try tons of springs at all of the tracks. I havent even tried lots of combos at the local tracks....I always end up RACING with too small a crew and something needs fixing or I want to do nothing but stand on the throttle

......... There just aint enough time in the sessions or MONEY to make everything happen. I would have to do a Chin event just to record data for each track with both drivers and cars to really get this right (probably need a lot of tires for all that..lol...). That would be sweet but nobody offered to pay yet! Still LOOKING HARD FOR THAT!!!!!