AT THE TRACK: Need more front grip

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?

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.....

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.

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

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.

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.

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

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.

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...

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

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 !!! :naughty: 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

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.

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.

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.

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 :lol2:

......... 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!!!!!

I tend to agree with Brian that springs over 550# in the front seem too much especially for the low powered school cars....but what do I know. Now you've got me wondering and maybe will try some swaps at our next test day. To get good data would require alot of testing time and several good drivers etc.

Maybe just an issue of feel and preferance, but I personally dont think the GTS cars are undersprung. We are also limited to spec springs in the GT2 class.

Our best GRIP investment so far has been to upgrade to 18x11 and 18x10 CCW wheels with the new Hoosier slicks this changed our average lap times at Thunderhill (Northern CA) from 2:02s (17" Hoosier R6s)to 1:59s with lots more room to gain courage and seconds. TBL for the slicks at this track should be 1:57s....big improvement. Hoosier indicates that they may come out with these in 17" tires this summer so good cost effective grip solution for school cars when available. Just make sure the frames are reinforced.

Kevin
GTS (SCCA GT2) & GTRA (fun for friends)

Hoosier indicates that they may come out with these in 17" tires this summer so good cost effective grip solution for school cars when available. Just make sure the frames are reinforced.

Is the difference in grip between these tires and, say, an R-compound really so great that the chassis is threatened by one, but totally fine with the other? It just seems like the frame of the car shouldn't be the weak link, as far as breaking stuff from cornering loads.

I tend to agree with Brian that springs over 550# in the front seem too much especially for the low powered school cars....but what do I know. Now you've got me wondering and maybe will try some swaps at our next test day. To get good data would require alot of testing time and several good drivers etc.

Maybe just an issue of feel and preferance, but I personally dont think the GTS cars are undersprung. We are also limited to spec springs in the GT2 class.

Our best GRIP investment so far has been to upgrade to 18x11 and 18x10 CCW wheels with the new Hoosier slicks this changed our average lap times at Thunderhill (Northern CA) from 2:02s (17" Hoosier R6s)to 1:59s with lots more room to gain courage and seconds. TBL for the slicks at this track should be 1:57s....big improvement. Hoosier indicates that they may come out with these in 17" tires this summer so good cost effective grip solution for school cars when available. Just make sure the frames are reinforced.

Kevin
GTS (SCCA GT2) & GTRA (fun for friends)

What do you think of the new hoosiers compared to the pirellis slicks? I have not tried the new hoosier slicks but the R6 compound is night and day compared to a slick. But again, when you change a tire it requires EXTENSIVE testing to get a setup for that tire. IT REALLY matters. We tried a bunch of tires and didnt have the time or money to setup for each so we stuck with the one that worked with the setup we know.

All good points, car setup is very subjective, especially at most of our levels of driving. No doubt we have some very skilled and none(or I am guessing at least most)of us have the time, money, and maybe even skill to notice or try every minute change that gain or lose a few tenths or hundreds.

I found a setup that worked for my car and IMHO it is night and day better than the way the car came. Brian or someone may drive my car and hate it, but for me it works.

I'm not one to make minor tweaks at each track or from session to session. I find a happy medium and change the driver to suit the changing track conditions.

I drove my previous best laptime at VIR - N in my old BMW M3 racecar with completely blown rear shocks. The car would bounce so hard coming out of hogpen it was scary, but fun! Drive the car you brought and enjoy!

Drew - I kinda know your car and I think it is the tires. I put a new (old) set of P3's on my car (same as you have on your car) and it was scary. Until the tires got really hot, they were just plain slick. I let another drive my car and got the WTF*** comment. The left over WC tires look good, but really are past their prime.

Your dad said they were fine, but maybe he is just driving too slow!:biggrin:

Brian,
we never tried the Pirelli slicks. I run GT2 in Northern California SCCA and it's my 2nd season. There are 2 other Panozs, mostly RX7s, and some other basic GT2 cars...no Porsches or really high end stuff in our group. We've run the R6s in the past, but the grip limited our lap times a lot.

Read about the Hoosier slicks and success in Texas (- 2sec over Pirellis I think) and decided to bite the bullet. The wheels from CCW are about $800 each and the tires are about $1700/set so no small investment.....drives like different car. Would be interesting to compare with other slicks.

Regarding the frame reinforcement there is a comprehensive discussion on this site. The school cars are designed for street tires and low HP engines (low forces) and most had the gusseting and bracing of the GTS cars left off....so if you run slicks and/or up HP you WILL break parts of the frame. We've had failures on reinforced GTS frames so no doubt the school cars will fail too.

Kevin

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?


Drew,

I'm sure you've already received lots of helpful hints and suggestions. However, do not under any circumstances lower the rear of the car. This will cause the car to understeer even more!

In fact, I'd recommend you check your ride heights to verify you have rake (front should be lower than the rear) in the car. The Panoz is sensitive to rake adjustments and needs the front at least 3/4" lower than the rear to handle well.

Also, if you have the Penkse adjustable shocks be sure you have them set properly. Poorly set shocks will limit the cars ability to transfer its weight to the front at corner entry. You can adjust your shocks all square (6 sweeps from firm to start), then go firmer with your rebound settings in the front to dial out understeer at corner entry.

From what you describe it doesn't sound like you're transferring weight forward at corner entry. Hope the this helps!

Rod

we run about 1/2" lower on the front then the rear....hmmmm

what lead you to the at least 3/4"?

we run about 1/2" lower on the front then the rear....hmmmm

what lead you to the at least 3/4"?

I think that was in the GTS alignment guide, I run 1" lower front, before I corner weight the car. Which of course screws everything up! lol

I have tried a set of the new Hoosier Slicks and they were great. They have a lot of grip. We lowered my car to the Panoz specs. I am not sure my mechanic ckecked everything and if I remember correctly the front is either 3/4" or 1" lower than the rear. Soflow1, I meet you ar R A and you told me about getting some used tires. Would you share the place with me so I could possibly buy some tires too?

I'm currently running the new Michelin slicks and obsolutely love them!

Panozracing - It's the published baseline setup PAD documented for the GTS. That baseline was developed over a couple years worth of input from early GTS drivers, and the Panoz Racing School instructors and mechanics. We realized over time (and was able to confirm with Joel Grewitt) that the car is rather sensitive to this rake adjustment. The lower the front gets relative to the rear the more loose the car will handle.

Dawgfan - Sorry, there must have been a misunderstanding. The only source for used tires I'm aware of is myself. I never run on used rubber. I'm at the point, where I'm looking for tenths of a second and NEED fresh rubber to do that. When I'm racing, I usually use at least 2-3 sets per weekend. When done, I have no more than 6 to 8 heat cycles on them at a maximum.

Erich1h - Yes, I agree. The Michelin slicks work great. Lots of grip and they're very consistent.

Soflow, got any used rubber currently?

On the springs comment, I had changed mine out to 900/750 and experienced all sorts of push issues - changed down to 750/550 and removed the rear sway bar and the car handles better than it did with the 550/350 setup. (Eric's advice for this change)...

A slightly heavier spring rate than what the series cars came with, new slicks, rear sway disconnect and it's a brand new handling adventure.

just my 2 cents.

Soflow I meet the guy that I was thinking about today and he is from Cumming. I would be interested in some good used tires if you have them. I'm still working on seconds. Doing R A around 1:45. I will start working on tenths when I get to 1:42. Are you going to be at R A next weekend for the N A S A event?

While I'm no expert in tires I can say that our initial experiance with the NEW Hoosier slicks is that they don't seem to break down quickly with heat cycles. We've got one set with 8 cycles (20-30' race/practice) and they are as good now as the 1st run! We'll keep trying them for practice to see where the drop off is, but they clearly last longer than the R6s (turn to rocks at 6 cycles with a drop after every run). Hoosier rep told me the slicks should last 125% longer than the R6s, but so far they seem better. A pleasant suprise. This may be an advantage over the Michilens or Pirrelis that seem to be good for 4-6 runs only. We are trying to arrange a test day to compare the Goodyear vs. Hoosier slicks and will post the subjective results.

Kevin

Soflow,

I to am looking for some used tires what size rims are you running.

David

the GTS goes much faster then 1:42 at RA

I was there once in 2004 with 17" rims totally stock for 2004. I had just baught the car and only had three weekends in it running the then spec Dunlop slicks and I ran consistent 1:37's. I would expect if I went back with all the updates and the mods I have done to run 1:30 or better. What do some of the other GTS's run?

boothkc - what rims did you get from CCW? Our CCW's are $450 each and we have had long term success with them.

I am doing a 1:45 and trying to get to a 1:42 or better. I am running a WC car that has the stock 4.6 Cobra and still learning the car. I figured I would stay with the 4.6 for the rest of the year and just have fun and enjoy the car and this winter go for some real horse power.

I am doing a 1:45 and trying to get to a 1:42 or better. I am running a WC car that has the stock 4.6 Cobra and still learning the car. I figured I would stay with the 4.6 for the rest of the year and just have fun and enjoy the car and this winter go for some real horse power.

All good points, sometimes brian forgets we all don't have 450hp! (yes even the stock GTS has 400+hp) LOL :nono:

Eric1h & David - I have no used rubber at the moment. I haven't had the car out since last year. When I do have rubber, I run the Michelin Pilot slicks on CCW 18" wheels.

Panoz26 - I don't find at all surprising the 900/750 springs didn't work, its far too stiff. The 750/550 springs would work better, but only with race rubber on the car as these rates are too stiff for anything other than a slick. You can run without the rear bar connected because you're running 550 rears. As you get faster you'll find the car will push again. If so, add the rear bar back in and/or lower the front spring rates maybe back down to 600 or 650.

Panozracing & Dawgfan - Yeah, the GTS was always faster than the school cars. Typical good times in the GTRA at Road Atlanta is 1:42 to 1:43, while times in the GTWC are 1:36 to 1:37. The best times in the original GTS (385hp, 17x9 wheel, and no Brembos) was a 1:35 with most quick folks running 1:36 to 1:37. Back in 2004, I polled the factory GTS for Joel Grewitt at the Petite running a 1:33.10. The car was quicker in practice as we were running mid 1:32s. Based on my experience the current up to date stock and sealed spec GTS (450hp, CCW wheels, and Brembos) is good for 1:30s if setup properly and driven well.

All I can say is, I have a long way to go. But a lot to look foward too.

Dawgfan,

What kind of times was Gary doing a the Mitty?

David

In his 66 GT 350 or in the Panoz?

Dawgfan,

What kind of times was Gary doing a the Mitty?

David

If I remember correctly he done a low 1:30ish in the Panoz. I think he was doing around a 1:36 in his pony. Don't quote me on that. Key word "think". Smoked a lot of DOPE years ago, memory is not what should be. Burned way too many brain cells up.

DOPE has no effect on da dain.....:yikes:

Panoz, y'all coming up to R A this year?

if you mean me, maybe.... we havent decided. Has to be for racing and not just track time.

I mean you, NASA has an event/race planed next weekend and I think 2 more this year. Would like to see y'all there. I running a little old 4.6, will wave as you go buy.

I mean you, NASA has an event/race planed next weekend and I think 2 more this year. Would like to see y'all there. I running a little old 4.6, will wave as you go buy.

I saw an ebay item with a new 5.0 cammer 32V motor....:icon16:

Of course you could buy another entire car and half for the price. :banghead:

All good points, sometimes brian forgets we all don't have 450hp! (yes even the stock GTS has 400+hp) LOL :nono:

Yes Eric, in Brian's case that would be 450RWHP so around 525hp at the flywheel. Most importantly though, Brians car will have absolutely loads of torque to slingshot the car out of corners.

I have yet to beat my old 1976 classic racers (car the Panoz replaced) times around my local track in the Panoz. The difference being the Panoz's current 335RWHP Vs the classics 460RWHP.

The difference is like night and day, especially on a track with not so many low speed corners where the average speeds are high and you need hp on the straights to "do the business". The old car had the drag coefficient of a Kenworth truck but man could it haul butt in the top end. I had tuned it so peak torque was at 6000rpm and peak hp at 7000rpm. The engine did not drop below 5000rpm on a good lap so spent all ist time from 5000 - 7000.

Have got the Panoz (in enduro trim) to within 1 second of previous best times in the last car and will go a lot faster with a little more straight line speed. I know the Panoz would kill the other car on most other New Zealand circuits though where there are more slow corners. The other thing that I know is that the old classic engine was so highly strung that it wouldnt last a 1 hour race little lone a 6 hour race............!!

Kel.

500 FWHP and LOADS of torque........

GIANT tires too....

500 FWHP and LOADS of torque........

GIANT tires too....

See! CHEATER! lol

My only hope is the 300lbs I shaved off my car, will still only be @ 380whp INITIALLY, going up over 430-450whp once i get it al sorted out, but should be sub 2500lbs without driver! at least I hope!

Oh and the new engine is 4" farther back, and almost 4-5" lower! so that should lower the center of gravity quite nicely!

Brian,
we just ordered the wheels from CCW a few months ago. They are spec for the GTS in SCCA GT2 and are 2 piece welded aluminum 18x10 front and 18x11 rear. I believe they also have 18x12s, but not legal in GT2. I'm pretty sure that 8 wheels were $6k and change or about $750 each direct from John at CCW.

Kevin

I thought Joel told me before he left PAD that the 3-peice CCW wheels are the spec? I guess not. Its too bad the 3-peice are cheaper (around 450 ea when I bought them) and they can be repaired when you smack them up. The only downside is they are softer.

http://www.ccwheel.com/files/wheelprofiles-display.php?id=Classic

Isnt this the current SCCA rules for the GTS:
http://cms.scca.com/documents/Club%20Rules/Tech%20Forms/PanozGTSRules.pdf

Brian,
maybe they are the 3 piece wheels from CCW. When I called them I thought the 18x12" (non SCCA spec) were 3pc and the 18x11 rears were 2pc, but cant remember for sure....I just know that I didn't get the 12" wides 'cause they didn't meet spec for us and the 11" cost as above.

KB

Greetings !!! In a early posting ; there was a mention of a new Hooser Tire that took heat cycles very well ... Is this the R-6 or some thing that was just released ???
The other question ; what did you experience when / why did you disable the sway bar w/ the 750 -- 550 set-up ???

Thanks / Paul M. Winship

I have tried the R 6 and loved them. A lot of grip and really good tire. Ran them part of 2 weekends and still look and feel new.

Paul,
the new Hoosier slicks are the tire I was talking about. These are not the same as the DOT legal R6 tires that also work well, but are about 3 sec slower on our car (GTS). Grip is better with the slick, but they are not as forgiving. Currently only available in 18" but maybe 17" this summer per Hoosier.

Call Hoosier for availability they are easy to work with.

Kevin

Well ; The 750 / 550 set-up is in ; Fantastic !!! I left the sway bar in , but took just about all the rake out of the car ... Sits almost dead level front to rear .... Sticks like velcro , corner 2 in 5th , carousel into a sweeping "S" solid in 3rd ... Braking improved too , less diving , rebound for exit improved ... The twichy ness that others have note from earlier threads maybe from the rear to high ???
Lower the rake ... :naughty: Try it ; you'll like it ...
Paul M. Winship

Well ; The 750 / 550 set-up is in ; Fantastic !!! I left the sway bar in , but took just about all the rake out of the car ... Sits almost dead level front to rear .... Sticks like velcro , corner 2 in 5th , carousel into a sweeping "S" solid in 3rd ... Braking improved too , less diving , rebound for exit improved ... The twichy ness that others have note from earlier threads maybe from the rear to high ???
Lower the rake ... :naughty: Try it ; you'll like it ...
Paul M. Winship

See, told you! :-D pull the rear sway, you'll stick even better! It really does make a huge difference

Wow, never saw this thread blow up. Lots of good info. I'm going back out to TWS this weekend but on Hoosiers. I'm going to see how it feels again and then read through a lot of this some more and go from there.

Luckily I'll have a pro driving coach with me there on Sunday who will also help me dial it in.

FWIW, about what do the GTWCs weigh? I'm running TTS with NASA, and with only 270rwhp I shouldn't have to worry about not weighing enough, but was just curious.

And after reliving the scenario and thinking about it more, and learning a little more about suspension, I believe the rake isn't setup properly. I'm going to check out the front end when I get there. It never felt like I had much weight on the front in, just not much feel to the steering wheel and it always felt like I was tip-toeing into the corners. I prefer a little less rear grip.

Also, that was on old Pirellis, this time I'll be on semi-old Hoosiers. Hopefully I can win 2 new Hoosiers this weekend!

Drew,
They weigh about 2800 + -50 w/o driver unless you've done things to lighten them. I think rake is very important for these cars. I think the steering feels a little dead because it is power and not that quick. Eric Hardcastle (EricH) went to a 2003/04 Cobra rack on his WC that made it quicker. A couple of guys (CRS) went to manual and seemed to like it better for feel. Hope to visit TWS this weekend and see you run.

Mike