100+MPH light in the front

[02ViperTodd]

Hi All,

I just changed my rotors tires brake pads..etc..etc..etc.. I went to bed the brakes and found that the 100-40MPH run (bedding the pads)..the Viper felt very light on the front end at high speed. I don't know if it's because of the 315's I put on the front or not. I've tracked this car before and not felt the floatiness on the front end above 100..Is it the tire size on the front that makes it want to feel light?

I've got racing shocks and I was thinking that I've got them set to 7 on a scale of 0-9. Maybe I need to loosen up the shocks to let the normal aerodynamics push the car down to the track. Maybe put the shocks at 2 or 3. The shocks are Alden Eagles.

Anyone got any ideas?

Thanks,
TOdd

 

[klamathpro]

315's on the front, that's huge. That's Z06 rears. I would say that's your problem. Dragsters go with narrow fronts for a reason.

 

[2002_Viper_GTS_ACR]

315's on the front, that's huge. That's Z06 rears. I would say that's your problem. Dragsters go with narrow fronts for a reason.

omg.. thats such a crock of $HIT.

I'm sorry, but I hate miss information.

First I have run my gen 2 for at least 30,000 miles with 315's both michellin pilot sport cup tires and michellin pilot sport. 315's ROCK, and my newest viper rims (just arrived last week from woodhouse) I had new 315's installed on them. 315's are the hot ticket for road racing. (I also tried 285's, 295's and 305's and different tire brands)

Dragsters go with narrow tires to REDUCE FRICTION AND TO HELP THE FRONT END COME UP OFF THE GROUND, to transfer weight to the back. My god that was the stupidest thing I ever heard that Dragsters go narror on the fronts for the very reason of not wanting a light front end...

Sorry, its tuesday, probably over reacting.

Check your tire pressures, make sure they are about 32-34 hot is what I always ran on my 315's on the street.

Also, have your alignment checked. IF something is off whack it can create an uneasiness at higher speeds due to its lack of surefootedness. Also, you really want to feel super stable at high speeds, get a "street/track" alignment done, Archer racing did mine, I loved it!

How many miles are on your shocks? Blown and worn out shocks will create "bouncyness" at higher speeds when you go over any significant irregularities

Hope that helped.
Jon

PS. All else failes and you dont want your 315's I'll definitely buy them off you for dimes on the dollar!! I love them.

 

[malcoll]

No.. I want his 315's.. I feel that the car is much more responsive with the 315's.

 

[Ulysses]

The Viper tends to be light at the front at high speeds, but usually at 135 + or so.

 

[Andrew2KRT10]

I have never felt the front end light

 

[02ViperTodd]

Nope..the 315s ain't going anywhere. I run the tires at 29 (cold) on all 4 corners.

The shocks aren't blown and only about 3K miles on them. I'm just wondering if there set too stiff..

Todd

 

[DEVILDOG]

Put a splitter on it.

 

[FlyBryViper]

Todd
Don't make any adjustments for the street, unless you can put them back for the track. Doing your brake bedding on the street can feel different than what you normally feel on the track. Don't worry about it. You have your car setup for the track, make whatever comprimises you can to live with it on the street. The 315's, irregular road surfaces, and bedding new brakes can all lead to unfamiliar feedback on the street. It could diminish after the brakes are stabilized, but don't worry about it.

 

[02ViperTodd]

will do..thanks Bryan

 

[Saint_Spinner]

Yeah, I remember reading about some kit where you cut out a part of your front bumper from underneath to help cool the car, but also to aid in aerodynamics (supposedly this car gets light in the nose at high speeds...something about pressure build up).

http://roeracing.com/ProductCart/pc/viewPrd.asp?idcategory=4&idproduct=228#details

 

[FlyBryViper]

Fastest we see in Viper Days is about a buck fifty. The front end does not get light, car tracks straight & true. But then again, we may thinking of other stuff, like how late can we go before braking.

 

[Cop Magnet]

Sorry, its tuesday, probably over reacting.

Yeah, I'd say so.

When you say light in the front end, are you possibly talking about dartiness or the willingness of the front to respond to small bumps and steering input? If so, that probably is the wider tires. At 100+MPH you are not really "accelerating" that much so there is little nose lift based on torque. There is more lift based on air flow, but that shouldn't change based on the mods you've added recently. So it comes down to the tires. I think what is happening is that your road speed exaggerates the effect of the wide tires on the road surface. So they pull, tram-track, dart, or whatever you call it even more than driving around town. This can feel the same as the "front end getting light". While you may hate it now, you'll love it on braking and turning at the track. Everything is a tradeoff.

Let me know what you all think, which I'm sure will happen with various degrees of politeness

 

[2002_Viper_GTS_ACR]

Sorry, its tuesday, probably over reacting.

Yeah, I'd say so.

When you say light in the front end, are you possibly talking about dartiness or the willingness of the front to respond to small bumps and steering input? If so, that probably is the wider tires. At 100+MPH you are not really "accelerating" that much so there is little nose lift based on torque. There is more lift based on air flow, but that shouldn't change based on the mods you've added recently. So it comes down to the tires. I think what is happening is that your road speed exaggerates the effect of the wide tires on the road surface. So they pull, tram-track, dart, or whatever you call it even more than driving around town. This can feel the same as the "front end getting light". While you may hate it now, you'll love it on braking and turning at the track. Everything is a tradeoff.

Let me know what you all think, which I'm sure will happen with various degrees of politeness

Disagree.. of course... (my tuesday is almost over )

 

[Paul Hawker]

Todd. My GTS began to feel a little light at over 110, but mostly only going downhill. On the level it felt rock steady till +125, and uphills always felt solid. Doing down hills in Open Road racing at +140 felt a bit light, but only what you would expect with all that air packing under the car.
Hard to give you a definitive answer due to your larger tires and upgraded shocks.

I loved my 315's on the tracks. Really helped with turn-in and reducing push. Best to increase your wheel width 1" to use all that rubber.

 

[joe117]

I thought the drag cars went for the narrow tires up front to reduce aero drag.

 

[DEVILDOG]

I thought the drag cars went for the narrow tires up front to reduce aero drag.

We have a winner.

 

[Bobpantax]

When I had my GTS, I experienced what you wrote about above 125 MPH. There is no problem with my SRT Coupe. I had the Roe front fascia air duct installed and it not only cured the uplift problem but also allowed cooler operating temperatures at speed. The downside is that you have to cut a piece out of the bottom of the front fascia to do it ;and, unless you are very careful, occasionally you may hit the bottom of the stainless steel duct work which sticks down underneath and have to straighten it out. To me, it was worth it.

 

[02ViperTodd]

I think my car is as low as it will go..In fact I've been told by other VCA members it's as low as they have seen..

I don't care about how low it is..l care about the floating on the front end..

I'm thinking about the splitter also...seems the most obvious choice.

BUT..Does anyone have any advise on the shocks?? Lots of turns on track= firm downforce....Lots of high straight aways = low down force???? Is thisd the rule?

THanks,
Todd

 

[Whoaa GTS]

I've had my car up to around 155-160 and it felt glued to the road. I have a front splitter and rear wing so dont have much basis for comparison.

 

[Tom F&L GoR]

Another vote for the Roe hole, although I shamelessly copied it. Look under the front of a Dodge Intrepid (mine is '97) and you'll see Dodge does this also.

 

[GTS02]

Yeah, I remember reading about some kit where you cut out a part of your front bumper from underneath to help cool the car, but also to aid in aerodynamics (supposedly this car gets light in the nose at high speeds...something about pressure build up).

http://roeracing.com/ProductCart/pc/viewPrd.asp?idcategory=4&idproduct=228#details

Does anyone have any photos of the kit installed from under the front to show the cut out section, thanks

 

[MoparMan]

2002_Viper_GTS_ACR - a couple of questions about the 315's in the front:
Did you run Pilot Sport 315's on the front of your car or just the PS Cups?
Was this with 18" rims?
How did you like this setup for the street?

 

[LETHAL GTS]

My car use to start to lift at about 165, but since I dropped it 1 1/2, I'd say it doesn't lift till about 170-175. It gets a little light at about 180.
No additional aero dynamic help such as wings/splitters. I don't want too much drag
But also still running the 275's on the front.

 

[02ViperTodd]

Moparman...don't hi-jack this thread from me..Start your own..No one is answering the shocks question yet..

My car is aerodynamically (sp) stock..I just need to know shock settings...Am I doing it right..Stiff for curving tracks and loose for high speed tracks...

I think everything else has been answered...

Thanks,
Todd

 

[Landman]

Both of my Vipers would get very darty above 130mph, only when I'd let off the gas. Pulling hard all the way to 160mph and smooth as hell, but as soon as I let off I better have both hands on the wheel. It's normal. My current 02GTS is lowered and has the rear spoiler and still does it. Don't be alarmed, just learn how to handle it.

 

[PhoenixGTS]

Does anyone have any photos of the kit installed from under the front to show the cut out section

Body shop tells me my facia with the hole cut for the Roe kit will be done getting the underside painted this week (of course they said that last week) so I hope to get the front end back on and the kit installed this weekend and hope to post some pics (my be hard to take a good pic as I do not have a lift).