Driving over 120 mph....

[Tomy]

I use my 930 for high way driving so very often drive over 120 mph. In case than I have only 100 miles from home to German non limit high way I use to drive fast if possible.
I just wonder how you feel yours cars over 120 mph and what suspension set up you have.

My car is still stock but lower then Euro set up a bit 24.4 " rear and 24.8 front with lot of negative camber front (-1 degree).My experience is that till 115 mph handling and response are perfect over this speed front going to be lighter and above 130 I have feeling on steering wheel that car is moving left right a little but still is OK.

[Reaper930]

Stiff, planted and firm as can be over 130, coil over setup front and rear (Bilstien RSR's with raised front spindles) 350lbs front springs and 500lbs rears, those should go up to about 800lbs rears for less softness.

[DDDD]

Originally Posted by Tomy

I use my 930 for high way driving so very often drive over 120 mph. In case than I have only 100 miles from home to German non limit high way I use to drive fast if possible.
I just wonder how you feel yours cars over 120 mph and what suspension set up you have.

My car is still stock but lower then Euro set up a bit 24.4 " rear and 24.8 front with lot of negative camber front (-1 degree).My experience is that till 115 mph handling and response are perfect over this speed front going to be lighter and above 130 I have feeling on steering wheel that car is moving left right a little but still is OK.

A little more front rake provides additional downforce and GT Racing makes a RSR type front bumper/spoiler with a bottom lip that will make your front end stick to the road at higher speeds if you want to get into bodywork mods that make the car have more downforce.

These cars all get lighter at the front than the rear, that is sort of a signature 930 feeling at speed, even the new GT2s...

[turbo3six]

[/QUOTE]I just wonder how you feel yours cars over 120 mph and what suspension set up you have.

My car is still stock but lower then Euro set up a bit 24.4 " rear and 24.8 front with lot of negative camber front (-1 degree).My experience is that till 115 mph handling and response are perfect over this speed front going to be lighter and above 130 I have feeling on steering wheel that car is moving left right a little but still is OK.[/QUOTE]


The specs of your set up (heighth and camber) seem fine. You do not mention 'tow' or 'caster'. You should have front set to maximum caster for straight line stability with total tow in of 1/16. Rear camber set -1 degree with 1/16 to 1/8 total tow in. Have you had your car corner balanced? This will also provide stability and sure footedness in all situations. As mentioned in previous posts it is the nature of these cars to get light in the front end at speed. The rear tail provides a goodly amount of downforce rearward and various aero aids are available to add downforce to the nose.

[e p slick]

I have run 183 at Silver State open highway event with good stability in a 1988 930 I used to own. Low front end stance and stock 930 wing. Tires at 34lbs. Recommend front splitter. Am going to run my 1979 at the Texas Mile in a month. No rear spoiler at all (though I will take along my small spoiler just in case) since I want to see how car runs with no rear drag from 930 wing. Did fabricate front splitter. All amature stuff with no common sense or intelligence applied.

EPS

[87 930]

Tommy;

My '87 is also lowered. I'm running Bilstein Sport Shocks, 23mm and 31mm torsion bars, 22mm rear Tarett adjustable sway bar, and adjustable rear swing plates. Using stock toe, camber, caster settings.

Over 120mph with OEM front valance and OEM tea tray, front felt a little light and darty. I installed a new fiberglass Euro 930S front valance and had more than a few heart palpatations while >120. BIG CHANGE!

Front end got REAL light and I really had to fight it to keep it straight. Extremely minute inputs were required and the feeling was not confidence-inspiring. The center oil cooler opening is letting more air under the nose than can be dumped out under the car/through the fenderwells. E P Slick couldn't be more correct; the front end needs a splitter. I ordered mine last week from GT Racing.

[Les Paul]

I doubt there is a time I don't do some cruising at 120-150 every time I take this car out which isn't often enough. Ruf type front and rear spoilers and TurboS tail.

As a matter of fact taking the beast out tomorrow morning. Supposed to be in high 50's. Sometimes I wish I hadn't taken out the adjustable boost.

[911nut]

I hit 120 last weekend while doing some testing and I wouldn't have known it without glancing at the speedo. Car was as solid as a rock.

[Tomy]

Scott

Have you any picture of your front spoiler ordered from GT Racing?

[87 930]

No pics, sorry. Go to www.gt-racing.com. On their homepage, go 2/3 of the way down the page, on the left, click on "911 Parts". Go to pg. 9. I now have the front valance that's on the white 930, p/n 48a. Difficult to fit, but I like the looks. (It doesn't appreciate gettin' bottomed out though.) The "splitter" I bought, and I know will give me some down force, is on pg. 8, p/n 44c. It mounts horizontally to the bottom lip of the front valance. There are many guys on this forum that use them. Search the forum. Good Luck!

[fredmeister]

here is mine going 120mph up thru the last bend in the esses at Watkins Glen.

It was pretty stable and the front feels tight, but this was with completely stock trim and suspension at USA ride height....which is too high in my opinion.
Lowering it should only make it better.

[nreed]

How many of you have calibrated your speedos. Most read high by at least 10-12%. It's simple to do. Just take apart the speedo, insert a variable resistor in place of the fixed resistor and use a GPS to calibrate. Then use a little glue on the pot to keep it there.

IC data sheet for UAF2115

http://www.datasheetcatalog.org/datasheets/700/489248_DS.pdf

It's the resistor off pin 4 of the ic. 120-130 ohms. So pick a pot with say a 200 ohm range.

[juan ruiz]

87 930

Same here, we are having a 1 mile event here in Florida and I will see what my car does, do you or any of you have a photo of that "splitter" mounted on the car ?

What else can be done for those high speed runs ?

[beepbeep]

Originally Posted by nreed

How many of you have calibrated your speedos. Most read high by at least 10-12%. It's simple to do. Just take apart the speedo, insert a variable resistor in place of the fixed resistor and use a GPS to calibrate. Then use a little glue on the pot to keep it there.

IC data sheet for UAF2115

http://www.datasheetcatalog.org/datasheets/700/489248_DS.pdf

It's the resistor off pin 4 of the ic. 120-130 ohms. So pick a pot with say a 200 ohm range.

I believe this is only done to keep manufacturers from being sued by soccer moms who crashed with bigger wheels and later claimed that "speedo said I was only doing 60". Thus they build some error margins to allow for bigger tires.

[911st]

I am not an alignment expert but I believe:

A little toe front and rear adds to stability.

Max Caster up front adds to stability.

-1 deg of camber is not very much in the front. Near -3 I have been told may effect stability.

Corner balancing helps stability.

Keeping air out from under the front helps stability.

Lowering the front to much (more than Euro Style) can contribute to toe change (bump steer) which can negatively effect stability.

There is more like shock rates, spring rates, spoilers...

[87 930]

Juan; No pics of splitter on car; haven't gotten it from distributor yet. I hope he doesn't mind, but check out x98Boardwell's thread on the 930"S"front spoiler at http://forums.pelicanparts.com/showthread.php?t=473561&highlight=front+splitter.

[juan ruiz]

This is why I hate this freaking forums !

Very interesting ! I saw that they sell for around $200.00 do I have any other more economical solutions ? Is only for one day

[lucittm]

Les Paul (great handle),
Do you still have your adjustable boost. I need one...

PM me.

Thanks,
Mark

[Ollies930]

For one day you can use a piece of plywood (as long as you don't mind a lot of ribbing). If you want to get creative, you can cover the plywood with fiberglass and finish it so you can reuse it anytime and make it look good.

[juan ruiz]

Originally Posted by Ollies930

For one day you can use a piece of plywood (as long as you don't mind a lot of ribbing). If you want to get creative, you can cover the plywood with fiberglass and finish it so you can reuse it anytime and make it look good.

thats a start, I'm thinking some sheet metal, but how do I figured the size ? meaning from the ground to the splitter ?