way to finish the race dave. Great job.

 

Wow! Your car looks stupid fast Dave! Bummer about the guardrail. Obviously it cost a lot of time. But way to stick in there! Looking forward to meeting you this summer!

 

You too! Keep us updated on the (re)build process - cool to see all the interest in the event.

Dave

 

Question to the road racing folks - Its looking like I'm going to move up to 285 18" road racing slicks this year and I'm guessing that means a spring rate change is going to be in order. I've got AST 5300s which were just serviced and brought back to their standard valving. Last year on the 255 17" Federal FZ201 semi-slicks I tried 600f 800r springs. I'm on stock sway bars, but do have a bigger rear I could use...but with the consequences of snap oversteer pretty high on The Peak, I don't really want to set it up too tail happy.

Vorshlag's website shows that common spring packages for the 5100s are:

GT 400f 500r
GTS 500f 600r
GTR 600f 700r

I had to give the 800# springs back to their owner when PP was over, so all I've got currently are 600# and 1000# springs. I don't think the 1000# ones are going to be suitable, so I've got to start somewhere. So, I guess the question is, what sort of front/rear spring bias do you guys run?

EDIT: If things go according to plan, the car should make more downforce than last year courtesy of the addition of a flat bottom and diffuser. I'm also hoping to shed somewhere in the neighborhood of 150 lbs off the car thru the use of more composites (doors and such) and a shorty exhaust. Last year the car weighed in at ~3300 lbs with both of us in the car and loaded with fuel.

Thanks,

Dave

 

I'm running 8K 9K on Robi's "race" KWv3's (not sure the # translation). I try not to rely too much on the bar either, more so on the rear diff on-throttle and weight transfer to do the turning. If the mountain is going to be super smooth, you won't need much since you'll be compressing almost every turn by going uphill right. So i'd say 6/7 or 7/8 would still work for an R-Compound, 9/10 or 11 for a full slick to keep the temp up. But if it's gonna be rougher in parts then you obviously don't want to bounce off the track so error on the softer side.

 

The road is all fresh pavement that's been laid down within the last 5 years. Pretty smooth, but certainly not glass smooth or anything. Biggest danger up there is now going to be sand and grit on the road surface.

Guessing that your measurements are in Newton/Meter. If so, here's numbers I grabbed off an online converter:

6k = 411#
7k = 479#
8k = 548#
9k = 616#

600# = 8.7k
800# = 11.7k

My car should be making over 1000 lbs of downforce at speeds just over 100mph, so that'll probably mean more spring rate is needed on my setup. Average speeds for Monster at PP is just ~76mph, so that's part of the reason for pretty aggressive aero (though I'm not sure going overkill on aero is as needed anymore now that the dirt is gone).

Dave

 

You want to stay in the 100-200 lb rear bias to avoid excessive oversteer, depending on aero balance. Don't go beyond 200, and less than 100 will require a larger rear bar.

You should talk to Chronohunter, Paul Gerrard, he is a Colorado guy and suspension setup expert.

 

Thanks for the input! I had paul drive one of my old cars a few years back - he rocks! I know he's got a new motor in his car...might be time to bribe him with a day at one of the tracks out east. I wonder if he has that splitter the CSU engineering students made? Might be time for a garage raid! ;-)

Dave

 

If 600 and 1000lb springs were my only options. I'd run the 1k's in the front with the softer rates in the rear with a big rear bar.

We have lots of testing to do. Luckily I have some experience from my autocross car to base off of. I have a feeling we will be on stock bars and relatively soft rates. Maybe 750 front 900 rear.

But who knows, I have very little track/high speed experience. So we will be doing testing to figure out what I like. Either way, don't think getting the spring rates down to the exact perfect rate will be a deal breaker. More likely, finding whatever works for the driver and is still reasonable fast should be sufficient.

P.S. Lowering compression should help with dusty/gritty surfaces.

 

Those are the springs I have, I'm certainly planning on buying some new ones, just trying to zero in on a couple different rates to start out with. With super adjustable dampers, I figure I could try a pretty wide range of springs, but basically was just looking for people to chime in with what sort of rates they were using and with what tires and sway bars.

Quick tip - if you have a good notes on your auto-x setup: throw it away, its crap, and the car WILL try to kill you. The dampers I picked up came off the car that won Street Mod at nationals in 2010. The settings as delivered were terrible for what I was trying to do even though they were top of the heap in auto-x. My advice is to start fresh, and that's my plan for this year. It does mean setup will take me a bit longer, but if I get a setup that's forgiving and gives a warm and fuzzy as it approaches the limit rather than nasty snap oversteer, that'll allow me to push the car a bit harder.

Yikes - not much high speed experience? Get as much seat time as can at higher speeds so you have a good feel for how the car is going to break away on you if you go over the limit. PP isn't a good place to learn with the consequences being so high. There are no gravel traps, no crash barriers...just trees inches away from the road on the lower section and cliffs up top. Thankfully there are some spots with guardrails (even though I think they ruin the view, I'm now a believer).

Dave

 

Dave, don't meant to clog up your thread.

What I meant was, with the autocross experience. It gives us a benchmark to start from. Because I know what does and does not work. Regarding over steer. You can eliminate the majority of that while maintaining aggressive spring rates with alignment and air pressures alone.

And don't worry, I'll have ample time to get comfortable with the car in a high speed environment. I didn't say I don't have any high speed experience, just not nearly as much as in Auto-x. I hope to turn many heads this year

 

my opinion, go some local hill climb (track events are not really ideal unless you are working on engine and drive train) events for practice even if you cant get anything else but a slower car. Can make tremendous difference. AutoX experience basically will be little to nothing on Pikes Peak hill-climb, if that is even slightly similar to MTWHC. Your previous high speed experience is the one will count and the hill climb events you will do before PP. Around here $150 per event a usual rate for this smaller hill climbs. Well worth it specially, if you think how much is your Pikes Peak en devour will cost.
Of course just my opinion on this, and sorry for the off topic Dave.

Rob

 

Nice! Just remember to keep a cool head during the week and focus on finishing...you'll come to realize how monumental a task that can really be on your first morning up on the hill.

This next part isn't directed specifically at you Jeremy, but I think it's worth saying:

There's tons of rookies coming out in wicked fast cars with no hill climb experience and my hope is that everyone gets to go home at the end of the week. Body bags are lame.

Dave

 

No worries Rob - I think that's solid advice! One of the tricky things about any 'open road' racing is that the surfaces are much more varied than what you'll encounter in a closed racing facility. Its those variables and "know unknowns" that really causes problems.

Dave

 

Dave, no offense taken. So how is hill climbing so much different than racing on any other paved surface exactly?

EDIT: I'm assuming you already know that autocrossers are extremely adept at judging a surfaces conditions, grip level and speed potential very very quickly.