Bitching about RR's

#21

I’m one of those “races only when he can afford tires” people. The cost of tires does keep me from running a lot of races. I loved the original RA-1’s. Every subsequent tire has sucked more money from my wallet with no noticeable advantage. I can’t afford to have more than two sets of drys. Heck, it’s a PITA hauling 2 extra sets of tires in my truck as it is to a race (one dry, one rain, one set on the car). I guess I just don’t take AMATEUR motorsports seriously enough.

I love racing. Love racing with the SE30 boys. Love the BMW. But I do ask myself each time they “improve” the tires if I can afford to keep doing this. I can’t believe there aren’t other tires that would last longer, be reasonably priced and still offer decent grip out there.

I’ve only won Toyo bucks ONCE. They vanished before the next race. I’ve won more Hawk brake pads than Toyo bucks, so to me the contingency thing hasn’t been a selling point.

#22

What you have to decide is where in the pack you want to run. If you want to run up front, tire costs will increase exponentially. Otherwise, you can continue to run old tires and mid pack. You will always have someone to dice with.

#23

I have had blueing of the outside edge of the tire on pretty much every set of RA1s and RRs that I have ever run. I haven’t had anyone be able to tell me why it happens though or if it is a bad thing.

My feelings are that if I don’t get at least 3 weekends out of a set of RRs, I will be upset. While I appreciate the fact that we get contingency dollars with only 3 racers, the fact that winning every race over those 3 weekends still only results in $240 or less than the price of two tires. I feel I am your average SpecE30 driver, and I, like Ranger, would like to get through a NASA regional season on two sets of RRs.

#24

Eh, the only time I had a gripe about dumping money into tires was at the nationals last year when I finally got to drive on 2 2008 tires, which dropped my lap times by about a second. This at a track where I have run for years. I was always wondering what the hell guys were joking around about when referring to “cheater tires.” I never realized until the nationals that this meant running tires from years ago that were significantly faster than the junk I was running. What annoys me more is the idea that Toyo took away the shaving, but increased the price of the tire, so we don’t see any cost reduction as the racers buying the tires, but Toyo makes more money.

Ideally, I would prefer the shipped cost be $500/set and be full slicks that will last 3-4 weekends. Taking weight out of the cars, optimizing suspension geometry and keeping them relatively slow will also help in that regard.

I will be interested to see how the RR fairs at Gingerman. I can only afford 3 race weekends this year, so i will see if I can get them to last.

#25

We are starting to see more frequent problems with axles and bearing failures. Anyone else?

#26

Yup…two weekends per set then they become practice tires.

#27

Dropping the weight to 2550 will certainly help the tire wear…Scott, you might propose that. Any of the cars can get there with no money spent. It makes everything last longer.

Bearings…I’ve gone through one LF wheel bearing in 5 years…none of the others. However, I do buy OEM manufacturer bearings. No axles in 10+ years.

#28

[quote=“cwbaader” post=72511]Dropping the weight to 2550 will certainly help the tire wear…Scott, you might propose that. Any of the cars can get there with no money spent. It makes everything last longer.

Bearings…I’ve gone through one LF wheel bearing in 5 years…none of the others. However, I do buy OEM manufacturer bearings. No axles in 10+ years.[/quote]

I’m not sure if we can get someone wrapped around this who really knows their stuff, but if someone has any connections to a person that specifically deals in race suspensions to give us an evaluation of our geometry, spring rates, damping curves and weight where they may be able to recommend some very engineering based opinions on where we should be going in terms of longevity/tire wear/etc.

While I completely agree that removing weight is a good thing, the numbers really tell the story.

#29

I have some experience dealing with E30 suspensions. The spring rates are fine. The max camber is fine. They could use stiffer sway bars, though. Don’t see that happening. Now, if you reduce weight, you have effectively stiffened the car on the current setup. That said, some camber will have to be removed to optimize the contact patch…which brings me to another point. Everyone needs to take tire temps in the hot pits after a hard run and adjust camber to get a temperature gradient of 10 degrees or less across the contact patch of the tire. Making the complete tire work will minimize tire wear.

#30

Is there any racer that is happy with the new tire? I do not think I have heard from one yet. They cost more, dont last as long and no one is happy with them. We need a different tire.

I do not think that dropping weight is the answer. Although I think it would help our cars in a lot of areas, there are a lot of guys that can not get there cars that light.

#31

I see your point…except…

Taking tire temperatures in the hot pit is an ok start, but really does not give you a good direction to do anything with camber. Depending on your track conditions and how far the pit is to the last corner you just took at full tilt will vary what the section temperatures are. Your damping frequencies mid corner, as well as the dynamics of the tire mid corner paint a very different picture than sitting in the pit after you have driven another 1/2 mile or so and slowed the car.

With the car running higher camber (over 2+ degrees) the inside of the tire will naturally be a higher temperature just due to hysteresis.

My RR’s broke in very nicely. Decent tire wear at ABCC, but I was more worried about the tire splitting more than wear.

#32

Maybe nasa will respond to a se30 race boycott in one of the big regions.

#33

Find an alternative.
Build customer power (consensus) behind alternative.
Encourage NASA to go along with the idea.
Apply customer power against NASA should they be insufficiently inspired by customer desires.

I’ve heard talk of various long-lasting alternatives over the years, but I’ve no personal knowledge of them. It would take a lot of testing before we had the buy-in of a decent fraction of us. Racers aren’t much good at consensus. Too busy signing autographs.

#34

Why don’t we simply push to go back to the RA-1?

I am going to start taking tire temps and trying to maximize lifespan with setup changes if necessary.

It could be worse…look at all these GTS guys ripping through Hoosiers at $1100 a set in one weekend.

#35

[quote=“JeffCal” post=72519]Why don’t we simply push to go back to the RA-1?
[/quote]
Not enough improvement to be worth the hassle.

#36

About tire temps…you are wrong!! If you can get to the hot pits within 15 or so seconds of running hard on track that is sufficient to take tire temps. Of the tracks I am familiar with, that is possible at all…Road Atlanta, Barber, CMP, Roebling, and Nashville. My personal preference is RR since T3 and T5 are such high speed corners and you can still be sitting in the hot pits in 15 seconds. In that time frame, cooling is negligible. So, getting to the hot pits is not a viable excuse in the SE region.

To emphasize…taking tire temps is the only way go maximize tire traction and life.

Chassis weight. My car weighs 2310 without me in it and a couple of gallons of gas. My 89 I built weighed under 2400 (too many years ago) so don’t tell me the E30 chassis can’t be races at 2550!

#37

For sprint length races my car carries 30lb of ballast for a start weight (with a full tank) of 2735lb. If I take all the fuel (~105lb) and all the ballast out I get 2600lb. My weight is only 150lb and the car is stripped as far as a strict interpretation the rules allow. There is no way, under the current rule,s that I could get down to the weights cited. A heavier driver could have a bigger problem.

The current 2700lb end of race number is reasonable and most everyone can get there. The tire wear/life/cost issue, while it could be improved by a weight reduction is really a different problem.

#38

[quote=“cwbaader” post=72539]About tire temps…you are wrong!! If you can get to the hot pits within 15 or so seconds of running hard on track that is sufficient to take tire temps. Of the tracks I am familiar with, that is possible at all…Road Atlanta, Barber, CMP, Roebling, and Nashville. My personal preference is RR since T3 and T5 are such high speed corners and you can still be sitting in the hot pits in 15 seconds. In that time frame, cooling is negligible. So, getting to the hot pits is not a viable excuse in the SE region.

To emphasize…taking tire temps is the only way go maximize tire traction and life.

Chassis weight. My car weighs 2310 without me in it and a couple of gallons of gas. My 89 I built weighed under 2400 (too many years ago) so don’t tell me the E30 chassis can’t be races at 2550![/quote]

I’ll just go ahead and respectfully disagree…about tire temps. I’ve actually taken data with on board pyrometers to show the difference. Does it mean you can actually change anything if spring rates and dampers are fixed? Maybe not, but peak tire temps mid corner tell a wildly different story than in pit measurements. Sometimes that speaks to a failure of the spring/damper combo, and other times static camber can be changed to fix. Depends on how much adjustment you have and what method you are using to compensate for the measurements you are logging. There aren’t any real math models to tell you exactly what to do.

And my car with a full tank and max ballast, still carrying all kinds of extra crap I don’t need that I could remove legally is usually between 3-8lbs. over at the end of the race. IF it was actually legal to modify the fuel system and I could just remove the ballast, I could drop 150lbs. without even really trying…post race. All said and done, I bet I could drop another 50 on top of that without getting really creative. 'nother subject, 'nother complaint.

#39

Having 2 sets of prime condition RA1s at the end of Nationals I was none too happy about having to buy new tires to be competitive for this season since everyone was saying the RRs were faster. Same story as the 888 fiasco. I agree it’s BS that Toyo is charging us more for a tire with less rubber on it.

I did do an interesting experiment at Putnam last weekend. I ran 5 prior heat cycle 2009 vintage RA1s in one practice session and then 6 prior heat cycle RRs in qualifying. I turned the same lap times on the RA1s as I did in the race the day before (heat cycle 6) but on RR heat cycle 7 I went 0.2 seconds faster (although I would have been an additional 0.2seconds faster on the RR but got blocked coming into the last turn) but this was mainly due to putting together a lap that I had yet to do that weekend. The RA1s were more lively in the back and the RRs more planted with understeer that’s beating up the left front. So I don’t doubt the RRs are noticably faster than 2011-2012 RA1s (just as the 2008/2009s are) but as you all are saying we need to get back to the durability the RA1s used to have. However having talked to Toyo “engineers” at the past 2 Nationals they swear nothing has changed in the ingredients or construction of the RA1s. However having worked in the industry (as a co-op while in engineering school) I know that pressure, curing temp, and aging have significant impact on rubber as well. Note: Toyo also says the rubber compound is the same on the RR but the carcass is different.

Next event we’ll be starting out on the 9th heat cycles for the RRs so I’ll report back on how the 3rd weekend goes. (rain sessions are why we are not at 12 cycles) I will also be trying to borrow a tire pyrometer probe for the next event as to check our current camber settings.

And in case it’s of some interest, here are the accelerometer readings on the laps referenced above.
red=2009 RA1 heat cycle 6, blue=RR heat cycle 7, orange=RR heat cycle 6

Link to larger image

#40

The RR is 2secs faster than a shaved RA1. Hard to imagine how it could be the same compound.