42 runs in autocross this weekend
04-25-2004, 11:24 PM
#1
Registered
Thread Starter
Join Date: Apr 2004
Location: Biggest Little City
Posts: 197
Likes: 0
Received 0 Likes
on
0 Posts
42 runs in autocross this weekend
At our Saturday autocross (scca), I took 6 competition runs, 6 runs for no points, and 6 other people besides myself took her out for fun runs (wanting to experience 50/50 weight distribution, handling, and etc. that has been written about the car). On Sunday, I took 12 more runs. In these 2 days, I got a good amount of seat time, and enough advice about the car, setup, and the line, to make my head spin.
Its still totally stock (sport pkg), since I wanted to get a feel for how it drives and what I need to learn to do differently (I used to be an AWD driver) before I start changing things.
The good: tire grip was better than I expected from street tires. Brakes are great! Handling is better than many cars starting out in stock trim. Car looks beautiful out on course. And learning to slide the backend is Fun!!!
The not-as-good (aka what I'll try changing over time):
A. understeer.
Change 1. get a decent alignment. It's been suggested I try 1.5degrees negative camber in the front, maybe a small amount of toe in. I'm undecided on whether I should try changing only the fronts for now, anyone have an opinion on this?
Change 2. wider tires. Based on info at tirerack.com, the biggest recommended width for the 18" is 245, so I may try 245/40/18.
For the guys running 265 or 275, is there no worry about the tire popping the bead, or some other bad thing happening with the wider tire?
Change 3. stiffer front sway bar. Lots of people here seem to prefer RB, so I may install theirs with their endlinks.
Change 4. shocks, tbd. Adjustable konis has been a preferred product, but it doesn't exist for rx-8 yet?
B. power, specifically low-end torque.
Change 5. different air filter, have to do research, the only one I'm familiar with is K&N.
Change 6. exhaust. I've seen limited data on cat back exhaust performance improvements but the data seems to suggest very limited power gains, and perhaps not enough to justify the cost? So, is a lighter weight catback exhaust worth it anyway, to lighten the car?
C. decrease unsprung weight
Change 7. lighter wheels. Besides a custom wheel carrying a hefty price, maybe the SSR Comps.
I hope all of this is accomplish-able this season. In advance, I appreciate any other feedback, and especially so from others who are autocrossing. Pros & cons, lessons learned greatly appreciated.
Its still totally stock (sport pkg), since I wanted to get a feel for how it drives and what I need to learn to do differently (I used to be an AWD driver) before I start changing things.
The good: tire grip was better than I expected from street tires. Brakes are great! Handling is better than many cars starting out in stock trim. Car looks beautiful out on course. And learning to slide the backend is Fun!!!
The not-as-good (aka what I'll try changing over time):
A. understeer.
Change 1. get a decent alignment. It's been suggested I try 1.5degrees negative camber in the front, maybe a small amount of toe in. I'm undecided on whether I should try changing only the fronts for now, anyone have an opinion on this?
Change 2. wider tires. Based on info at tirerack.com, the biggest recommended width for the 18" is 245, so I may try 245/40/18.
For the guys running 265 or 275, is there no worry about the tire popping the bead, or some other bad thing happening with the wider tire?
Change 3. stiffer front sway bar. Lots of people here seem to prefer RB, so I may install theirs with their endlinks.
Change 4. shocks, tbd. Adjustable konis has been a preferred product, but it doesn't exist for rx-8 yet?
B. power, specifically low-end torque.
Change 5. different air filter, have to do research, the only one I'm familiar with is K&N.
Change 6. exhaust. I've seen limited data on cat back exhaust performance improvements but the data seems to suggest very limited power gains, and perhaps not enough to justify the cost? So, is a lighter weight catback exhaust worth it anyway, to lighten the car?
C. decrease unsprung weight
Change 7. lighter wheels. Besides a custom wheel carrying a hefty price, maybe the SSR Comps.
I hope all of this is accomplish-able this season. In advance, I appreciate any other feedback, and especially so from others who are autocrossing. Pros & cons, lessons learned greatly appreciated.
04-26-2004, 06:10 AM
#2
Registered User
Join Date: Jan 2003
Location: Houston, TX
Posts: 436
Likes: 0
Received 0 Likes
on
0 Posts
A.1 ABSOLUTELY get a decent alignment. Just a note, though, toe-in (front) will give you MORE understeer - not a good idea.
A.2 If you are talking street tires, I wouldn't go bigger than 245's as the sidewall strength isn't what a race tire would be. If race tires, 275/35's fit fine and there are NO issues with interference (VERY stiff sidewalls). LOTS of pictures from the recent National Tour (with 275/35/18 Hoosiers) at the link in the signature.
A.3 Absolutely! This will actually lessen the understeer, as the bar will prevent the car from "sitting down" on the bump stops and the spring rate going to infinity. This is where the push is coming from now.
A.4 Koni's will be the first adjustables available for the 8, with stock springs. However, they will be very difficult to adjust, as the rears will have to come off the car to be adjusted, and the fronts can only be adjusted by removing the strut brace. Not the ideal solution.
B.5 Proceed at your own risk. If you get the Mass Airflow Sensor oily (from the K&N), you will be surprised how bad the car will respond to the throttle in autocross situations. I speak from experience........
B.6 It matters. It may only be a few HP, but it's a noticable increase in throttle response. Do this one first.
C.7 If you can duplicate your autocross runs exactly, every time (you are getting 100% from the car and the driver), you "might" notice the 1 - 2 pound difference in wheel weight. Mazda's wheels are surprisingly light (for OEM), and VERY strong. You would notice the difference in unsprung weight from race tires a lot sooner.
Just my $0.02 worth. As Dr. Phil would say, I don't expect you to substitute my judgement for yours.
A.2 If you are talking street tires, I wouldn't go bigger than 245's as the sidewall strength isn't what a race tire would be. If race tires, 275/35's fit fine and there are NO issues with interference (VERY stiff sidewalls). LOTS of pictures from the recent National Tour (with 275/35/18 Hoosiers) at the link in the signature.
A.3 Absolutely! This will actually lessen the understeer, as the bar will prevent the car from "sitting down" on the bump stops and the spring rate going to infinity. This is where the push is coming from now.
A.4 Koni's will be the first adjustables available for the 8, with stock springs. However, they will be very difficult to adjust, as the rears will have to come off the car to be adjusted, and the fronts can only be adjusted by removing the strut brace. Not the ideal solution.
B.5 Proceed at your own risk. If you get the Mass Airflow Sensor oily (from the K&N), you will be surprised how bad the car will respond to the throttle in autocross situations. I speak from experience........
B.6 It matters. It may only be a few HP, but it's a noticable increase in throttle response. Do this one first.
C.7 If you can duplicate your autocross runs exactly, every time (you are getting 100% from the car and the driver), you "might" notice the 1 - 2 pound difference in wheel weight. Mazda's wheels are surprisingly light (for OEM), and VERY strong. You would notice the difference in unsprung weight from race tires a lot sooner.
Just my $0.02 worth. As Dr. Phil would say, I don't expect you to substitute my judgement for yours.
04-26-2004, 09:05 AM
#3
www.TeamWTF.org
Join Date: Nov 2003
Posts: 747
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by tpryor
A.1 ABSOLUTELY get a decent alignment. Just a note, though, toe-in (front) will give you MORE understeer - not a good idea.
A.2 If you are talking street tires, I wouldn't go bigger than 245's as the sidewall strength isn't what a race tire would be. If race tires, 275/35's fit fine and there are NO issues with interference (VERY stiff sidewalls). LOTS of pictures from the recent National Tour (with 275/35/18 Hoosiers) at the link in the signature.
A.3 Absolutely! This will actually lessen the understeer, as the bar will prevent the car from "sitting down" on the bump stops and the spring rate going to infinity. This is where the push is coming from now.
A.4 Koni's will be the first adjustables available for the 8, with stock springs. However, they will be very difficult to adjust, as the rears will have to come off the car to be adjusted, and the fronts can only be adjusted by removing the strut brace. Not the ideal solution.
B.5 Proceed at your own risk. If you get the Mass Airflow Sensor oily (from the K&N), you will be surprised how bad the car will respond to the throttle in autocross situations. I speak from experience........
B.6 It matters. It may only be a few HP, but it's a noticable increase in throttle response. Do this one first.
C.7 If you can duplicate your autocross runs exactly, every time (you are getting 100% from the car and the driver), you "might" notice the 1 - 2 pound difference in wheel weight. Mazda's wheels are surprisingly light (for OEM), and VERY strong. You would notice the difference in unsprung weight from race tires a lot sooner.
Just my $0.02 worth. As Dr. Phil would say, I don't expect you to substitute my judgement for yours.
A.1 ABSOLUTELY get a decent alignment. Just a note, though, toe-in (front) will give you MORE understeer - not a good idea.
A.2 If you are talking street tires, I wouldn't go bigger than 245's as the sidewall strength isn't what a race tire would be. If race tires, 275/35's fit fine and there are NO issues with interference (VERY stiff sidewalls). LOTS of pictures from the recent National Tour (with 275/35/18 Hoosiers) at the link in the signature.
A.3 Absolutely! This will actually lessen the understeer, as the bar will prevent the car from "sitting down" on the bump stops and the spring rate going to infinity. This is where the push is coming from now.
A.4 Koni's will be the first adjustables available for the 8, with stock springs. However, they will be very difficult to adjust, as the rears will have to come off the car to be adjusted, and the fronts can only be adjusted by removing the strut brace. Not the ideal solution.
B.5 Proceed at your own risk. If you get the Mass Airflow Sensor oily (from the K&N), you will be surprised how bad the car will respond to the throttle in autocross situations. I speak from experience........
B.6 It matters. It may only be a few HP, but it's a noticable increase in throttle response. Do this one first.
C.7 If you can duplicate your autocross runs exactly, every time (you are getting 100% from the car and the driver), you "might" notice the 1 - 2 pound difference in wheel weight. Mazda's wheels are surprisingly light (for OEM), and VERY strong. You would notice the difference in unsprung weight from race tires a lot sooner.
Just my $0.02 worth. As Dr. Phil would say, I don't expect you to substitute my judgement for yours.
So far, I've only done three events in the car. The first was on the OEM Potenzas in the rain on a very slick course. The second was also on the Potenzas but in the dry. The third was in the dry on 245/35-18 Hoosier A3S04s. I have prototype Koni DA shocks and the rebound adjustments are as Tim described...a real PITA. However, I should be getting another adjusting tool this week that should (hopefully) allow the fronts to be adjusted without removing the strut bar.
Turn in was very good with the street tires with the front rebound set about halfway. Using those same settings with the Hoosiers resulted in a somewhat sluggish turn in. Generally, the Hoosiers respond better with firmer damping forces so I'll be upping the rebound on the front shocks at the next event where I run the Hoosiers (two weeks from now). I'll probably increase the front tire pressures too as I only ran 44psi last time and from waht 've been hearing that probably isn't quite enough.
I'm running the OEM front sway bar up front right now too. I expected to buy/install the RB bar, but understeer hasn't been a issue for me so far. We'll see how that goes.
I'll be having the car aligned again this week with more aggresive settings than I've been using and will have the front toe set to zero for the first time, which should also help with a quicker turn in.
I'll be driving the car at the DC Tour next month and I may have someone that knows what he's doing codriving at the event. It should be fun.
04-26-2004, 10:45 AM
#4
Registered User
Join Date: Jan 2003
Location: Houston, TX
Posts: 436
Likes: 0
Received 0 Likes
on
0 Posts
Mark told me he was co-driving "one of these" at the Atlanta event, so he must have meant yours, huh?
He did mention that the one he was driving had the Koni's on it.
I can't wait to hear how it goes. I'll be curious if you think the 245's are enough tire for the car. With the additional rebound, it may be, but I'm curious.
Please keep us informed about the results, and any feelings you may have about the setup. Thanks.
He did mention that the one he was driving had the Koni's on it.
I can't wait to hear how it goes. I'll be curious if you think the 245's are enough tire for the car. With the additional rebound, it may be, but I'm curious.
Please keep us informed about the results, and any feelings you may have about the setup. Thanks.
04-26-2004, 12:10 PM
#5
www.TeamWTF.org
Join Date: Nov 2003
Posts: 747
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by tpryor
Mark told me he was co-driving "one of these" at the Atlanta event, so he must have meant yours, huh?
He did mention that the one he was driving had the Koni's on it.
I can't wait to hear how it goes. I'll be curious if you think the 245's are enough tire for the car. With the additional rebound, it may be, but I'm curious.
Please keep us informed about the results, and any feelings you may have about the setup. Thanks.
Mark told me he was co-driving "one of these" at the Atlanta event, so he must have meant yours, huh?
He did mention that the one he was driving had the Koni's on it.
I can't wait to hear how it goes. I'll be curious if you think the 245's are enough tire for the car. With the additional rebound, it may be, but I'm curious.
Please keep us informed about the results, and any feelings you may have about the setup. Thanks.
Based on the one event I've done with the Hoosiers, I know that the car is faster than I am right now. I really didn't feel like the car didn't have enough tire/grip with the 245s, but that may be due to my relative inexperience (maybe not getting everything that the tires had to give) and my RX-8 being so much better than my last car. More seat time with the Hoosiers and a better setup should give me a better idea. I've learned quite a bit from following your posts and I'll do what I can to contribute to the pool of knowledge/experience.
04-26-2004, 12:24 PM
#6
Registered
Thread Starter
Join Date: Apr 2004
Location: Biggest Little City
Posts: 197
Likes: 0
Received 0 Likes
on
0 Posts
This is exactly what I was hoping for, some real-life practical advice & findings! If I ever meet you guys at an event, I'll have to remember to buy you a beverage of choice, for sharing your wisdom.
Yes re: street tires for now, and thx for filling me in on the race tire/stiffer sidewall fact. That gives me confidence that when I switch to race tires I can try to go wider with low to no risk.
It was enlightening to watch my car on course while the other drivers tried to keep the car from plowing thru the turns. I could see where the front, then rear outsides would lose grip and push. I 'felt sorry' for the car, well I guess I mean the driver, because I know if the turn in could've been crisper, then acceleration would've put them so much faster thru each turn.
Tim, sorry to hear you learned the hard way about the K&N. Ugh.
I think many of us will be watching with great interest to see how these setup combinations like the adjustable Konis are working out. I need to see whether there might be a happy medium for most courses as far as settings. I hate the idea of having to remove parts or uninstall the shocks in order to adjust them.
Yes re: street tires for now, and thx for filling me in on the race tire/stiffer sidewall fact. That gives me confidence that when I switch to race tires I can try to go wider with low to no risk.
It was enlightening to watch my car on course while the other drivers tried to keep the car from plowing thru the turns. I could see where the front, then rear outsides would lose grip and push. I 'felt sorry' for the car, well I guess I mean the driver, because I know if the turn in could've been crisper, then acceleration would've put them so much faster thru each turn.
Tim, sorry to hear you learned the hard way about the K&N. Ugh.
I think many of us will be watching with great interest to see how these setup combinations like the adjustable Konis are working out. I need to see whether there might be a happy medium for most courses as far as settings. I hate the idea of having to remove parts or uninstall the shocks in order to adjust them.
Thread
Thread Starter
Forum
Replies
Last Post
Touge
Canada Forum
3
09-10-2015 08:07 AM