View Full Version : Hot Track Pressures on OE Tire?


thewird
04-10-2010, 09:51 PM
Hey, I'm gonna be taking my car to Shannonville tomorrow to see what a stock RX-8 can do before I start making my changes and was wondering what hot pressures I should run on the OE tires if anyone has experience already? And what you would start with cold might be helpful too :). Don't really want to spend the whole day learning the car and trying to set the tire pressures at the same time lolol. Thanks.

thewird

nate340
04-11-2010, 02:26 AM
i start at 32 and bleed off anything over 40 seems to work. i have very little experience running oe tires thu usual run the slicks. i run a 2:13 on the long track would be nice to see what a driver such as yourself does and how i compare.

RXeckless
04-11-2010, 08:06 AM
wird, I'm no expert but last fall at shannonville I start at 40 psi by the end of the day I was at 30-32 psi for better grip with all those twisties on stock tires (RE040), but even this was a compromise as you lower the psi the tire wall was not as stiff and there seem to be more tire roll. I'm heading to Calabogie April 24th weather permitting for lapping with instruction. After that my tires should be toast and time for replacement!
Any tips for Calabogie as you've been there a few times and this being my 1st of hopefully many.
Looks like a great track.

P.S. The weather looks better today, so this is probably irrelevant, that day started around just above freezing and the high was 10 or 12 and overcast.

thewird
04-11-2010, 06:47 PM
Alright, I just got home from Shannonville and here is my first experience with the a bone stock RX-8 (only upgrade done was Hawk HPS brake pads)....

Well first I forgot my lap timer in my dads car so I had to go pick that up which delayed my like an hour so I only arrived at 2:10 at the track. So I took the car out and started getting used to it and the first thing I thought to myself was jeez this feels like a boat with jello for bushings. Fast forward a little and I realized I have to treat the car differently then the RX-7 since its closer to a full race car then a street car. Pulled off and tire pressures were at 44 so I dropped them down to 40 PSi. Went out again and after a few laps tires started getting greasy, came off and dropped the pressures down to 38 PSi. Again, went out and it started to feel better but would get greasy after a few laps, came back and dropped them to 36 PSi. Went out and "now we're talking" came to mind. I'm pretty sure I could have dropped them further but I didn't have an air pump in case I went too far so I just left it at that and kept taking air out to match 36 PSi after every session.

So around ~4pm I set a 2:10:68 on my GPS lap timer after which the battery died. Towards the end of the day, I'm sure I was doing 2:09's since all the corners were flowing better and I started quick shifting but had no lap timer to record it so I can't claim that. Also, it was very difficult to set quick laps since there was always traffic and I'm not sure what the rules were (since I came late) but nobody signaled when they wanted you to pass. They would just turn on there 4 ways and slow down in the corners which is kinda >_> since your not sure when they want you to pass lol.

Anyway, what I think about the RX-8 on the track is it handles extremely well and is balanced but you have to keep it in the high RPM (6,500+) at all times. I found myself downshifting into 2nd in corners I never used to use 2nd in. Also, its very difficult to turn the car with the throttle which is something I do a lot of with the RX-7. The car understeers quite a bit and takes some work to get it to turn. All in all its a great car at the track and I enjoyed my 3 hours with it there. With more time and playing more with tire pressures, I'm sure I could have gotten into the 2:08's.

On a side note, I couldn't get the car into 6th on the way home until I pulled over and went through all the gears a few times. The transmission was overheating I'm sure since I could feel plenty of heat coming through the shift boot.

Also, I liked how my lap timer fit perfectly between the A-piller and the gauge cluster lol... Didn't have to tape it or anything, just shoved it in there.

http://www.rx8club.com/attachment.php?attachmentid=154756&stc=1&d=1271029264

wird, I'm no expert but last fall at shannonville I start at 40 psi by the end of the day I was at 30-32 psi for better grip with all those twisties on stock tires (RE040), but even this was a compromise as you lower the psi the tire wall was not as stiff and there seem to be more tire roll. I'm heading to Calabogie April 24th weather permitting for lapping with instruction. After that my tires should be toast and time for replacement!
Any tips for Calabogie as you've been there a few times and this being my 1st of hopefully many.
Looks like a great track.

P.S. The weather looks better today, so this is probably irrelevant, that day started around just above freezing and the high was 10 or 12 and overcast.
Yah, I should have lowered my tire pressures further but oh well. I've only been to Calabogie once and spent half the day fighting boost issues due to wastegate problems. The only thing I would suggest is to take your time learning the track fully in the morning and then start pushing hard in the afternoon. There are a lot of corners and some corners you dont see until your on them (with the RX-7 there were some corners I had to brake before I could see the corner which was interesting). I a lot of the corners link together so if you get the lines down you can cut a lot of time.

thewird

climacus
04-11-2010, 08:10 PM
but I didn't have an air pump in case I went too far so I just left it at that..

If you still have your run-flat kit in your trunk, you have an air compressor, a damn good one too.

thewird
04-11-2010, 09:28 PM
If you still have your run-flat kit in your trunk, you have an air compressor, a damn good one too.
Yah, its in the trunk but to be honest I never opened the box lol. Wouldn't that be injecting the foam too though :P

thewird

Kafka
04-12-2010, 12:29 AM
Excellent post...thanks for sharing with us :)

nate340
04-12-2010, 01:37 AM
thanks for the info, suppose i'm running too much pressure when im out on my street tires. glad to see you enjoying the 8 more and more.

RXeckless
04-12-2010, 05:30 AM
Yah, I should have lowered my tire pressures further but oh well. I've only been to Calabogie once and spent half the day fighting boost issues due to wastegate problems. The only thing I would suggest is to take your time learning the track fully in the morning and then start pushing hard in the afternoon. There are a lot of corners and some corners you dont see until your on them (with the RX-7 there were some corners I had to brake before I could see the corner which was interesting). I a lot of the corners link together so if you get the lines down you can cut a lot of time.

thewird

Thanks for the info, if anyone else is interested in joining me at Calabogie on the 24th weather permitting please pm me. I've not booked yet waiting till next weekend to check the weather, really don't want to spend the time and money if the track conditions aren't good to great. I found shannonville really hard on the car brakes, but I was on the short track.

thewird
04-12-2010, 10:12 AM
i start at 32 and bleed off anything over 40 seems to work. i have very little experience running oe tires thu usual run the slicks. i run a 2:13 on the long track would be nice to see what a driver such as yourself does and how i compare.
Are you running 40 PSi on your BFG R1's?

thewird

geox
04-12-2010, 10:54 AM
.......Shannonville - RX-7 - 1:58.61, RX-8 - 2:10:68.........


I would like to believe...that Rx7 must had plenty mods....:scared:

20b-3rotor
04-12-2010, 04:33 PM
Looks like you were having fun. I didnt get to take the rx8 out i was in the protege trying to get it ready for next month.

01Racing
04-12-2010, 04:49 PM
We run our BFG R1 34lbs hot at Shannonville, our fast lap was in the 1:54's and getting up to speed when the tranny broke (again). Our RX7 seems to work a lot better at Shannonville (I think its the driver......me). We can actually run 2 classes faster at Shannonville than Mosport, again its probably me and my confidence level at the different tracks. On long track we make 12 shifts per lap between 1st and 3rd gears, ( prbably why the tranny breaks lol) never getting close to 4th even on the back straight!

I am going to rent Shannonville sometime between now and the end of May to test for the June race there.

thewird
04-12-2010, 05:55 PM
So I went to go drive the RX-8 today and look what I noticed lol... The whole outside edge of the front left tire is shredded and chunks missing. That tire didn't like what I was doing at all lol!

http://www.rx8club.com/attachment.php?attachmentid=154815&stc=1&d=1271112883

I would like to believe...that Rx7 must had plenty mods....:scared:
It has enough mods but the car itself can go faster, I just need to get better ^_^

Looks like you were having fun. I didnt get to take the rx8 out i was in the protege trying to get it ready for next month.

Hehe yah, Shannonville is one of those "fun" tracks where its a lot easier to play with the car. I was pretty rusty for my first few sessions, I was all over the place lol

We run our BFG R1 34lbs hot at Shannonville, our fast lap was in the 1:54's and getting up to speed when the tranny broke (again). Our RX7 seems to work a lot better at Shannonville (I think its the driver......me). We can actually run 2 classes faster at Shannonville than Mosport, again its probably me and my confidence level at the different tracks. On long track we make 12 shifts per lap between 1st and 3rd gears, ( prbably why the tranny breaks lol) never getting close to 4th even on the back straight!

I am going to rent Shannonville sometime between now and the end of May to test for the June race there.

Yah, I think nate is running too hot, thats why I asked. I thought he was talking about the OE tire when I first read it so thats why I tried 40 PSi hot first.

Are you still running the N/A transmissions or Turbo II? You might want to try a JDM (for the shorter 5th) FD3S transmission. They take a good beating.

Hey, if you go invite me :). I need some low traffic track time :D

thewird

REV-illusions
04-12-2010, 06:08 PM
Yah, its in the trunk but to be honest I never opened the box lol. Wouldn't that be injecting the foam too though :P

thewird

nawh... you can use it without pumping foam into the tire... few of us did that last year at the shannonville rather then go to that gas station out there last year.

Chris_Bangle
04-12-2010, 06:38 PM
So I went to go drive the RX-8 today and look what I noticed lol... The whole outside edge of the front left tire is shredded and chunks missing. That tire didn't like what I was doing at all lol!

http://www.rx8club.com/attachment.php?attachmentid=154815&stc=1&d=1271112883



Street tires are depressing - that's is why I am offering a set of track tires (hoosier koni spec) mounted on 17x8 wheels for 600$ in the for sale section :rolleyes:

thewird
04-13-2010, 01:08 AM
^ Well, you have to keep in mind the tires are 5-6 years old with 78,000 km on them. They're pretty hard. I probably gave them the most extreme use they ever saw in their life.

On a side note, the car feels torquier now. Possibly cleaned out the carbon with the constant 9k RPM but that might just be some placebo effect.

thewird

01Racing
04-13-2010, 08:28 AM
We took a brand new set of Falkens to Mosport on the Speed 6 last year for the Motorsport Hall of Fame day, I was taxiing people around Mosport. I did all 4 tires like yours except across the whole tread. The reason street tires chunk is that there is too much tread. If you shaved the street tire down to 4/32nds you wouldnt have that problem. In the Speed 6 you could hear the tires shredding like machine gun fire in the fender wells lol

nate340
04-13-2010, 10:36 AM
when i said 40psi hot i was talking about oe tires. I've only had a few dry hot laps with them. remember last yr at shannoville in the rain and it dried up a little at the end.

with the toyo ra1's i run 38-42psi depending on track and weather. this yr ill be running bfg r1's and from what Alans saying i should be running similar pressures.

about the car feeling faster many have reported it and it seems that the ecu recalibrates its self and is more responsive after spending so much time wot

thewird
04-13-2010, 10:10 PM
Nate, you might want to try 35-36 PSi on the BFG R1's.

thewird

20b-3rotor
04-14-2010, 07:39 AM
We run our BFG R1 34lbs hot at Shannonville, our fast lap was in the 1:54's and getting up to speed when the tranny broke (again). Our RX7 seems to work a lot better at Shannonville (I think its the driver......me). We can actually run 2 classes faster at Shannonville than Mosport, again its probably me and my confidence level at the different tracks. On long track we make 12 shifts per lap between 1st and 3rd gears, ( prbably why the tranny breaks lol) never getting close to 4th even on the back straight!



Wow AL You Should run GT-2 class for Shannonville. With that time you should be top 2 for GT-2

rx8inthe540
04-14-2010, 08:01 AM
Street tires are depressing - that's is why I am offering a set of track tires (hoosier koni spec) mounted on 17x8 wheels for 600$ in the for sale section :rolleyes:


where are these at?

Chris_Bangle
04-14-2010, 10:24 AM
^ There are here: http://www.rx8club.com/showthread.php?t=194028

But they should be sold in the next couple of days. contact me if you are interested.

nate340
04-14-2010, 02:09 PM
Nate, you might want to try 35-36 PSi on the BFG R1's.

thewird

will do, thinking of heading to the track early May.