Pettit RX8 going to NASA Time Trial
 

Well----after a lot of consideration I have decided to make the jump. After 6 yrs of hpde's in this car i am going to get into Time Trials with NASA South east region.
Great bunch of guys and a well run program.
With my power output and mods, +car weight it looks like I will be in the TTB class.
Some fast and well driven cars in that class. ZR-1"s Porsche 993's, the ever present E 36 BMW M3, Lotus (non boosted), S2000"s with mods etc.
My wgt/hp ratio has to be no less than about a 10.6/1.
I will not be doing this until the fall season (gets HOT in the SE and the car can handle it--the driver doesnt want too!)
I will not be trying to win every event, but I will be competitive.
Updates to follow!

Awesome OD! Best of luck to you and keep us posted. Wish i was closer, I'd come down to cheer you on. I'll surely follow the thread though!

thanks dude---i think i will be the 1st FI rx8 in actual competition?
TT is competition:)
OD

You mean in your region or in general? :suspect:

How heavily modified are the E36 M3s? I just came from a lightly modified one and the RX-8 put in better lap times my first day out. Other M3s would pull on me a bit in the straight, but the RX-8 cornered better. I wasn't even totally used to it that first day. (didn't have the balls to really trust it - turn 2 at brainerd is a 115 mph corner according to my old M3s speedo)

Great stuff OD . eep us updated with your progress .


And to think you were ready to ditch the 8 not that long ago ....

LoL B--I know due!

MM yep--speaking of the SE region.
Do you know of anyone running a boosted 8 in competition elsewhere?

E 46 M3's in this area are usually very well prepped --with full cages etc.

TTB records in the SE are a 1:37 at Road Atlanta and a 1:19 at Roebling Road for example
both by the BMW's.
I did run a 1:22--1:23 on 2 1/2 yr old nittos and a 1.5 camber all the way around alignment. i also limited my rpms to 7.2K
So I may be competitive with a little more prep:)

Yep, right here in Phoenix.

shifting at what now??

:)

and good for you. just wish it was in my region.. would love to drive less and watch more..

beer :beer:

Ah Ha Flash --i suspected that would be the region that would be running one. Sweet! TTB also?

Scott---been shifting at 7.2K at times and 6.8K at others --remember a road course it not all about power--more about smoothest and power. Think about it?
i am going to do a more proper tire diameter/gearing analysis before that actual TT participation begins.
OD has some more ticks in his bag:)

Subscribed Denny, this is interesting!

methinks that is too early , would shift at 7.6- 8k if i were you ....

you have to had been there:)
But in all fairness--to go faster I do need to wind it out a little more but it will not go to 8K.
OD

/\ sounds like a plan .
I think max. out your SC rpm at whatever engine rpm you decide is your redline :dunno:

Please explain...

I wish that were true, but most of the big road courses have considerably long straights.
FIR main has a 1/2 mile straight. PIR has two 1/4 mile straights tied by a NASCAR oval.
Speeds are well into the triple digits at the ends of those straights.
Fontana and both Vegas tracks are similar.

The 1/2 mile straight at FIR is honestly a PITA. I spend the whole time fighting with more powerful cars that only hold up traffic in the back half.

That's probably why FIR west is my favorite track. A 1/4 mile straight and twisty turns are all you have. Power doesn't do anything except make it easier to play in the sand.

Agree -- different characteristics of your car play stronger to certain track designs.
The tracks i have ran and will be running are pretty fast tracks with good twisties and hard braking zones thrown in.
Road Atlanta has a long back straight, couple good uphill turns (power sure helps there) etc, Roebling Road in savannah area has a long front straight also. These tracks have a higher top speed than some others.
CMP--i have not ran--but a lot of my club friends have.-- It is a slower top speed track.
Barber--slower top speed track also-- i dont like that track. Love the grounds--hate the track design.

Routinely see 130+ speeds on RA and RR ( i have been holding back a little so I have only been seeing 130-132 mph true speed).
Braking is very important on a high speed road track and the 8 usually shines here. On tracks that you have to hard brake from 130+ our brakes start giving up some weaknesses. None that cant be fixed.

One trick about road racing is getting the gearing as dialed in as you can to minimize shifting . Every shift is loosing time no matter the who the driver is or what gearbox is being used. So I may end up with different sets of wheels/tires for different tracks. Dont know yet--gearing/power curve analysis continues.
I have work to do! Excitement is back:)
Plus I have to make a living-----why is that?
OD

Mazdatrix and their RedLine Time Attack car (using a ProCharger S/C rig) are running out west...

http://www.mazdatrix.com/mazdatrixra...=119&nggpage=2

Axial vs centrifugal S/C: FIGHT! ;)


All kidding aside, OD, great news and looking forward to the tale.

Jim Holloway won PTB at the NASA natls last year in his Robert Davis Racing RX-8, sporting a Greddy turbo - reportedly only making 265hp.

ooh this should be fun. subscribed.

sweet glad to here another TTB (PTB) car battling it out. Obviously he went with light weight since TTB on our 4 door car can be in the neighborhood of 10.6/1. Thats the smart way of doing things.
I will have to look up that dude.
Dyno scheculed for next month.
Weight to be done at Road Atlanta June 19th. Fellow competitor has scales---sweet.
I can only run water injection-----NO METHANOL ALLOWED.
If I decide to run R 6 Hoosiers I will have to back down to a 245/35/18 size due to being over the allowed points.
R-6's are a +10
KW varient 3 coilovers +the coils themselves are a 9
Sways are a + 2
equal to 21
Allowed tire size is a 265. Going to a 245 will give me 2 points credit.
OD

Might I suggest using the correct tire size of 245/40r18 instead of the 35s?
You need the RPMs and top end, not low-end, especially since you shift before the HP peak.
(Not to mention the way that having the wrong aspect ratio screws up the fuel mapping.)

appreciate the thought. Remember, I am running the 09 transmission with a 4.44 diff so my final drive is a little different than the oem 04 car.
Heres my thoughts and please ; all suggestions and ideas will be considered.
In finalizing my final gear ratios, my power band and the adverage track speed, the 40 sidewall tire may have a slight advantage at Road Atlanta. That track has multiple areas of 100+mph. Only 1 straight that will see over 130mph and 2 areas that will see between 105-120. So a 5th gear that is good to 130+is good.
The 40 sidewall will require me to go to 3nd gear in 2 areas. Turn 7 and 10A. This may not be a bad thing really.
Now at every other track the 40 sidewall, I believe will be a disadvantage as I will be having to go to 3nd more often and at times i will be in that inbetween 3-4 gear need.

A 35 sidewall tire at road atlanta will req 6 th gear use in 2 areas (At my redline). The 09 6th gear is tall and this sidewall will help with that. It also has 3 uphill turns (using 4th gear)were low end grunt can be really put to good use.
3nd gear may be to short for 10A/B requiring a shift going up the hill to 4th and another shift approaching turn 12 to 5th. yet if i run 4th through there I may end up with too low rpms for that steep uphill approaching the bridge.
Decisions, decisions:)

For RR a 35 sidewall will be a hands down favorite. 6th gear presently kills me on the long front straight. I have ben running 275/35/18 nto1 that if i am not mistaken is about the same diameter as the 245/40/18 hoosier? if i went with the 40 sidewall i could continue in 5th to 139mph at 8K for that front straight, but 4th gear will not have as much grunt for the backside of the track. RR only has one area in which you will see above 110mph. Adverage speed for the entire track is between 80-90mph.

It may end up a different tire for that particular track?
What are the particulars for the tracks you are running ?
OD

Denny, do you have your registration in to Julie yet? I'm really looking forward to you being out on track with us. What is going to be your first event, RA, CMP or Roebling?