2009 RX-8 R3 the Ultimate Autocrosser
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2009 RX-8 R3 the Ultimate Autocrosser
Now that you have seen the specs on the 2009 RX8 R3, will it be the RX8 to have in B Stock? Will the gearing give it more grunt in 2nd gear?
https://www.rx8club.com/purchasing-financing-insurance-56/official-2009-rx8-info-info-sheet-order-form-spec-deck-colors-inside-140437/
I know there is only one autocross tire that will fit the 19" rims. The Hoosier P235/35ZR19 A6.
And how limited is the rim selection in light weight after market rims?
Can anyone comment?
https://www.rx8club.com/purchasing-financing-insurance-56/official-2009-rx8-info-info-sheet-order-form-spec-deck-colors-inside-140437/
I know there is only one autocross tire that will fit the 19" rims. The Hoosier P235/35ZR19 A6.
And how limited is the rim selection in light weight after market rims?
Can anyone comment?
#3
As Mark indicated, much of the 2nd gear advantage of the R3 may be offset by the taller 19" tire options.
245/35r18 - 24.8" OD (V710)
295/30r18 = 25.3" OD (A6)
235/35r19 -25.6" OD (A6)
265/35r19 -26.1" OD (A6)
295/30r19 -26.1" OD (A6)
If the new car can be had with the lower rear axle ratio, new trans and 18" wheels (I haven't looked close enough to know), it may end up with a net acceleration advantage. Weight and updated rear suspension are still question marks in my mind.
Chris H
245/35r18 - 24.8" OD (V710)
295/30r18 = 25.3" OD (A6)
235/35r19 -25.6" OD (A6)
265/35r19 -26.1" OD (A6)
295/30r19 -26.1" OD (A6)
If the new car can be had with the lower rear axle ratio, new trans and 18" wheels (I haven't looked close enough to know), it may end up with a net acceleration advantage. Weight and updated rear suspension are still question marks in my mind.
Chris H
#4
We are running a 2008 40th anniversary so it's got the foam filled this and the bilstein that...
shocks are crap!!! did one event then ordered koni's. the urethane filled cross member probably is more of a vibration dampener then actual performance piece.
The 19's will be heavier and as stated will only have 2-3 mph difference in the end over the existing cars.
be interesting to know what that rear suspension geometry change is about though.
shocks are crap!!! did one event then ordered koni's. the urethane filled cross member probably is more of a vibration dampener then actual performance piece.
The 19's will be heavier and as stated will only have 2-3 mph difference in the end over the existing cars.
be interesting to know what that rear suspension geometry change is about though.
#7
If effective gearing, with the 19" rim and taller tire, ends up being a wash with the current car on 18's, I'd say advantage to the current car, given the increased rotational mass of the 19" wheel/tire and the "no torque" Renesis...says the guy with the torquey, 'murrican V8
The rear suspension interests me...the current car has something going on with rear toe/camber changes on full compression, I believe...
![Lol](https://www.rx8club.com/images/smilies/lol.gif)
The rear suspension interests me...the current car has something going on with rear toe/camber changes on full compression, I believe...
#8
I have to admit I'm a tad disappointed in the new car-it looks porky. That may change once I drive one, but at this point I'm sticking with the 2004-especially since I think the price tag on the R3 is not going to be insignificant.
#11
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the trans gearing changes too and this also has to be taken into account, as discussed in this thread
https://www.rx8club.com/series-ii-technical-trouble-shooting-160/2009-rx-8-transmission-gear-chart-discussion-135710/
that thread fails though because nobody considered the tire diameter change
I ran the calcs between 24.7 spec diameter (V710 245/35-18) vs 26.1 spec diameter (A6 265/35 or 295/30 19) and it came down to this
1st - 2009 3.0% shorter overall effective gearing
2nd - 2009 1.4% shorter overall effective gearing
3rd - 2009 5.1% taller overall effective gearing
so slightly lower in 2nd, lower in 1st but with a increased rpm drop on the upshift to 2nd, and you're F'd if 3rd gear is required due to a significantly larger rpm drop on the up shift because you'll run out of 2nd sooner
without a noticeable weight drop or engine output gain this looks like a turkey on paper
https://www.rx8club.com/series-ii-technical-trouble-shooting-160/2009-rx-8-transmission-gear-chart-discussion-135710/
that thread fails though because nobody considered the tire diameter change
I ran the calcs between 24.7 spec diameter (V710 245/35-18) vs 26.1 spec diameter (A6 265/35 or 295/30 19) and it came down to this
1st - 2009 3.0% shorter overall effective gearing
2nd - 2009 1.4% shorter overall effective gearing
3rd - 2009 5.1% taller overall effective gearing
so slightly lower in 2nd, lower in 1st but with a increased rpm drop on the upshift to 2nd, and you're F'd if 3rd gear is required due to a significantly larger rpm drop on the up shift because you'll run out of 2nd sooner
without a noticeable weight drop or engine output gain this looks like a turkey on paper
Last edited by TeamRX8; 06-04-2008 at 10:57 PM.
#12
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With natls not at HPT for 09' the value of a shorter geared car becomes potentially lower. I am just glad to see are worthless older cars should not take an even bigger hit now.
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#13
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I think I read somehwere that the R3 was 45lbs lighter than a similar '09 RX-8.
#15
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I don't see the gearing as being advantageous with the same engine output specs, even at Heartland Park
with 1st being lower and 2nd almost the same it will only exacerbate the turns where you're too fast for 1st and too slow for 2nd, it only helps in the turns where you're in 2nd that are a touch slow for the current car in 2nd, 1.4% doesn't really buy you that much
I also don't see the R3 coming in at the weight of the older car in race trim, my bet is it will be heavier
with 1st being lower and 2nd almost the same it will only exacerbate the turns where you're too fast for 1st and too slow for 2nd, it only helps in the turns where you're in 2nd that are a touch slow for the current car in 2nd, 1.4% doesn't really buy you that much
I also don't see the R3 coming in at the weight of the older car in race trim, my bet is it will be heavier
Last edited by TeamRX8; 06-05-2008 at 03:10 PM.
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from the pictures posted of a 2009 GT model in the other section, the
new cars have a triangulated front strut bar now. i can't tell how solid the
firewall connection is but this should help chassis flex.
mebbe i should run down to the dealer and see what else i missed...
new cars have a triangulated front strut bar now. i can't tell how solid the
firewall connection is but this should help chassis flex.
mebbe i should run down to the dealer and see what else i missed...
#17
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#19
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it probably has more to do with interior NVH than actual chassis stiffness
the RX-8 chassis has phenomenal torsional rigidity
https://www.rx8club.com/rx-8-discussion-3/torsional-rigidity-why-i-like-rx-8-a-10961/
the RX-8 chassis has phenomenal torsional rigidity
https://www.rx8club.com/rx-8-discussion-3/torsional-rigidity-why-i-like-rx-8-a-10961/
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