Eric1987

What do you think it'd take to get the RX8 on terms with a stock S2000 in straight line speed?

neXib

I'd say a shortshift could give the same advantage as a light flywheel depending on your shiftskills in a drag. Afaik the RX-8 has a tight gearbox, so with a shortshift you'd probably be able to really smoothly accelerate without much effort.

Has anyone tried running with light 15" alloys?

Renesis07

iTrader: (1)

Im successfully running with 18" alloys

RedefineRX8

iTrader: (-1)

My 2 best friends have s2000s, one is an AP1 and the other an AP2. For power adders on my car I have the AEM intake, Racing Beat flash, HKS hi-power, AP pulley, Mazsport Dual Resonated Midpipe and Z-Ent grounding wires. My car is also a sport 6MT model without the leather or sunroof.

When I race the AP1 s2000 (HKS Hi-power, T1R grounds, AEM intake, ACT clutch) in 3rd gear pulls, he gets me by a small amount. I have since added the Mazsport Ignition Solution, and haven't tried to see where I stand yet against it with that installed.

The AP2 is stock, and that car is significantly faster than a stock 8 in 2nd and 3rd gear.

I'll need a lightweight flywheel to do the job on both of them, then nitrous for a finishing touch

Anyone who says they beat these cars with a heavier GT at rolls with less mods than mine is either racing people who can't shift to save their lives or jumping hard. S2k is definitely a bit faster stock than a RX8.

Renesis07

iTrader: (1)

Agreed, just by looking at 1/4 mile times, the times arent too much different but the trap speed is significantly different, concuring your statement that an S2000 will pull away in 3rd.

Ike

S2K's can run high 13's stock (13.8 is the best I've seen), as you've found out running just a mid 14 in an RX-8 is a lofty goal.

VikingDJ

I can vouch for the S2K. It's noticably faster then my RX8 was. The AP2 of course has added power and torque over the AP1. It's listed as the same HP, but dynos have shown the car gained about 10whp as well as the increased torque.

Spinning Sushi

iTrader: (21)

The brakes on the MTs WILL NOT clear anything below a 15.5'' inside circumference.

eviltwinkie

If I get a chance, I'll get down to the SA strip and get a time slip...

I've got the AP, Rev8, RPF1, KDW2 275/35...along with an assortment of crap I cant even recall anymore...

Anywho...we will see what it all adds up to hopefully...according to the AP (which I do not trust), my 1/4 is already in the low 14's...and I'm still working on setup...

YaXMaNGTO

Okay, critical thinkers, does anything jump out at you about the so-called "virtual performance gain" numbers for a lightened flywheel? Ike, you're not allowed to play. Let the other students answer one.

The claim is that it's worth .3 seconds in the quarter mile...

eviltwinkie

It simply affects power delivery...only way its worth .3s in the 1/4 is if its coupled with lightening everything else up in the drive train as much as possible...

Only thing I have left to replace is the rotors and flywheel...everything else has been swapped out...

Flywheel and clutch is next as soon as I can get the car to the dealer to get the trans replaced...

Heh...I'm gunning for you dude...I'm not going to go down quietly...haa haa

chancejat

iTrader: (2)

virtual gain would be different for every car, it depends on the difference in weight of the flywheel vs stock and the hp/lb ratio of the car and gear ratios as well and 10lb/hp is not true either....its really messed up but you kinda get the idea

YaXMaNGTO

Don't make me change my sparkplugs

13bturbofc

yeah if im going to the track im taking my 400whp 2nd gen rx7 not the N/A rx8 . dont get me wrong i love my 8 but N/A rotaries are not very fast unless you mod them to the point that its no longer good for a daily driver.

eviltwinkie

Man I gotta take a pic of the plugs...I would never have believed it made such a difference...it like...added a whole .025 ft/lbs of raw unadulterated torque...

It almost made me pee myself...it was THAT noticeable...heh

Seriously...ha

Fer reals...

eviltwinkie

bah dude...no way...mine is totally a daily driver...and totally had its warranty voided in unholy ways...

shes lovely for track days...and a kitten on the twistehs on the way home...hot off the track...

still have A/C and a radio...which is all i need...

and according to the CobbAP i'm a 5.6s 0-60 14.2 1/4mi N/A! haa haa...

told my bud in SA to setup a track night with the local cobra boys...see if i can get in with them on the cheap for a few runs...see how accurate the Cobb is...

i'm sure its going to be hella off...

YaXMaNGTO

It may not apply to lower hp cars, but the "1 hp to make up 10 lbs" is surprisingly accurate as you climb into the 400-500-600hp range. Basically, you can equate for every 100 lbs more you weigh, you have to have 10 whp in order to compensate. Example is with the GTO vs a C6 corvette. GTO is 3750lbs and Vette is around 3200 lbs. In order to match the C6, which traps 112mph, I have to come up with 55 whp to make up for the difference in weight. Stock GTO's dyno 345 whp, and modded GTO's that make 400 whp commonly trap 112mph. This 10 whp / 100 lbs. has been accurate in many other comparisons and racing we've done.

The other general equation to use is that you'll need 10 whp or weight reduction of 100 lbs. to decrease your quarter mile ET by a tenth of a second. This where the "virtual flywheel power" argument falls on its face. I completely agree that 30whp increase will buy you .3 seconds in ET, but if you reference the chart, power decreases at least in half for each gear after 1st. You don't even use the extra power in 1st gear when launching at high RPMs, and you're stuck with just 7hp gain for all of 3rd? No way you'll get .3 seconds from a flywheel.

The last one is you can gain 8-9mph of trapspeed for every 100 whp. A good example is a stock RX8 vs. the Protech turbo RX8. A stock RX8 traps 95mph with 175whp on the dyno. The Protech RX8 made 330whp and trapped 109mph.

Some may confuse this as ricer math. It's not. You can use these calculations to assist in estimating the level of mods you'll need to keep up with cars that have more hp or less weight than you have.

smitht0789

so i went to the track tonight for the first time, and ran 3 times, with my first and best time being at 15.7

13bturbofc

well 14.2 is quick for a N/A rotary, im referring to the guys with the huge bridge ports that are running 10s... they are no longer DD. im running 11.5s in my 2nd gen and while its fun as hell on the street its not comfortable at all and now that i have to have a roll cage i cant even recline my seat lol

Renesis07

iTrader: (1)

Dont feel bad, Ive went 2 times so far and had 5-6 runs and my best time so far is 15.5@89 mph. These cars are tough for drag racing but its still fun. I get a tiny bit better of a time each time I go.

YaXMaNGTO

The Cobb AP has a timer and just reads off the speedo, right?
An accelerometer based device like the gtech would probably be more accurate, but the Cobb could be used to measure relative performance change.

If you want to do a side by side, I have a Beltronics FX2... might be interesting.

smitht0789

no i have a 6 speed, and ya, its still a good time. im glad i went, im sure ill do better next time, i have no read what so ever on my tires either, so i spun alot, but jus got a new set of tires, and am putting them on whenever i get time!

Razz1

The Ap unit from Cobb will help you achieve your goals.