Ike

Yeah, I want to see this slips as well. Hell, Ito doesn't even have a slip for his 14.3 run and I'm starting to doubt that one.

Yanje

so basically they recover a percentage of the HP lossed during drivetrain?

RX8-TX

Something like that.

visitor

exhaust, what's that, 5hp?
intake...hahahaha
pulley? maybe another 5?

lightweight flywheel? so you can get more of the 238hp to the wheels?

so at best, 10rwhp.

and that's gonna get you low 13's?

hahahahahahahaha

look at it this way, rx8's weight/hp ratio's 12 3000/238.

a cobra's 9, 3660/390. A cobra will do high 12's , low 13's.

how exactly will 10rwhp get you into low 13's?

Ophitoxaemia

low 15's is pretty embarassing by any measure, but i think its a difficult car to launch. what are the 60' times?

light flywheels sure make a car feel faster! my guess is with the rx8 and that long-long climb through the tach is it will get you to the power band more quickly in 1st gear. a lower 1st gear would do the same thing- minimize the amount of time spent below 6K rpm.

james

Lawerence

Man your acting like a flywheel is going to magically make the rx8 a fast car.

IF you want to go fast without a turbo, nitrous or whatever.

Your only choice right now is canzoomer. And even with canzoomer/I/h/E/flywheel you wont see low 13s. Unless you are on radials and can drive like a madman. Maybe then a low 13 with an evo like trap.

The car hasnt been out too long and really has little aftermarket. Be patient adn things will get better.

GeorgeH

iTrader: (2)

FYI, it is not possible to assign a single HP number to the effect a lightened flywheel has. This is because it varies per gear - the lower the gear, the greater the effect. In my Miata, the Mazdaspeed flywheel I installed was very noticeable in first gear, less noticeable in second, and inconsequential in third and up.

You can, however, come up with an approximate number that characterizes the effect of the flywheel for every gear. Bascially, compute the reduction in the moment of inertia from the factory flywheel to the aftermarket unit, and then divide by the average acceleration for each gear to get the torque "liberated" by the flywheel. Since your acceleration reduces with each gear change, the effect of the flywheel reduces too.

In that regard, it's like any other "adding lightness" mod, except it is sensitive to the angular acceleration of the motor instead of (or, more accurately, in addition to) the linear acceleration of the car. But make no mistake - 10 lbs off a flywheel is much more important than 10 lbs off the body, or even 10 lbs out of the wheels, at least from a straight-line performance perspective.

I did the calculations for my Miata and came up with something like 10 ft-lbs in first gear. Now mind you, this affect will be felt (more or less) across the entire power band, not just at peak. So it's a very real way to increase the performance of the car, particularly "street start" 0-60 times, as well as in-gear times in second, and perhaps third, gear.

Now, if you are into serious wheel-spinning drag racing, the effects won't be as noticeable, and may even hurt launch times, since you are counting on that flywheel to keep the tires spinning. I suspect in an RX-8, a lighter flywheel would be a good thing even in these circumstances, but some cars really need that rotating mass (say, a car with a super-light drivetrain but with very sticky drag slicks).

But for improving around-town throttle repsonse, and for autocrossing, a light flywheel is a very real performance enhancement, particularly in a rev-happy car.

rexi

European Car magazine independently dynoed a Vw golf 1.8 t a few years ago and found the following increases in rwhp

1. First gear 18 extra rwhp
2. Second gear 11 extra rwhp
3. Third gear 4 extra rwhp.

Therefore acceleration in 1st and 2nd gear is MUCH faster.
The rx8 having limited torque and with a 9500 rpm would offer even more hp improvements, making this modification a must have.

Standing quarters could improve by up to .4 to .5 seconds in my opinion


Regards
Rexi

Lawerence

I love it when people pull #s out thier @$$


but who know you may be right

GeorgeH

iTrader: (2)

This is excellent confirmation, but I do wonder about the magnitude of the gains reported. Given that the car is accelerating rollers (I'm assuming a chassis dyno), as opposed to the car itself, the gains in each gear wouldn't directly correspond to the gains you'd experience on the road, since that the rollers would (likely) not be the same effective mass as the car. In otherwords, the engine would not accelerate at the same rate on the rollers as it does on the road.

Of course, they may have accounted for that - I'm sure the MOI of the rollers is known, and therefore you could scale the results. Do you remember if something along these lines was mentioned in the article?

George

MRX_Rotary

iTrader: (1)

Catalytic converters on rotaries are very restrictive to meet emmision tests. So, an aftermarket exhaust system wouldn't be that bad of an idea. Sure results won't be phenominal, but you would gain more power than you would on a piston engine similar to the Renesis (say, an S2000 engine).

Of course, the best deal would be Canzoomer. Then you could just download Stage 2 if you ever got around to adding an aftermarket exhaust.

Anyone up for streetporting their Renesis? :D

winter

Gimmie a die-grinder and a case of newcastle.

I'm very curious to see what kind of port jobs we can do to the renesis... that's probably where the NA power is going to show up.

XDEEDUBBX

yea its an 8th mile time..i wish it was a quarter..haha

Velocity-8

My CZ1 is installed finally. I will be taking the 8 back to Atco for some 1/4 runs next week. Then we will see the real difference the CZ1 makes.

-8-

You better not be lying - too many people have said that, but then never actually do it. I look forward to the results.

Lawerence

for some reason, I believe him.

He seems to be honest enough and wants do do good and show the community what a difference it makes.

Velocity-8

I'm going Tuesday. Open racing early then jet cars and top fuel after dark. I've already posted my base time slips so why would I lie?

Velocity-8

Thanks... here's my stock run from Atco...

Car #202

Velocity-8

It looks like there will not be open racing tomorrow because of the Thrill show. I'll probably go this Thurs or next Tuesday.

AbusiveWombat

Any new runs Velocity?

Velocity-8

All racing got rained out last week. I plan to go tomorrow (Tues) for open racing. I should be able to get about 5-7 runs in. I'll post the timeslips.

Silvermister

I was at Atco last Friday, Street Night. Let me tell ya I did NOT represent for the rotaries.I was my first time with my 8 at the track and the best time I got was 15.7. I kept missing some gearsand wheel hopping. It was embarrasing. I was the only rotary there. Not a good night. Wed I should be getting my tanabe springs. It lowers the car 1.5 inches. Maybe that should help and also I've been practicing my high rev shifting.I might go this next Friday before Hot Import Nights in Philly.

Velocity-8

I'll be there tomorrow if you can make it. I hope it does rain, again.

Velocity-8

Not the best day for time trials. 104 degrees at the track with 100% humidity. Here are my best runs. I'll post the actual timeslips tomorrow (sanner is at work).

CZ1.1 Off

2.26 60'
15.47 1/4 mile @ 91.6


CZ1.1 On

2.28 60'
15.20 1/4 mile @ 93.6

adrian-1

Ouch, that's some hot weather.
Nice 60ft times. I couldn't break 2.3's but I won't go above a 5k rpm launch.

So, with the CZ in you gained 0.27 seconds. That's well short of the expected 1 second 1/4mile gain.