help for the quatermile..
 

i hav an o4 rx8, looking to dramaticaly improve my 1/4 mile time, what would the best rim and differential gear combo?? i was thinking about dropping the rims to 17's and the 4.7778 gears. is this effective??im not worried about the gas or drivability. also im not really to savvy on the gears and rim size thing any thing will help thanks

The improvements won't be much but they do help.

What times are you looking for?!

If you mean dramatic like under 14 seconds then F/I is your only solution...

I disagree.

Nitrious and alcohol fuel mixture!

moved to racing forum


i agree with charles. the rest of you - if you arent going to give him tire/rim and gearing suggestions find another thread.

17s would help. you are also going to need some suspension tweaking to manage wheel hop. tirepressures as well.

i cant say on the gearing but there is probably a gearing calculator online that will help you figure it out

oh like this one http://www.f-body.org/gears/ there are many more with a quick google search. dont forget to ask around for local resources . people are usually surprised to find they have people close by that can help them find their way at the track.

edit- well that one might not be the bestt but you get the idea

Tow it behind a vette? :yelrotflm

I kid, i kid.

Lightweight 17's and drag radials will help a little. If you're willing to throw gas mileage and comfortable driving (read not having to shift every .2 seconds) I would go even higher than the 4.77. Maybe 5.10's would be high enough and still streetable without too much worry. Not sure if 5.10's are out there for our cars as I haven't checked. Also look into the suspension to try and eliminate wheel hop as stated earlier

If you aren't planning on FI, I would get a catless midpipe, and hunt down a used AccessPort and have MazdaManiac tune it for you. I good dyno tune if there is somewhere in your area with a lot of experience to do it for an 8 will get the most power out of it.

I'm not into drag racing at all but I can tell you that 5.12 gears are available for our cars (I have a set in the garage). As far as I've been around, this is the lowest available gearset without something crazy custom or switching to a 9" rear.

+1 brother....

I am seeing positive reinforcement from Zoom and Team; the less I say the more they agree with me. :grouphug:

Will you two please send a similar memo to Flashwing for me. :lol2:

5 main areas to address in order to decrease 1/4 mile times:

Driver skill: I dont drag race but read about it and talk to other drag racers and rx8 owners who do. What I do know is the the rx8 needs a high rpm launch, something near 5-7K is what I have heard produces the best times.

Power: Nitrous, a solid ignition (plugs, wires and coils like the BHR kit) no cat and some tuning will get you about all the NA power possible.

Get power to the ground: Upgraded the clutch so you can do 7K RPM launches. Sticky wide rear tires and narrow in the front.

Suspension to reduce wheel hop.

Weight:

While you are replacing that clutch you may as well install a lightweight flywheel, more to free up HP but saves a little weight.

If your going to have dedicated drag tires, why not go with a lightweight 16" wheel in the back with a much smaller overall diameter tire. Less weight, rotational mass and its the cheapest way to effectivly lower gearing. Look at tire weight, race tires dont weigh as much as street ires. A good 5lbs on many occasions. a lightweight 16" rear wheel/tire setup would probably be 15LBS less on all cornors over the stock wheels/tires. Plus you can put your street wheels/tires back on later and be more streetable. For the front you might as well put the smallest wheel you can fit and a thin tire. I dont know if 16's will fit but a 17 will.

Pull out everything you dont need under the hood and in the interior. It will get expensive but you can get race seats, lighter brakes (rotors and calipers) dry carbon body panels get real pricy but can save some weight, single oil cooler instead of the heavier dual coolers with 10 hoses, air injection removal, A/C does not weigh much at all so keep it for your comfort.

Wind resistance:

Suspension was already mentioned to help with well hop, but lowering the car will also reduce drag at higher speeds.

I am not an expert by any means so if I am wrong or left something out, someone please correct me or add things I missed.

prove it.........

+1`

Just because it wasn't posted doesn't mean it hasn't been proven ....

anybody tried the ole 'bag o cement in the trunk' trick to get a decent launch ?

thanks for the responses, Just wondering where you got the 5.12 gears?? thanks, as far as the rest of the mods, my car isnt very stock, FRONT Back sway bars exedy stage 1 clutch, ACT streetlite flywheel, tokico spec D struts and shocks, megan racing camber kit, however stock exhaust and cat...also before i started getting into racing super heavy 19'rims and tires..LOL

oh i meant to say i know rx8 will not be a 12 sec car N/A im just trying to beat my friends 350Z without F/I

Sorry but I don't think its gonna happen even after you do all the mods, you might stand a chance if you get a hold of Team's RX-8 and the skills of the Schumi1996.

Moroso Power Speed Calculator , part # 89650

I'm pretty sure my 5.12's came from MazdaComp, now MazdaSpeed. You used to be able to purchase them from Racing Beat and/or Mazdatrix back in the day but I don't know anymore.

It's provided through Mazda Motorsports, but you can likely purchase it through any number of hardcore Mazda aftermarkets parts sellers including Mazmart ...

Question: I know to get a good start you need to launch from 5-7K rpms but do you dont just drop the clutch do you? Because that would cause unwanted wheel spin? Do you slip the clutch or?

This is one of the questions ive been wondering about, I usually just try to slip it a little but no too much so I get unwanted wheel spin... is this the right way to do it?

I drop the clutch at 7k+ and modulate my throttle foot, others slip the clutch, search should get you some past discussions

Me, too, as tires are cheaper and easier to replace than clutches.