Uhh, yeah, regular math does not apply here. A mod on one end can affect the results of the mod on the other - both positive AND negative. You don't really know until you do some dyno runs and try out different combinations. That's why I'll wait a while before purchasing these things.

 

SIGH.

 

colin204, what B-Nez and Lee Chun are saying is the HP gains from common bolt-ons (I-H-E) is rarely cumulative. You also need to look at the actual dyno results from some independent testers. I would like to believe that a Borla exhaust makes 12-15HP at the wheels and a simple filter kit makes 8-10HP, but I really need some more proof than what the manufacturer claims--that RX tuner mag might be a good source .

 

The Dyno chart David Borla sent me showed 10HP on their test car with 5 or 6 on torque. Just email him and ask for it.

Think I'll probably just do an intake change first.

 

Is it "header" or "headers"?

 

header

 

What would be your approach? And how far would you go, realistically???

here's my plan

1. Wait for a recall ECU reprogramming will happen, mainly to address mpg and hp loss due to the lame "hack" job they did for us yanks...

2. lower the car 1"-1.5" with camber correction.

3. Replace current wheels with lighter titanium wheels and wider tires overall (Front 275/35/R18 & Rear 285/35/R18).

4. Add Mazda speed frontend kit for improved airflow.

5. Swap out intake/exhaust system with aftermarket high-flow exhaust and intake/filter. (requires additional ECU tuning, hopefully will be available).

 

Why camber correction? We ain't got no stinkin' struts - the RX-8 suspension is already fully adjustable. Since the limits of the front suspension are about -1.0 degrees right now, a bit of lowering will allow more negative camber at the limit of adjustment. However, you could still dial the camber back to a less extreme value with the normal adjustment range even with the car lowered.

Regards,
Gordon

 

You know that this will NOT improve performace, and will drastically degrade fuel economy and acceleration, right?

 

errrr... okay well maybe there are a few things on this list I don't know much about

I thought lighter wheels and thicker tires will not only reduce the overall weight, but gain some additional grip off the line...sounds only logical to me...

*BUT* I'm sure you guys will give me a more technical breakdown...

(Which, BTW, I certainly am interested in reading about)

I have no real experienced with souping up cars--I only make logical assumptions about these things...and of course I wouldn't actually go through with it unless I got some good opinions on it from this board.... that's why I threw it out here for discussion.

 

Well, as far as I'm concerned, the tire width could become helpful on a track situation -where handling is a 'must'

If you increase tire width, YES you will increase grip, but you'll also increase friction and therefore acceleration losses. The wheel & tire combo could be lighter than their OEM counterparts. However, an excess in patch area won't help you get better straight line performance. If you read some of the threads (sorry, its 2am and Im lazy to post them, maybe later!) you'll find that the 8 doesn't squeal its tires that much (even with DSC off.)

I agree that, according to some mags (take it from where it comes from) the best launch technique is a clutch dump at 8K rpm. I am pretty confident this will cause a huge amount of tire spin. But not necessarily beat up your 1/4th mile time...in other words I don't think the 8 has enough 'juice' to move its mass from a standstill that fast; it needs to get its tires spinning.

I guess I could get a bit more technical on it....but I would have to do some research to backup my (so called) theory.

I'll edit this post once I can keep my eyelids open!

Cheers!

 

i went to englishtown and raced my rx8 6 speed with a 8000clutch drop alot alot of wheel hop and spinning through 1st gear and i got 15.00 at best

My 60ft was 2.51 or something like that

 

TURBO
its just a matter of time

 

turbo... oh yeahhhhhhhh

how much would that typically cost to install on a car such as this one?

 

Installing a turbo setup on a naturally aspirated car usually ends up costing around $5500 once all things like proper engine management are taken into consideration.

 

The wider tires will increase your cornering grip, but it will reduce your off the line grip. Think about it for a minute ... the weight of the car remains the same. So that means that the tires still have the same load (ie: the same number of pounds per square inch). However, when you change the width of the tire, the shape of the tire that is actually contacting the surface of the road changes. A tire's contact patch always spans the width of the tire, which means the variable width is the front/back portion of the contact patch. Get a wider tire and keep everything else the same, and you reduce the front/back contact patch.

This is why people drop the pressure in their rear tires when at the track (unless the car is fwd, in which case they lower the pressure in front). The width remains the same, but the front/back portion of the contact patch increases.

Regarding weight ... the wider tires & rims will have more mass towards the outside of the wheel than the stock equipment. The mass at the outside is MUCH more important than the mass at the inside. With the wider rims, you'll be putting more mass towards the outside of the wheel, which will negatively impact acceleration.

Your option #2 will also not help acceleration. In fact, depending on how you set up the car when you lower it, you could hurt it. RWD cars hook up better than FWD cars because the weight of the car shifts back to the wheels putting the power to the ground, which increases traction. Reduce the weight shift, and you reduce traction on launch, hurting your overall acceleration.

I don't know about option #4, but I doubt it will make a measurable difference in 1/4mi times. Your money would be better spent on other upgrades if you are only interested in straightline performance.

 

For a good 1/4 mile time with the 8 this is what I'd do

1. Get the base or sport model

2. Remove anything simple. seats anything in the trunk

3. Put some R compound racing rubber on the rear end i would'nt go any larger than 235 width and maybe on some light weight 16in rims

4. Drop the clutch at 7250rpms to reduce wheelspin/hop and be ready for the shift to second

5. HANG ON TIGHT!!

 

Tha'ts great and all, but can you suggest some practical solutions instead, rather than ones specific only to drag racing...

I don't think I'll be taking mine to the track anytime soon.. (for at least my 7/100 warranty period, anyway)

edit: speaking of maximum wheel sizes, can someone elaborate on this? Such as the ranges of sizes the typical 18" rim can handle.. or more specifically, the RX-8's 18s. The 8 comes standard with 225/45s... you are suggesting that you can put a 235 on 16s??? How large can I go before I need to replace the wheel to something wider?

 

I'd only look into some kinda supercharger / intercooling type setup. I'd like to get faster linear speed, but I still want that 50/50 weight distribution for awesome handling so its a tossup. Adding a supercharger and intercooler will change the distribution though :\.

 

We're thinkin some light wieght 19x8.5 up front and 9.5 out back for starters. Full exhust, grounding kit, intake, lowered with coil overs probably, along with lots of suspension work. That should keep us busy till the body kit comes in and gets painted.

 

For tire and wheel combos it really depends on the width of the rim not the hieght. the rx-8 has 18x8s so i would guestimate that a 255/35 tire might fit on it. I know i've been looking at 245/35 and 245/40 for when the stock tires are worn out. It just depends. For my miata i put 225/35R18 tires on 18x7 rims and the whole thing(4) weighs about 20lbs less than stock. I looked at some tires online while posting this and i saw a 275/50R15 and a 245/50R16 so yes a 235 tire will go on a 16 rim.

To make the rx-8 faster overall i'll probaby put a slightly stiffer suspension on the car and sit back waiting for some upgrades like exhaust or intake. Maybe a turbo, or lighter flywheel? Or an aluminum radiator and higher output fans? One can only hope....

 

Id do full exhaust and suspension and ecu when it comes out. I would definately investigate grounding kits as well.

 

lighter wheels will improve acceleration (and braking, and to a lesser extent, cornering). lighter wheels are very important because they are rotating mass as well as unsprung weight. this is the same thing as why a lightweight flywheel improves acceleration.

bigger contact patch with low pressures is one reason its good for drag racing, the other reason is the sidewall can then absorb the shock of launch. smaller diameter wheels might help too.

of course, i think a 90's DOHC neon can remove the air filter and run a 15.0- the rx8 is no drag car. not until we fix the ecu.

i am an autocrosser, not a drag racer, but my other car is a 2100lb 360hp beast, so ive done some amount of tuning for hookup.

james
http://thevenom.net

 

your link didn't work for me

 

any chance the RX8 against the S2000 in 1/4 mile???