nuove13

Dear all.

I'm a new rx8 owner, barely 7months into ownership and am definitely enjoying the drive. it's an '07 6MT that I'm driving.

Me and my mate, an 05 4AT, is contemplating a mod set-up to our cars at the end of the year, after my warranty ends.

The aim is to boost engine efficiency in terms of fuel consumption and power output without installing forced induction (maybe after..)

So we're thinking of getting an air intake and exhaust set-up combi. Due to the lack of information available in our country, can the good people here advice on what are the options for a good setup and what can we expect in terms of improvement.

Thanks in advance to everyone who is sharing their experience and wisdom.

alnielsen

iTrader: (4)

I see your from Sydney. I'm going to move your post to the Australian Forum for assistance.

Nemesis8

iTrader: (3)

I would study bell mouth inlets on a short tube or long tube inlet. Wet or dry elements, whatever you like. The key is velocity with minimal entrance losses and frictional losses. The go for a custom built high flow cat that can take the heat, resonate the midpipe, and keep the stock muffler. Stealth is the key and your friend - then lower it, tint it, and wax it.

Cromax

Do a search in this forum and you'll find out, but I'll give you some tips.

There's a company called smb that apparently provide good quality exhaust components ... I believe they have a high flow catalytic converter and cat-back specifically designed for our cars ... ask and find out how much (and let us know how much you paid as I'm flirting with the idea of getting an exhaust from them as well but I'm worried about drone).

In terms of your air intake ... honestly, just take out the baffles in your airbox and replace the filter with a K&N panel. I currently have a pod in my airbox myself, hence I'm advising you to go panel. If you want to get cold air in, there are a few different types of scoops you can buy to replace the stock VFAD that are available from Odula and Racing Beat.

One caveat, you won't see any significant gains from a CAI or cat-back exhaust in an RX8 without a remap of your ECU ... so if you're just looking for power gains, go for a highflow cat and do the airbox mod, get the ECU remapped and away you go.

But before you do all of this, go to the DIY forum and have a look at what you can do at no cost (removing baffles in the airbox is one that's there).

Good Luck,

Nate.

Cromax

Good advice!

Revolver

Cromax, Matt13B has an SMB exhaust, so ask him what he thinks of it. I've heard it, including at freeway speeds and didn't notice any drone. Looks like a good quality product if you want more than just a catback. I'm thinking of going the same way once my Hymee S/C kit is fitted.

I agree with the advice about intakes if you want to play around with it but be aware that even with ecu remapping the power increase is only a mild one and it's not really worth throwing a lot of time and money at it. Simply put, Mazda optimised the NA intake characteristics of the Renesis very well and the only real way to gain a significant power/torque increase is through FI.

You should also check out rx8club.com.au, which has more local info these days, including cruises, etc which will allow you to meet more experienced owners.

nuove13

thanks for the great advice guys.

unfortunately i'm based in singapore now. so i wonder if the parts are available here as well.

right now i can clock 220km/h at 6th gear 7000rpm.

If i can bring it to 230km/h at the same gear and rpm, the project would be half successful.

as for Fuel Consumption, it's currently 360-380km per full tank at the moment. if i can bring that up to 400km per full tank, it would complete the aim of the mods.

Like i have mentioned, the emphasis is on efficiency. =)

thus a Cold Air Intake with an improved high flow Exhaust set-up is the way to go?

Revolver

No problem but I am a little mystified at your objectives.

Particularly in Singapore, what is the utility of another 10km/h on your top speed? As for fuel economy, you bought the wrong car if that's your goal - plenty of cars out there which will go as quick on less fuel.

If it's just playing around with the car for its own sake, well there's plenty of us guilty of that, lol, but otherwise I don't get the efficiency drive you're on.

Not being critical at all, just curious.

nuove13

indeed. the utility part is not actually considered. just want to mod the car for fun to see how certain things can be improved.

of course, comparing car to other cars, there will be better ones in terms of this and that. but i'm only interested in tweaking the rx8.

let's not take it too seriously. just want constructive inputs and advice on how i can improve the mentioned factors using the requested solutions. CAI and Exhaust.

Revolver

Fair enough. I'm all for having fun with cars.

Good luck with it...

takahashi

I doubt there is any power gain in the NA rotary engine. I drive the RX-8 for corners. I tried but nothing works. I CBF to spend money to improve the power. I found clean spark plugs and clean engine oil does more than other expensive mods.

I have another weapon for straight line jobs.

generis

I may be wrong but....

My understanding is that if you are doing 220 km/h in 6th gear at 7000rpm and want to be able to do 230km/h in 6th gear at 7000rpm, you will need to change your gearing ? Try doing 8000rpm in 6th and see what happens!

Revolver

Hahaha, good point Tony. It redlines at 9 for a reason after all.

And Taka, if people stuck to mods that actually worked which they actually needed, think of all those poor starving after market suppliers and workshops who would go out of business. They have kids too you know!

rotarenvy

it is debatable if exhausts and intakes that make enough power to be worth the money. especially here in .au where the cost of an exhaust system is inflated compared to the US.

I reckon your better off spending the money on the Hymee pro-tuner software. with this you can lean out the mixtures for better fuel economy and power. you can also play with the radiator fan temps that can improve the cooling or adjust dwel for LS2 coils for better reliability.

unless I'm mistaken the cobb accessport isn't really an option for .au as the self-tuning software wont work for us and your forced to use a tuning service or shop. A big negative IMO.

nuove13

good point on the gear ratio part. how can i miss that.

well, looks like the exos plus air intake mod isn't going to do much beyond making me feel like i've done something at least.