Intake Talk
 

Every forum including the rx8club i see talk about on the rx8 the stock intake is the best for performance.. is this true? if so why? I also see in the forums that the aftermarket intakes actually make you loose hp ? so someone please school me up on this. I found so many intakes for the rx8 but nothing really good on them. Besides people talking about noise.. i dont care what kinda of noise it makes.. i want to know which aftermarket intakes you actually get some power from.. and whats the deal with the stock. thank you for your time.

The only ones that have been noted (dyno proven) has been the Racing Beat REVI intake and duct. All the others have either been for no change or a loss. Just like the exhaust. Mazda squeezed as much as they could out of the Reni. So after market stuff doesn't really get huge gains compared with earlier rotaries. Generally this means you are changing for looks or sound more than anything else. Yes there are a few exceptions to this but this has been what has been found out over the past ten years of the Reni.

The stock intake is pretty much a straight shot ram air intake from the factory, not like other cars where there are expansion chambers and built in silencers to keep the engine bay quiet. Those chambers and kinks slow the air down, so those cars benefit from an 'intake'.

I did the intake box 'mod' from the RX-8 club and didn't notice any difference...at all.

Hell, reddozen here has a bridge ported Renesis and still runs the stock intake.

I don´t understand why anyone could take this as tragedy, disadvantage etc.
Stock paper filter has superior filtration than any aftermarket intake and doesn´t posses pressure drop at NA flow. SpeedSource GrandAM guys are supposedly using stock RX-8 intake element - on 20B peripheral port engine with way more mass flow than renny is capable of. Reason - filtration. Also, IIRC RX-8 intake is ducted and exposed to ambient temp, not engine bay heat....

If you want gain power on Renesis, concentrate yourself on exhaust system, heat management and tune. Healthy engine is essential

I got the RB Revi for mine just because I wanted to buy the car a new toy, but there wasn't a big improvement. As above, the stock system is well designed. Not sure why this is a bad thing.

But, so far the best performance for the $ has been the Cobb AccessPort. It would have been the first thing I did if I had known. (Although it's probably best to be having it tuned with my intake and exhaust on.)

so the stock intake is just a good design.. so the best thing to do is just work on keeping this cooler under the hood.. i have been looking at a few hoods. thanks guys

You can install the RB intake duct with the stock airbox. This is probably the best "bang for the buck" on intake. You won't see huge advantages on the dyno, but at speeds on the track or highway it will keep your intake temps down. I run the stock box w/ a k&n drop in.

Using an access port is definitely worth it, but in my opinion, its not worth the cost if all your doing is a drop in filter and catback. The stock tune will work well with those mods. If you've changed coils, aren't running a cat, etc... this is where the AP shines.

I'm probably going to add some heat deflection material to the intake box and duct to avoid as much heat soak as possible in the grid (I auto-x the rx8).

With full exhaust (headers, high flow cat, and catback) with the RB intake and duct and better Bosch coils, I've seen the reni make 194whp. Best power I've seen so far. I know others have posted up 200whp or more which is PROBABLY possible, but it would take a very healthy engine and the right combination of parts. That same rx8 making 194whp has an AP but no tune yet... I'm sure there is still some power left to be had... but 200whp may be a stretch.

I will be redynoing my 8 in another month so I hope to try a few different tunes to see how it works out...


Long story short, if you want big power in the 8... you'll need FI.

what kinda tunes to you use... is there a plug and play so we can do things our self?
i dont plan on FI any time soon.. but im going to do some exhaust work high flow cat and stuff.. but thats going to be later.. right now its intake.. and work on keeping things cooler for now.

Personally, I think the AP is worth the money if only for the reliability benefits of being able to lower the turn-on point of the fans, and boost the output from the OMP.

As far as tuning the AP, you can download the AccessTuner Race application and have a go at it, but, all reports I've seen/heard say the RX8 is tricky to tune properly and you leave the door open to make a mess of things. (And that long-term use of the maps Cobb includes is bad as they aren't very good.)
Love him or hate him personality wise (hoping not to get moderated here) but the only source for new RX8 APs is MazdaManiac, and he includes a 6 month remote tuning subscription with the purchase. (You send him logs, he sends you back revised tunes.) I've been happy with the process.
The baseline maps he includes with a purchase (no tuning required) will do the above of boosting the OMP and lowering the fans turn on point.
The other benefit is, I've picked up 3-4MPG on the highway with the refined tunes.

Agreed with the above.. and I should clarify that I think the AP is a great product, but not for the faint of heart if just looking for a few HP.

I do all my own tunes. I've actually tested all the tunes from Cobb and they are horrible (on my '04 MT). I can pull up the dynos on those runs if people want to see them.

Not trying to start anything, but there were members of this forum with me when we tested some of the MM base tunes and they too were pretty bad. Not trying to trash his tunes - its just that I would definitely recommend getting the tuning service if you decide to use his units so he can get it fine tuned for your car. Do not run around on the base tune, lol.


Also, for the OMP... I run premix. Its a preference, and yes.. the AP is a good alternative.

I premix as well. I'm paranoid. :)
(and I'm on v7 of my MM tune. I haven't had the time to really delve into learning how to tune it my self properly.)

I'm nervous about using the Racing Beat intake duct because it blocks off a portion of the radiator. It's my understanding that the RX-8 radiator is already perhaps not up to the task of cooling the engine coolant in hot weather and spirited or track driving, so I'm nervous about reducing the air flow cross section to the radiator by installing that duct.

From everything I have read, not many aftermarket radiators, excluding BHR's, has been able to show any improvements over stock; in fact many have proven worse, with the end result being the owner going back to stock. Racing beat does alot of R&D with these cars, some of which is funded by Mazda, so I would trust their products. All cooling issues I had were solved by making sure the sides of the RAD were blocked off, and thats here in Florida were the heat is miserable and oppressive, at 100 regularly.

the stock radiator is HUGE, its WAY bigger than any other stock rotary car's radiator. the cooling "problem" might need a different solution, like a colder thermostat, or ducting or something.

i say "problem" because the rotary actually gets better mileage, and lower emissions when its hotter. so just because mazda has it running a little warmer doesn't really mean its bad.

there is less margin though if something goes wrong

Speaking of intakes though... There may be a new option on the market in a couple weeks...

Just sayin...
>_>
<_<

new intake option... what do you know? share with us! lol

I'll let everyone know once it's ready. It'll be a week or two till it's ready to show off. I'm making 2 test pipes currently. I'm running behind since some of the parts I needed were out of stock...

any set up ideas yet or any progress? thanx

Going on vacation next week, but i'm hoping to have all the molds done before I leave. I have the rough prototype mold of the curved pipe done. once I'm done with the 2 prototypes, I'll make some real molds with molding resin and be able to mass produce them fairly quickly. Everything will be made to order though, so there will be about a 2 week turnaround, but you'll be able to specify weave pattern, color, etc.

The finial molded pipes (not the prototypes) will be 3 layer, 1 piece pipes (no cutting and refusing), so they will be strong. I can't comment on pricing till I get the prototypes finished and I can establish the total based costs of supplies etc.

Curved pipe for CAI
http://diviniaro.com/files/car/curved_pipe.png

Carbon for Prototypes One will be black, one will be orange.
http://diviniaro.com/files/car/carbon_rolls.png

nice keep us posted buddy

WOW! How did I miss this thread until now? MR. Conn, your the man! let me know when your back from your vacation. I will be glad to help out. Long story where I have been at

I just bought the AEM .... I like that one the best .. plus you can integrate it with greddy piping

but does the AEM actually give you gain in power.. alot of intakes actually takes some of the power away but leaves you with a cool sound.. nice it integrates with the greddy pippinhg though.. but im N/A and want to intake for the most power gain.. so far havent really found nothing yet.

so how is the project coming along on the prototype? have you had them tested?

family issues etc have slowed things down. I've also changed my mind on several aspects of the pipes, so there's nothing to show just yet.

its ok man, i understand with the whole family issue things... im wrapping up some loose end stuff and will be home from deployment in a month. would you need help with the design or anything when i get back? hit me up a PM if you want. good luck man.

temp
 

About cooling temp :try an additive (red line water wetter ,etc.) helps brake surface tension of the coolant . I dropped 15 degrees with additives . The cheap way: 1 shot glass of windex glass cleaner , ammonia is the key to breaking the surface tension of the coolant . Newer additives have been engineered to help other coolant issues such as ph level control for dissimilar metal contact .

What does that have to do with intakes?

If you read ALL the posts you will know.

It was a brief off topic discussion that came from a question as to weather the AEM CAI filter blocked the radiator air flow. Not to mention that it was like 5 months ago...

just trying to help people ,don't understand why some are so rude on this forum. Sorry to interrupt your tube design thing .

I have no problem with information, it just seemed misplaced in an intake discussion. Sorry if i offended you, I was just confused by your post.

Tube design thing... :rofl:

no problem ,but if someone has an intake and a concern about over heating is an issue than its all relevant . As you probably all ready know after market "kit"parts can open a whole new can of worms for issues not related to the direct systems that they are intended to help.

pretty much what i was looking for what is the best intake system that actually have gain of some hp.. i know theres been arguments over whats best... you loose power.. stock is best..and i wanna know what is the best system.. so maybe a costum one would be best? or is there a aftermarket one that can be proven for hp gains?

Simple answer is none. the most that I've seen documented is 5HP, but that can be argued as just a tighter motor/better tune. I would stick to stock, AEM, Mazda Speed (repackaged AEM), or Racing Beat. They're the only things proven to not loose HP.

You think people are rude on this forum, you should try asking a simple question on the "evil forum" as it is widely known around here. Yikes! Most on here are graduates of charm school by comparison.

those are the brands i noticed in forums, not discontinued or ones that are common people pick up.. well thank you for your time and ill go from there.

Hey guys, I have this snail looking thing in my engine bay with a pipe and a filter attached to it, I'm not sure what brand it is but do you think it's better than the stock intake? Thanks.




:suspect:

Yes until you pop the engine.