Undisputed performance improvements
 

I have been looking around to find out which performance improvements are verified or butt dyno'd and yield a noticed power to the wheels improvement. The only one I could find that was almost unanimous in this forum was the Mazdaspeed or RB flywheel swap.

Have any of these following improvements really yeilded ~90% agreement among rx8club members that HP/torque increase was made?

Pulleys
CAI / Removing the front screen from the MAF
Header
Highflow Cat
Catback
Weight reduction (where is a common place for the weight loss? Lighter battery, etc...)
Anything else ???


Thanks,
Splan8

good luck with this one, looks like you have a ton of searching ahead of you

Yeah, and I'm not trying to shortcut by starting this post. I have been doing some searching in the forums here and most of the threads kind of trail off without any real evidence or some large number of participants agreeing. The flywheel one was the only one that stuck out with nearly everyone saying performance was improved.

Can't say the same for CAI or catback in general as Mazda apparently did a good job with the existing system. Pulleys seem to be a good idea, but not sure there were any real gains. Can't say Canzoomer helps everyone. The screen removal from the MAF seemed interesting, but kind of evaporated and hasn't been mentioned too recently.

Dunno, just seems like there should be a "recap" thread going on while we wait for more aftermarket improvements. What have we learned so far about increasing HP, besides that it seems to be difficult to improve the stock config?

-Splan8

Pulleys... I remember hearing that some under drive pulleys appeared to help. I would wait for cortec to finish his titanium pulley set before making any claims, as his will really prove it. This is something that you won't be able to get 90% of forum approval, as probably less than 1% have actually done the mod.

CAI / Removing the front screen from the MAF... Intakes in general don't seem to be doing much. Racing Beat is unveiling their new one next weekend. I'm hoping that the R&D they did on it will help, though I've heard 3-4 HP is added. On racing beats page, they have a break down of what different exhaust mods did to power. Go to racingbeat.com and check it out. They are respected for their honesty. The stated gains are listed on the first RX-8 page (click on the rotors then the RX-8 tag and scroll down).

Header - See above.

Highflow Cat - See above. RB does one w/o the cat at all, so a high-flow cat will still be more restrictive than this.

Catback - See above.

Weight reduction - Cortec is doing the most weight reduction as of yet. Mostly, however, he is doing unsprung weight (eg wheels, lug nuts/bolts, brakes). He's getting more responsiveness out of it. Most people that put SSR Competitions on their ride notice a bit more response. So, clearly lighter wheels are good. Not many people have started removing sprung weight from the car. If they have, they'll have to remove alot of weight before it will make a difference. I think we'll see more of this when people decide to make the '8 into a track only car, as most of the weight reduction inside will lead to a less "comfortable" ride. I plan to do this one day, but I'm waiting until the warranty ends and I get a new daily driver.

I've been folowing performance mods for the '8 for some time now... many of which I have had on my car. Here's what I think is worth pursueing:

Lightweight Flywheel <== Totally worth it. May not add that much quantifiable HP (although it feels like around 20 HP or so) but makes a huge difference in the performance of the car nonetheless.

Pulleys <==Worth it if not spending $500+ dollars on them. ~10 HP gain.

CAI <== Some are ok (RE and SR) but probably not the most cost-effective mod. Adds 5-10 WHP, but may cause idling problems too depending on your individual car.

Removing the front screen from the MAF <== This was an experiment done in the early days of the car. It didn't give any performance gain, but what it DID do was destabilise the airflow over the MAF and cause idling problems.

Header <== Not worth the $1000 + that those currently on the market cost. Watch for Borla to come out with one, it's apt to be as good as one can get without porting because they are taking their time researching what works and what doesn't.

Highflow Cat <== Definite improvement if you can handle the noise. They are a lot louder with an aftermarket catback exhaust. Adds ~ 10-15 WHP.

Catback <== Worthwhile mod IMHO, even if they only add ~5 HP. The improvement in sound alone is enough to convince you that you've added more HP than you actually did.

Weight reduction <== Probably worth it, but pretty hard to accomplish.

Other mods to consider:

CanZoomer Piggyback. No, it doesn't work perfectly for everyone, but it does for most. And you can tune it if not perfect out of the box and make it run really well with your car. Adds up to 25 WHP, usually a bit less though.

Nitrous: Adds 55-75 HP. Still in development, but looks promising.

Forced Induction: Supercharger or Turborcharger. Still in development, but I expect to see a couple of kits within a month or so (Sunflower-ATI/Procharger and SFR) and probably 3 more on the market by December. Adds 80-120 WHP, maybe more if the Renesis proves to be strong enough to handle it.

Porting: Still in development. May add 50-75 WHP.

Good synopsis.......:D

You might tweak 1 WHP out of a good quality grounding kit, like MazdaSpeed or Lineage, the idle smooths out and the electronics seem to be happy.

pardon the idiocy, but what is a grounding kit?

According to a drag racing show on Speed, yes I watch it a lot, you have to remove 100 lbs to run one tenth faster in the quarter. Doesn't seem to be worth all the trouble and money.

It is a cable with a series of bolt points that you run around your engine bay, bolting to various points, eventually ending at a ground. I seriously doubt it will gain you any power, but it does seem to make the electronics happier. There is a thread on it somewhere already. Run a search.

id have to agree with omi's assesment(and not just because he threatened me that "junior member" crack:)0 and would like to re-iterate one point- leave the MAFS screens alone. removing it only causes problems. i firmly believe most of the idling problems with cai's are due to improper placement of the mafs and /or screens.

Thanks! I really appreciate the breakdown and am glad to hear from folks who really have tried a bunch of stuff and know.

As far as warranty goes, is CAI the only one that would really not void the warranty?

nothing voids the warrenty unless that part can be proven to have caused what ever problem you need fixed. if your tranny breaks they cant say it was the fault of the cai or catback or even cz unit for that matter. but if your mafs fails they could say it was because of improper placement in regards to installing the cai and it got dirty because of it.

>According to a drag racing show on Speed, yes I watch it a lot, you have to remove 100 lbs to run one tenth faster in the quarter. Doesn't seem to be worth all the trouble and money.

It probably isn't worth it, if you're going to miss what you took out more than that 1/10th or slight differences in braking distances or what not. The suspension is also set up to work with the stock weight and balance of the vehicle. SCC magazine had an interesting article where someone stripped like 600 pounds off a 350z ... their results are worth the read.

The RX was meant to be driven around things, like cones. It is NOT a dragster. Get your mods in order of acceleration first - the flywheel, unsprung weight, MS brake & clutch lines, lighter wheels, etc.

If I could start over, I would have done the flywheel first.

what sort of power does the mazdaspeed clutch give you roughly?

flywheel is expensive though eckkkk cant afford it yet as a student... ill replace it when i have to replace it with my clutch... so i can put a sports clutch and a light flywheel at the same time (less labor charge i hope?) does a lighter flywheel really give u 10-20whp?? i doubt that....

as i've said a whole bunch of times before, a flywheel gives you no improvement in power, it gives that illusion on a dyno (like using lighter wheels on your drive wheels).

a clutch will give you no more power (how on earth would you think it could?). yeah, they'll probably save you 0.5 hours or something if you do both together, but that's like $40 - $60 depending on where you get it done: not exactly a whole lotta coin.

I noticed something missing in this list....

The post is: "Undisputed performance improvements "

...Get a front sway bar!

some of us see performance in other aspects :D

from the list he made, it looked like power gains, not over-all performance. that might be why it was left out. if the label was bad, there are lots of handling upgrades to mention...

Yeah, when I wrote this the emphasis was on power gains, but it would be nice to also collect feedback for suspension tuning, etc... What has had a noticable impact in the suspension/handling department (I think this is perhaps one area that is easier to improve from stock).

Is there some way to quantify the gains in performance in these areas (probably not too many folks heading to the skidpad to tune their suspension)

this is a good thread. Thxs Omi(i spelled it right!) for your condensed version. Yes my CZ works too. I have been trying NOT to spend the money for the flywheel but it sure seems all who have it swear by it. Well if 2 or more people are trying to tell you something you should listen . Thats one thing I believe. So I guess I better start searching. Again good thread
olddragger

what is the best Flywheel? SSR or MS?

SSR is lighter. MS will be easier for inexperienced M/T drivers to handle.

As far as suspensions, most descriptions are pretty vague, especially to someone who has never ridden in a car with aftermarket suspension (which is a pain when you don't want to spend 1000s of dollars trying to figure out what spring setup you like the best).

ms may be because it doesnt affect your warrenty. honestly I dont know ----yet>
olddragger