You are using some light 17's wheel/tire combo if you can get 6lb avantage over the 18's that come with the vehicle (you mean 6 lbs at each corner correct?)

-Mr. Wigggles

 

Emissions legal, or not, would your random tech cat with the resonator advertised on your site be too loud and noticeable on
the streets in your opinion?

 

FONZIE: Canzoomer stated in another post, that the Random Tech cat, Mid-pipe and Resonator that he is going to sell, is about 4 dbs louder than stock. I dont think it's going to be and attention getter with the noise.

 

Yup, 6 lbs at each corner. My wheels are the 17" Konig Holes, and bare those wheels weigh 17.x lbs each. I bet the Mazda 18" wheels are 22 lbs each - pretty porky!

Regards,
Gordon

 

Thanks. I did a search, but couldn't find anything on that.

 

Sorry Fonz, I can't remember where I saw the post, I guess Maurice will come out with that info soon enough. About the wheel size: I think we all know that the larger the wheel, the more rolling resistance it has,and therefore worse 60ft times, but when you move to a 17'' like some of you have, are you replacing it with a thicker tire, anotherwords keeping the diameter the same, if not, won't this confuse the computer? I like the look of the 18'' wheels, although I guess we could put 17s on and lower the car to minimize the gap!

 

Stock wheels are 21 lbs each.
17" decent, not too expensive wheels are 17 or so.
Savings: 3-4 lbs.

17" tires are lighter than same model 18 by around 3 lbs each.

Total per corner: 6-7 lbs.

 

Random Cat will block a bit less noise than stock.
If you buld mid-pipe with no resonator in it, more noise, add a cat-back, probably pretty loud..

I would say that the combo will be definiotely louder than stock, but not a nutsoid screamer.

 

Sounds Great Maurice, I'm excited about getting stage 2!

 

Are you sure about your numbers?

Typically higher profile tires with the same overall outer diameter are usually heavier*. For the RE040's that the RX-8 comes with this is defintely true (see attached). The 225/45-18 is 2 lbs lighter than the 225/50-17 tire. This is typically true of the S-03 line as well but there isn't a 225/50-17 for direct comparison.

As far as the weight of the wheel. Considering the RE040 weighs 26 pounds, the wheel would be 20 according to this persons measurement:

https://www.rx8club.com/showthread.p...l+weight+stock

But even if he was a pound off and the wheels are really 21. That includes the tire pressure monitor and the balancing lead weights which together equal about a pound. That puts the wheel at 19 to no more than 20 lb with that removed.

To keep things apples-to-apples moving from a RE040 225/45-18 on stock wheels with pressure monitors to 225/50-17 on 17 lb wheels with pressure monitors, yields the following calculation:

20 + 26 + 1 = 47 lbs for stock
17 + 28 + 1 = 46 lbs for aftermarket.

1 lb will be negligible.

-Mr. Wigggles

*I am sure there is an exception to this rule and I'm sure with enough digging you guys are going to turn one up.

 

VERY. I own Nokian WR all weather winter tires on my RX-8, along with some 17" aluminum wheels.
I weighed them!
The assumption you made is that I am running higher profile.
I am not. The Nokians are 225/45/17's

http://www.nokiantyres.com/nokian_wr_en.html

Yes, this lowers my car an inch.
It also changes the gear ratio 5% as I mentioned earlier.

I also weighed my stock wheels and tires.
The stock tires weigh 25 lbs ( 6800km of wear on them)
The Nokians weigh at 21 lbs ( brand new before mounting)
The stock wheels weigh 21 lbs, WITH hub cap centres, NO weights.
My inexpensive alloy winter wheels weigh 4 lbs less at 17 lbs.

Mine is a perfect example.
My winter wheels and tires weigh 8 lbs. less at each corner.
Actually a touch less, as my 17's required less weights than the stocktire/wheel combo, but we are only talking about a couple of ounces!

 

That depends mostly on the cat-back exhaust.

With the Random and resonator the noise level would be very little difference from stock. Most of the muffling is done at the back.
If you run no cat, or no resonator, or both off, you can definitely tell the difference over stock.

 

Maurice, were you going to get the chance to dyno the car with the Borla on? I thought I remember you telling us that you may do it this week.

Thankx!

 

I too have the Borlasystem installed, and would like to see some graph results before I would order. The posts say your company has a car mith a Borla.
felix

 

While I agree with all of this, the thing you need to remember is that all of these actuations are done with air from the air pump just as the actuators were done on the later 2nd gen RX-7. These open fairly slowly. During the time that these valves are opening, they exibit stages of being partially open which creates uneven and very turbulanet flow through those runners. If a runner is partially open due to a valve not at its peak point, there isn't enough air flowing through that runner to be very beneficial. The faster you can open these, the less power will fall off at the transition points. The maf sensor shouldn't really detect a stumble or an inconsistency if everything opens fast enough. The air just wouldn't have enough time to "back up" at all. I would rather actuate them electronically with very fast, strong servos.

 

The duct actuators on the Renesis are already electric.

The air pump only runs on start-up for the catalyst temp.

Only the short variable air duct, up front, is not an electric motor, but an electrically controlled vacuum servo, and it does take its time.

I am open to correction....

S

 

No Stealth, you are correct.
The ports are all electric.
An, as a further correction, the mix runs lean when these events occur, not rich as RotaryGod indicated.
This is what I am tuning with the E-Manage now.
I'm trying to introduce a slightly rich spike right as the ports open to counteract the lean dip that ensues when the air column suddenly accelerates.

 

Quite right. It is like on a motorcycle carbuerator.
If you open the throttle wide open really fast the engine bogs.
The cure was to use a pumper carb that if opened more quickly than a certain pre-set amount has a piston that injects an extra squirt of gas.

It is a bit tricky to tune for as the amount needed varies with rpm AND throttle opening. AND with how fast the rpm climbs.

In other words in 1st gear WOT your requirements are different than in 5th gear.

 

Electric heh? I apparently stand corrected.

Where did I ever say it ran rich at transition??? I didn't. I did say that there would be uneven and turbulent flow through the runners as they opened but I never specified a rich or lean condition.

 

Yeah, sorry.
That was in a quote by "kristopher_d" that was inside your post I was quoting from. You didn't address that directly, so I assimilated it all.
Too much stuff floating around in my head to keep up with actual facts, let alone who stated them! :p

 

CZ, I may be staring too hard at the dyno chart or something, but you breifly mentioned that there is no increase in peak hp rpm's? I'm wondering why especially since the chart shows a basically steady increase in hp right up to the last dip at 86mph (is that 9500rpm?). You also briefly mentioned downloading 5 charts at the same time (took 5 seconds)? Do all of your runs show a definite brick wall there? And if so, why? Thanks. (I'm buying stage 1 or 2-complete, not sure which or when yet, but I am )

 

The power drop off after 8500 is substantial.
I do not know with certainty, but I believe the two factors driving this are:
A) We are reaching the maximum air flow capacity. Dyno charts with aftermarket exhaust and intakes all show increases in the 8,000 and higher ranges, and next to nothing at lower rpm.

B) The stock ignition basically reaches it's limitations at those higher rpm's. At a certain point the coils do not charge fast enough to get full spark output, the circuit is not fast enough to maintain a clean signal, and power suffers.

Thing is, while one may work on mo repower in these higher regions, it is not going to show up as useful power for street use so we are not likely gaining much in the exercie of trying to improve this.

My $0.02 worth on the subject.

 

Do you guys plan on posting another dyno plot with the latest settings combined with the "L" flash?

Thankx a lot for your comments.

 

Is there a plot that StealthTL or somebody with aftermarked exhuast and Stage 1 could post to show how that improves the top end.

 

There is yet another flash out this week.

I am going to the dealers to have it done Thursday, and after that we will data log, tune as needed, and so on.

I am planning some dyno sessions next week, as we are testing our maps for the new flash, plus ones for the various combinations of our midpipe, and with the Greddy SP2 cat-back.

So, about a week from now I should have some dyno runs to post.