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-   Series I Engine Tuning Forum (https://www.rx8club.com/series-i-engine-tuning-forum-63/)
-   -   First dyno plot for stage 1 (https://www.rx8club.com/series-i-engine-tuning-forum-63/first-dyno-plot-stage-1-a-18178/)

Z88M 01-08-2004 07:56 PM

On Gordon's point regarding altitude, I wonder how well will the custom A/F map created by Canzoomer will work for a sea level car (assuming the map was built at 3000' above sea level). I suspect a different map might be required for best results. Any comments?

MazdaManiac 01-08-2004 08:09 PM


Originally posted by Z88M
On Gordon's point regarding altitude, I wonder how well will the custom A/F map created by Canzoomer will work for a sea level car (assuming the map was built at 3000' above sea level). I suspect a different map might be required for best results. Any comments?
Won't be necessary.
The BARO sensor will correct for altitude.
You will make even more power at sea level.

Genom 01-08-2004 08:21 PM

Wasnt he talking about the first set at 3750? Their tune shows a little boost right after that.



Originally posted by Maniac
Yeah, according to your plot, they kill power!:mad:
When the VFAD opens, there is an immediate loss of power on your plot.
WTF?!?


StealthTL 01-08-2004 09:08 PM

Dyno!....
 
THAT is what I have been waiting for!

Over 24 horses at 8600 rpm is a GOOD result.....(and should be even more, closer to sea level).....but the REAL difference is that '5K Push'....in the next 600 revs you gain 20+ horsepower!

You all know how quickly the engine can zing up from 4K to 6K, you can imagine what it feels like when another 20 ponies all join in, over just a 600 rev range! It's quite a rush!

The peak horsepower is nice, but that mid-boost is AWESOME!
It is WAY more useful than peak horsepower in day to day traffic, I find it is right where I need it for a fast downshift pass, or a short quick on-ramp blast. A better 'pilot' would probably use more of the rev range than I do, and I hope that someone with 'more better' literary skills installs a 'Zoomer Mod soon, because I am as bad at describing how it feels on the road, as I am at driving!

S

family_man 01-08-2004 09:23 PM


Originally posted by Speed Racer

A lot of us took Mazda's word on the Hp and blamed the low numbers on the ECU going into safe mode. Well Maurice has found a way around the safe mode and his numbers are still low. :(

[/B]
Is this run with the safe mode disabled? I'll admit I haven't had a chance to look through all the posts, but last I recall he still hadn't gotten around this issue.

family_man 01-08-2004 09:24 PM

CZ
Got your email and ordering soon. Thank you for all of the hard work and patience with those of us who had such a hard time waiting.

FM

Speed Racer 01-08-2004 10:18 PM


Originally posted by family_man
Is this run with the safe mode disabled? I'll admit I haven't had a chance to look through all the posts, but last I recall he still hadn't gotten around this issue.
Maurice has found that the ECU freaks out if there is a large difference in speed between the front and rear wheels. Which is what happens when you dyno a car and the ECU intervenes with its safe mode.

One way around this is to trick the ECU into thinking that all four wheels are spinning at the same speed. Maurice accomplished this by taking one of the signals from a rear wheel and sent it back to the ECU for all four wheels. He says that it works great.

kristopher_d 01-08-2004 11:40 PM

There are some many events happening at various Rev levels, it's hard to say which one may be causing those dips. You have only the primary intake ports open up to 3250, then the secondary intake ports open. At 5500 the variable fresh air duct opens. At 6250 the tertiary intake ports open, followed by the VDI at 7500. That's 4 events that introduce turbulence into the intake system momentarily, resulting in a brief loss of mass air flow and thus a brief reduction in power. Add to that the very brief moments of over rich fuel from the secondary and "Second Primary" (tertiary) injectors coming on line. I haven't found any documentation on the timing of the fuel events, but it seems logical that they would coincide with the secondary and tertiary intake port openings. All of these complex intake events are why the car has such a wonderfully gradual power rise. That very broad power band is why we have so much fun in the twisties. Lucky us, mazda rotaries have had variable intake timing for 20 years, while honda and nissan are just figuring it out, and not getting the same silent, relatively smooth results. The renesis is much better than the old 6P 13B's in the 2G 7's. If your gronding isn't flawless in a 7, it's a very noticeable stumble at 5K.

skagen 01-08-2004 11:55 PM

Could the max HP been higher had the mph had gone up higher?

brothervoodoo 01-09-2004 12:18 AM


Originally posted by skagen
Could the max HP been higher had the mph had gone up higher?
The horizontal mph line is actually RPM's..

neit_jnf 01-09-2004 07:07 AM

Can we see a stock / CZ Torque graph? That jump at 5500 looks awesome! Like a vtec jump, don't you think?

doccable 01-09-2004 12:46 PM

All this talk about altitude... has me kinda wonderin' just whats gonna happen up here at 7200'. I'm guessing probably just a little less power increase, but all in all probably worth the money!
Thanks for the graph! I guess the wait time is going to take a little longer than I thought... 700 units ordered already?
WOW!:)
-doccable

Landon_Starr 01-09-2004 05:58 PM

<-----kickin' myself in the ass for not ordering before Jan. 1st.

This would be where the dealer takes all my money. BAD GAMBLE.

RX-8 friend 01-09-2004 10:45 PM

Just a few comments.

First, the blue line is stock (stage 0). The red line is stage 1. The graph is of HP. HP is torque times RPM. As there is no gear change in these pulls, the graph is easy to convert to torque. MPH was used as dyno operators have trouble getting RPM from rotary engines. I keep telling everyone to use a spark wire inductive pickoff, and to select 4 cylinder, but they never listen. In this case, I wasn't there either. Oh well.

The engine was taken to 9500 RPM. You will note that power was starting to drop so the answer is no, it would not have gone higher if the speed was allowed to increase even more.

The car goes into "limp mode" after 15-20 sec. The runs took less than that. ABS was "fooled", and DSC was off.

Yes, the HP drops when the intake switches, but that is because the tuned runners are only approximations. Note that it increases steadily afterwards. It would probably not without the change.

The peak HP is nice, but not useful (as commented above). What is desireable is "area under the curve". It is the real indicator of useful output.
I would like to compare this "area under the curve" to the 3rd gen RX-7, because even though the HP of the two cars is quite different (typical stock 3rd gens put down 230 or so rear wheel HP), the 3rd gen falls off rapidly after 7500 RPM. This may expain why Canzoomer's car is so close to a stock 3rd gen in performance even though the HP is lower. I just have to find a good dyno of a stock 3rd gen.

compaddict 01-09-2004 11:28 PM

Here is a comparison with a 3rd gen 7.

Vince

family_man 01-10-2004 09:08 AM

Torque = (HP x 5252)/RPM
This should give you the curve. Also it is important to realize that the delta change is what is significant in this case since too many variables influence the Dyno results

davefzr 01-10-2004 03:21 PM

Hey.. a question.. that really needs to be validated since I am using the calculation posted above and I am not an engineer by any means. I did some very barbaric estimates and found that the torque on this dyno sheet is less than 159 @5500 like mazda is claiming. Can someone comment on this?

Thankx!

murix 01-10-2004 04:20 PM

The numbers you are seeing are to the wheels on the dyno and Mazda quotes flywheel. With the numbers you are showing, the torque would actually be much higher than 159 stated.

JimW 01-10-2004 07:44 PM

So according to RX8 friend the car still goes into safemode, but it now takes 20 sec, is this something thats incorporated in the stage 1 unit or is this something he did separately while recording dyno runs, nevertheless, very nice mod for all of us to enjoy, but I'm waiting for the stage 2!

JimW 01-10-2004 07:58 PM

Can I assume that the stage 2 mod will have another 20 WHP, for a total of 212 dynoed WHP without mods and another 20 WHP with intake, exhaust and random tech cat? I'm thinking 222 WHP, what is the drivetrain % loss, My former, 03 EXV6 accord was a 22% loss, for a front driver, I'd imagine the RX8 is at least 10% more. So can we be talking around 317 crank H.P. with the stage 2, or am I way off base with these figures?

brothervoodoo 01-10-2004 08:08 PM


Originally posted by JimW
Can I assume that the stage 2 mod will have another 20 WHP, ... and another 20 WHP with intake, exhaust and random tech cat?
I think assuming 20whp from additonal mods beyond Stage2 is speculation at this point. I have not seen anything solid from anybody, especially given the difficulties with the RX-8's temperamental nature when trying to dyno it. Canzoomer, did comment on feeling additional power using his Stage 1 Mod combined with the Borla exhaust on another test car. How much exactly is still left to be seen. I'm not jumping on any intakes and exhausts quite yet.

JimW 01-10-2004 08:20 PM

Thanks brothervoodoo, that's a smart bet, but like most of us, I have a lot of anxiety with this car, although I did see a claimed 10 WHP for the Borla exhaust and 10 WHP for the K&N Typhoon intake, but we all know a lot of the times, that's not the case.

brothervoodoo 01-10-2004 08:28 PM

Yeah, I'm with you on that sentiment. Also, when you necessarily add multiple mods doesn't mean the horsepower adds up correspondently. I'm way leery of intakes because the RX-8 ECU will sense extra air or whatever and then probably adjust... Or as CZ and RX-friend noted maybe a mod does increase HP in the upper band but makes less at lower RPM's where the majority of your driving takes place.. not a very useful mod IMO.

MazdaManiac 01-11-2004 12:09 AM


Originally posted by JimW
My former, 03 EXV6 accord was a 22% loss, for a front driver, I'd imagine the RX8 is at least 10% more.
Wow. No. That is WAY off.
Your Accord was probably loosing closer to 17% - 20% to the front drive.
The RX-8 will loose less as the rear drive platform is more efficient. Most likely in the 15% - 17% range.
If I lost 30% to a drivetrain, I'd get a different car.
Even the WRX doesn't loose that much and it is 4-wheel drive.

canzoomer 01-11-2004 12:36 AM


Originally posted by zerobanger
just a dumb question, why does it show dyno run 1 and dyno run 2 done at the same time? didn't you have to un-install the unit between runs?
Time is when the files were transferred to my laptop.
As all the run files ( 5 of them) were dumped at once from the dyno computer ( took about 5 seconds) it shows the same time.


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