ximbuex

I wish there was a dyno section on the forum, but i couldn't find one, so I wanted to post my results here.

I don't have the graph yet, but I did 3 runs at our clubs dyno day, 5th gear, then 4th twice.

Max power was about 181 I think.

It seems like the engine pulls a lot of timing on the dyno, cause the engine got hot very quickly. The coolant was boiling at the end of my last pull.

This seems like a pretty avg number compared to the other dyno results I've seen. Someone suggested i try to get my hands on a Japanese ECU. Anyone have any thoughts on this?

-Matt Ford

StealthTL

iTrader: (1)

Canzoomer had a couple, don't know if he would still have 'em....

S

zoom44

the ecu wont work in your car

ximbuex

That's cool, I wasn't sure if anyone had tried yet. Then after searching some more I found the short thread w/ canzoomer.

I know the HP issue has been talked to death, but is there any official consensus? Are we missing power for sure, or just on dynos?

ucfracerx8

It has been posted on this site that Dyno numbers have been anywhere between 160-200. It has also been mentioned that the ECU plays tricks with the engine and it does pull a lot of timing out of it. I think it has something to do with the sensors in the wheels for the TCS and DSC and detecting that the front wheels are stationary and the rear wheels are spining. Still 181 is a decent number based on those factors, most likely it IS making more than that.

Go by the seat of your pants, if it feels like it has more power than that it does.

Xyntax

What dyno machine was this on?

mlx8

There is a ton of comparative dyno data, including actual run sheets/graphs posted through out the Rx8 site. Try running a forum search on "dyno graph" or dyno results ~> almost too many hits to useful. There must be some way to pare the results down, but just for yucks, see for example:

https://www.rx8club.com/showthread.p...ht=dyno+graphs

just one comparative result. Be cautious however in trying to directly compare results from one dyno to another, and in trying to be sure your chart is actually referencing the "same" bhp & torque values. First, many charts can be "set" to display varying units, i.e SAE values vs. JIN vs. PS etc. Second, some dyno numbers are "adjusted" or corrected for transmission or "drive line" losses. A 180 SAE bhp "at the wheels" figure (i.e., NO drive line or transmisson correction factor applied) would be in line with the general range of figures posted for the car that I've seen. Second, as a couple of threads have pointed out, different dyno can, and often do, yield different results, sometimes what even appear to be very significant differences, just because of the dyno design features, ... notwithstanding they're numbers are SAE "normalized" for altitude, temperature and humidity.

Personally I take all compatative dyno bar stool racing with a grain of salt unless the results you are trying to compare come from the same dyno. Even then you need to be some what cautious in your comparisons (e.g. tire types and/or pressure; extent of dyno facility cooling fans and test bed setup features etc.)

At one time I believe some one on the list was trying to create a sticky thread to collect most of the posted dyno runs. Unfortunately, can't remember where that thread was at, or.... worse yet find it with the search functions on the list. HTH

ximbuex

I have read most of the other dyno threads, and they seemed to get the same results as I did. (It was on a dynojet btw)

I didn't see anyone mention their coolant boiling though, which I'm guessing is a timing issue.

Time to lock the thread I guess, nothing to really add at this point.

Razz1

I wish we did have a dyno thread. Only makes sense to me.

MadDog

I think that pulling timing would reduce engine temps. Otherwise, why would the engine pull timing as a defense mechanism? It doesn't make sense. reduced timing=reduced power=reduced temps.

The reason that your car overheated was that dynos are very stressing. You are asking for max power, over a large RPM range, and you are missing the airflow that would oridnarily remove the heat generated. If your dyno operator was worth a damn, he had a large fan directed at your radiator. Did he?

KJ238

Are we talking at the wheels or at the flywheel? Coz I did 193.4 @ the flywheel... Mods were an HKS Legamax exhaust... Had some probs with the aftermarket air filter so i tossed it....


Pics of the car + graphs:
http://www.nopistons.com/forums/inde...howtopic=57685


==================

swoope

iTrader: (5)

what chew talkin bout willis????????

you tested at the flywheel, how??????

beers

YT1300

Hmm. He probably meant "at the wheels". At least, I hope he did. Could he be driving an auto version, however, and for whatever reason, took the motor out?

Xyntax

Sorry to hijack for a bit, but here: https://www.rx8club.com/series-i-tech-garage-22/dyno-results-compilation-77031/

^^^ That's the dyno thread we all have been looking for. Help fill it.

therm8

I agree.

Even a fan isn't going to do much, but it would help. I can't imagine anyone running a dyno without a fan. Coolant temps will skyrocket on a 100F day in the city. And with the minimal airflow on the dyno, I can see the same thing happening rather quickly.

RB (and any scan tool) has shown that the ecu pulls major timing out on hot coolant, and for that reason dyno numbers really should be taken with a grain of salt. I've never been a fan of dyno numbers for any car, unless they are used to compare before and after modification (assuming the dynos are done same day). Trap speed is just as effective at estimating power, maybe more so in this car.

dmp

While on the track, 240hp M3s would only 'slowly' pull away from me on the straights - and I'm assuming they were stock, power wise. All in all, I'm guessing the 220-230hp (Flywheel) number could be about right.

ximbuex

We had a bigass fan blowing on the cars that day, ambient temp was probably around low 70s. I need to get the dyno graphs off of my buddy and put them up.

This is what I was curious about, I'm glad someone else has heard the same thing.

As for trap speeds, i did some searching on that too, but it seemed non conclusive, too many variables.

Zero_Rotary

What brand model was your air filter?

cleoent

guys, if the tcs/dsc was pulling timing and stuff, wouldn't there be cars out there (The base 6 spds without those features) pulling 210+???

The fact that there aren't (highest stock dyno i've heard of was 200) leads me to believe that the cars are just making 180hp to the wheels and we need to learn to live with that.

ximbuex

All cars have speed sensors at each wheel that the ECU monitors whether you have traction control or not.

cleoent

I would think that without the brain of the tsc/dsc those would do nothing to affect the power output of the car. I'm just speculating.