Let's go over this offer. If your engine makes the power I get to pay the dyno time and buy you your seals. If it doesn't make the power I get nothing and you have to pay for your own seals and to get your own engine dyno'd.

How come this doesn't sound like a good bet to me???
"There's not a man alive who'll take 8 for 5"
But that sounds better then this by a long way.

 

Hi Hymee,
Thanks for the effort :-)
I am interested to know the maximum rpm the engine was turning at peak
power? also at which rpm was the maximum torque produced?
Is there any chance of a dyno chart pic?

I think that a longer induction would probably improve the flow into the engine?

Depending on the use (race <g>) how about adding couple of large round
holes to the rotor housings for the exhaust gases to leave by?

Regards
Michael

 

What do I win if I get 260 HP on the engine dyno? Supply the engine and dyno time?

Cheers,
Hymee.

 

I would agree with Ceramic seal. 260 HP is a realistic number with the right seals and management.

 

So are we saying the ceramic seals will give more RPM, reliably?

We have already run stock renesis to 10,500.

Cheers,
Hymee.

 

looks like the big guns are finally putting it to rest

good to see you posting MR. Haskell and thanks for representing our beloved RX-8 in racing, great job!

congrats on getting back where you belong on the podium

 

Pity you can't tell us more... good luck on the rest of the season! Looks like the new regs. helped a bit.


As for 9500 all day Richard, it has been done before. Recall the two 8s that ran 24 hours flat out only to stop for fluids and drivers...

http://www.seriouswheels.com/top-200...Record-Run.htm

3,174 miles WOT. Stock except for safety features.


Best of luck Hymee. Always anxious to hear more info.

 

A double ended *****.

 

that was my idea ya know!

 

What I'm saying is they will make more torque at elevated rpms (HP) even to the point where the lesser equipped one drops off due to better sealing by way of higher spring pressure. You simply cannot run as much pressure in this way with steel seals unless you are trying to make sparks. Obviously there is an rpm at which this motor runs out of breath but with inferior seals it just happens earlier than the ports are fully capable of. These seals are so much better that they can continue making this increased power for many cycles than would be imagined otherwise (as seen in racing applications) whilst being gentle on the rotor grooves and the rotor housing surface. There's a reason they are so expensive.

 

"There's a reason they are so expensive."

b/c someone is a capitalist? ;P

 

The material and R&D that goes into those seals is amazing.

 

Can we take seal discussion to another on-topic thread please... And put this comment there: "I wonder who has spent the most $$$ on seal development?"

Cheers,
Hymee.

 

Those evil capatilists .
Now back to our regularly scheduled program:
Hopefully all this testing will yield great results and products (But make sure you aren't seaking to profit by this).

 

My aim, is for everyone to gain!!

 

I recently did a 3200km road trip, mostly in remote parts of Australia, so I had plently of opportunity to look at the top speed of my RX-8 under different conditions. Here is what I learned:

Over time the long term fuel trim (LTFT) in my car seems to gradually creep up. It was at 11% at the start of this trip. The result was that above (160km/h) 100mph, AFR's were pig-rich (<0.75). This not only effected fuel economy, but also max speed. Under this condition, I only got a max speed of 205km/h. Running that rich must really kill the power.

Seeing this, I reset the ECU by disconnecting the battery, and immediately my AFR's leaned out by 10%. My top speed also increased to 216km/h. As the trip progressed, I found that the LTFT would stay at 0 for about 3 hours max, and then it would start increasing gradually - first 2%, then 5% etc. This also resulted in the AFR's becoming richer and economy getting worse. In all I reset my ECU 3 or 4 times during the trip to reset the LTFT back to zero.

Note that these AFR problems only seem to be an issue in Closed Loop. I have found that the cruising speed needed to be in closed loop varies - anywhere from 130km/h to 160km/h. So most people aren't going to encounter this LTFT problem at all. Unless you are trying for max speed. I have no idea what criteria the ECU uses to adjust LTFT.

The second thing about top speed is that I think wind direction and speed make an pretty big difference. On this drive, I had headwinds all the way, and the fastest my car ever got to was 220km/h. 6 months ago in exactly the same configuration, it got 240km/h with a slight tail wind.

With regard to the RB intake, taking it out 6 months ago did make a difference to top speed, but here are two possible contributors:

1. The MAF is one of the primary sensors used in Closed loop and changing the intake may have changed the signal the MAF was sending to the ECU. This may have effected Closed loop operation, hence AFRs, hence top speed.

2. I think when I changed intakes, I reset the ECU. This would have cleared any bad long term fuel trims that may have been present, which would have imporved AFRs, hence top speed.

So blaming the RB intake as I did at the time was probably incorrect. It's frightening how much the ECU controls this car and how little we know or can do about it. It seems that it can easily rob 10 or 20hp from the car without you even knowing about it - and here we are spending all this money to gain 3-5hp from mods like intake and exhaust. Understanding and controlling the ECU seems to be the key to reliable performance. Environmental conditions, including wind, are also crucial at top speed.

Sorry about the small hijack, but I thought I ought to share this experience.

 

Good work Wildcard. #2 seems more plausible, don't your reckon?

As you know, I don't have much legal opportunity to test at speeds over 110 km/h, but I did find my car would drop into open-loop at about 120km on cruise.

Thanks for the report.

Cheers,
Hymee.

 

current flash int he states drops you back out of open loop after an extended period at cruise- the afr then goes richer. must be extended cat protection

 

it almost sounds like one of his o2 sensors is off just a bit.

beers

 

Wildcard, just reading your report and Hymee's reply and I'm a bit confused.

When you discuss your RX8 going into 'Closed Loop' mode anywhere between 130km/hr and 160km/hr did you really mean 'Open loop'? Hymee's reply says he goes into open loop above 120km/hr which is what I understood occurred at higher speeds.

Cheers,

Jared.

 

Yes I really meant open loop. The terms really make more sense to me the other way around. Closed loop uses a continuous open feedback loop, while open loop is a closed circuit with no external feedback. That's how I would describe it anyhow.

 

Phew, thought I was going crazy for a sec there! hehe.

Cheers,

Jared.

 

Hymee - read somewhere that having no intake caused the Renesis to lose power (8kw from memory) . Any thoughts on this ? Sorry if it has already been covered.

 

whats also confusing to me is that we had a friend that reset his pcm mid dyno session and LOST 5-7 hp.
olddragger
ps dont forget that no water pump run--i think a little is there,

 

That's a really interesting topic: Back in Japan & some Asia markets, they can still claim that the engine has 250hp as it first announced. I'm just wondering is there any differences between ours & their 13B. Anyone can tell me the answer?

Good work, Guys!