RICESP Water Injected RX7

[RICE RACING]

R35 GTR tested yesterday at EC circuit. ~242kmh on straight max speed.

Boost up, exhaust, tune, smaller wheels, minus passenger seat and a bit of weight etc (1750kg run weight)

90km/h-140km/h time's 2.83 seconds to 3.04 seconds, not allowed to tell you lap time. But does show ~325awkw on VBOX on track and runs 125+mph at EC Drags too.

^ Some may find this a bit interesting given all of the hype around the R35GTR, shows a little old Mazda Rotary can hold its own I think. My VBOX module turned up today, I will run the current specification on 17.5psi boost pressure and put up the 90-140 analysis for you to look over.

Getting better and better by the day.

[RICE RACING]

Yes I am very happy with it, especially the power band of the engine mostly. These days too much emphasis is put on "hollywood" power outputs with no consideration given to the rest of the power story.

Massive rain storms here so no testing this week, but will recommence soon.

[RICE RACING]

Well I tested it today with the VBOX3i hooked up.

My on board Blitz boost/power meter showed 278rwkw @ 6600rpm and the VBOX3i with my own formula gave 273rwkw @ 6650rpm

I have done up an Excel sheet summarizing the 90-140 time V's the R35 GTR

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http://img12.imageshack.us/img12/7232/vbox90140test.jpg

In summary the power went up from 235rwkw to around 273rwkw @ peak (16.8psi v's 14.5psi), on a linearized scale (for boost difference) you can see that the Water/Meth mixture account for another 20+rwkw as I measured it. I did test at a higher location (100meters higher than normal location) and the weather was about 7 deg more than the base run. I have trimmed the fuel a bit more after this run today (you can see it went rich) I have also put the WI system back to 2.5 turns), these adjustments should bring it back to my target of around 11.5:1 or so.

[RICE RACING]

O.k. Here are the testing graphs I promised. In summary they are the first ever setting ~230rwkw region on water. Then I changed to 50/50 and up rated the boost to 1.2kg/cm setting (can see actual logs figures across RPM ranges on various graphs) along with refinement of fuel mixture to point of last graph where its at the target range of 11.2:1 or there abouts.

The difference on road is excellent with power all the way to 8000rpm. In 2nd gear traction control needs to be turned on.... I have done a months worth of testing at this level and its very strong with no problems, system parts can tolerate the mixture too (tested 2 months now or more).

The last graph today was a bit warmer in weather, but test location was exactly the same and it shows the extra power in last few hundred rpm due to just the mixture change alone. All tests car was exactly 1320kg as tested (complete with driver)

I will eventually turn it up to 1.4 to 1.5kg/cm boost but am happy with the way it is now has more than enough power for track work and an good spread too. My experience with the meth mix in my own case yielded some more power for like conditions so I am glad I went down that path, improved 90-140 from 3.11 seconds to repeated 2.89~2.87 second range (probably faster as these tests were 100m higher and also in ~10deg C hotter test conditions).

1.00kg/cm boost setting WATER


1.20kg/cm boost setting Water/Methanol, to rich at high revs


1.20kg/cm boost setting Water/Methanol, better mixture across range


Spread sheet of VBOX data showing average data for both 1.20kg/cm boost tests (repeated sub 2.9 sec 90-140 tests, note higher average power in last part of rev range for correct mixture setting)

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[RICE RACING]

Forgot to add: (Avg-b) *for boost and power* between test lines are averages for those measures between test line obviously (separated in 10km/h) figures, and you can see the rpm at each 10kph test line. You can see the repeatability of performance for like figures and the obvious gain in average power for the last 10kph incremental (~6600rpm to ~7200rpm).
Peak power for both tests was 273rwkw and 271rwkw (first at 6600rpm and second 6800rpm, but holding near this peak level over a much broader range) and holding this to 7800rpm, rev limit is set to 8300rpm and changing point is ~8000rpm.

Hope people find this of some use.

[RICE RACING]

Originally Posted by RICE RACING

I have some preliminary results: (This is what I e-mailed a customer of mine who is thinking of trying it himself)

Giving you an update on my W/M 50/50 test.

I mixed up a batch yesterday (will take pics of what I did if it helps you) I went out today for a 200km drive. On the first few km I gave it a few squirts to make sure the remaining water was used out of the line. About 10km down road pulled out of a junction and selected 2nd gear and it was drifting up road just about to activate the traction control and the engine note was totally different to ever before (much nicer and louder)  *good start*

I built up my confidence along the way and started opening her up and the feeling I had in second was observed in 3rd and 4th, on my journey I was overtaking cars and 4wd?s towing caravans with crazy speed just leaving it in 4th (going to 160kph stupidly well). On my return leg after almost 2 hours running of the engine nonstop I overtook one car and revved it out in 3rd gear to 7100rpm on dead flat road I normally use, thing felt better than ever before (today is 25deg C). In this weather and on 1.20kg/cm boost at those revs it showed 254rwkw on my Blitz power measure, the previous highest was 232rwkw on 1.0kg/cm on about a 10 deg C day and engine was very cold (when I went to do my 90-140 test).

The impression of the 50/50 mix is that it does work far better in my engine set up when the water jet is set to 3 turns out (as today) on pure water I was having the jet out at about 2.5 turns and for like conditions the car now feels to me at least 10% more in power if not maybe a bit more? Can?t tell for sure till I hook up VBOX, it?s still got well over ? tank of fuel in it so when it works its way down to ? as per my other tests I will go out early in the morning and do another 90-140 test and get some more comparable figures.

I doubt I will ever go back to straight water again.

Specs:
3 turns out (water injector) = ~500cc/min on my system at this boost
AFR 10.9:1 at full throttle (was before 11.2 to 11.3)
About 13 deg ign timing 8 deg split
50/50 by weight methanol to water.
254rwkw on Blitz (from my experience engine is making around 450bhp region)

Peter

**foot note**
This power measure is off my on board boost controller which has a power meter also it reads a bit lower than what I obtain from the VBOX. The peak power as recorded on the Blitz data logging was at 6900rpm and the engine def does not fall off power nearly as bad as before, it does feel allot stronger especially given the car was heavier and also in about 15 deg C hotter test condition (not to mention motor had been running for 2 hours straight).

Gave here a hit today and its up to 282rwkw on the on board power meter at 1.2kg boost, running 11.2:1 AFR and max power was at 7500rpm

Fine tuning to the AFR curve and spark timing and WI delivery all helped heaps ....... its awesome, want to try 1.4bar now ! hahaha

[Richard L]

A lot of fun info for the weekend. Did get much time to enjoy those wonderful information yet. Thanks for posting.

[RICE RACING]

Any time Richard

I am real happy with it as she makes solid power to near 8000rpm, I did have to modify a few spots to do with my Fuel table where interpolation was not enough between arbitrary 500rpm points, so at 6100rpm and I thing 7350rpm I had to put it specific lines to mention just 2.

All of these things add up to make a big difference in how the engine operates when trying to set it at this minimum AFR point while still giving plenty of fuel for cooling. As the motor was dropping into say high 10 AFR points it showed very obvious drop offs in power which you could feel in the drivers seat.

Once I got onto all of these such mapping points and it was hitting the target 11.2 through the whole rev range it literally transformed the way the engine worked (I think as I posted earlier? or that may have been the diff of going to 50/50? either way similar reaction was noted).

I feel now I have a good base to work from and the power for boost in street trim is right up there, the rest (more power) can either be from increased boost pressure or maybe overall trim to target AFR (might try 11.8:1 and then 12.5:1). There was a quantifiable difference in my own car to trimming up the AFR firstly on the water alone (from way back in early posts) then the W/M. There is obviously heaps to refining any one set up is the moral here I suppose. Only extensive testing and on road or dyno analysis will give you the answer maybe as to whats the best settings for any given car and its combination of parts.

That last sentence is the hardest thing to get across to most folks. I've seen seemingly identical cars react differently from what would appear to be different sensor readings(inputs) and ECU builds.

Everyone always asks what they will get get out of a system, and I have to say the same as you, it really depends on how much you datalog and refine it. Each car and application is somewhat unique.

Congrats on getting yours where it is. That sounds like a very fine setup.