Not finished, but a good start..

http://www.youtube.com/watch?v=WQ5tb...&feature=email

 

Picked up another 15 ft lbs of torque going from 500 to 750cc of 50/50 water/meth mix( by volume) and this was 1 point fatter afr...

 

Thats pretty interesting. Guess this means you could run 50/50 without retuning the AFR's and still pick up power. Were the Air temps cooler?

 

I didn't return and thats the power I picked up. If I were to retune I know that figure would be doubled. I don't know how much cooler the air is, I don't have a temp guage on it( its carb'd). I go back tuesday to hopefully wrap it all up...

 

pretty nifty. when i switched over to 50/50by volume recently i noticed my afrs got 1 point richer as well.

 

Nice, that engine's using all that turbo's got at 1 bar. Pre or post turbo?

 

Pre-turbo. I put a milder tune on it today and finished @ 418rwhp. I could have eeked 450 out of it, but the owner said its got enough. I stopped at 7500rpms and it was still climbing and torque hadn't fallen off either..


Keep in mind this vehicle is around 1600#s...

 

How much boost did you run to squeeze 418 out of it, or any more? Man, that's some nice Power/Weight, it'd be like driving a 700+whp FC!

What kind of porting is on it? Sounds like a fair-size streetport.

 

That was @ 15psi, I didn't make any more power above 15psi( only because there is no air to air Intercooler)
The power is retarded, I took a crew chief of a nascar team out and he was impressed.
The intake ports are stock, exhaust is ported..

Not to put HC on the spot, but...


https://www.rx7club.com/showthread.p...83#post5717883

 

That's theory for you. Some rotaries will make 7 hp per lb of air, some will make 8+, and seeing how this engine is an S4 with lower compression, that doesn't seem to have affected it any, but you are making over 8 hp per lb of air in the worst case scenario. Pretty darn good!

 

I have a similar built car going on shortly, just has a intercooler in addition to the AI, and a GT35R compressor wheel

 

Here is the graph. As you can see the HP is still rocking where I let off. Even the torque curve looks awesome.

I did fix the big bump in the torque curve too... Not bad for locking timing at 15degree advance.

 

I´ve been looking for HP and mainly torque numbers of unrestricted N/A 4-stroke racing engines and compared it to racing rotaries(mainly R26B due to the torque figure) and always end up with 86-89% of power/torque on equal capacity for rotary. Even BSFC increase is matching with these values...
BTW, FIA specified R26B as 4708cc which again is 90% of equal capacity.

 

We took it out a few weeks ago and it did well, but we needed to make some changes.
We're doing a new turbo manifold to eliminate the boost creep, lowering the boost to 12psi, adding an intercooler, and switching to just pure water injection.

Owner never went more than 3/4 throttle either, he said he was too scared!

 

What's your take on pure water injection? Have you compared it versus pure Alcohol to see how it compares in terms of knock levels, IAT's and power levels?

 

Water is a lot better at knock control. A previous engine for this rail blew on dyno when I switched to pure alochol, after making many pulls at 50/50. There was a cross fire problem. Even with a problem that serious the water kept it from blowing..


IATs don't drop even half as much with pure water, but thats what the intercooler is for. Without changing the tune to an aggressive one, the alcohol seems to make more power.

 

my apologies on the V1/2. the turbo makes 52.5 pounds so it should do approx 760 CFM/1.92 = 396 SAE rw rotary hp.

or 52.5 X 10/1.3 = 404

i note your dyno chart is un-corrected so let's see your numbers in SAE.

caveats are:

hp from airflow is always an estimate.

dynos do differ

SAE only.

none of this is to be taken as a criticism of anything you have done. i appreciate your accomplishments and the fact that you have taken time to share them.

cooling per gallon:

gasoline 952

methanol 3136

ethanol 2398

water 8087

good job,

howard