I want!

 

How would the engine be able to cope with that amount of airflow then? Would you have to rev it beyond 10k?

 

nasty build

 

Yeah basically. Maybe 12,000 rpm or so. The amount of air needed at high rpm seems to be exponential. In the future I wouldnt mind shooting for power over 10k with some more internal mods to handle it.

 

What would happen to the power band if your semi PPs inlet tract was really short with long your side ports inlet tract being exceptionally long?

Would this bring your torque lower whilst only on the side ports, then once the semi PPs open the torque would be shifted up further allowing power all the way up to and beyond 10,000rpm?

Or would this make it difficult to setup?

 

proper one. Good work

 

Congrats Logan. Looking forward to your next round of mods, and maybe seeing the car again at DGRR12 (sans 85' car hauler Dragon run?).

 

That was basically the very first setup. The p-ports were almost half the length of the sideports. The issue is once you build a exhaust to resonate, it will only work with one set length of intake. Double edge sword really. The latest adjustments proved to be much more powerful in both torque and hp however.

This setup as-is would continue to make effective hp past 10k, but not any higher hp.

 

Got on the dyno for the final time this year. Took a risk and just did runs in 4th gear instead of 3rd. Eats up more horsepower on a car like mine because the pulls are going into the 175mph range.

Results were still pretty good. Matched hp, and gained torque and a lot more under the curve. 475rwhp and 281 rwtq. In the standard 3rd gear run it would be 481rwhp and 284 rwtq.

Tuning gave me a bunch of issues. The fuel pump seems to be maxed out (walbro 255) so it was very inconsistent. AFR's on the best pull were still 12.6's so some more was in there.

interesting results-

Race gas lost hp and tq. Not a huge amount, but it did drop power. 93 octane seems to still be the best.

 

Obviously you are using high compression rotors with the engine being NA, but if you were to change the rotors for some custom made rotors and not the standard iron rotors would an increase in compression using race gas yield better results?

Also I have been thinking about WI on a non turbod motor, obviously the same gains would not be seen like the turbo engines do but possibly some would be seen?

 

From what I understand, raising the compression ratio does not always increase power on a high output NA rotary as it limits the effectiveness of ignition advance.

This is because the mixture is ignited when the trailing side of the combustion chamber is larger then the leading side (split by minor axis in rotor housing) and then all the expanding combustion gasses must pass through the slot in the rotor as the rotor turns and the leading side of the combustion chamber becomes the larger one and then finally the only side of the combustion chamber.

Raising the compression ratio makes the rotor slot smaller raising the pumping losses of the combustion chamber location transfer.

 

have you come up with some more crazy idead to squeexe closer to 500HP?

 

Since you need a fuel pump upgrade anyways-

lets see how it does on E85!

 

Of course If everything goes well, it should go past 500rwhp a decent amount. We will see.

I could try it and see, going to need more injector to do that though. I doubt any more power would result but I could be wrong of course. 100 octane already lost some power...

 

100 octane just burns to slow i believe, you aren't moving enough air to utilize it, it seems. The e85 atomizes differently. I think e85 will yield more power.

 

How soon before you're up and testing again??

 

Always worth a shot when every horsepower counts I will try it out at some point

Depends, there is so much to do at the shop right now this is kinda on the back burner. Luckily there wasn't a whole lot to change on the setup. But hopefully no later than mid april

 

Cool. Can't wait to see your results. Also waiting to see what you finally cook up for Chris' Red GTUS. Great work Logan!!

 

looking forward to the upgrades

 

Have you hit 500 HP yet?

 

I enjoy the faith everyone has in us. Not a question of "if" but rather "when" will it happen Well basically its been a super busy year. But all the new engine modifications are finished, and just need a free day or so to assemble it and replace 3rd gear in the tranny. After that its off to the dyno for results.

Very exciting to do the modifications internally I've been thinking of for so long. Will post some pics and results hopefully in the next month!

 

Just wanted to chime in and say great build those numbers are pretty impressive on pump

 

That one bad 7

 

Just finished reading this start to finish again. Just as a question, do you think the semi-pp setup has more potential than a full peripheral engine? It seems like a lot of the tricks you're doing are related to runner tuning and the like, which would apply to a full peripheral as well.

Also, any thought to running less than 93 octane?

 

Thanks guys!


That is a age old question around here. So I decided to do more testing of a full p-port motor with all the tricks side by side with this one and find out Yeah years ago we tried 87, 89, 91 and 93. Lower octane used to always make more power, until the engine reached better development. Then the higher octane was a benefit.