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Oh just to let you guys know... these numbers were pulled at about 600 ft above sea level here in Toronto.............so i'm sure being somewhere with a lower elevation would yield greater numbers..
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Originally Posted by MazdaManiac
Uh, I managed to get a T3/T4 into that spot without too much difficulty...
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Originally Posted by Greddyturbo1
Hey Rotarygod, you might be right , but don't say " these guys don't know what their talking about....
Because these guys are from down under and have a tremendous amount of knowledge about rotaries.... But I still hope your right.. |
Originally Posted by T-von
Personally I would tune for a lower A/F ratio since this is a street car. Your really asking for trouble running close to 12.0 A/F ratios with pump gas on a boosted rotary at around 15psi. Tuning to the ragged edges does nothing for long term reliability. With the turbo running out of it's efficiency range, all it's doing is heating up the air and will increase the chances of detonation. Your not going to have any margin for error in a slightly lean situation with your current A/F ratio. Remember, a perfect tune can't always be relied upon when something else goes wrong. Example fuel injectors don't always spray perfect forever and not all fuel is the same. This is exactly why the FD was tuned to a A/F ratio of 10.0 and one of the reasons why my orginal Fd engine has over 100k and still runs perfect. Now I'm not suggesting you re-tune that rich, but I am suggesting you leave some more room for error. I'm tired of seeing our engines blow for stupid reasons.
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nice numbers.... well done
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Originally Posted by Aseras
I hate to tell you but it's pulling more than 400 cfm NA.. if my numbers are right... which is what MM said
Originally Posted by MazdaManiac
the 400+ CFM the Renesis ingests at WOT and 9 PSI. |
Congrats! Hybrid, are you running stock injectors and fuel pump?
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Originally Posted by rotarygod
To say that a certain a/f ratio is dangerous is a misconception. You can't say with any certainty that any a/f ratio is safe or not without knowing how the ignition timing is done at that point.
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Originally Posted by zoom44
see 400+? where's the disagreement?
I believe he is using the standard CFM = CID x RPM x VE ÷ 3456 formula, but using a VE of 100% and double the true displacement - both of which are mistakes. |
Originally Posted by rotarygod
Which is also a fairly small turbo. That's what it takes to fit down there. It was a tight fit if I remember correctly. The point was that no one is going to get a 60-1 or a T66 or other fairly large high power turbo down there. It'll have to move somewhere else.
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The best way to install a turbo that large would be to do it in front of the engine like the PTP or SSR kits.
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Originally Posted by MazdaManiac
I think he means WAY more than 400 CFM.
I believe he is using the standard CFM = CID x RPM x VE ÷ 3456 formula, but using a VE of 100% and double the true displacement - both of which are mistakes. for say 6000 rpm we get 240 CID x (6000 rpm)x 1/3)/1728 = 277 CFM I used a 98% throttle position as well so my numbers I posted are a bit lower than a 100% WOT. |
Thats what i thought but it was an idea.
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Originally Posted by mike1324a
RG, do you think it could be possible to fit a 60-1 or maybe even a t66 if you pushed it a farther back. I dont know if you are know how the APS turbo kits ( http://www.airpowersystems.com.au/35.../it_system.htm ) and the speed force racing kits for the 350z and g35. ( http://www.speedforceracing.com/imag...it/g35_1_2.jpg ) Both of those seem to have the turbos farther back and dare i say, nearly out of the engine bay. I dont know how much room there is under the car in that area. Would it be possible to push the turbo back and possibly put a bigger turbo in there.
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Originally Posted by blksf8
Originally Posted by epitrochoid
neither...but you're opening a whole can of worms that this thread doesn't need to see
Originally Posted by swoope
duh,
i just tought of this, are you doing scotts kit?????? beers :beer: |
Originally Posted by Aseras
I used 40 CID per rotor 2 rotors 3 face per rotor for a total 240 CID.
for say 6000 rpm we get 240 CID x (6000 rpm)x 1/3)/1728 = 277 CFM I used a 98% throttle position as well so my numbers I posted are a bit lower than a 100% WOT. Two rotor faces go by per RPM. 80 CID per RPM. Use WOT - there is no way to calculate for anything less. Assume a VE of 80% for N/A operation and 100% for FI. |
Originally Posted by MazdaManiac
OK. That is all wrong.
Two rotor faces go by per RPM. 80 CID per RPM. Use WOT - there is no way to calculate for anything less. Assume a VE of 80% for N/A operation and 100% for FI. There is some disagreement about how to calculate airflow for a rotor. It appears to me that each the three faces of the rotor sweep the chamber area during one revolution of the rotor. If each face is consider a piston then it is similar to a 3 piston 2 cycle engine. In thr rotor case, all three pistons use the same cylinder rather than having a separate cylinder. If you accept this hypothesis then: For a 2 cycle 6piston engine (equivalent to two rotors) 40CID x6(pistons)=240CID Displacement. Then for a 2 cycle engine at 2000 (rotor actual rotation speed at 6000 rpm eccentric shaft) rpm this becomes CIDxRPM/1728=CFM of airflow or 40CID x 6(pistons) x 2000 (rpm)/1728 = 277 CFM for a six cylinder (40 CID each) 2 cycle engine Now for applying this hypothesis to the rotor motor. 40 (CID of one rotor) x 3 (faces)=120 CID displacement for one revolution. Therefore, for two rotors this becomes (40CID)X2(Number rotors)x3(faces)=240CID per revolution The rotors turn at 1/3 the Eccentric shaft speed, from which: (240 CID x (6000 rpm)x 1/3)/1728 (conversion factor) = 277 CFM which is close to what a 13B draws at 6000 rpm. If you take the 80CID displacement give for the 13B and knowing the rotors turn at 1/3 the speed of the eccentric shaft, then at 6000 RPM for eccentric shaft the rotor turns 2000 rpm. If you try 80CID X 2000 RPM/1728= 92 CFM which is clearly far below what the rotor flows at 6000 rpm. Therefore, if the hypothesis of a rotor sweeping 3 times its volume in one revolution is incorrect (and it may be), I have no idea of the magic the rotor uses to get the airflow it does. |
You are confusing power creation (combustion) with total swept volume (pumping).
All we care about is how much air is taken in per shaft revolution. Every time a piston motor turns, half of its pistons have open valves. This is true and is a particular idosyncracy of a 4-stroke piston engine (that it only ingests 1/2 of its volume per rev). However, a rotary motor has two swept rotor areas pass the intake ports per revolution. That is all that is need to know for intake volume. It matters not that this can occur continuously - we only calculate per rev. 80 CID of swept volume pass the intake ports per rev. That is .046 cubic feet, assuming 100% VE. 9200 RPM would yield 338 ft^3 per minute at 80% VE. In any event, the conclusion in the logic above is wrong. |
Awesome Hybrid! Looking forward to seeing your setup at the April meet!
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Jeff is correct in that the effective volume is ~80in^3, for both rotors. But, I'm not so sure about the NA VE of 80% though. I looked at some scanalyzer graphs posted by Hymme that show the g/min of air that pass the Maf, this showed a VE in the high 90's from 5500 to 8500 rpms.
Based on my calculations I found the max airflow for an NA Renesis to be around 350cfm at 90% VE. The max airflow for a Renesis at 9psi, with: 78% compressor efficiency, 80% intercooler efficiency, 70deg ambient temp, 0.7psi suction loss, 14psi ambient pressure, 8500rpm, and 100% VE would then be around 618cfm. Above 8500rpm, VE decreases faster than revs increase. Airflow decreases to 589cfm at 9000. |
The OEM MAF maxes out at 600 CFM.
Even under full 9 PSI boost at 9200 RPM you are still not maxed out on the OEM MAF. The effective volume is 80 in^3, not 160 in^3. |
Originally Posted by MazdaManiac
The effective volume is 80 in^3, not 160 in^3. |
Thanks for all the positive comments guys, I must say the support of the club does help my efforts. Here is the Breakdown:
The fuel was 94, the boost was 13psi and the air temp according to the dynojet was ~55f. The Interceptor-X has complete control of all 6 injectors and I have reached the limits of the factory fuel system. I do not believe I can get anymore power out of this turbo kit without switching to at least 100 unleaded as some other members run. This of course would allow more timing, more boost and a leaner mixture but at $5 a gallon to run "high boost" most would rather not. Damons ride is very,very nice and quite fast as well :evil_laug B.T.W. For those of you who want more power than this you might want to wait just abit longer ;) |
OH! Spill it scott!
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Hey scott, what are you talking about. You know I always run 100 octane.. I call you Thursday, we'll talk. rich....
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