Defined 20b n/a semi p-port. 421rwhp

[GtoRx7]

Perseverance---

: continued effort to do or achieve something despite difficulties, failure, or opposition :

This is the word anyone in the sport of n/a tuning would learn to live and love. Having no boost pressure, auxiliary injection, or even supercharger pulleys to play with, naturally aspirated is both difficult and also very rewarding.

With that said, here is our most recent shop car results! Using all learned knowledge over the years from my original ITB 20b, the good ol' 230wheel 1st gen "test mule" and many other projects, finally have the semi p-ports in action! Its a beta version, and really just the beginning. No rumors, no theorizing today. Just the findings and results.

The engine setup-
20b n/a, 9.7:1 rotors, CLR balancing, race rotor bearings, stock stationary bearings. circuit porting, and exhaust porting, semi p-port. Dry sump mazdaspeed front cover. Oil and coolant modifications.

Intake setup-
Stock 20b intake with custom sheet metal plenum and 90mm TB. 3 x 35mm individual throttle bodies for p-ports. 9 fuel injectors. Triple staging.

Accessories-
Racing beat front pulley, mazda comp waterpump pulley.

Exhaust-
Custom stepped inconel header, fully adjustable design. 3.5" main exhaust going to twin 2.75" pipe and dual center exit

Standalone-
Electromotive Tec3R ecu, and inductive coils.

Fuel-
ATL 13 gallon fuel cell, Walbro fuel pump, 550cc x6, and 200cc x 3

Dyno Video
http://www.youtube.com/watch?v=oXzuPuNWpXA

Dyno Charts





Engine shots





Car pics

[Mazdabater]

That is incredibly awesome.

[djmtsu]

I am amazed! And confused.

Why am I seeing both an intake manifold with a massive TB, and 3 ITB's on the same engine at the same time????

[RETed]

The intake is a staged system.
Low RPM operation is through the regular intake system + TB through the usual side ports; semi-PP is still closed at this point.
At a certain point / RPM, the outboard TB's open up for the semi-PP to kick in.


-Ted

[djmtsu]

I have never seen that sort of set up before. Pretty impressive.

I want to see this thing in person. You need to bring some toys to DGRR in the spring!

PS- please tell me that Corvette is getting rotary power.

[GtoRx7]

Originally Posted by RETed

The intake is a staged system.
Low RPM operation is through the regular intake system + TB through the usual side ports; semi-PP is still closed at this point.
At a certain point / RPM, the outboard TB's open up for the semi-PP to kick in.


-Ted

Reted is mostly correct. This is how I had wanted to do it. But its actually staged through mechanical operation. Half throttle is the side ports, and past that it will start to open the p-ports. So whatever rpm I am at, once its floored, the p-ports are open. I thought this would destroy torque. But it actually didnt hurt at all except between 4k and 5k.

Originally Posted by djmtsu

I have never seen that sort of set up before. Pretty impressive.

I want to see this thing in person. You need to bring some toys to DGRR in the spring!

PS- please tell me that Corvette is getting rotary power.

I will be going to DGRR for sure. And no unfortunately that corvette is staying V8. lol

[RX-Heven]

Great work.

[diabolical1]

what kind of water and oil temps are you getting at full song?

[NoDOHC]

Did you have any pictures of the engine with the intake manfolds in place and it not in the car? I am interested in how you snaked the PP through the intake runners.

I am also curious what your ignition timing was set to, as I have never dyno'ed a rotary with that high of compression (I intend to run with 9.4:1 in the spring). Where you able to run more than 30 degrees?

If you have AFR, that would be cool too, but I don't expect you to divolge all your secrets. I am mostly trying to learn from others experience, so I can decide the direction of my own projects.

I will never be able to afford a project like this, so I can only live vicariously.

I am surprised by the torque, I would have expected at least 280 Wlb-ft from a P-port.

The power is awesome though!

good work - keep it up.

[GtoRx7]

Originally Posted by NoDOHC

Did you have any pictures of the engine with the intake manfolds in place and it not in the car? I am interested in how you snaked the PP through the intake runners.

I am also curious what your ignition timing was set to, as I have never dyno'ed a rotary with that high of compression (I intend to run with 9.4:1 in the spring). Where you able to run more than 30 degrees?

If you have AFR, that would be cool too, but I don't expect you to divolge all your secrets. I am mostly trying to learn from others experience, so I can decide the direction of my own projects.

I will never be able to afford a project like this, so I can only live vicariously.

I am surprised by the torque, I would have expected at least 280 Wlb-ft from a P-port.

The power is awesome though!

good work - keep it up.

I will have a build thread that will show every part of the car including the manifold. Timing up at 10k was 30 degrees. Pre ignition occurred at 32. Afr's varied but 12.9's are average. The torque is excellent. This is not a full p-port so its not going to quite match that. But the BEST of the BEST full p-port 20b's are making 305 FLYWHEEL torque. That is 260rwtq. I am only 19ft lbs away, and I think 10-15 more is possible.

[RETed]

Originally Posted by GtoRx7

I am only 19ft lbs away, and I think 10-15 more is possible.

I agree that more gains in torque is just a matter of tweaking and tuning!
The torque curve is really good for not a full-on PP.


-Ted

[GtoRx7]

Originally Posted by RETed

I agree that more gains in torque is just a matter of tweaking and tuning!
The torque curve is really good for not a full-on PP.


-Ted

Exactly. Now the real challenge and fun begins!

[NoDOHC]

I think that I misunderstand what a PP does for the Volumetric efficiency. I thought that they ran 125-130% VE at 9,000 RPM. My engine is making 102% VE at 7,700 RPM and making 160 WLb-ft (= 240Wlb-ft on a 20B) at 6500 rpm where it makes 98% VE.

I would expect the torque to be significantly better for an engine with better VE.

I also would have expected this engine to make about 8% higher torque/VE due to 9.7:1 vs 8.2:1 compression. This should put the torque output at 175 Wlb-ft / 100% VE for a 13B or 263 WLb-ft / 100% VE for a 20B. This is why I expected 280Wlb-ft out of it, I guessed 110% VE. Do you have a VE curve for that engine?


Your AFR is similar to mine, your timing is similar to mine (given the differences in Compression ratio).

This thread is scaring me, as I am beginning to worry that adding compression ratio adds enough flow resistance past the cusp in the housing to destroy any gains that are made by it (I have read that somewhere).

I will have to wait until spring to find out now (I will run my engine with 9.4:1 rotors instead of 8.2:1 rotors).

[GtoRx7]

Originally Posted by NoDOHC

I think that I misunderstand what a PP does for the Volumetric efficiency. I thought that they ran 125-130% VE at 9,000 RPM. My engine is making 102% VE at 7,700 RPM and making 160 WLb-ft (= 240Wlb-ft on a 20B) at 6500 rpm where it makes 98% VE.

I would expect the torque to be significantly better for an engine with better VE.

I also would have expected this engine to make about 8% higher torque/VE due to 9.7:1 vs 8.2:1 compression. This should put the torque output at 175 Wlb-ft / 100% VE for a 13B or 263 WLb-ft / 100% VE for a 20B. This is why I expected 280Wlb-ft out of it, I guessed 110% VE. Do you have a VE curve for that engine?


Your AFR is similar to mine, your timing is similar to mine (given the differences in Compression ratio).

This thread is scaring me, as I am beginning to worry that adding compression ratio adds enough flow resistance past the cusp in the housing to destroy any gains that are made by it (I have read that somewhere).

I will have to wait until spring to find out now (I will run my engine with 9.4:1 rotors instead of 8.2:1 rotors).

Well honestly the 160rwtq is probably the highest I've seen from any n/a 13b. Short of a full p-port. After reviewing the setup, I do not know how it pulled it off. That exhaust is terrible in a high efficiency standpoint, and the correct resonance. The most torque I have made is 152rwtq on a 9.7:1 13b. But only after getting the exhaust in correct length. 135-140rwtq was with a off the shelf Rb header. Remember rotaries are not very efficient. 15% less is normal. I am half tempted to send you one of my headers and see what your car could do. The other half of me thinks the dyno wasnt calibrated correctly. lol. But in short its WAY different to get the 160rwtq at 6500 and getting 160rwtq at 10000. You have not considered frictional losses which go up exponentially with RPM. The engine is getting more friction, the water pump and alternator are getting more, the weight of everything takes more energy to spin, and the transmission friction is rising a bunch too. Then add into the fact air velocity is moving much faster, well you get the idea. Compression does not change HP alot on rotaries, you are correct. Lastly, I can tell you personally that the FC coils are great. There is not 30rwhp from a ignition upgrade. Feel free to PM me though, you are on a very right track for sure!

[NoDOHC]

Originally Posted by GtoRX7

Well honestly the 160rwtq is probably the highest I've seen from any n/a 13b. Short of a full p-port. After reviewing the setup, I do not know how it pulled it off. That exhaust is terrible in a high efficiency standpoint, and the correct resonance. The most torque I have made is 152rwtq on a 9.7:1 13b. But only after getting the exhaust in correct length. 135-140rwtq was with a off the shelf Rb header. Remember rotaries are not very efficient. 15% less is normal. I am half tempted to send you one of my headers and see what your car could do. The other half of me thinks the dyno wasnt calibrated correctly. lol. But in short its WAY different to get the 160rwtq at 6500 and getting 160rwtq at 10000. You have not considered frictional losses which go up exponentially with RPM. The engine is getting more friction, the water pump and alternator are getting more, the weight of everything takes more energy to spin, and the transmission friction is rising a bunch too. Then add into the fact air velocity is moving much faster, well you get the idea. Compression does not change HP alot on rotaries, you are correct. Lastly, I can tell you personally that the FC coils are great. There is not 30rwhp from a ignition upgrade. Feel free to PM me though, you are on a very right track for sure!

I thought the same thing (about the dyno) I made him show me the certificate of calibration (it was 5 months old and done by Mustang dyno themselves).

Maybe I am listing the wrong number. I found that the sheet shows a WC Torque Number, I asked the guy and he said that this was to compensate for engine inertia (which was determined by a rolldown after the run). The torque without WC was 154 W lb-ft and 205 WHp. Maybe this is the more correct number - The dyno guy said that the WC was the correct number to list.

EDIT: After looking at the manual for the dyno, the WC is Weather Corrected. This means that the numbers are corrected to a standard temperature and humidity. It was about 38 C (100F) in the dyno room while we were doing the tests as the door was closed (noise concerns) and I was the fourth car to run that day.

I was running 15W-50 Full Synthetic oil in the engine, 75W90 synthetic in the differential and straight gear lube in the transmission (which had bad bearings, which didn't matter for the dyno run as it was done in 4th gear, but made me not want to buy synthetic oil for the transmission). I had 205-60 R15 tires on stock rims on the car. The tires were nearly bald.

I can say this, my G-tech put it in at 235 WHp@8,200 rpm and 165 WLb-ft@7,200 rpm with a 2800 lb weight entered. 0-60 (datalogged matched G-tech) = 4.7 seconds. 1/4 mile (G-tech) = 12.6 @ 122 mph (lets not say where this was tested). The car was not a slouch.

With 245/40R17s on the back, it would pull the tires loose when it hit about 6,000 rpm in a straight line - full throttle - acceleration.

Anyway, I have replaced the rotors - let me know if this makes sense to you:

It has INSANE low end (I'm talking almost like a V8). It will pull hills at 1700 RPM with a 0.72 overdrive that it wouldn't pull at 2,000 rpm (0.80 overdrive) before. I am pleased with the 42 mpg instantaneous that it will give at 60 mph (before I maxed out at 34 instantaneous at 75).

Unfortunately, I seem to have lost my volumetric efficiency up high (same engine, same exhaust, same intake, same ecu, different rotors). The VE now appears to peak at 96% at 4,500 rpm. I have not yet put the car on a dyno, so I am not certain of the AFR and VE numbers.

Flooring the car at 2,500 rpm will cause tire spin on 245 40 R17s. Flooring the car at 6,000 rpm will not. I have no high end data due to insufficient fuel from my injectors (I hate the E6X staging for an NA car, so I turned the secondaries off). I run about 17:1 AFR at 9,000 rpm, so I can't say anything about VE past 6,000 rpm.

Fastest 0-60 is 5.7 seconds (gentle launch and shift at 7,500 rpm), 1/4 on g-tech = 13.3 @ 101 mph (gentle launch)

Gtech shows peak torque at 5,000 rpm (180 Wlb-ft).

I should have cited my findings before when referencing your above post, as I have been disappointed with my results, the data above only served to reinforce my theory about the compression. Your experience of the compression number not changing the torque matches what I am seeing, I am saddened.

Whatever my engine does, I am pleased to see that you are making this much power. Maybe someone should try a high powered NA build using 9.0:1 rotors...

I will PM you about the headers, I am very interrested in this idea, as I was thinking about building a set of my own.