Thread: Roller Rocker Virtual Dyno Testing

Now that I finally swapped in and got the RR working, I could finally do some virtual dyno's to test some different mods. Some tests were done on the same day, others a day or two apart. I noted down the Temperature and Barometer pressure after each run, this keeps the numbers SAE standard and doesn't require back to back runs to be consistent.

Please do keep in mind that these are virtual dynos, they consist of doing a log with your tuning software and then it calculates the power output based on that data and vehicle specifications. These numbers seem to be within the ballpark of real RR power numbers. This is not a dyno of how much the car is making, more of dyno's to compare changes between mods. I used the same stretch of road for all of these, but did other stretches to make sure data was within margin or error.

Intake Test
This test is comparison of stock intake box vs a flow-stack WAI setup.

Constant Mods: SR20DE RR (110k miles), SSAC 2.0" Header, 3" Catback, NEMU ECU with B13 Base Tune and JDM RR Fuel/Timing maps, UR WP Pulley, Z32 MAF, Shell 93 Gas, BKR6EGP Plugs, 6700 Redline (fuel cut starts at 6500)

Stock Intake box:


BPi Flow Stack and Flow Stack filter (coned in on the end)




As you can see the BPi Flow Stack made the run leaner, I knew the flowstack makes the mixture leaner thus I figured I would try leaning out stock airbox mixture too. I cut the fuel back by almost 50% to get it into the same AFR ranges as the flow stack. Results where disappointing, I didn't gain or loose any power. But this shows that stock tune is way too rich and you can restore some MPG's by tuning it a bit.


Header Test
This test is comparison of stock RR header (with cat in the primary) vs SSAC 2.0 and 2.5". All I did for the SSAC tests is change out the downipe, header it self stayed the same.

Constant Mods: SR20DE RR (110k miles), SSAC Header, BPi Flowstack, 3" Catback, NEMU ECU with B13 Base Tune and JDM RR Fuel/Timing maps, UR WP Pulley, Z32 MAF, Shell 93 Gas, BKR6EGP Plugs, 6700 Redline (fuel cut starts at 6500)

Stock RR header is not meant for reeving high (RR Redline is low), this thing is a flow disaster, even cylinder pairing is less then ideal for performance. What is impressive is the 2" crush bent downpipe on the Stock header, most OEM ones are 1.75 or smaller.


SSAC 2.0" vs 2.5" Downpipe




I gotta say 5whp gain from header swap is disappointing, but low redline is to blame here. Revving the roller rocker out to 7500 RPM would probably show much much greater improvements, you can see how the stock header just refused to flow past 6k rpm! Also what impressed me is how little the 2.5" gained vs 2.0", but once again I believe the low redline is the fault here.

If you plan on keeping the redline at stock level, get the 2.0" SSAC or maybe the 2.25". The 2.0" has a lot more low end torque, which would help you with your daily driven automatics.

Intake Manifold
This test is comparing the stock Roller Rocker Intake manifold to a Low Port Intake Manifold. When switching to a 16 bit ecu, going to a Low Port manifold is almost a must because it allows you to use old school IACV, otherwise you have to get creative to keep the car idling.

Constant Mods: SR20DE RR (110k miles), SSAC Header, BPi Flowstack, 3" Catback, NEMU ECU with B13 Base Tune and JDM RR Fuel/Timing maps, UR WP Pulley, Z32 MAF, Shell 93 Gas, BKR6EGP Plugs, VE Valve Springs, 8000rpm Redline (Reved it until it didn't sound good!)

Other Variables: From 259cc Top Feed injectors to 520cc Side feed injectors.

I think Nissan designed the roller rocker manifold horribly on purpose, they saw what a great motor the RR is and how much more power it makes then regular low ports and they had to detune it. At first I thought Roller Rocker manifold was really designed for low end torque, that's why they suck for power getting, but after doing these tests I'm convinced Nissan just wanted to screw us.

Stock Roller Rocker manifold


It is good for having secondary runners being very smooth, it's actually semi polished, which is impressive compared to any other SR20 manifold's I've seen, which all have horrible casting marks.



Low Port manifold on the other hand has a much bigger plenum that can house a bunch of air.


It also has smoother runners that are slightly longer with less bends.



On the same exact tune I made 10 more wheel horsepower! Also as you may have noticed my power went down, this could be because of stiffer VE valve springs, or because of hot December day, Virtual Dyno does have temperature and pressure corrections which I utilized, thus it's hard to say what could have dragged the power down a bit.



I also had a different tune that I've been working on, this one has a lot less fuel and a lot more timing then stock. The max I could get out of it was 120whp on roller rocker manifold. On the lowport, same exact timing (with slight fuel adjustment for bigger injectors), got me 20whp!


The car feels a lot beastlier now, I was actually quite impressed by the felt torque while doing some runs tonight!

Very good post, Vadim! Keep us informed.

good info! you might find a hp or two by changing out the stock rubber piping behind the maf to the TB. im curious as to why one 5whp with the header, then again you do state that you have a 3" exhaust on the car as well. im curious how different the RR is with a b13 base tune and RR fuel timings.

this is a good thread to compare with

Dyno'ed my car yesterday - SR20 Forum

I think only 5whp simply due to low redline honestly. This is also untuned, and self learning disabled.

Also check DE stock VS ssac header difference:
http://www.sr20-forum.com/product-reviews/9082-ssautochrome-2-5-header-ebay-special.html

Something to consider about his flow stack test too, it's a WAI, thus with an Open hood it will do a ton better then in real life with a closed hood. This is why I always wanted to enclose my flow stack and create a cold box for it. I boosted before I got enough patience to make that though :o.

Nice Vadim. We need to get a set of S3R's from someone to test. They are hard to find used though.

Dyno with some cams!!

Looks like velocity stack intakes really works.

More RR dyno sheets from jpsr20det. In a great thread by Meeners:

http://www.sr20-forum.com/information-library/57194-jdm-usdm-roller-rocker-sr20de-info-thread.html#post121403

I would get heavier valve springs so that I can rev higher before I get S3R's .



JP has a lot of awesome work. What really motivated me to do this is stock header vs SSAC. After installing the SSAC 2.5" on wife's car, I felt like lost a lot of low end torque. And I think that is really the case with the 2.5", seems like 2.0" or 2.25" would be the most ideal for stock RR's.

Vadim could you do a write up on how to setup the NEMU to get those CVS files to open them on Virtual Dyno!!
Also parts should be tested tuned vs tuned to see the real gains since each part can affect the tune and also make the motor react different!!

It's simple, record a single run, then press save to CSV. You will be asked if you would like to export to Virtual Dyno (You will need to first go to Settings and input the Virtual Dyno Location). Or you can open Virtual Dyno and then select the correct CSV file.

I purposely didn't want to really tune them. Main reason is not everyone wants to convert 32 bit RR's to be 16bit and the legwork involved in it. Plus I didn't have too much time, I had to steal the stock header from my wife's P11. I will be doing a few more mods, then I will start tuning around and seeing what the RR can do with better tune.