Dyno on Stroked 2.2T

[georryan]

I’ve seen a couple different dyno numbers for legacies running RobTune 440 ECU tunes while on ej22T engines with stock heads. On my car, I have a RobTune 550 tune and my motor is stroked. I figured it would be a good thing to have some numbers on this kind of setup. I have a set of RS-RA heads I’ll be putting on the motor pretty soon, and I wanted to have a before and after dyno set of numbers to see how things compare.

For reference and comparison sake: I have a full 3” exhaust, stroked 2.2T using the wiseco pistons. I’m running an AWIC with a larger than stock frozen boost radiator and larger than stock water lines. I’m also running a VF23 turbo. The heads are stock other than being converted over to roller rockers. The cams are stock.

Rob’s 550 tune is set for 18 psi on a 2.0 liter with a 16G turbo I believe. With my car having higher displacement, SOHC, and a different turbo, I haven’t dialed in the safe maximum boost levels. It can safely support more boost than I have been usually running.

The last time I had it on the track I was running right around 16.5 psi of boost and I was watching the MAF voltage. I was getting close to 5v when stretching out 4th gear.

When driving to the dyno I noticed some knock indication from the check engine light (rob tune feature) in lower rpms. Maybe it was picking up a rattle in the engine bay because WOT over 3.5k didn't seem to pick up anything. But out of caution, I lowered the boost a bit and put in a can of octane booster to see if it would help.

One thing I recently realized is that when I purchased the tune, I had told Rob that wiseco states the CR for their hybrid stroker build was rated at 8.5:1. I’ve recently been doing calculations for head gaskets for the RS-RA heads on the 2.2T stroked block and realized that the wiseco calculation is based on the motor using 2.5 DOHC heads. So with our stock heads, the CR is actually closer to 9:1 or a little more. If you are running stock heads with this stroker setup, just be aware of that. My goal was to get a baseline, not find the maximum power this setup can achieve. I’m hoping to run the same boost on the DOHC heads once I’m done to see how the power curve changes. Still, I thought the numbers would be good to have to see how a different setup might perform or affect things.

I did one run at 13.5 psi of boost and two runs at 15psi. I did my pulls in 3rd gear starting at 3k rpms.

I forgot to look at the MAF voltage so when driving home I tried do a pull on the freeway in 3rd gear and see where the voltage sat. I was able to see it sit at around 4.6v so I’m pretty confident that is just about what it was seeing during the dyno run as well.

Ultimately I ended up running 234 hp and 277 ft lbs of torque. The motor seemed to get the peak torque in the mid 3k range, and the peak horsepower right around 5k.

[jefferson]

To me that sounds pretty good and I would be happy with that. Crank hp should be quite a bit higher. Not sure how much drivetrain loss is normal for these cars.
I have a set of the roller rockers, but I was going to have a roller profile put on some stock cams. If they work on the stock profile without issues I may go ahead and put them on. How long have you had them on?

[Legacy777]

Nice numbers and the curve trends seem similar to my setup. The stock heads just run out of breath at the higher rpms

https://main.experiencetherave.com/suba ... no_plots2/

[georryan]

I've had the roller rockers in the heads for years. No issues at all. I really like them.

To be honest, the dyno numbers surprised me. I was expecting a little lower HP numbers. The driving experience in the car is great. I'm quite happy with how the car drives and with its performance. I think if I were to do cams on the SOHC heads, I'd do a delta cut to get more HP instead of torque because the low down torque is more than adequate. On the track, I can feel the lack in the top end, but it isn't terrible. The car is still accelerating and pulling, just not with quite the same vigor it has in the mid range. Plus, since I have the 3.9 gearing, I spend a lot of time in 2 and 3 in track corners and that I capitalize on the low end grunt. It's not an engine that revs super high anyway. So you don't really notices the lack of higher rpm power until you get to a long straight. For me, I really like the thrill of the corners and the acceleration through and out of them more than the drag down the straight.

Going to DOHC wasn't really on my radar until I met someone selling some 20G heads. Then I found out they were the RS-RA heads, and decided to go for it. I've been sourcing parts for the changes and finally have everything ready to go. Once I get the heads in, I'll get another dyno run from the same place and post the graph. I'm curious to see how the heads change the curves and numbers given all other things being the same. Hopefully the information will be helpful for anyone else wondering how that change will alter their car's character and performance.

My rob tune has an rpm redline set at 6750, and Rob has gone silent, so I'm not sure I'll be able to adjust the redline to make use of the heads extra performace. The stock RS redlined at 7k, and the RS-RA redlined at 7500. I am pretty sure the peak power for the 2.0 engine was around 6600 rpms, though, so I still might get rpms that reach peak power, but we'll see. I have an order on an ESL chip for a spare EJ20G ecu I have laying around, but I'm not sure when that will come in. Then I'll have to get it tuned, but with the ESL board I can change my rpm redline. I managed to find and purchase an RS-RA gauge cluster with the 7500 redline and 9k rpm dial. In any case, its just tinkering curiosity. Ultimately, the setup I have is really fun, lively, and plenty powerful. The boost comes on early and hits like a truck and pushes all the way through to the redline. I really like the VF23. I've also run the car with the stock turbo and the VF8. I've had a vf48 and TD04 in my Forester XT, and I think I like the VF23 the best.

Josh, I really like your charts. Super informative! And yeah our trend line looks very much the same.

[georryan]

Josh - Are you running 550cc injectors? Are you still running a MAF or have you converted to a different setup? I'm sure you have this detailed somewhere. I can go look, I'm just lazy and multitasking at the moment. =)

[Legacy777]

HI Ryan,

Yes, I'm running the 550 cc/min yellow injectors from the 04 era USDM STi. Here are the calibration records for them:

https://main.experiencetherave.com/suba ... _calib.pdf

I am running a Link G4 stand alone ECU and have gone to a speed density system and ditched the MAF. While I haven't updated things in a long time, most if not all the info can be found in my build journal.

viewtopic.php?t=47942

[georryan]

Ok, so I finally got the Legacy RS-RA heads onto my stroked motor. Almost everything is the same as the last dyno run. There are three differences. First was the heads, second was a set of UEL Tomei headers, and third I ran my boost a smidge higher to start with.

So, testing the car, I found that I can run 16 psi of boost all the way to redline with the VF-23. If I run it much higher than that, the boost will start to drop as the RPMs rise. So if I'm running 18 psi, the boost will drop down to 15 PSI by 5000, and hold that to redline. The vf23 can't seem to keep up in the upper RPMs. If the boost is set to 16 psi, it can hold that all the way (at least in my car). I'm running a GFB manual boost controller.

So the first two runs I ran at 16 psi (as apposed to 15 psi being the highest I ran in the previous setup). I then turned the boost up a smidge to see how things changed. So the second two runs I was running 17 psi. The pressure did drop as I approached 5k rpms.

Numbers were better with the RS-RA heads but they surprised me as well. Torque was still much higher than I expected. I figured the high torque that we often see in the 2.2T was due to the heads, and figured other heads might drop that ratio a bit. The RS-RA heads also produce a fair amount of torque. I was thinking my numbers would be a lot closer to being equal, but the ratio between hp/torque was pretty close to the same. Max HP was achieved a little earlier, and MAX torque was achieved a little later. All in all, 264 HP and 316 ft/lbs of torque at 17 psi.

The butt dyno, I notice a couple things. The lower compression ratio of the engine is noticeable but not really an issue. I notice it in contrast to what it felt like before, and in contrast to my forester XT, but as a driving experience itself, it isn't a problem. I'm probably running close to 7.8:1 on the compression ratio with the thinner than stock head gasket I have. Between the head gasket and the stroked motor, the compression ratio with these heads isn't as bad as it could be. I feel like the turbo takes a slight bit longer to spool up and kick in than before. That could be due to the headers though. I wish I would have gotten some data showing the car with the stock headers now, but I don't have a lot of free time to with two kids and the dyno is a fair bit of a drive. Anyway, I am happy to see how the two setups compare.

The next thing I'm going to look at is my AWIC. I picked up a second intercooler and had temp sensor bungs welded into it. I'm going to run a temp gauge for air coming in and out of the intercooler to see how it is doing. I took it to the track a few weeks ago and ran 16 psi for three 20 minute sessions. I have a thermometer on the cap of the intercooler, and the water temperature never got much above 100 degrees at the hottest. I'm curious how the actual air temperature is behaving with my setup.

[Legacy777]

Very nice numbers and good data point on the various mods!

With AWIC setups you shouldn't see that much of a change in air temperatures if your water temperatures aren't increasing because water can absorb more heat. This is one of the benefits of the AWIC setups. However, if you do get some air temp data it would be good to see