Independent testing of the Grimmspeed Intake

Due to customer demand, I will be conducting a head to head comparison of the new Grimmspeed intake. I will use controlled settings for boost, timing, and will calibrate each MAF curve to a consistent AFR.

Subject:

2005 LGT Limited Wagon 5MT

VF52

Stock Tmic

Grimmspeed Downpipe Catted

Grimmspeed Up-pipe

FMS 3" CBE

TGV deletes

Location:

Enhanced Street Performance

Sterling, MA

Test parts:

Stock Intake with Stock Filter

Stock Intake with K&N Filter

Grimmspeed Intake

Lets discuss the Dyno results.

We found very interesting results, and did some additional tests based on our findings. We found the GS intake to be getting much hotter on the dyno and in low flow conditions (stopped), with the provided air box. The factory airbox has a provision for an air duct which supplies fresh air to the intake box. The GS intake has no provision for fresh air intake, aside from pulling from the fender well. This was a big issue on the dyno and we opted to remove the GS box and re-install the factory fresh air duct. We also tried many positions for fans and extra fans, but could not get cool air into the intake with the provided air box. It seems odd to me this was over looked.

I wanted to take a base line with the stock panel filter. However I wanted to be sure everything was in good running order, safe and, making reasonable power. So I began by tuning the car with a conservative timing map, 17 psi boost target, flat wastegate duty (54%), and edited the primary fuel table to get a flat 10.8 AFR. This took about 3-4 partial pulls, and 2-3 full pulls to dial in. I noted the last run on this setuo (run 1) to be the base for comparison. The we installed the K&N panel and did a full pull to see how much AFR would change. It was about 11.0 AFR most of the run and made good power gains. To offset the gains for running lean I added 1.8%, and did another pull which was 10.8-10.7 AFR and used for comparison (run 2) The we removed the stock air box and installed the Grimmspeed intake. I added ~10% on top of the panel filter maf curve so roughly 11.8%, did a full pull and it was around 11 AFR. Power wasn't that good and I noticed a dip in the powerband. Checking the log the ecu had some fbkc and pull 2 degrees, also noticed the intake temperature was pretty high over 100 degrees at the end of the run. Most the subaru ecu's are setup when above 104F IAT timing is reduced by 2 degrees, which means any runs above that temp make less power. So I began to try a few different fan locations to remedy the high intake temps. I added a bit more fuel to approach 10.8 AFR and did a 3-4 partial pulls testing blower locations and even an additional large fan. None of this solved the issue and IAT's remained high. I decided to pull the air box and try the stock duct. Re-aligned the fan in front of the car again and IAT came down to reasonable temps, still higher than the stock box(details of the IAT measured are below). As the temps came down the AFR fattened up slightly so the first full pull was a pretty rich at 10.6-10.7. I took some out some fuel and did another pull which was used for comparison (run 3) it was in fact richer(than the stock comparison run), hit slightly more boost, and likely due to a slight change in load calculation ran slightly more timing.

http://i463.photobucket.com/albums/qq357/tuningalliance/GS%20time%20table.png

Run 1 Stock intake, with stock used panel filter.

AFR @ full boost: 10.8 flat

Peak boost from dyno sensor: 17.0 psi

6200 rpm Boost from ECU: 14.1 psi

WTQ: 264 ft-lb

WHP: 247

Run 2 Stock intake, with K&N panel filter.

AFR @ full boost: 10.7-10.8 flat

Peak boost from dyno sensor: 16.8 psi

6200 rpm Boost from ECU: 14.2 psi

WTQ: 266 ft-lb

WHP: 253

Gained with the K&N panel 6whp with a slightly richer AFR, and slightly less peak boost, certainly a good improvement over the stock filter!!!

Run 3 Grimmspeed intake, with stock fresh air duct, removed GS air box.

AFR @ full boost: 10.7-10.5 mild taper

Peak boost from dyno sensor: 16.6 psi

6200 rpm Boost from ECU: 14.8 psi

WTQ: 263 ft-lb

WHP: 256

Gains of 3 WHP above the K&N panel filter, slightly rich AFR, less peak boost, but more redline boost.

Road tune: After the dyno session was complete we wondered if the airbox worked okay, and decided to compare it to the fresh air duct. I cruised around until my intake temp was settled, then I did a 3rd gear pull to 6200rpm. We did this with both configurations to determine how much delta IAT occurred during the run. IAT was slightly better with the fresh air duct, although the Delta during the pull was very similar. I think if Grimmspeed had cut a hole in there air box to allow for use of the stock fresh air duct this would have helped quite a bit. Especially at stop lights, traffic, etc.

Calibration of the Grimmspeed intake was found to be 12-13.5% above the stock MAF curve (12% from 1-4 volts tapering up to 13.5% @ 4.1-5 volts). The K&N panel filter was ~2.0% above the stock Maf curve from 4.1 volts and up.

A few dyno videos

Thanks !

GS intake test.pdf

Can you also compare iat?

I can provide that data as well.

Wow. Interested to see how it goes

Sent from somewhere in Potatoland

Aren't you close to maxing out the stock fueling anyway? Not sure that the intake will really be your weakpoint so is this really going to tell much?

Not sure what your getting at? The point is the determine whether this intake provides gains above the stock intake.

I don't expect to be running out of fuel. I plan to run a nominal flat waste gate solenoid setting. If the GS intake achieves more boost at the same duty cycle then certainly that would support it being beneficial. If that is the case I will also run them at the same boost level.

The game plan is to tune his entire setup to a nominal lets say 16.5-17 psi peak boost, 10.8 AFR, and very conservative timing map with the GS intake and all. Then we will swap the stock back in and do a few pulls, then k&n panel, few pulls. I will run the same waste gate duty cycle (flat), same timing, calibrate each intake to 10.8 flat as reasonable at full boost. My focus is to conduct this test as fair as possible, and not stress the engine too much.

Then I will complete the tune as normal with more boost! If there are gains at 17psi then certainly you would gain more at 20 psi.

I think the other interesting factor would be the relative pressure in the intake/inlet. Obviously a less restrictive intake or larger intake should have less vacuum, during the pull. However this may not translate to power. We shall see.

The other thing is that with less vacuum, you will have less crank case and valve cover venting. Which is not really a good thing.

How do you feel about an audience? I'm in Enfield, CT and I'm a huge grimmspeed shill. Plus i love tuning

Your're welcome to come, we will be at ESP in sterling, MA. You can ride up with me if you want, I live in Vernon, ct.

Not really trying to "get at" anything, just trying to figure out how you were going to go about things which you explain here completely.

 

I guess my concern was if the starting point was possibly something with maxed or nearly maxed fueling, at which point looking for any gains would be kind of silly. The baseline that you are using and the thought of gains seen at lower levels will likely manifest at higher levels also seems solid.

 

Looking forward to results and thanks for doing this.

I'll admit I am skeptical, because to your point if your system (turbo, fueling, etc) is already maxxed then you dont stand to gain much. Sorry I just wasnt sure what you meant.

*if* you're maxing out your injectors, (which is hard to do on a vf52 with pump gas), you are only going to suffer right at the top of the rev range. By that time, you've already gone way past max torque and you might even be crested past max horsepower. But, let's make the assumption that you can't increase your max horsepower number, you're still going to see more torque sooner if in fact the intake allows better flow properties. So yes, area under the horsepower curve, high torque numbers, higher boost, sustained boost, faster spool

Pretty accurate, I agree!

I am going to the Brentuning dyno day (starts at 10AM) over in Charlton, but I can swing by after, unless you're an early bird and will be feasting on tacos by lunchtime instead of breathing in exhaust gases

Ill be on the dyno around 9-930, but generally take 3-4 hours to complete a tune with the dyno and road tuning after (i like to check everything). Plus the additionally testing, so Ill be around for a while.

Tacos!

Just FYI, 3 of us that Mike contacted (in addition to rang0) who were wondering about the GS intake agreed to chip in $10 to help pay for this public service.

Just in case anyone else is interested, rang0 is paying for this, so paypal would go to him.. Not trying to guilt anyone into giving, but it's definitely worth $10 to me (vs. buying the GS intake, re-tuning, etc) to see if the gains are actually there. Mike is my original tuner (I had throttle happy make a few tweaks to his base tune), and has been very responsive, etc. If we can get him a nice tip for sharing his results and being totally open about it, I think that's perfectly in line with the spirit of LGT.com..