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View Full Version : Who needs boost!! Lean is mean: +35 hp and +38 ft-lb



Looney Tuning
04-06-2009, 02:52 PM
This Evo X GSR belongs to MR 4G63. He has this handle because he used to own an 06 MR before Sam SMASHED him. The car had the following mods:

AEM intake (The best intake for the Evo X)
MXP downpipe
RRE test pipe
Ultimate Racing Dual Exhaust
Dejon Tool MBC
Zeitronix AFR meter with MAP sensor (the MAP sensor works great with PCMScan)

The first order of business was to log the car and collect AFR, boost, timing and load data. Two things surprised me about this car. First, it was running really rich, richer than Gear Grinder’s car. I turns out that the owner did not get the factory re-flash and that meant that the car ran richer than it should have with the AEM intake. Second, the MBC worked so well on this car and held boost as good as ECU boost control (w/o the pill) and did not trigger a CEL. This is really good news to those who have an MBC on their cars. I did not even have to modify the BDEL tables even though the car was running roughly 26 psi.

So what did the boost and AFR look like stock? Below are the before and after boost logs. All logs were done in 4th gear; three logs before the tune and three logs after the tune.

http://www.sr20deracing.com/EVO/Ray/boost_unchanged.gif

As you can see above, the boost was almost the same. The boost did spool up faster in part because of the mivec map and in part because I leaned the car at peak to aid spool up. At peak boost, however, the average boost was 25.82 psi tuned and 25.68 psi “stock.” The most remarkable thing about the boost, is the capacity of the MBC to hold an average of 19.80 psi by redline. In one of the runs peak boost registered 20.80 psi by redline. That is simply amazing. That really reduces the advantage of ECU boost control (with stock pill) over an MBC on the Evo X. While I do not have the compressor maps for this turbo, I suspect that given the smallish compressor housing, this turbo reaches its efficiency around 19-20 psi.

The biggest improvement was in the AFR. Below is the before and after 3D AFR charts:

http://www.sr20deracing.com/EVO/Ray/afr_b4_after.gif

The AFR is leaner everywhere from load cell 180 @ 3000 rpm to load cell 200 @ 6500 rpm. At 7000 rpm the AFR was relatively the same before and after the tune. At peak boost AFR was 1.26 points leaner that before, at 5000 rpm it was 1.41 AFR points leaner, and at 6000 rpm it was 1.42 AFR points leaner. These are all average numbers of three back-to-back 4th gear runs.

Nothing illustrates the difference between the stock flash and the tuned flash than an overlay of two 4th gear runs:

http://www.sr20deracing.com/EVO/Ray/chart.gif

The dotted line is the stock flash and the solid line is the tuned flash. The numbers in brackets in the tags are for the dotted line and the numbers w/o brackets are for the solid line.

First, you will notice how the boost spools earlier than before thanks to the ninja mivec map and the lean spool up. The boost, however, is just about the same across the power curve. Also notice how smooth the power curve is when logging the boost with the ZT2 MAP sensor via PCMScan.

Second, take a look at the AFR curve. The solid pink line is the tuned AFR and the dotted line is the stock AFR. Notice how much leaner it is, but also notice how it tapers to the same level as stock by redline. Keep that in mind when you look at the power graph below.

Third, take a look at the timing. The solid bleu line is the tuned timing while the dotted black line is the stock timing. I have highlighted three areas in red rectangles to show you how the timing was getting pulled on the stock tune. Pulled timing usually indicates knock. The pulled timing that concerned me the most was above 5500 rpm. You can see that the timing gets pulled by about 2-3* between 5700 and 6200 rpm and 6800 to 7500 rpm. Overall, you will notice that the timing is lower on the tuned flash than it is on the stock flash.

So how did the car do power wise. Below are the average of two stock runs and the average of the two tuned runs. I picked the last two stock runs and the last two flashed runs. All runs are done in 4th gear on the same day on the same stretch of road.

http://www.sr20deracing.com/EVO/Ray/dyno_b4_after.gif

This chart is a classic example of peak numbers meaning absolutely nothing. If you look at the peak hp number, they are almost identical. Why? Well the boost is the same and so is the AFR and timing. So the power MUST be the same at peak.

But look at the area under the curve. Look at the gains from 3000 rpm to 7000 rpm. They are everywhere and that, my friends, is due to three things: leaner AFR, ninja mivec map, and retarded timing. Yes, I said retarded timing. When you retard timing on a car that is knocking, you make power.

I am beginning to form a hypothesis about the 4b11 engine. I believe that this engine responds the best to a lean AFR. Once we have a logger that allows us to log knock sum, I will reduce timing, reduce boost and lean out the AFR to ~12:1. I have a feeling that this will give more power on the 4b11 than higher boost and advanced timing. But until Evoscan for the Evo X is out, I will tune to 11:1 AFR. This is just a hypothesis and I could very well be wrong, but given how this car responded to leaning out, I am very optimistic about the results.

The biggest power and torque gain was 35 hp and 39 ft-lb from 4500 to 5000 rpm. There was also a 37 ft-lb gain from 3000 to 3500 rpm. The rest of the gains are noted on the chart. Kudos to the owner, becuase he felt these power gains at the low end the moment he drove the car after the first flash.

2muchboost
04-06-2009, 02:56 PM
Very nice!
DO you tune AEM EMS?

Looney Tuning
04-06-2009, 03:02 PM
Very nice!
DO you tune AEM EMS?


I only tune ECUflash. The stock ECU is good for about 500 hp.

evo ippo
04-06-2009, 03:36 PM
hey Naji when are you gonna make time to tune our Evo X ????

greekven
04-06-2009, 04:37 PM
Congrats again Naji for another successful tune.

1WkdEvo
04-06-2009, 05:51 PM
Very nice!
DO you tune AEM EMS?


I only tune ECUflash. The stock ECU is good for about 500 hp.


Or way more. Mellon is well above 700whp at this point on stock ECU. EMS is becoming less relevant as each day passes.

Nice write up as always Naji

Looney Tuning
04-16-2009, 06:02 PM
hey Naji when are you gonna make time to tune our Evo X ????


We have a tuning date on the 25th of April. Don't forget. Get that car ready. Do you want to do Torco as well as 91 octane?

silvrEVOIXn818
04-16-2009, 08:29 PM
congrats mr 4g63.* *O0* And congrats to you Naji!* Another X well done.*

I'll be calling you very soon to schedule a day.* *;)* Almost have my car leak free...*

Do X's like more boost than IX's?* Im noticing quite a few ppl running 26-27 lbs.* I didnt think I would see you tune above 24 psi.* *:roll:

Looney Tuning
04-16-2009, 08:59 PM
congrats mr 4g63. O0 And congrats to you Naji! Another X well done.

I'll be calling you very soon to schedule a day. ;) Almost have my car leak free...

Do X's like more boost than IX's? Im noticing quite a few ppl running 26-27 lbs. I didnt think I would see you tune above 24 psi. :roll:


Did you fix the whistling sound. I would check the accessories belt for that. That might be it, especially when the car is cold.

The stock car runs ~23 psi. So I run around 24-25 psi depending on the mods that the car has.

silvrEVOIXn818
04-16-2009, 09:03 PM
I thought I had fixed it...* But the whistle still lingers...* Fixed another huge leak, but not the pesky whistle. Workin on finding it.* Damn leaks/whistles!* :tickedoff:* I'll have them check the accessories belt when I can get back into the shop.

Mellon
05-14-2009, 05:06 AM
true I have my own car over 700awhp on the stock ecu/mas but this thread is about the X, nobody has pushed it that far YET ;)

alan678
05-14-2009, 08:11 AM
Hey NJ! You are producing some sweet ass gains from these X's! Congrats!



true I have my own car over 700awhp on the stock ecu/mas but this thread is about the X, nobody has pushed it that far YET ;)


Chris! Didnt think I would see you posting over here! 700awhp on the OEM ECU....gives me hope :D

Mellon
05-14-2009, 01:10 PM
Hey NJ! You are producing some sweet ass gains from these X's! Congrats!



true I have my own car over 700awhp on the stock ecu/mas but this thread is about the X, nobody has pushed it that far YET ;)



Chris! Didnt think I would see you posting over here! 700awhp on the OEM ECU....gives me hope :D


I know alain, it's been awhile hehe :) I ran completely out of fuel at 40psi on the HTA86, got a new fuel rail to go in and now the clutch is mad at me again lol.* I can't catch a break lately :) How is your car, haven't heard from you in ages bro.