Spool, boost, and power comparisons with a 20g setup.

I thought I’d share some data I have from my build. I generally replace one part at a time, so I can see what affect it has on performance. I have graphs that compare my setup with/without stock mufflers, with/without intake, and with/without a turbo inlet. No serious tuning was done, except in the case of the intake. I had to rescale the MAF so as not to ruin my engine.

 

I like to use boost, Airboy dyno, 50-80, and 60-80 times to gauge whether or not there was a difference from a part. I use the same stretch of road in the same direction and always use 3rd gear. I do pulls with 3/4 to 1/4 tank of gas. My car weighs 3740 with me and 3/4 tank of gas.

 

Altitude is 4200’.

 

All graphs are compared with the previous set of graphs unless noted otherwise. All acceleration times are calulated subracting the first instance of the low speed from the first instance of the high speed in the datalog. I don't use the Airboy numbers because they change depending on how much smoothing you use.

 

Baseline graphs and setup:

 

Stock intake

Stock inlet

AVO TMIC

Turbosmart BPV

Kinugawa TD06H-20g

Kamak EL header and UP

Invidia catless dowpipe

Invidia Q300

Hallman MBC

Meth injection

DW 750s and DW65c

Romraider/ECUFlash for tuning

 

Intake temp: 72

 

50-80: 3.097

60-80: 2.033

 

On this pull boost comes up slow and drops off quite a bit. I was a bit disappointed and knew there had to be a restriction somewhere. http://i1231.photobucket.com/albums/ee505/bkatter/1boost.jpghttp://i1231.photobucket.com/albums/ee505/bkatter/1dyno.jpg

 

 

Cobb SF intake and airbox:

So, I replaced the factory airbox with a Cobb SF intake and airbox.

 

Here’s the first full WOT pull with the intake. I made a couple partial pulls before this to get the MAF scaling close enough to do a full pull. I made no changes to the MBC.

 

Intake temp: 82

 

50-80: 2.981

60-80: 1.927

 

50-80 difference: -0.116

60-80 difference: -0.106

http://i1231.photobucket.com/albums/ee505/bkatter/2boost.jpghttp://i1231.photobucket.com/albums/ee505/bkatter/2dyno.jpg

 

Perrin inlet:

Since I noticed a bit of a gain from the intake I thought I’d also try an inlet. This part didn’t really require any MAF scaling. There were a few changes, but nothing major. This pull was the final pull. I turned boost up to 24 psi. Notice how much better boost holds to redline. Spoolup is better too.

 

Intake temp: 75

 

50-80: 2.851

60-80: 1.915

 

50-80 difference: -0.13

60-80 difference: -0.012

http://i1231.photobucket.com/albums/ee505/bkatter/3boost.jpghttp://i1231.photobucket.com/albums/ee505/bkatter/3dyno.jpg

 

Stock mufflers:

So, the Invidia catback was too loud. My neighbors didn’t appreciate it when I was starting my car at 6 am. I installed the stock mufflers with a TurboXS mid y. No change to MBC on this pull. Huge restriction. Spoolup is horrible.

 

Intake temp: 86

 

50-80: 3.124

60-80: 1.992

 

50-80 difference: +0.273

60-80 difference: +0.077

http://i1231.photobucket.com/albums/ee505/bkatter/4boost.jpghttp://i1231.photobucket.com/albums/ee505/bkatter/4dyno.jpg

 

Cutout:

So I can’t be losing that much power to the stock mufflers. The solution was to install an electric cutout in the downpipe. I turned the boost up a bit. The MAP sensor is maxed out. My gauge was somewhere around 25 psi. This turbo holds boost nicely now. The clutch was slipping on this pull, so I don’t know how accurate the Airboy numbers are. The 60-80 was faster though. These graphs are compared to the Invidia Q300 graphs, not the stock muffler graphs.

 

Intake temp: 81

 

50-80: 2.938

60-80: 1.904

 

50-80 difference: +0.087

60-80 difference: -0.011

http://i1231.photobucket.com/albums/ee505/bkatter/5boost.jpghttp://i1231.photobucket.com/albums/ee505/bkatter/5dyno.jpg

 

Here’s a comparison of the first graph and the cutout graph:

 

50-80 difference: -0.159

60-80 difference: -0.129

http://i1231.photobucket.com/albums/ee505/bkatter/6boost.jpghttp://i1231.photobucket.com/albums/ee505/bkatter/6dyno.jpg

 

The cutout graph is where I’m at now. I can’t do much more tuning because the clutch slips in any gear above 2nd. Once I get a new clutch I’m going to make some adjustments to boost and timing to see if I can get a bit more power and then get it to the track before the season is over.

Are you sure you want to run that high of boost? 25 lbs is a lot!

About what I thought.

 

25 is within the compressor maps I have seen, I run 22 but im very conservative.

 

I wonder if the TMIC is holding you back now.

Wow, awesome comparison! It would be interesting to see the differences without the changes in boost, but I understand why you stepped it up gradually.

While dialing in boost I've seen as high as 27 psi in 4th gear

 

Boost isn't finalized yet. I need a clutch so I can do a good pull at 25 psi. It may be too much and I might end up at 23 or 24. But from what I've seen the car is still faster at 25. It didn't start blowing the clutch away until I turned it up to 25.

 

A FMIC is definitely in the plans. I'll do a before and after of that but intake temps might be significantly colder when I do it. One thing I'm excited for is not having to drive around to get the heat out of it before a pull after having stopped to tune.

 

Clutch is hopefully going in tomorrow.

You aren't getting knock running a TMIC on 93 octane with 25+ PSI?

I'm using meth injection.

Very interesting post. I have a very similar setup running a TMIC and Kinugawa 20G. I am using the TD05 instead of the TD06, but my spool and power curves are much different. I know you are are at 4K elevation vs mine at sealevel, but I am hitting 20psi by 3500 in 3rd gear and I would think you would reach 20psi around 4000 rpm's. Power wise you are making around 90HP more which is probally a factor of more boost up top and meth injection.

 

How much timing are you running at the top? Can you please post a log from your 3rd gear pull?

Here's a datalog from this morning.

romraiderlog_20130909_065157.csv

Does this have the billet wheel? Spool seems a little slow as it is about 800 later than my TD05. Regardless you are definitely making a lot of power. You are flowing about 10% more than my mine and since you are running a lot higher timing (I peak around 18 degrees) you are making far more power.

Spool is normal for all the 6 speed td06h 20g dyno graphs I've seen. I found quite a few over on IWSTI and in 4th gear they reach around 20 psi at 4k with peak torque around 4500. Mine does the exact same in 4th gear. I'm at 20 psi by 3900. 25 psi by 4200.

 

Here's a graph comparing 3rd and 4th.

http://i1231.photobucket.com/albums/ee505/bkatter/8.jpg

Excellent post and data. Almost exactly how I tune mine in regards to the 60-80, air boy dyno and etc. I'm finding the stock exhaust data extremely interesting. I really need to do something about my OEM catback.

Didn't see you are a spec B. You hit 20psi by 4K, so I think you are doing good for this size turbo.

 

This is some great info. I am also running the stock catback. Looks like I am going to have to find something which isn't as restrictive.

Nice set up. Where in SLC are you? Did a tune on an STI with a similar cut out for the same reason.

I live in Midvale.

I live in Midvale.

 

Cool. I'm just a bit north in Millcreek.

 

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How do you like the 5th gen? I sort of wish I had one. The bottom mount turbo is how Subaru should have done it since day one.

 

Also, I've got a front mount coming. I'll get some before and after graphs up when it gets here.

I dig it. Feels a bit bigger than my 4th gen lgt, but I really like the extra space in the back and trunk (though not as pretty either). The low mounted, no up pipe turbo placement is awesome. No where near the heat soak and lower IAT, in general. Stage 1 pulls pretty well and it can actually boost over 17psi with just tuning, although, because of the rest of the components being stock and our altitude, it falls pretty hard after 5,000rpm.

 

Interested to see your results after putting the fmic in.

it falls pretty hard after 5,000rpm.

 

Some of that is OEM TMIC, most is OEM Turbo. I know a fix for both issues.

Some of that is OEM TMIC, most is OEM Turbo. I know a fix for both issues.

 

One thing I can't fix is altitude. Makes a difference. But if you want to send me the $, I'd be more than happy to fix it

 

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When you say stock exhaust, is it stock from the downpipe back, or just mufflers. Forum knowledge is that the mid/Y is the choke point, not the mufflers. I'm looking for data to prove it one way or another.

He said just mufflers. TurboXS mid and y

 

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Yup, it very clearly says that. -1 for me for not reading.

Eh, no worries.

 

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