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Old 03-01-2006, 02:13 PM   #1
chinoWRXL
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Default Dyno Results 2.5 sti sb, wrx heads, vf39

Mods are:

hybrid 2.5l sti shortblock, wrx heads
VF39
Pinkies
Sti Intercooler
Samco Turbo Inlet
Invidia equal length 4-2-1 header/upipe
Invidia Bellmouth down, divorced
Borla Hush catback

Results on a Dyno Dynamics Dynanometer:




Im am disappointed in the high end. Harv, the tuner, himself said he didn't get the numbers he'd expect from this setup. we had difficulty holding boost at 16psi. Even with an MBC we could get it to hold. The wastegate duty cycle is pretty much maxed out. In 5th gear at WOT I can hold 1.5 bar but i get a CEL. Wastegate Solenoid Range Code twice.

We believe that the Invidia headers may be drawing power up top (could be the flow charachterisitcs might only be beneficial at higher whp, like 350whp ish). Gonna throw the stock headers with my catless PDE up back on soon and get her back on the dyno.

Anyone ever seen anything like this? BTW I have been running through oil like crazy (1 qt a week) but not leaking oil and I am getting a good amount of blow by. Would the timing belt be off a degree or two do that? What about the factory boost control system? Could it have something to do with the oil/blow by? Headers? Those tiny smurfs that steal my socks?
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Old 03-01-2006, 02:53 PM   #2
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looks rich on the top end?

by a one theroy you should never ever be below 11.1
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Old 03-01-2006, 03:47 PM   #3
chinoWRXL
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Quote:
Originally Posted by Jaxx
looks rich on the top end?

by a one theroy you should never ever be below 11.1
r u suggesting that the rich mixture could be bogging down the top end.

I did forget to mention that Im at 6000 ft but am unclear about if that would indicate a need for lower AFR.
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Old 03-01-2006, 04:01 PM   #4
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that plus advance ..but no hadn't taken 6k feet in to affect

something odd is happening at 4700 to make that kind of fall off compaired to most other subaru dyno charts
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Old 03-01-2006, 04:20 PM   #5
chinoWRXL
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Quote:
Originally Posted by Jaxx
that plus advance ..but no hadn't taken 6k feet in to affect

something odd is happening at 4700 to make that kind of fall off compaired to most other subaru dyno charts
Notice how the boost dips down at . Do you think that Invidia headers are not allowing the turbo to spool well? Ever seen or heard anything like this?
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Old 03-01-2006, 05:10 PM   #6
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This needs to get moved to the proven power forum.

That does look odd though, something is up. Heres a dyno from a WRX with a 2.5 shortblock swap but with stock td04, intercooler, injectors, etc. (but with a tune and an uppipe):

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Old 03-01-2006, 05:19 PM   #7
Hurley 2.5 WRS
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are you the blue wrx widebody wagon with the pink flake in the paint running around?

that graph is interesting though, it really does loose too much up top
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Old 03-01-2006, 07:30 PM   #8
chinoWRXL
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Quote:
Originally Posted by Hurley 2.5 WRS
are you the blue wrx widebody wagon with the pink flake in the paint running around?
Yup. where in colo u at?

It is weird up top. There are a few theories and Im really hoping that its the headers or the stock boost control and not internal.

Kostamojen,

Its not proven power yet, more like scratching head mid range power... (feel free to move it). Thanks for the comparison charts. There does seem to be some similarities in shape of the torque curve but im still at a loss at why my HP drops off so hard.
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Old 03-01-2006, 07:56 PM   #9
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How do u like the dyno up at tarmac? I am thinking of getting my car dynoed there when I get my clutch and cat off. I am hoping for about 250whp on my set-up. Good to see a graph at altitude for me to go off of. Were you at the red rocks meet?
Thats a weird looking graph. Something has to be wrong up top. Good luck finding whats up w/ that.
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Old 03-01-2006, 11:30 PM   #10
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ChinoWRXL- Here's my observations on it...take it for what you will.

I don't think anything is particularly too far off.

-It's a dyno dynamics, that's pretty close for a tuned vf39
-You are at very high elevation.
-The STi SB with WRX heads is not an optimal combo. Pump gas/Elevation/Smallish TMIC is only compounding your issues.

Your boost issue is likely just due to the high elevation. A vf39 is certainly not suited for the high PR's you are running the turbo at to get the 16psi relative boost pressure your seeing. You could try a helper spring on the wastegate to see if that stops it from dropping off so hard.

Yes you may be able to lean it out a bit up top...but i don't think you'll see 'that' much gain. It may not be worth the trade off, try it and find out.

I don't think the headers are a problem, if anything they are helping you out on a vf39. You mention alot of blowby/consumption. (seems like alot to me) I'd do a compression test before i started swapping headers.

Yes you do drop off alot of torque...and the hp curve doesn't look terrific.

That's my 2 cents, take it for what you will. Wish you the best with the car, and good luck with it

Louis
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781-551-3399

Last edited by dentsport; 03-01-2006 at 11:37 PM.
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Old 03-01-2006, 11:50 PM   #11
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A compression test and a cylinder leak-down test as well. For what it's worth....my Sti SB with WRX heads and a VF22 put down 276whp/282wtq on a Mustand AWD dyno here in West Palm Beach, FL. Now, I know elevation is way off but here's the kicker......My boost will spike to 19psi and level off to about 15psi by redline. Oh, I've got Sti-Ra gears.

Jose
Japtrix.com
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Old 03-02-2006, 01:09 AM   #12
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get an ebc and yous should be able to hold better boost.
the dip in the tq is probably from a bit to much timing.
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Old 03-02-2006, 02:02 AM   #13
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Quote:
Originally Posted by chinoWRXL
Yup. where in colo u at?

It is weird up top. There are a few theories and Im really hoping that its the headers or the stock boost control and not internal.
im in fort collins right now, but i am from littleton.

who knows about the whole thing, it could be a combined mixture of all the theories here. best thing is to check them all
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Old 03-02-2006, 03:57 AM   #14
chinoWRXL
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Thanks for the replies and many very good points. One things for sure though, Even if it is a bit peaky, Its a lot funner to drive than before the swap!

Still exploring possibilities... Staring at the charts I feel that the massive dip in boost is a prime suspect, but it could be something. Im also curious about the CEL (wastegate solenoid range) at WOT on 1.4 bar (20 psi), could be hinting that it is the Factory boost solenoid wanting to pull back the boost.hmmm. but we got the same pattern after the MBC was put on. which makes me think its mechanical in the boost control system.
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Old 03-02-2006, 10:58 AM   #15
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Quote:
Originally Posted by Pacobeagle1
A compression test and a cylinder leak-down test as well. For what it's worth....my Sti SB with WRX heads and a VF22 put down 276whp/282wtq on a Mustand AWD dyno here in West Palm Beach, FL. Now, I know elevation is way off but here's the kicker......My boost will spike to 19psi and level off to about 15psi by redline. Oh, I've got Sti-Ra gears.

Jose
Japtrix.com
Apples and oranges. Your turbo is larger than his teeny little turbo...
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Old 03-02-2006, 11:03 AM   #16
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Quote:
Originally Posted by silvialost
get an ebc and yous should be able to hold better boost.
the dip in the tq is probably from a bit to much timing.
He's got an ECUtek reflash from a very good tuner. I know his tuner and know that he fought with this car for sometime to get it tuned to where it is. There is something funny going on with the car, and an EBC isn't going to fix it.

Also, to agree with Dentsport, this tune is really pretty close to the limit of what you can get out of a vf-39 up here. There is nothing particularly "bad" about the performance of the set up and the turbo size is the limitng factor of the equation.

Though the oil comsumption issue does raise some questions. Was this a new or "good used" shortblock? There could be ring land damage on that block if it is used, and you could be pissing oil into your combustion chamber and throwing everything off a bit. I have seen a number of folks with STi blocks drive around for literally months not realizing they had blown ring lands with the only symptom being oil consumption...
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Old 03-02-2006, 11:08 AM   #17
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i would have to disagree w/ you jaxx. the 11.1 thing is a just a number. someone might make good power at the AF, but some settups might run a little better w/ more/less fuel...this is where dyno time comes in handy
my .o2
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Old 03-02-2006, 11:11 AM   #18
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just for another comparison....i have a 2.5sb and wrx heads and i had a vf23 which is roughly the same size as the vf39 and put down 310whp and held around 20psi. this was on a dynojet at xotics motorsports
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Old 03-02-2006, 12:43 PM   #19
chinoWRXL
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Quote:
Originally Posted by Matt Monson
Though the oil comsumption issue does raise some questions. Was this a new or "good used" shortblock? There could be ring land damage on that block if it is used, and you could be pissing oil into your combustion chamber and throwing everything off a bit. I have seen a number of folks with STi blocks drive around for literally months not realizing they had blown ring lands with the only symptom being oil consumption...
It was a "good used" block. There was only one visual minor defect and that was some really small scratches on the cylinder wall #3. Something you could feel with your finger tip but not your finger nail, if thats a good explaination at all. Troy had cautioned of some potential blowby. Gonna get her compression tested soon, if #3 is way off the rest, then this theory could be teh best one yet. Thanks Matt.

Leo
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Old 03-02-2006, 12:51 PM   #20
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hmmm. Scratches on the cylinder wall of an STI block is usually a tell of a blown ringland. Sorry to be the bearer of bad news...
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Old 03-03-2006, 04:30 PM   #21
chinoWRXL
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Quote:
Originally Posted by Matt Monson
hmmm. Scratches on the cylinder wall of an STI block is usually a tell of a blown ringland. Sorry to be the bearer of bad news...
Any news is better than no news...I dont know too much bout engine internals, so this may be a newb ? but can ringlands be replaced without replacing the piston? I know the block will need to be dropped to get to it, but just curious if in need to buy new piston(s) and would the new ringlands "fill in" the scratches?

Leo
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Old 03-03-2006, 04:51 PM   #22
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Here's what a cracked ring land looks like on an STi piston. You do need to pull the piston and replace it. Regarding the scratches, it really depends on the depth. When Harvey popped his, he just got new pistons and rings and threw them in there. Most people will tell you the "proper" way to do it is to totally open up the case, measure, hone, and potentially bore it, if it's too deep. It really is a case by case sort of thing...
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Old 03-05-2006, 10:48 PM   #23
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Compression test results are:

#1 holds 145
#2 holds 95
#3 holds 142
#4 holds 130

argggg. I do believe that it has something partially to do with the scratches/piston ring land. Gonna get a leak down tommorow to confirm its in the cylinder and not the heads.

I did however get my inlet house to seat a lot better and also discovered my intercooler clamp to the throttle body was not tightened . My boost holds alot stronger and It doesnt dip as much so now i want to get her back on the dyno after i get this piston fixed.

As for the headers, seems they are not the culprit but i may switch back cuz i prefer the boxer rumble. Boost control seems not to blame as well. Just some details that got overlooked.
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