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Old 05-26-2004, 03:36 PM   #1
volkl23
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Default STi Accessport Dyno results! What do you guys think?

Here are the dyno results of the STi Accessport that's set to be released on June 7th.

Here is a stock STi with just accessport



Here is their Stage 2 setup which entails a TBE + accessport

?

This is what Trey had to say about the results:

Quote:
A few notes regarding the results. On our dyno, a stock STI makes between 235HP and 240HP to the wheels. One major limitation we have to deal with here in Salt Lake City is the 4500 feet above sea level altitude. While this isn’t as big of an issue on a turbo car as it is with a naturally aspirated car, it can still have an effect when you’re dealing with a turbocharger that struggles to provide the necessary air flow at higher RPMs – such as the case with the stock VF39 used on the STI.

Unlike our friends at sea level, we are unable to carry boost very well above 5000 RPM at this altitude. That obviously greatly limits power production at the higher RPMs. At lower RPMs, total air flow is obviously a lot less so we’re able to get the little VF39 to spool up better and thus make pretty good low to mid-range torque. At sea level, this torque would carry further up the RPM band and thus we’d have a higher HP figure.

Our boost curve brings the onset of boost on at a lower RPM to a mid-range peak of 16.5psi that gradually tapers to 12psi by redline. Again, due to altitude, 12 psi at redline is all we can get…period. For you sea level folks, we’ve actually targeted a slightly higher than stock 14.5psi by redline which nets us some additional safe gains.

Another point is that the STI was not detuned from the factory to the same extent as the WRX. In fact, the factory fuel curve is actually more aggressive in nature than our own WRX Stage 1 fuel curve! We spent a good deal of time smoothing things out with the fuel delivery but simply leaning it out isn’t going to produce any gains worth the extra risk and wear-n-tear on the motor. On our dyno, we tuned with an A/F curve that settled in at 11.4:1 on boost and gradually tapered to 11.0:1 by redline.

A lot of work was done to smooth out the overall driving experience. The STI is already a pretty nice car to drive, we just attempted to smooth out some of the rough edges. The maps will be continuously refined. I’m pleased with the mapping as it is now, but not 100% satisfied. And yes, we’re starting off conservative. I already have plenty of STI motors sent to us for rebuilds from owners that have gone down other routes and I don’t need AccessPORT owners contributing to that statistic.

We’ve also been having an independent shop at sea level testing our maps on their dyno so we’ll have sea level dyno results to post shortly. Until then, you all get to see how the rest of us live up here with 4500 ft and 91 octane.

Cheers,
Trey @ COBB Tuning




Overall impressions:

For the stage 1 Kit (just accessport), the gains are not as much as I was expecting (compared to UTEC). An increase of 16.6 HP while TQ is pushed up at 33.7 @ 3800RPM.

Stage 2 seems a little low as well.

I was planning to get the accessport for my stock STi with the assumption that I would get 20-25HP out of the box. How much can I expect to notice with 16-17 of HP increase? Not much?

What does everyone think?
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Last edited by volkl23; 05-26-2004 at 05:45 PM.
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Old 05-26-2004, 07:30 PM   #2
Jimbo
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I don't know the elevation in St Louis, but I'm going to assume you are a good deal lower than 4500 feet. Combine that with what Trey says about more power up top at sea level, and you could probably count on at least +20whp which you will notice.
What you will really notice is the big bump in low end torque. That alone should make the car seem much quicker. It will be interesting to see the sea level dyno.

Jimbo
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Old 05-26-2004, 07:43 PM   #3
doNOTtell
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I"m on the pre-order list and was a little disappointed too. I was hoping for 40+lbs of torque on stage1. Oh well I'm not going to complain as the numbers are not final and they are not corrected. It's still making a nice amount of torque and doing so alot earlier than stock. I'm at sea-level on 93 octane, so according to Cobb's post I should see a little more power. They've got another week of tuning and tweaking since the release date was pushed a little furthor out. That's probably the most disappointing thing. Whatever the case the accessport is still $400 cheaper than competitors and the potential to receive it in 2 weeks is enough to keep me on the list.
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Old 05-26-2004, 08:53 PM   #4
volkl23
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I think I'm still going to get the AP when it does come out as I'm still a neophyte when it comes to engine tuning. How did you get on the preorder list?
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Old 05-26-2004, 09:01 PM   #5
doNOTtell
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Quote:
Originally posted by volkl23
I think I'm still going to get the AP when it does come out as I'm still a neophyte when it comes to engine tuning. How did you get on the preorder list?
Hit up the Vendors on Cobbs Site. I think all the pre-orders had to be in a long time ago, but perhaps there are a couple of vendors that have ordered extras. I ordered mine from Forced Induction because they are here in Texas.
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Old 05-27-2004, 01:30 AM   #6
volkl23
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thanks tell,

I wish they had a vendor here in Misourri! Oh well, I guess I'll wait when it's released to the general public on the 7th.
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Old 05-27-2004, 09:01 AM   #7
t00h0t
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There are many things to look at here... Cobb's results were on 91 octane (I know some people are stuck with that, I'm not :-P ), 4500 feet above sea level, AND 16psi of boost!

Most of the UTEC #'s were on 93, sea level, and up to 19psi.

I'd say Cobb has plenty of room to increase....
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Old 05-27-2004, 09:38 AM   #8
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looks like we going to wait even longer for the access ports to ship

http://www.wrxforum.com/cgi-bin/ulti...;f=11;t=000429
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Old 05-27-2004, 10:28 AM   #9
TreyS
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sigh
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Old 05-27-2004, 01:58 PM   #10
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you know ive been talking to trey in regards to the sti ap, well he told me himself that the usdm sti is very very well tuned, and just like stated aggressive moreso then the wrx was in its factory USDM states.

a lot of tuning was done factory side to the usdm sti, and didnt leave a lot of room to play with as the wrx cars. i wouldnt rule out cobb just yet, esp since they are known to tune at a relative conservative rate.

the stage 2 maybe the route most sti owners may want to consider since it is much more of a dramatic difference in power, and wow, for the street thats almost cutting it. thhere are many other tuners out there who can tune to the state of almost going broke, and there are choices available if people dont want to got he cobb route, but honestly its teh safeset route unless people have contingency plans if their motors blow.

i myself is running the Cobb Stage 2 on my WRX, and i love it! plans on the way to upgrade to the VF34 map... so we'll see...

-Eiji
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Old 05-29-2004, 03:16 PM   #11
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I'm still going with AP. I'd rather err on the side of "conservativeness" rather than long term motor problems and damage. Besides, it's still an upgrade! I'm not interested in squeezing every drop from the car.
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Old 05-30-2004, 01:29 AM   #12
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Well said. Look what happened to Mazduhhhhh. They overrated their HP and got you know what. Their REPUTATION is gone. Being conservative like Cobb. . .could be a good thing. I certainly wouldnt complain if I made more HP / Torque then he advertises. Would you? Numbers are for bragging rights. Face it we drive our cars daily. . .drivability is the key.
I agree with others which like the fact that it is an safe,reliable upgrade. Its smoother and more responsive from what I read. . .My STI AP is on order. The STi is pretty MAXED out from the factory. . .so to get another 20-25 more HP out of it while still meeting emissions (Cal & NY) and make it for $650.00 is AWESOME. <Stage 1>
ADR
ps: I would rather have a $650.00 AP then a $700.00 factory radio. . .how much HP did that add? just weight. . how do you like those apples?

Last edited by ADR 04STi; 05-30-2004 at 10:53 PM.
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Old 05-31-2004, 02:29 PM   #13
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Quote:
Originally posted by ADR 04STi
ps: I would rather have a $650.00 AP then a $700.00 factory radio. . .how much HP did that add? just weight. . how do you like those apples?
I like those apples just fine. I'll have both.
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Old 05-31-2004, 06:43 PM   #14
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Thats funny :~)
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