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Old 04-23-2010, 05:19 AM   #1
Simes
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Member#: 138641
Join Date: Jan 2007
Chapter/Region: International
Location: Melbourne, Australia
Vehicle:
2002 STi w/'07 body
Black

Default Not too happy with my ATP 35R

..........compared to my old FP-Red.


Specs:

2.4 litre stroker (2.2 block, 2.5 crank, CNC overbore pistons, Eagle Rods)
Kelford 264 cams
ATP 35R (stock location, IWG)
GT-Spec UEL headers, derestricted
3" TBE, Catless
AVCS STi heads, CNC ported with Supertech 1mm OS valves
Decapped STi pink injectors
Hyperflow Monster FMIC and CAI
Tuned on 98RON pump fuel. FP Red was tuned with the 264's, but the heads were NOT CNC ported at that time.

So, I had the car tuned last Friday (red plot 381hp atw). We set the car up to run a little less timing and less boost, so that's why the power is down a little from before (the 296.6kw/397.6hp atw tune).

Just a note on the difference between the 381hp and 397hp tunes: on the 397hp tune the EBC was incorrectly set by the tuner to open at only 14psi. That was corrected for the latest tune. Because of this, the new 381hp atw tune has given me a heap more midrange than the 397hp tune which is great, but what's really odd is that this plot shows my old FP-Red 8cm to be making more power earlier than either. I think this could have something to do with the smaller ports on my original heads having faster velocity than the ports on my new CNC heads, but I am not sure?

I don't understand why my car hasn't made significantly more power than before, especially given that I have a larger and more efficient Hyperflow Monster FMIC, better EBC (as opposed to my old AVCR), CNC heads with 1mm bigger valves and a 35R???? Am running a Romraider tune.....Is the stock ECU holding me back?

By the looks of things, I kinda didn't need to spend the money on the heads ($3300). In my situation, it appears they haven't appeared to have done much except smooth out the airflow a little up top. Maybe if I was running C16 on the track (or maybe water/meth) I would see a benefit, but for a car tuned on pump fuel, it doesn't appear so. Am I wrong?

Yes, my car is making more power up top with the 35R, but the FP-Red might have done the same if it too had been tuned with the CNC heads? Why is the FP making boost earlier given that it is a sleeve bearing turbo and they are supposed to spool slower than a ball bearing turbo?

Any ideas on how to extract more powerfrom my setup? I'm keeping the 35R however.

Perhaps the dyno plot isn't everything? In summation, the car hauls ass, and what's funny is that it feels faster and more torquey than the FP-Red. It's also a tough dyno that it was tuned on, but the power hasn't increased even though I have better/superior bits now. And I don't know why.

Depressed. Kinda over my car at the moment. I have spent so much money and I don't seem to have much 'more' to show for it. It's got all the good bits too......apart from the ECU, I don't think there is anything 'better' that I could put in it now.

What to do?

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Last edited by Simes; 04-23-2010 at 05:32 AM.
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Old 04-23-2010, 05:29 AM   #2
Pavlo
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It's pretty simple, you need to use more boost.

You've gained quite well you're making more power with less boost, but you can't work miracles and expect another 100whp at the same boost with a moderately different turbo. To get 500whp I would expect to have to run about 280-30psi.
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Old 04-23-2010, 05:39 AM   #3
sjobing
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2003 Impreza HTS
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What is your exhaust backpressure?

Have you set your camtiming properly with adjustable cam gears?
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Old 04-23-2010, 06:49 AM   #4
Simes
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Black

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Quote:
Originally Posted by sjobing View Post
What is your exhaust backpressure?

Have you set your camtiming properly with adjustable cam gears?
Not sure on the exhaust backpressure. I'm running ceramic coated and wrapped GT Spec headers that have had the restrictor removed from the uppipe. I have ported the exhaust inlet on the turbo to match the uppipe, and I am running an AVO 3" mandrel bent TBE with a cast dump and without a cat.

Stock cam gears. Do adjustable cam gears make a big difference?
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Old 04-23-2010, 06:52 AM   #5
Simes
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2002 STi w/'07 body
Black

Default

Quote:
Originally Posted by Pavlo View Post
It's pretty simple, you need to use more boost.

You've gained quite well you're making more power with less boost, but you can't work miracles and expect another 100whp at the same boost with a moderately different turbo. To get 500whp I would expect to have to run about 280-30psi.
Thanks......although I am at the limit right now on pump fuel before I we're seeing the beginnings of detonation. Interestingly, the FP Red was tuned on the same brand of pump fuel and we got more boost without knock.

I guess water/meth is in my future? Have heard the ATP35R doesn't really come alive until past 24psi. Perhaps there is some truth to that?

Cheers,
Sime
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Old 04-23-2010, 12:17 PM   #6
modaddict
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Location: Pasco, WA
Vehicle:
sold to a good bud
awaiting next car

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The fp red has the same compressor wheel as the atp35r, right?

So you changed very little between the turbo's?

Your head velocity is most certainly lower.
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Old 04-23-2010, 01:11 PM   #7
Danomite
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i've heard that porting your heads for the most part moves the powerband overto the right.
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Old 04-23-2010, 03:40 PM   #8
DuckStu
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Doesn't the ATP turbo use a very old and small compressor cover to try to squeeze it into the stock location? I.E. ,... isn't your 384 hp about what they do normally?


Here's a link to the ATP's own website, where their advertising department displays this dyno-graph for that turbo on pump gas.
Not including spikes,..it looks to have made 390 hp / 365 tq on a Dynojet with full spool by 4,300 rpm,...which might be what??? 360 / 335 on a Mustang? (Not meaning to start a dyno argument.)


By that standard,...your 384 or 391 is really good.

http://www.atpturbo.com/root/release...I_35R_pump.jpg

Last edited by DuckStu; 04-23-2010 at 03:47 PM.
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Old 04-23-2010, 06:20 PM   #9
Danomite
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Quote:
Originally Posted by DuckStu View Post
Doesn't the ATP turbo use a very old and small compressor cover to try to squeeze it into the stock location? I.E. ,... isn't your 384 hp about what they do normally?


Here's a link to the ATP's own website, where their advertising department displays this dyno-graph for that turbo on pump gas.
Not including spikes,..it looks to have made 390 hp / 365 tq on a Dynojet with full spool by 4,300 rpm,...which might be what??? 360 / 335 on a Mustang? (Not meaning to start a dyno argument.)


By that standard,...your 384 or 391 is really good.

http://www.atpturbo.com/root/release...I_35R_pump.jpg
it is about average. but his fp red should spool sooner due to the smaller 8cm hotside also.
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