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Discussion Starter #1
Hi,
I have just fit stage3 ecu from maptun into my 9000cs2.0lpt(auto box) .

The boost reading is same as stage1 though. At the rev.~4000-5000rpm, the boost max at ~15-15.5psi. This is for both ecu since I tried swapping them a couple of time.(I still have the stage1 ecu with me) I thought the stage3 max boost should be more than that of the stage1's?
I have checked APC and wastegate actuator, both are working fine. The boost pressure rise smoothly and stay stable at max before taper off after 5000rpm+. Could it be the dump valve leaking? I still use standard one.

I have another question about boost spike. I used to get the boost spike when I first fit the stage1 ecu, but there is no boost spike now. The boost just rise to max until taper off just before red line. Is this normal?

Thanks in advance for any comment.

Cheers,
POM

remarks. I use 95octane gasoline. The temperature down here is normally 25-30+ degree celcius. I use forgemotorsport actuator. Basic boost is set at 0.49bar.
 

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I heared that the max boost doesn't differ that much thru the different stages. Only for the stages 1 thru 4 this max boost is available for a longer period of time in the higher stages.

erik
 

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Originally posted by pomlpt:
[qb]I use 95octane gasoline.[/qb][/b]
Is that 95 RON? If so, I would think that might be limiting your boost. My Stage 3 9000 Aero only gives full boost on fuel over 97 RON. It might be worth trying a higher octane. Do an adaptation run after filling up and see if the maximum boost pressure has increased by the time you have used a tankful of higher octane fuel.
 

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Discussion Starter #4
95octane is the highest available here.

I still wonder if the 15.5psi for stage3 is max already or there is something wrong with my car because boost patterns for stage1 and stage3 are identical.
The stage3 is more
. Probably I should stop looking at the boost guage.

Cheers,
POM
 

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As my car was custom programmed, I can say that my max boost changed a bit from stage 1 to stage 3 but not by much. My stage 1 was 13 psi max dropping to about 11 at 5500. Now, my new programming peaks at 17 psi and drops to about 14 around 5500 rpm. I can see though, how max boost may be the same for some tuners from stage 1 to 3 with boost staying higher longer and coresponding changes in timing and fuel delivery. This would still give plenty of more power. Also, consider that you want more flow at high rpms to make power and more boost with a small turbo will sometimes make flow worse. As the rpms build, if the backpressure in the exhaust manifold gets higher than the boost pressure, the cylinders may start to backfill and power will start to suffer. I think your ECU is probably fine if you are getting more power just by the feel of it. Have fun!
 
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