The 3-port is by far the best bang for the buck mod I've seen. I just installed mine this weekend and holy **** did it make a difference! I'm spiking about 23 psi and holding 21 at redline. I still have a little more tuning to do with the boost response, if I floor it at 2k rpm in 6th, it'll spike to about 27 (with only 2 counts of knock the one time I did it, oddly enough), then the WGDC correction will go way negative and it'll sit at around 13 psi until I let off the throttle. Other than that, it works beautifully.

The difference in power is unreal. Saturday night, I took off somewhat hard to make a left turn onto a road and ended up almost spinning the car. Before this mod I could have kept my foot in it the whole way with no problems. After the mod, lots of countersteer...

I'm seeing some odd stuff though. I installed my wideband and DP last weekend and just started playing with it this weekend. As I mentioned in the E10 thread, I'm running 93 octane E10. My wideband was showing AFR's about 1 point above where you want to be (13.5 on spoolup, tapering down to 12ish at redline). No knock. I've only pulled about 2 degrees of timing from the stock map. Anyway, I richened up the mixture a little bit, but I need to do a lot more logging to get everything really dialed in. That and schedule some dyno time.

 

What sort of EGTs are the result of all this boost and (presumably) retarded timing? Things must be getting silly hot on 91oct...

 

True, depends what the drivers intent is and how crazy he went with the timing. If its a tune for 1/4 mile, track courses or long highway type runs it will depend on whats considered a safe tune I guess.

If its an overall average tune, you gotta tune for the worst case scenario. I'm a 1/4 mile guy so my tune is set to reach about 1600*F (and not exceed) as I cross the finish line. I know my tune is this way so I wouldn't ever do some highway run against a guy for a good mile straight. I have map switching now so I can switch between my 1/4 mile tune and a SAFE tune witht he flip of a switch on the fly...gotta love that.

 

good question, I'd like to know too?

 

I posted something about this earlier this month on here but now I can't find it so I guess I will retype some of it.

Obviously, alot of evos that come on our dyno do not have EGT gauges. But the ones that do I always test things like this. I've found that as long as you have a 8* advancement or so from peak torque to redline that the EGT's seem to stay in check. Again this car is put together well as far as flow. The ported bits help a TON with the abililty to run this kind of boost without problems. The more efficient you make the car the easier it is for the motor to make power.

Here is the timing map for this car, it's pretty close to what I run on most 91 oct Evos here.



Normal load-target boost control, not psi-target like mrfreds.

The wastegate solenoid map is when the solenoid "turns off", with the GM 3 port, since most likely you are using less than 100% wgdc up top, you need to raise the "turn off" point higher than you rev or the WGDC will jump to 100% at around 7k.

Try setting your WGDC lower in the lower RPM to combat this. Also use a smaller number for WGDC correction update and also make sure you have *some* additive error correction or it will indeed do what you are seeing, correct for overboost but then never correct it back up to target.

 

I tried that. The problem is, it made the boost spike worse. In higher gears where RPM was climbing slowly, the boost control would "wind up" during spool and the WGDC correction would go up to 10 and sit there. Then it would overboost and overcorrect back to -18 or whatever the minimum is and then slowly climb back to target. I kind of like having it default to 13 psi when it overboosts. It's good feedback to let me know, "Hey, idiot, something's wrong!"

Right now my boost targets are 22.5 psi across the board until I start tapering off at 3500 RPM. WGDC is 65% from 1k-4k rpm. So would lowering the target in the 2k RPM block to around 19 psi and setting the WGDC to match that would give me a 'soft start' in higher gears without affecting spool in 1st and 2nd?

 

Well you aren't going to get full boost at 2000rpm so don't have your load target as high as full boost at 2000rpm. Make sense? Take a look at the error correction and BDEL table I posted in this thread.

 

Thanks, I'll give that a shot.

That looks almost exactly like my 22 psi WGDC table.

 

No, that's me...but I only made 333.3whp on 91.

However, the most boost I ran was 21psi @ peak because I had some phantom knock issues going on. Hopefully I have dealt with most of them



-Erik

 

Stock car thought, so the turbo has to work harder to overcome the exhaust back pressure...

i guess

 

I'm still not a big fan of the open element air filters in a hot engine bay. I know they show more power on the dyno but it seems dangerous in real life. I found I could get more boost out of the car up top with the conical filter but the car runs better on the street with the stock box. What is your take on it?

I'm interested in the difference in power that car would see running 20psi with more timing instead of 22psi and less timing up top.

I'm not sure what kind of temp changes you get out there on the west coast but my car barely holds 20psi at 7k in the summer but this time of year it will easily hold 22. I'm using WDC only for boost control and since I'm on 100 octane 24/7 I don't really care where it spikes. Same day pump to race gas tuning sessions indicate almost all of the additional power above 5k comes from increased timing. Running it harder (more boost) doesn't really increase airflow or power.

 

Mine's just got a downpipe. I'm surprised it makes that much difference, especially since the exhaust goes back to 2.5" at the cat (test pipe is not currently installed).

 

stupid question there: I am assuming your load offset is 200. Am i right?

Also I do not see the activation/deactivation RPM's for my rom (88840016).

Are there addresses documented? Do I really need them?

Thanks.

 

Me either.

 

I just ran into the same issue. I've got the four activation/deactivation variables defined in four boxes, and three of them don't have any data in them to edit. Here's the definitions (88590015 ROM):

<table name="Wastegate Solenoid Activation RPM-Active" address="1668"/>

<table name="Wastegate Solenoid Activation RPM-De-activate" address="166a"/>

<table name="Wastegate Solenoid De-activation RPM-De-activate" address="166c"/>

<table name="Wastegate Solenoid De-activation RPM-Re-activate" address="166e"/>