About what I expected. Spools up decently, but that tiny little turbo is running out of steam at the top end. Even though IAT was still decent, going from ~12.5 PSI to ~14.5 PSI yielded smaller returns than expected, which says to me that turbine backpressure is probably the limiting factor here.

Spark advance was in the 18-20° range here. (This is with WI @ 5 GPH.) I saw a little knock at about 5,000 RPM when I got up to 23°.

Leaning out the mixture gave large gains in the midrange from where we started. On the first run, I was down in the mid 11s the whole way. Bringing that up into the mid 12s was beneficial, and I could probably still stand to lean out that dip around 5,000.

All in all, not too bad for a Greddy. Putting aside that little burble at ~7,000 RPM it put down an honest 205 HP and 202 ft/lbs.

 

What size are the charge pipes/exhaust piping?

 

I like the nice, flat boost plot once target boost is reached with no tapering towards redline.

 

Inlet pipe is 2.5" from air filter to compressor (no MAF/VAF), 2" at compressor outlet, 2" to 2.25" coupler at the downturn behind the radiator, 2.25" to 2.5" coupler at the bend around the radiator, then 2.5" through the IC and into the throttle body.

Exhaust is a TurboTony downpipe (non-seperated) and the whole system is 2.5" from the turbine to the tailpipe, with a ceramic-core cat. Manifold is stock Greddy.

So basically, I don't see any room for improvement there, short of removing the cat. I think we're just looking at what happens when you have a small turbine putting a lot of exhaust backpressure on the head.


That's mostly a function of where you take your boost reference signal from. A lot of folks use the little nipple on the compressor, so you see a tapering off due to the pressure drop across the intercooler as airflow increases with RPM.

The fix is very simple. Just install a nipple in the piping after the intercooler, and feed your boost controller with that. Presto-chango, nice flat boost curve.

 

Hmm, haven't we seen better numbers from greddy setups before? not being a dick, just curious where the improvements are there versus here

 

Didn't Ben get 250 from his?
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Very solid and smooth. Looks like a very street friendly powerband. nice jerb

 

not only that, but kotos sig indicates he is as well

 

judging by the spool speed, im going to suggest teh 2.5" exhaust is hurting you.

 

this, also. looks a lot like how mine FELT when it was still running. :-) wish i had gotten mine on the dyno...

 

Were you running water/meth or straight water? I also would have thought slightly higher numbers, but Brain may be right with the 2.5" exhaust since you have a cat. When the shop finishes my motor, I guess I'll find out. I plan to run 15psi with water/meth, BEGI downpipe and 3" exhaust with no cat. They haven't even had a chance to look at my pile of parts yet, so who knows when that'll be...

 

That was on 93 pump and a little more boost (15 tapering to 13). I was also running EBC. Best MBC pull is the dotted trace.

 

That's a pretty nice plot, Ben. What ignition advance were you running up there?

I am running 91 octane SoCal gas, which isn't exactly the happiest combustible liquid around. Even with WI, I was definitely running into the knock limit. And I imagine that pulling the cat (or at least replacing it with a metal-core) would help things a lot.

TrickerZ, straight water.

 

Maybe it's just me, but it seems like you are injecting a lot of water. What made you decide on the 5gph nozzle?

 

91oct needs LOTS of help to keep from detonating.

They don't call it camel **** for nothing

 

I doubt the difference between 91 california camel **** and 92 octane seattle hobo **** is that drastic.

 

 

How does this compare to yours Joe?

General disclaimers: This was on my car for a couple of years. I assume it's still on the car, but I haven't heard from the new owner in more than a year.
It is a very aggressive table, created from many hours on the dyno. I post it for reference only and in no way advise anyone to copy it. If you simply slap my table into your ECU, you may possibly destroy your motor. I would suggest the MSPNP basemap's ignition table as a better starting point.

 

Wow, I never knew the difference between MBC and EBC was so huge.

Any idea how much timing has to be pulled to run 91oct from 94oct?

 

I don't doubt it at all. Granted Seattle is relatively liberal, but the difference between CA91 and TX93 is about like the difference between Old Rasputin Imperial Stout and wine with a screw-top from an engine perspective. My guess is that Seattle 92 is the equivalent of say Amber Bock. Its not getting passed around at the Waldorf, but it isn't brewed under an overpass by the I-5 either.