View Single Post
Old 08-24-2010, 02:00 AM   #43
Maxwell Power
Former Vendor
Member#: 190729
Join Date: Oct 2008
Chapter/Region: NWIC
Location: Marysville, WA

I was honestly a little surprised by the lack of spool. I played with the AVCS quite a bit and it didn't yield much for gains in spool. Not sure why...

we have a few things to work on still with the tune, so I'll probably be giving the tune another shot pretty soon to see if I can lean it out a bit during spool and knock it down a few hundred rpm. I wonder if the 90 right off the turbo is affecting the performance much.

Interesting thing though, my 2.3L gets full boost by 4850rpm on a standard 35R .82 hotside. Mine has a small exhaust cam that really helps get the turbo spinning, but chokes out the top end. The CNC porting in my heads helps a bit too. You can see the power curve on this has practically no choke at all. I had really anticipated that the turbo would come in a lot sooner. I do need another 35R for my other car, so maybe I could buy this turbo from the OP and convince him to switch to a BW.

Regarding 3rd gear. This is an 07 so 3rd isn't as short as other sti 6mt's. I tune in 4th on the 07's as well. I use as many gears as possible to ensure the tune is ideal. I'll have to see if I have a graph from that on my dyno computer. One thing to think about though, if I published a graph of 4th gear, it wouldn't represent what the car does on the road. [disclaimer] With 07's, you have to be hauling ass to actually use 4th (>85mph) and it wouldn't/shouldn't happen on public roads. [/disclaimer]

As far as RPM is concerned: we blueprint our motors at MPS and perform a few mods to the oiling system. This car held over 85psi at 8500rpm. Looking back I should have shimmed the pump a little- in addition to the porting/polishing/deburring- to bump the pressure to 95psi (85 is the relief setpoint of this pump). This engine also has longer rods which help the engine maintain reliability at higher rpm.

Head work: When we put the +1mm valves in the head, we enlarged and radiused the valve seats. I did a little bit of cleaning up on the bowls as well to help the airflow.

anyway, we'll be at this car some more to see what we can squeeze out of it.
* Registered users of the site do not see these ads.
Maxwell Power is offline   Reply With Quote