sk8007 said:
So are you using the stock valve locks/retainers? i know earlier you said it was the eibach springs, do you have the specs on the cams? were they sent to crower for there regrinding process? What size exhaust are you running? were the pulls done in 4th gear or 3rd? was this on pump gas?(91 or 93) and What was the a/r ratio around for the dyno?(12.5:1 or around 13.0:1) What was the overall spark advance around? sorry for all the questions but i am trying to get some more knowledge for the future...
The headwork was done by some engineers at penn state for me...just some friends, but guys with more engine building experience than I had...I built the bottem end myself, they did the head...
the cams were just uncut blanks from AWR that were customed lathed by those guys...I will have to dig up the specs, I don't remember if I ever posted them...they were well aware of my hp goals, and built the head accordingly...
the exhaust system is only temp right now, but it using a modified bosal header from a Probe 2.0...a 2.375" cat-less midpipe, and a 2.375" custom cat-back with a simple magnaflow muffle welded on the end...loud as s***...but I couldn't use the stock system with this...I have a Mazdaspeed 4-2-1 JDM factory header ordered, and a Racing beat was ordered on Wednesday... (which is why I used 2.375" custom piping in the first place...thats the RB size...that is the only exhaust I would consider because it is fairly quiet)...yet another example of how you do not need a 3" exhaust on an NA small displacement engine...
The only part I ordered for the head was the springs...so I am assuming they are utilizing the same locks, retainers, tappets, etc...but I will ask them in the morning just in case they came up with something custom in the lab...
gas used was 92 octane from Sheetz...a fairly large mid atlantic chain that seems to have decent gasoline. all dyno runs were done in 3rd gear, and the dyno is equipped with a torque converter...so we entered the exact third gear ratio/final drive into the computer and it adjusts the numbers according (torque is affected by gear ratio...hp is not...but on a machine that only measures torque and then derives hp, that is important...)
A/F was held tight around 12.7 near max v.e. , so roughly 4,000 rpm...then leaned out slightly up to 13.1:1 to redline...
Note though that this was utilizing a high load closed loop system by using a Wideband o2 sensor w/ a knock sensor too...since the computer was self learning, it sort of did that number on its own...it drastically shortened the tuning time...it pung once on the first pull when I first rolled onto the gas and the entire system went into a safe mode...we reset it with the laptop and the datalog showed that it was holding stoich until 3,000rpm!!! where the engine was already making over 100lb/ft of torque...I am lucky it didn't scatter right there...
but after some minor adjustments to the closed loop control, we were able to get it to immediately richen at least slightly with throttle input...being that this thing is very prone to detonation with bad tuning, anyone doing this setup I would recommend NOT using high load closed loop for the street...Any ecu only has so many load "points" so once you factor the fuel needed for each one...its a done deal...High load closed loop only changes something after it is registered in the exhaust gas...so if something is wrong, there is at least 3-4 engine cycles before it is read by the computer...that is what I ran into...for the street...I will not be doing that...