David Buschur's RS/BADBISH 2010 build
#199
Seat pressure I will not disclose, nor open pressure, sorry. Yes, we've done a LOT of testing on valve springs. I've got a folder with more notes than you guys can imagine on head flow, spring pressures, coil bind on springs etc.
I wouldn't doubt if the problem was more a lifter issue than a spring issue after taking the lifters out. As I said they were original and they've been compressed to get the oil out on cam installs in this car I'd guess from day one close to 50 times. Not sure how good that is for them.
The old head hasn't been taken apart yet, when it comes apart we are going to get data on each spring that was in the head to see where it was seat/open pressures so we can get a better grip on the problem.
I wouldn't doubt if the problem was more a lifter issue than a spring issue after taking the lifters out. As I said they were original and they've been compressed to get the oil out on cam installs in this car I'd guess from day one close to 50 times. Not sure how good that is for them.
The old head hasn't been taken apart yet, when it comes apart we are going to get data on each spring that was in the head to see where it was seat/open pressures so we can get a better grip on the problem.
#200
Dave i was at spo com nationals and was completely impressed with the Bish. So much so that i traded in my supercharged cobalt on a stock EVO 8 about a week later. Thanks for the dreams, possibilities, and great info.
#201
Thank you! I wish the car had been at 100% at the race but I can't complain about 9.3's either given all the issues we fought. Regardless of who you buy your parts from, getting a car to run like that requires the best parts you can find, be careful what you buy as it will save you a lot of time, effort and money in the end.
#203
Evolved Member
iTrader: (35)
Thanks for taking the time to keep us updated on the car Dave! I've also been building mine with similar mods as yours and keeping it a total street car with full interior. You have proven that you don't have to run a hacked car to make low 9 second passes at the track.
#205
Evolved Member
iTrader: (25)
wow, I just read all pages of this thread.. and I gotta say, Dave your pretty amazing, that graph is phat as hell, I'm very impressed with the mid-range power. I persoanlly love mid-range power instead of all up top lag.
Very Quality, always like watching your builds and advice
Very Quality, always like watching your builds and advice
#206
The car is back together and I put it on the dyno briefly Thursday.
I put the big cams back in the car as I was confident that with the new springs/retainers and a few tricks to the head that they'd work.
The first pull I did with the boost controller set on the low side, 34 psi, the car made a crazy 670 whp at a brief peak boost of 34 psi. That is the best power it's made at that boost level.
I had to add some fuel as the cams changed the AFR's by over .5 AFR points. I also needed to pull a few degrees of timing out of it. Power after a few adjustments stayed at 670 at 34 psi.
Flipped the switch on the boost controller to high, 44 psi and the power saw a peak of 755 BUT the chart was extremely rough again. There is a problem and I need to find it.
I've got a feeling that I've just pushed this 35r turbine wheel beyond what it was intended to do. I'm guessing I'm fighting a back pressure problem. This week I hope to find the time to either install a port to measure it or just make a few changes to see what happens.
I'm running our 3" exhaust as you all know and have two mufflers in the system. The choke point though I am guessing is the turbine wheel/housing, this is a lot of power on that "small" turbine wheel.
I also need to make a few steps between 34 and 44 psi as I may find it doesn't need much boost to make well over 700 and do it smoothly.
Damn I want this 8 second time done and over with.
I put the big cams back in the car as I was confident that with the new springs/retainers and a few tricks to the head that they'd work.
The first pull I did with the boost controller set on the low side, 34 psi, the car made a crazy 670 whp at a brief peak boost of 34 psi. That is the best power it's made at that boost level.
I had to add some fuel as the cams changed the AFR's by over .5 AFR points. I also needed to pull a few degrees of timing out of it. Power after a few adjustments stayed at 670 at 34 psi.
Flipped the switch on the boost controller to high, 44 psi and the power saw a peak of 755 BUT the chart was extremely rough again. There is a problem and I need to find it.
I've got a feeling that I've just pushed this 35r turbine wheel beyond what it was intended to do. I'm guessing I'm fighting a back pressure problem. This week I hope to find the time to either install a port to measure it or just make a few changes to see what happens.
I'm running our 3" exhaust as you all know and have two mufflers in the system. The choke point though I am guessing is the turbine wheel/housing, this is a lot of power on that "small" turbine wheel.
I also need to make a few steps between 34 and 44 psi as I may find it doesn't need much boost to make well over 700 and do it smoothly.
Damn I want this 8 second time done and over with.
#210
BF272's went back in the car this morning. My 12 year old son did about 80% of the job for me! Poor kid. haha
Regardless of the rest of the testing comparing these cams to our cams I know I am not willing to give up the low/mid range.
Might run the car this week....
Regardless of the rest of the testing comparing these cams to our cams I know I am not willing to give up the low/mid range.
Might run the car this week....