67 Chevelle twin turbo winter revamp and car history
#88
I thought I'd bring this one back from the dead as I have some changes from near a year ago.
I didn't realize I didn't post some of my other successes I had after my May races, and some of my other failures.
Not long after my 5.0 passes, I went back to Woodburn, but still couldn't get my short time to work there, just not enough track prep. Below are are couple passes where the backhalf was decent.
You can get a sense of what the car will do, as my 8.0 177 pass below was only 5.25 @ the 1/8th. After that pass I pushed turned it up a bit more, spun at the hit, and was only 5.45, but was rewarded with 181 out the back! Not bad at 3800lbs, but also the reality set in that I was far out of the realm of being safe.
The other thing that hurt on the 181 pass was having a bad fire at the stripe, I had a fitting at my fuel regulator come lose. The killer mph was also a killer with the fire, and it took out all wiring, fuel lines, 4 injectors, several coil packs, hurt the hood, firewall etc.
I went like a madman to fix everything inside of a week to make another race. Because of the fire, I decided to replace my fuel regulator, and switched from my Holley to a Magnafuel, and at the same time I replaced one of my 12-1800 Holley pumps with a Magnafuel Prostar 750 to fix my lack of fuel issue. At the next grudge race, I didn't make any fuel pressure under boost on my first aborted pass. Since I don't have a crew helping me, I didn't get my data logs checked in time before the next round. 2nd pass, same condition, and I took out 4 rods. Cause was 25lbs shy of target fuel pressure. Unfortunately it cost me the rest of the season.
I didn't realize I didn't post some of my other successes I had after my May races, and some of my other failures.
Not long after my 5.0 passes, I went back to Woodburn, but still couldn't get my short time to work there, just not enough track prep. Below are are couple passes where the backhalf was decent.
You can get a sense of what the car will do, as my 8.0 177 pass below was only 5.25 @ the 1/8th. After that pass I pushed turned it up a bit more, spun at the hit, and was only 5.45, but was rewarded with 181 out the back! Not bad at 3800lbs, but also the reality set in that I was far out of the realm of being safe.
The other thing that hurt on the 181 pass was having a bad fire at the stripe, I had a fitting at my fuel regulator come lose. The killer mph was also a killer with the fire, and it took out all wiring, fuel lines, 4 injectors, several coil packs, hurt the hood, firewall etc.
I went like a madman to fix everything inside of a week to make another race. Because of the fire, I decided to replace my fuel regulator, and switched from my Holley to a Magnafuel, and at the same time I replaced one of my 12-1800 Holley pumps with a Magnafuel Prostar 750 to fix my lack of fuel issue. At the next grudge race, I didn't make any fuel pressure under boost on my first aborted pass. Since I don't have a crew helping me, I didn't get my data logs checked in time before the next round. 2nd pass, same condition, and I took out 4 rods. Cause was 25lbs shy of target fuel pressure. Unfortunately it cost me the rest of the season.
#89
Fast forward to today, and the winter changes.
I changed over to Oliver billet rods, new pistons that bumped the compression up by half a point, swapped the cam for something a bit bigger, and decided to change from Pac 1237x to 1238x valve springs. We also went through the heads as some valves weren't seating very well, and replaced the exhaust valves for preventative reasons.
We put the car on the dyno two weeks ago, and immediately saw the fuel pressure issue I had that caused the damage. I ran home and got the Holley regulator that was in the fire, and crossed my fingers and put it back on the car. Problem solved, fuel pressure was rock solid.
With some of the changes, the reward was making 1433rwhp with 2lbs less boost, and 1 degree of less timing as last year, but, we blew thru the converter and it never locked up, so it was a short aborted pull. I can only dream what it would have made with the converter setup for the power levels I'm now shooting for. So that's on the hit list to get replaced in the next few weeks. The other big reward was seeing the impact the Prostar 750 pump, only 79% duty cycle!
To keep myself safe, I've also decided to cut the cage out, and a 25.3 cage is going in for over kill. The hard part right now is trying to get some weight out, so away go the factory buckets in place of Kirkey's, and I'll probably take the exhaust off for a track setup that will save me 40lbs. I still have the stock brakes up front, so those are going away as well. Lastly will be a much lighter wheels. I just dropped the car off yesterday for the cage work, so I'll get those posted up when it's finished. Lastly, I need to ditch my .81AR turbine housings haha and get a .96 on the car.
Here is the 22lb pull, converter was still ok. Still flashing a bit higher than what I've seen before
Here is the 28lb pull that didn't go so well.
I changed over to Oliver billet rods, new pistons that bumped the compression up by half a point, swapped the cam for something a bit bigger, and decided to change from Pac 1237x to 1238x valve springs. We also went through the heads as some valves weren't seating very well, and replaced the exhaust valves for preventative reasons.
We put the car on the dyno two weeks ago, and immediately saw the fuel pressure issue I had that caused the damage. I ran home and got the Holley regulator that was in the fire, and crossed my fingers and put it back on the car. Problem solved, fuel pressure was rock solid.
With some of the changes, the reward was making 1433rwhp with 2lbs less boost, and 1 degree of less timing as last year, but, we blew thru the converter and it never locked up, so it was a short aborted pull. I can only dream what it would have made with the converter setup for the power levels I'm now shooting for. So that's on the hit list to get replaced in the next few weeks. The other big reward was seeing the impact the Prostar 750 pump, only 79% duty cycle!
To keep myself safe, I've also decided to cut the cage out, and a 25.3 cage is going in for over kill. The hard part right now is trying to get some weight out, so away go the factory buckets in place of Kirkey's, and I'll probably take the exhaust off for a track setup that will save me 40lbs. I still have the stock brakes up front, so those are going away as well. Lastly will be a much lighter wheels. I just dropped the car off yesterday for the cage work, so I'll get those posted up when it's finished. Lastly, I need to ditch my .81AR turbine housings haha and get a .96 on the car.
Here is the 22lb pull, converter was still ok. Still flashing a bit higher than what I've seen before
Here is the 28lb pull that didn't go so well.
#96
Picked up the car on Saturday with the new cage from Ryan Saiki at Free Form Motosports. Drove home 7hrs, pulled seats out to get the carpet back in, rewire a couple toggle switches, temporary setup my old window net to get past tech, install and adjust new belts, minor maintenance on car, all to do test n tune the next day
First full pass car went 8.09, second pass finally got the official 7 second pass, went 7.93, and I backed it up with a 7.94. Down side is, head gasket let loose at the stripe on the 7.94 pass. Looking at the logs, the rpm certainly confirms it's blowing thru the converter. I guess I was too hopeful for it. The RPM log showed no drop in rpm at shifts, I can't even tell where the shifts are.
First full pass car went 8.09, second pass finally got the official 7 second pass, went 7.93, and I backed it up with a 7.94. Down side is, head gasket let loose at the stripe on the 7.94 pass. Looking at the logs, the rpm certainly confirms it's blowing thru the converter. I guess I was too hopeful for it. The RPM log showed no drop in rpm at shifts, I can't even tell where the shifts are.