The Single Turbo Caprice Classic is Alive!
#21
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I was running into some issues in the 18-20psi range on the dyno and suspected valve float above 5200. It wasn't nearly as noticeable on the street as it showed on the rollers, The car just started to feel flat and not pull, and regardless of what I did with the controller, I could not get the car to load over 20psi.
My friend Tony (thank you) was kind enough to deliver a set of Brian Tooley Racing Springs yesterday, and I spent my fourth getting them swapped over. Obviously a much nicer unit than the LS9 springs I removed...
![](http://i128.photobucket.com/albums/p195/bfurches/temporary_zps2f54f0a7.jpg)
![](http://i128.photobucket.com/albums/p195/bfurches/temporary_zpseaa1644f.jpg)
![](http://i128.photobucket.com/albums/p195/bfurches/temporary_zpsb9de282b.jpg)
![](http://i128.photobucket.com/albums/p195/bfurches/temporary_zpsa7b80ae1.jpg)
After changing the springs, I turned down the controller on the side of caution and pulled some logs....I was pleasantly surprised!
*Monday night on the way to a local cruise night I data logged a pull with the old LS9 springs.
-Hit Started at 53mph (3888rpm 2nd Gear) 144* IAT and 4.5psi
-Lifted at 109mph 145* IAT Max Boost of 20.2psi
....It took 6.677 seconds to cover the above hit
*Today I did another pull which just happened to end at 109 as well. The ONLY change made was the springs!
-Hit started at 35mph (4226rpm 1st Gear) 145* IAT and 2psi
-Lifted at 109mph 144* IAT Max Boost 19.2psi
....it took 6.334 seconds to cover the above hit
Looking at the data to compare is pretty damn impressive! I guess the valve float issue was a little more sever than I had realized.
I covered an additional 18mph and shifted another gear... all with 2.5psi less on the hit and 1psi less overall. In the end, I covered the original hit by over 3 tenths!
Looking forward to turning this thing up at the track and seeing what it runs.
My friend Tony (thank you) was kind enough to deliver a set of Brian Tooley Racing Springs yesterday, and I spent my fourth getting them swapped over. Obviously a much nicer unit than the LS9 springs I removed...
![](http://i128.photobucket.com/albums/p195/bfurches/temporary_zps2f54f0a7.jpg)
![](http://i128.photobucket.com/albums/p195/bfurches/temporary_zpseaa1644f.jpg)
![](http://i128.photobucket.com/albums/p195/bfurches/temporary_zpsb9de282b.jpg)
![](http://i128.photobucket.com/albums/p195/bfurches/temporary_zpsa7b80ae1.jpg)
After changing the springs, I turned down the controller on the side of caution and pulled some logs....I was pleasantly surprised!
*Monday night on the way to a local cruise night I data logged a pull with the old LS9 springs.
-Hit Started at 53mph (3888rpm 2nd Gear) 144* IAT and 4.5psi
-Lifted at 109mph 145* IAT Max Boost of 20.2psi
....It took 6.677 seconds to cover the above hit
*Today I did another pull which just happened to end at 109 as well. The ONLY change made was the springs!
-Hit started at 35mph (4226rpm 1st Gear) 145* IAT and 2psi
-Lifted at 109mph 144* IAT Max Boost 19.2psi
....it took 6.334 seconds to cover the above hit
Looking at the data to compare is pretty damn impressive! I guess the valve float issue was a little more sever than I had realized.
I covered an additional 18mph and shifted another gear... all with 2.5psi less on the hit and 1psi less overall. In the end, I covered the original hit by over 3 tenths!
Looking forward to turning this thing up at the track and seeing what it runs.
![](http://i128.photobucket.com/albums/p195/bfurches/1981%20Caprice%20LR4%20Turbo/marks_zps2e2975d1.jpg)