G8 GXP A6 with small cam at 6 psi TVS 2300
06-04-2014, 01:25 PM
#1
G8 GXP A6 with small cam at 6 psi TVS 2300 I've had this car for almost a year now and I finally decided to change out the camshaft. The biggest reason for me was to try to make it less sensitive to timing and get the timing out of the gutter (single digits). Running that low makes for a pretty inefficient burn, your exhaust gas temperatures tend to get fairly high (not good for cats), and obviously it's pretty sensitive at that point if it's that low. Here in AZ we have crappy gas and lots of heat which keeps it VERY octane limited and also means you better keep it conservative or suffer the consequences. The other obvious reason is that it will make more power and do it "more" safely in the process. 
Being my daily driver and an automatic with a stock torque converter it also had to drive perfect otherwise it would bug the hell out of me which meant it had to stay on the small side.
For background this is a stock LS3 motor with ARH 1 7/8" longtubes with cats and a custom catback with a magnaflow mid-muffler welded in, magnaflow clone axle-backs and custom j-pipes. It also has a rotofab box/filter with the original Magnusson inlet pipe with an LS3 card style MAF in a 90mm housing. The TVS 2300 had a 3.1" pulley and it would make ~6 psi before the cam install, after the cam install I put on a 3.0" pulley to bring boost back up to the same ~6 psi as before to keep it consistent.
Running conditions between both runs were a good comparable 97 degrees, 18-21% humidity, 40 psi in the rear tires, Mobil 1 0W-40 up to full operating temp, coolant at 190-195 degrees, and intake air temps were comparable but I will go into that more later. I tried to keep track of most of the factors that contribute to changes in dyno results but I was limited in time doing other peoples stuff as usual. LOL! The other thing I mentioned before was the intake air temps. In between these two dyno sessions I had added the Lingenfelter Varimax intercooler pump as it's a good upgrade from the older bosch pumps that come in the maggie kits. During the pull with the cam with the Varimax IC pump intake air temps rose from 117 deg F to 129 over the duration of the pull and on the before with the old Bosch pump it went from 118 to 135. Now that might not mean much just because it took less time to make that pull with the cam then the before but it's also moving more air so that has to have a factor in it.
In this dyno graph I've got the before and after shown together to see the difference. Timing was in the single digits before and with this small cam I was able to add a few degrees of timing pretty much everywhere at WOT at the same boost level with the same conditions before running into detonation. I was glad to see this because I was worried that even with the small cam it wouldn't tame it down enough as you would normally use a larger camshaft at that point to bleed some more off but this worked great. This cam is from Ed Curtis at Flowtech Induction and in the upper 21X intake duration and upper 22X duration on the exhaust with around .600 lift on a 115 LSA plus a few degrees advance ground into it so it's going to be really nice on the valve train and not beat up valve springs, lifters, etc. It also needed to drive like stock as this is my daily driver with a stock torque converter which necessitated the smaller cam.
With any luck in the next few months I might be testing Magnussons new blower with this config back to back but it's up in the air at this point.
Being my daily driver and an automatic with a stock torque converter it also had to drive perfect otherwise it would bug the hell out of me which meant it had to stay on the small side.For background this is a stock LS3 motor with ARH 1 7/8" longtubes with cats and a custom catback with a magnaflow mid-muffler welded in, magnaflow clone axle-backs and custom j-pipes. It also has a rotofab box/filter with the original Magnusson inlet pipe with an LS3 card style MAF in a 90mm housing. The TVS 2300 had a 3.1" pulley and it would make ~6 psi before the cam install, after the cam install I put on a 3.0" pulley to bring boost back up to the same ~6 psi as before to keep it consistent.
Running conditions between both runs were a good comparable 97 degrees, 18-21% humidity, 40 psi in the rear tires, Mobil 1 0W-40 up to full operating temp, coolant at 190-195 degrees, and intake air temps were comparable but I will go into that more later. I tried to keep track of most of the factors that contribute to changes in dyno results but I was limited in time doing other peoples stuff as usual. LOL! The other thing I mentioned before was the intake air temps. In between these two dyno sessions I had added the Lingenfelter Varimax intercooler pump as it's a good upgrade from the older bosch pumps that come in the maggie kits. During the pull with the cam with the Varimax IC pump intake air temps rose from 117 deg F to 129 over the duration of the pull and on the before with the old Bosch pump it went from 118 to 135. Now that might not mean much just because it took less time to make that pull with the cam then the before but it's also moving more air so that has to have a factor in it.
In this dyno graph I've got the before and after shown together to see the difference. Timing was in the single digits before and with this small cam I was able to add a few degrees of timing pretty much everywhere at WOT at the same boost level with the same conditions before running into detonation. I was glad to see this because I was worried that even with the small cam it wouldn't tame it down enough as you would normally use a larger camshaft at that point to bleed some more off but this worked great. This cam is from Ed Curtis at Flowtech Induction and in the upper 21X intake duration and upper 22X duration on the exhaust with around .600 lift on a 115 LSA plus a few degrees advance ground into it so it's going to be really nice on the valve train and not beat up valve springs, lifters, etc. It also needed to drive like stock as this is my daily driver with a stock torque converter which necessitated the smaller cam.
With any luck in the next few months I might be testing Magnussons new blower with this config back to back but it's up in the air at this point.
Last edited by NicD; 06-04-2014 at 01:33 PM.
