Got my first cobra about a month ago. It has 72,000 Kilometers its a Canadian car. Car had a 2.93 top pulley, a 4lb metco crank pulley, a 3.2 alternator pulley and a aftermarket filter. It came with a SCT programmer with a 91 Octane tune on it. The guy I bought it from had the car for a month and wanted a 2008 Cobra and did not know what the tune was. I took it to a reputable tuner to see if the tune would hurt the car. They put it on the dyno and did a pull. I wish I knew how to add it. The results were:
CEngTq 444.8
CEngPw 398.3
WhlTqr 392.7
SAEPwr 346.2
They said tune was Ok and would not hurt the engine but they wanted to do a exhaust back pressure test to see how that was. They ran it again and told me there was 1.5 bar or 21 psi of back pressure on drivers side before the cat advised me to drive easy and they would put high flow cats on. They installed cat and measured a 1.4 bar of pressure, really did not change much so they unhooked the mufflers and still had a .4 bar exhaust pressure. I was upset that after 1500 dollars things had not changed much so told him to put mufflers on and I took the car home. I did a back pressure test at the EGR valve and at 4000 rpm did not get more than 2 psi with a manometer. Wanting to verify that I had been lied to another shop did a back pressure test that verified what the first guy told me. So now I am going to put the car back to stock and put the stock tune back on. Well I'm glad I got a Cobra there must be some reason why that Back Pressure is present. I am open to any ideas or reasons why.
Thanks to Bob from this forum for suggesting I post this
CEngTq 444.8
CEngPw 398.3
WhlTqr 392.7
SAEPwr 346.2
They said tune was Ok and would not hurt the engine but they wanted to do a exhaust back pressure test to see how that was. They ran it again and told me there was 1.5 bar or 21 psi of back pressure on drivers side before the cat advised me to drive easy and they would put high flow cats on. They installed cat and measured a 1.4 bar of pressure, really did not change much so they unhooked the mufflers and still had a .4 bar exhaust pressure. I was upset that after 1500 dollars things had not changed much so told him to put mufflers on and I took the car home. I did a back pressure test at the EGR valve and at 4000 rpm did not get more than 2 psi with a manometer. Wanting to verify that I had been lied to another shop did a back pressure test that verified what the first guy told me. So now I am going to put the car back to stock and put the stock tune back on. Well I'm glad I got a Cobra there must be some reason why that Back Pressure is present. I am open to any ideas or reasons why.
Thanks to Bob from this forum for suggesting I post this