AutoMods
08-05-2011, 10:40 AM
upgrading from 3" to 3.5" exhaust, hopefully I see similar gains
http://www.modified.com/tech/modp-1102-exhaust-test-tech/index.html
Catback test: Our 3-inch exhaust baseline netted 527 whp at 19 psi. With the 3.5-inch exhaust, it climbed to 567 whp with a peak gain of 66 whp at 6000 rpm in fourth gear. At 29 psi, we went from a baseline of 699 to 740 whp. Peak gains here were 52 whp at 6100 rpm. The icing on the cake is the fact the turbo spools up a 150-200 rpm quicker with the larger-diameter exhaust.
Full turbo back ehxaust test: With the short bottleneck still at the turbo exit, our expectations weren't optimistic - once again, we were pleasantly surprised. Although gains didn't start until the exhaust was flowing at least 500 whp, at 19psi we hit 610 whp with a peak gain of 52 whp at 7000 rpm from the downpipe alone. Compared to our baseline, at this boost setting, the entire exhaust system is netting a whopping 103-whp gain!
Setting the boost back up to 29 psi, the larger 3.5-inch system started to expose the octane limits of our engine with pump fuel still coursing through its veins. At 764 whp, the AEM EMS pulled a couple of degrees of timing up top, limiting the gains to 30 whp at 6100 rpm. Still, compared to our first baseline, our total gain was now up to 70 whp at 6100 rpm with the full 3.5-inch exhaust. With a couple gallons of race fuel in the mix, surely we could have clipped the 775-whp mark.
http://image.modified.com/f/tech/modp-1102-exhaust-test-tech/30079997+pheader_460x1000/modp_1102_01_o+toyota_exhaust_test+rear_view.jpg
http://www.modified.com/tech/modp-1102-exhaust-test-tech/index.html
Catback test: Our 3-inch exhaust baseline netted 527 whp at 19 psi. With the 3.5-inch exhaust, it climbed to 567 whp with a peak gain of 66 whp at 6000 rpm in fourth gear. At 29 psi, we went from a baseline of 699 to 740 whp. Peak gains here were 52 whp at 6100 rpm. The icing on the cake is the fact the turbo spools up a 150-200 rpm quicker with the larger-diameter exhaust.
Full turbo back ehxaust test: With the short bottleneck still at the turbo exit, our expectations weren't optimistic - once again, we were pleasantly surprised. Although gains didn't start until the exhaust was flowing at least 500 whp, at 19psi we hit 610 whp with a peak gain of 52 whp at 7000 rpm from the downpipe alone. Compared to our baseline, at this boost setting, the entire exhaust system is netting a whopping 103-whp gain!
Setting the boost back up to 29 psi, the larger 3.5-inch system started to expose the octane limits of our engine with pump fuel still coursing through its veins. At 764 whp, the AEM EMS pulled a couple of degrees of timing up top, limiting the gains to 30 whp at 6100 rpm. Still, compared to our first baseline, our total gain was now up to 70 whp at 6100 rpm with the full 3.5-inch exhaust. With a couple gallons of race fuel in the mix, surely we could have clipped the 775-whp mark.
http://image.modified.com/f/tech/modp-1102-exhaust-test-tech/30079997+pheader_460x1000/modp_1102_01_o+toyota_exhaust_test+rear_view.jpg