ZR-1 Net Registry Forums - View Single Post - loss of power???? installed new clutch and exhaust?

cward · 03-26-2007

Interesting thread. I thought I would throw in my opinion. The first thing I did to #364 was headers thru stock exhaust, no cats. It gained hp and torque. Then put on ported plenum and IH. Gains in both. Then Power Effects mufflers thru stock resonators. A little gain. Then removed resonators and put in X-pipe. No gain in torque and may have lost a couple of lbs. Then changed plenum for one that was ported about as much as you can without cutting. Also custom 3" SS exhaust with X-pipe and nothing else. About as free flow as you can get. Torque stayed about the same or might have lost a couple of lbs. Rwhp went up about 20 hp. At that point, my torque was right around 350 lbs and rwhp about 392.

When you said it backfired a little, I would check vaccum lines etc. Should not backfire at all. And I would not worry about putting on B&B with X. More (a little) hp and probably same torque.

About roasting tires in 2 and 3 gears. That should not happen with stock or even lightly mod Z. Some spin in 2nd and maybe a squeek in 3rd but no roasting. If that happens, get better tires. :-) Even with 4.10 gears. In fact, even when I sprayed, and was probably putting out about 600 rwhp and close to that in torque, I would not roast 3rd. I could in 2nd but had to try, and that is not the goal so just a little technique and good tires made everything OK. I know of one person that went from 4.10 to 3.73 but that was for running standing mile. He ran out of gear before the end of the mile, over 180, not for street or strip driving.

Curtis

03-26-2007	#23
cward Join Date: Dec 2004 Location: Luling, TX Posts: 97	Re: loss of power???? installed new clutch and exhaust? Interesting thread. I thought I would throw in my opinion. The first thing I did to #364 was headers thru stock exhaust, no cats. It gained hp and torque. Then put on ported plenum and IH. Gains in both. Then Power Effects mufflers thru stock resonators. A little gain. Then removed resonators and put in X-pipe. No gain in torque and may have lost a couple of lbs. Then changed plenum for one that was ported about as much as you can without cutting. Also custom 3" SS exhaust with X-pipe and nothing else. About as free flow as you can get. Torque stayed about the same or might have lost a couple of lbs. Rwhp went up about 20 hp. At that point, my torque was right around 350 lbs and rwhp about 392. When you said it backfired a little, I would check vaccum lines etc. Should not backfire at all. And I would not worry about putting on B&B with X. More (a little) hp and probably same torque. About roasting tires in 2 and 3 gears. That should not happen with stock or even lightly mod Z. Some spin in 2nd and maybe a squeek in 3rd but no roasting. If that happens, get better tires. :-) Even with 4.10 gears. In fact, even when I sprayed, and was probably putting out about 600 rwhp and close to that in torque, I would not roast 3rd. I could in 2nd but had to try, and that is not the goal so just a little technique and good tires made everything OK. I know of one person that went from 4.10 to 3.73 but that was for running standing mile. He ran out of gear before the end of the mile, over 180, not for street or strip driving. Curtis