Turbo Bob

Looking to find out what year was the fastest bone stock Camaro Z 28 with auto trans. 93-97. Thanks.

Critter

i would assume 96, or 97 due to the 2 cats on it. And the fastest 1/4 is probably gonna be the one that ran closest to sea level with the best air, 13.8ish on an auto. Just guesses here though.

shoebox

As it has been discussed in the past, I don't think there was any clear answer. Too many opinions and variations by driver.

Turbo Bob

Then I will take it a step further Shoebox. Has anyone ever dyno'd stock 93-97 Camaro Z 28's with auto trans and found a significant different between years?

Z28SORR

93 thru 95 they were rated at 275hp/325tq, for 96 & 97 they were 285hp/335tq.
So, That would make the 96's and 97's GENERALLY faster.

yungin' w/a z28

How do cats give you more performance and HP...? Just curious..

LSWHO

The newer LT1s had a 2 cat setup, so it flowed more. The earlier ones had only one. (the earlier ones had better sounding exhaust too.)

yungin' w/a z28

Yeah the earlier ones did sound a little better. Does that mean that my car originally had dual exhaust? Or 2 cats to a single chamber muffler?

shoebox

I have never understood what the difference is if you take 2 pipes and Y them into one cat (93-95) or take two pipes that each have a cat and Y them into one pipe (96-97). They both go into the same single intermediate pipe going to the muffler, so where is the gain made? How do you get more flow out of the same pipe?

I tend to think the reason behind the 2 cat setup was for emissions purposes. The 1995 California emission A4 cars had the same 2 cat setup that was used on all the 96-97s and it was still rated at 275 HP.
I think the the 10 HP difference for 96-97 was in tuning or just marketing hype, given 93-97s are so equal. A lot of people say the SD 1993s are the fastest.

Turbo Bob is really looking for real dyno numbers and not factory advertised specs. We all know how the factory advertised ratings on the LS1 were lower than actual.

Turbo Bob

Shoebox,

Thanks for all of the info. Just one thing what makes a lot of people think the SD 1993's are the fastest versus the mass air 1994 through 1997?

shoebox

It is mostly the 1993 owners that say that, but it may be due to the amount of people that really know how to tune the SD system and get the best out of it. There may be more parity between the years now, because there is lots of tuning experience for MAF cars, too.

JakeRobb

Catalytic converters restrict flow. Putting two of them before the Y-pipe joins into a single pipe means that each one only has to handle half of the flow. That means less total restriction, which means more total flow.

Turbo Bob

Thanks Shoebox and all others that contributed. But would still like to see some dyno numbers on the 93-97's.

Also is there a big weight difference between the 93 through 97's?
I am a big fan of hardtop F Bodies. Do F Bodies with t-tops weigh more?

FASTFATBOY

Yes, about 15lbs


David

shoebox

So, why does the 95 California emissions 2 cat car rate 275 HP when the 96-97s have 285 if all the difference is in the number of cats? Seems curious. The extra cat obviously was not added for HP gains.
If even the single cat system was restrictive, then adding an aftermarket cat back would produce little, if any, HP gains (but it does add HP). I just can't buy the whole 2 cat extra flow scenario [= HP].