WhiteZ
06-18-2007, 01:29:32 AM
For all of you out there with the Z28 350 High Performance engine, I wanted to know what kind of RPM you get. My recently-bought 73 Z has this engine, (modified with Edelbrock Performance manifold and a high-rise Holley carb) and when I run it at 60 mph, it's cranking at 3000 rpm. At 55 mph it's at 2800 revs. This seems high to me, since I have a 94 Formula with basically same engine (LT1, but with a 4spd automatic instead of a manual) and it will give me 75 mph at about 2400 rpm.
This is the first Camaro I've owned with a really high perf. engine. Are you guys getting RPMs as high as this at freeway speeds?? Thanks.
74RAT
06-18-2007, 01:35:54 AM
sounds like maybe you have 3.42 or 3.73 gears in that Z. start of a nice performance street strip setup. you'll want more power soon,, and the gears will already be done.
LTjames
06-18-2007, 01:50:11 AM
Your 94 has an overdrive transmission whereas the 73 does not (stock).
WhiteZ
06-18-2007, 02:04:37 AM
Went back and checked some of the other specs, and it also has angle plug heads with 202 valves, and a "30/30 Off Road" Z28 cam. It goes up thru the gears real quick, so I guess I shouldn't be surprised it's no cruise ship on the highway! And yes, it's got a 3.73 ten bolt Posi.
night rider
06-18-2007, 02:24:12 AM
Yeah the gear ratio plus the non over drive trans.
Your 4 speed man trans, 4th gear is 1.00.. It's not an over drive 4th gear ratio like your 94 has.
If you want to see the diff in the two apple to apple type test. Try this.. Take your 94 out on the road and move the shifter from OD to D. This will put the trans in third gear which is a 1.00 gear (same as the 4th gear on your 73)
WhiteZ
06-18-2007, 02:31:48 AM
Actually 4th on the Fbird doesn't show as Overdrive on the shift plate (just a D), nor was it "advertised" as being an overdrive transmission, but I get your drift.... 4th is a longer gear than on my Camaro. Sounds like you guys are saying nothing is abnormal with the way the Z is running - Thanks!
night rider
06-18-2007, 02:41:47 AM
Yep, nothing is wrong with your 73. Thats how it should be.
1984 through 2002 only had 4 speed over drive autos. For that matter all the man. transmissions was all overdrive too.
Then 1967 through 1983 all has 3 speed autos and 4 speed non over drive man.
I'm not sure how the 4th gens has the shift plate wrote out.. It may just be D, 3, 2, 1
On third gens I know its OD, D, 2, 1
