Im confused...

[JoeliusZ28]

Ok, as a preface, ive been trying to figure out what gear is in my car since i bought it.

It DRIVES like it has a 3.73 or 3.90 in it. Finishes the quarter mile in fourth gear at 104 mph... not exactly sure of the RPM but its higher than 5200 (half red line). At one time i even thought it had a 4.10. 75 mph is about 1800 rpm.

It TURN TESTS a 3.42 though. according to the gear calculator (www.f-body.org/gears) that doesnt make any sense at all.

Im beginning to wonder of my trans has different gears in it because this is confusing me almost as much as the one time i saw an airplane that wasnt moving (i have a witness to confirm that too).

[WMCCjames]

Jack the rear of the car up and find out for sure.

[JoeliusZ28]

Jack the rear of the car up and find out for sure.

thats what i just did, and why im confused. my RPMs and speed dont seem to match the gear i have. It seems to turn test 3.40ish spot on, i did the sharpie marker test.

[c0ncEpT]

4th at 104 should be 4650 RPM If it has a 3.42, 3.73 would be 5100 RPM at 104 in 4th, A 3.90 would be 5300 at 104, and a 4.10 would be 5600.

[WMCCjames]

Another note...factory tachs are known for being inaccurate.

[c0ncEpT]

Your 4th gear sould be 1:1. So a gear calc should be accurate in 4th gear

[JoeliusZ28]

Your 4th gear sould be 1:1. So a gear calc should be accurate in 4th gear

thats a good point, ill check that out.

[96mikez28]

interesting...