It's my daily driver...I'm all about ease of driveability, gas mileage, etc. but I'm just plain sick of waiting all day for my car to get in a decent powerband from a stop...stupid pegleg 2.73s...AND I'm TIRED of ONE WHEEL PEELS...anyway, I digress - because of a tall 5th, 80 MPH = 2000 RPMS...which is even too big for highway cruising. Could someone please do the math and tell me what RPMs 80 would be with both 3.23s and 3.42s? Would they both work? Which would you recommend? Thanks...

------------------
'89 RS LO3- 140,000 miles
14x3 K&N Open Element
Ram stock replacement clutch
Edelbrock TES (Jet-hot coated)
Catco cat
Edelbrock 3" Cat-back
KYB GR-2 Struts and Shocks
Pioneer DEH-P77
Midland 77-115 with 3' Firestik and 100 watt police PA
Dual .50 caliber machine guns just under ground effects

Coming:
Edelbrock Strut Tower Brace
Spohn subframe connectors

When your buddy reaches for a 10-pound sledge and says "I think we're gonna have to modify the floor pan, okay?" the answer is NO.

 

3.42 = 2582 RPM at 80 MPH
3.23 = 2438 RPM at 80 MPH

Go with the 3.42 gears.

------------------
1988 Formula 5L/5sp 3.45 gears, SLP cold air kit, MAS gutted, TPIS air foil, TPIS AFPR, MAC headers, Mac under drive pulleys, MAC cat back, Relocated MAT.
Best ET street tires 13.85
Best 60 FT street tires 1.930
Best MPH street tires 99.29

 

Really? Wow, those numbers seem a bit steep compared to the current 80 = 2000...is that taking into account my big 5th gear with 2.73? Yeah, I guess it's a long way from 2.73 to anything, so that does make some sense...thanks for the reply.

------------------
'89 RS LO3- 140,000 miles
14x3 K&N Open Element
Ram stock replacement clutch
Edelbrock TES (Jet-hot coated)
Catco cat
Edelbrock 3" Cat-back
KYB GR-2 Struts and Shocks
Pioneer DEH-P77
Midland 77-115 with 3' Firestik and 100 watt police PA
Dual .50 caliber machine guns just under ground effects

Coming:
Edelbrock Strut Tower Brace
Spohn subframe connectors

When your buddy reaches for a 10-pound sledge and says "I think we're gonna have to modify the floor pan, okay?" the answer is NO.

 

2.73 to 3.42 is exactly 20%: from 15 and 41, to 12 and 41. It's exactly a 20% change since the difference, 3 teeth, is exactly 20% of the 15 teeth on the 2.73 pinion.

If you work out the possible ratios based on the only possible integer (whole numbers) that the ratios can be based on, since you can't have fractional teeth, it's alot easier to understand. It's even easier in the case of the 7½" GM since there are so few ratios available (unlike say the F*rd 9" or GM 12-bolt)

------------------
"So many Mustangs, so little time..."
ICON Motorsports