Funky final drive?
03-20-2006 | 09:27 PM
#1
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Joined: Apr 2005
Posts: 2,550
From: Slidell, LA
Funky final drive?
Okay, now that i have my 240 street legal, its time to address some issues. My first beef is that my 240 gets terrible mileage. I think this is because of the final drive ratio in the rear end. I was wondering what RPM everyone is running from 70 -85 mph. I run about 3500 @82 mph if memory serves me correct, and that is awfully high IMO. My old Acura Legend used to run about 2800 RPM at 80mph, and got pretty good mileage, but my 240 burned a quarter tank (from full) in about 80 miles. Is this normal? I was thinking that it was either the wussy final drive or an O2 sensor, because i have a lot of black soot on the inside of my exhaust tips, and ive only had the car legal for like 2 weeks. Im also running no cat, so i think that has something to do with the soot. Any info would be greatly appreciated
Last edited by LA_phantom_240; 03-21-2006 at 01:53 PM.
03-21-2006 | 09:26 AM
#2
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Joined: Dec 2004
Posts: 593
From: Cokeburg, PA
Unless somebody changed your final drive it's not that. I can almost guarentee it's the o2 unless you need to do a tune-up. 80 in a half a tank is terrible......i just got back from a 1200 mile trip...i have 350 miles on the tank with a 1/4 tank left.
03-21-2006 | 01:57 PM
#3
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Joined: Apr 2005
Posts: 2,550
From: Slidell, LA
oops... sorry i meant a quarter tank. Yeah if i burned half a tank in 80 miles id be kinda alarmed... anyways, the car doesnt need a tune-up, i changed the plugs, wires, cap and rotor last summer, and ive only driven the car about 200 miles since then... Im going to check my timing, but thats for a different reason. What RPM does your car run at 70 mph?
) and I get 80mph at 3k. 80 Miles on a quarter tank is good actually.
03-22-2006 | 07:17 PM
#7
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Joined: Apr 2005
Posts: 2,550
From: Slidell, LA
okay, so the final drive hasnt been messed around with.... i wonder if i can change it to have a little more top end to it by having a shop build me an LSD?
I have another question which pertains to possible crappy mileage... I get a LOT of black soot in my exhaust tips, more than i think should be normal, and a lot of times if i shift at high RPMs, itll backfire through the exhaust. Im running a pacesetter exhaust, and a high flow test pipe/cat, so im not getting rid of the unburned hydrocarbons, could that be my problem, or is the car running rich?
I have another question which pertains to possible crappy mileage... I get a LOT of black soot in my exhaust tips, more than i think should be normal, and a lot of times if i shift at high RPMs, itll backfire through the exhaust. Im running a pacesetter exhaust, and a high flow test pipe/cat, so im not getting rid of the unburned hydrocarbons, could that be my problem, or is the car running rich?
03-23-2006 | 06:31 AM
#11
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Joined: Apr 2005
Posts: 2,550
From: Slidell, LA
Originally posted by motegineon
yea id say ur running rich, do u ever smell gas from the motor bay? i know when i had the ka i smelt gas sometimes and i had a lot of black soot buildup..
yea id say ur running rich, do u ever smell gas from the motor bay? i know when i had the ka i smelt gas sometimes and i had a lot of black soot buildup..