Question about highway speeds

[NkTyson06]

Hi, I have a 98 v6 Camaro y87 A4 and GU6 on the RPO list. My car came with 3.42's and they were replaced about 2 years ago. When I am driving on the highway at 74-75 mph with cruise control on, my rpms are steady 2400-2500. I have been reading the stickies above and people having been saying with the same gears I have that at 75-80 mph they are cruising at 1800 rpms. Is this because they have a v8 and with more power it doesnt have to struggle as much to move the car? Like because I have a 3.8 it has to push harder to move the car of the same weight? And ever since I had my 3.42's + rear axle replaced (with a used set) there has always been this woo woo whoo noise at highway speeds. It is not loud but it is "hearable" if that is a word lol. Its a dull noise I have been told it may be my tires. Once I upgrade my rims/tires I will see if it was them but I still feel strongly it is coming from the rear end. Sorry for the wall of text, but thanks for the help.

[Smoke Panther]

Re: Question about highway speeds

When I am driving on the highway at 74-75 mph with cruise control on, my rpms are steady 2400-2500. I have been reading the stickies above and people having been saying with the same gears I have that at 75-80 mph they are cruising at 1800 rpms.

Provide the URL of where you read that, because you must have misread it.

Is this because they have a v8 and with more power it doesnt have to struggle as much to move the car?

it has more to do with the gear ratio.

And ever since I had my 3.42's + rear axle replaced (with a used set) there has always been this woo woo whoo noise at highway speeds. It is not loud but it is "hearable" if that is a word lol. Its a dull noise I have been told it may be my tires. Once I upgrade my rims/tires I will see if it was them but I still feel strongly it is coming from the rear end.

Is there a question somewhere in there?

[IDoVoodoo]

Re: Question about highway speeds

at 80 mph you should be right at 2500 rpms, regardless of how much power you have

[NkTyson06]

Re: Question about highway speeds

Provide the URL of where you read that, because you must have misread it.


it has more to do with the gear ratio.


Is there a question somewhere in there?

I'm sorry it was on ls1tech.com in the suspension forum. They have a sticky at the top of the page.. I will try and find it

[NkTyson06]

Re: Question about highway speeds

Yes my question was basically do you have any idea what it might be

[elkindw]

Re: Question about highway speeds

at 80 mph you should be right at 2500 rpms, regardless of how much power you have

When my car is at 80 mph I am right at 2500 rpms with the stock 3:23 gears. If you have 3:42 gears you should be running a little bit higher rpms. Right?

[crushedout]

Re: Question about highway speeds

Lots of things will cause a sound, it's really hard to diagnos a problem like that not being in the car and knowing where the noise is coming from.

[Mr. Logger]

Re: Question about highway speeds

Quite possible they have an M6, and you have an A4.

[Smoke Panther]

Re: Question about highway speeds

I'm sorry it was on ls1tech.com in the suspension forum. They have a sticky at the top of the page.. I will try and find it

The M6's 6th gear ratio is a full .2 shorter than your 4th gear ratio, so that's why they're able to do turn those RPMs

Yes my question was basically do you have any idea what it might be

more likely to be your tires than your ring gear

[greasemonkey]

Re: Question about highway speeds

LS1's cruise at 2,000 rpm at 80mph with 2.73 gears and stock tire height. With a 6, you'll be at higher RPM no matter what because none offered that gearing, the longest gear is 3.08.

[Camarorulz]

Re: Question about highway speeds

A 3.8 automatic with 3.42 rear will cruise at about 2600 rpm at 80mph. At 70mph, rpm should be about 2250. This is regardless of power, and unless you have a different transmission or have modified your transmission gear ratios.

If you read that you should be cruising at 1800 rpm @ 80mph you either misread the post, or didn't read it fully, or the person that wrote it is full of $hit. For that matter, they might have been talking about an LS1, in which case they still might be incorrect.

Assuming your computer is programmed correctly for your rear gear ratio and tire/wheel combo, your speedometer should read as specified above. Judging from what you said in your post, your car is cruising at the right rpm at any given highway speed.

[TheGr8Schlotzky]

Re: Question about highway speeds

The guys running at 1800 rpms probably had M6s, which, as stated above, has a much lower ratio in 6th gear, allowing them to run at lower rpms. My 3.42s leave me about 2500 at 75mph.

Btw the word for "hearable" is "audible."

[crushedout]

Re: Question about highway speeds

.

Btw the word for "hearable" is "audible."

Blahahahahahahahahahaha

[NkTyson06]

Re: Question about highway speeds

me = pwned by T3HGR8SHL0TSK33 !!!!