Top speed and distance

[ediconu]

Theoretically:

In my stock LT1, the top speed is about 135 MPH.

There has to be a time limit on red-lining the car in 5th gear, but what is it?

There's a lot of air passing by to keep it cool, but that's a lot of wear to put on the engine at one time. Does anyone have a good estimate/exact figure of how long the LT1 can withstand redlining in 5th?

Also, if I switch to 6th, will I be able to keep the speed up? It "felt" like it was losing speed when I had it nearly floored, but i could've been feeling wind resistance or something else.

Mike

 

[warren s]

Mike

Your stock 95 should top out at better than 160.

With a 3.42 rear end gear ratio, 5th gear at the red line is way over 135, and you should get additional top end in 6th.

I made a video of my brothers 94 going through the gears, I can send it to you for comparison if you like.

No need to keep it floored at the red line in any gear.

 

[Tuna]

In my experience, top speed occurs in 5th gear and should be some where around 160 for an LT1. You will not be at the redline either.

If you shift to 6th, you'll slow down as 6th gear drops the motor too low in the power band to hold top speed. (this is assuming that you have the stock 3.42 gears)

Are you thinking of going to Bonneville? or cruising on the Autobahn?

 

[cplbilski]

do you have the video as an mpeg? if so id like to see it!!

 

[ediconu]

I was at 130 and i was at 5,000 RPMs... i don't think it'll go much faster....

Please do send me the video, my email addy and AIM name are both in my profile on the site.

Mike

 

[warren s]

Ok, I will email the mpg, it is about 7.5 megs. It shows me hitting 141 in 5th gear.

 

[ediconu]

I have a manual transmission... doesn't that have a different rear-end gear? like a 3.7 something rather than 3.4?

 

[warren s]

I think the manual trans for 95 has a 3.42 and the "performance" rear end for the automatic is a 3.07

 

[ediconu]

I went through my codes last night and the rear-end should be 3.25. I don't think it was ever changed.

Mike

 

[Tuna]

Never heard of a 3.25 gear in a Vette.

As far as I know, all 6-speed C4's have come with the 3.42 rear gear including the ZR1.

Autos were available with 2.59 and 3.07. There were a few odd 3.33 gears available before the 6-sp intro.

What codes are you reading that lead you to believe that you have a 3.25 gear?

 

[ediconu]

I'll get it tonight, it's on my computer at home.

It could be wrong because I couldnt' find the code on any corvette sites specifically, but thirdgen.org had it.

Mike

 

[Tuna]

I just did a check of the Tech Center, Model center, base here and found the following RPO codes that apply to late C4's - most of this info was listed under the 93 or older C4 but the RPO codes for the 94-96 are the same.

GHO - 3.54 ratio
GM1 - 2.59
GU2 - 2.73
GW4 - 3.31
G44 - 3.07
GM3 - 3.45 <--- this is the 6-speed's ratio, not 3.42 as said before
GT7 - 3.33

When you look at the RPO codes, you'll find GM3 listed there somewhere - along with MN6 for the 6-speed.


BTW, I've aired my 92 out in 5th gear and I've seen 155 before running out of space to continue and the tach wasn't that close to redline - can't say as I remember what the tach was reading. A couple of times above 150, I shifted to 6th and it lost speed.
Now that my motor has been tweaked, I'm not sure what it will do. I may have to find out after a proper break in period.

 

[ediconu]

I stand corrected; I remember the GM3 on the list.

I need to goto an airport. Drive straight fast for a while.

Would a dirty air filter lower my top speed?

Mike