I have a quick Question.
Right now in my 85z28 i have 3.23 Gears and im looking
to go to like 3.73 or 4.10s.
Which do you think would be better?
Considering i track it during the summer about 5 times and i tend to drive highway mostly.
I want to have my top end at the track, consider when i hit 3rd gear it slows down. ( Auto 4speed 700r4 with shift kit)( 350 H.O.)
Running 13.9s.
I feel it would increase my top end and track time, Also would this change my mpg changing gears?
If i do change my gears to do need to change anything else in the rear? besides the gears for the speedo.
Please, i could use your input and help, thanks everyone =)

 

If you drive mostly on the highway then your fuel mileage will suffer with this gear change. I don't recommend it. You will also probably pick up a harmonic vibration at highway speeds because the drive shaft will be turning higher RPMs and will probaby distort at those speeds.

You need to decide if you want a highway car or a race car. Then build it that way. Using shorter tires at the track could help with the problem that you are having.

 

What's your trap speed?

Doesn't sound to me, at this point, like you need gears; sounds more like it would benefit from some exhaust and fuel system work.

 

The 2 posts above this are probably better input but IMHO I can't imagine 3.73 being that bad. Especially if you got an aluminum driveshaft. Use the gear calculator to see how much your rpm will change with each gear. 4.10 is a pretty serious gear for any street car.

 

I had 456 in my last T/A and wow off the line (TH350) she really honked! But at 55 mph... yeah not even a car I liked taking on the high way for one exit down. My new 91 RS I am installing 373's. (deployed right now) and with the alum drive shaft and a 5 speed she will be just right.

 

Well i would like to make it more a race car cause i do have another car to drive.
But still enough to have fun on the road to cruise and such.
Yeah right now i have 17"s on my car and im going back to 15x7 and 15x8 in the rear.
This will probably help at the track.

R/T... .065
60'... 2.008
330'... 5.828
1/8... 8.942
MPH... 78.90
(this is were the other people i race pull on me)
1000'... 11.643
1/4... 13.925
MPH... 98.86
I have Flowmasters and 750cfm double pump holley on my 350 H.O.

Im looking into getting a aluminum driveshaft. Need to find one,
i see them on ebay but i dont have a paypal account so i was trying to find a website and such.
So 3.73 would be the best bet?
Thanks for the quick response everyone =)

 

No; just, the ABSOLUTE MAX tha twould be even remotely reasonable in your situation.

More gear will make that problem MUCH worse.

YOu have 2 problems: your motor has no upper-RPM HP, and your car has no leave.

You haven't told us what your exhaust is; I suspect that's the key to the first problem. That, plus the stock cam in that motor, if it's still there.

For the 2nd problem, 700-equipped cars respond MUCH better to torque converter upgrades than gear changes.

I'd suggest abandoning the gear idea. Instead, get a GOOD set of headers and a BOXED cat-back of your choice; a Comp XR276 cam, along with a set of beehive springs; and a converter with about a 2600 RPM stall. Smaller diameter is better in a converter.

 

Headmen Headers is whats on it now, http://www.summitracing.com/parts/fl...t/model/camaro This is pretty close to what i have on my car.
But im not sure, 3" all the way back. there is a cat but nothing in it, i could remove it.
I know its not a stock exhaust considering this engine was put in replace of the of old one http://www.jegs.com/p/Chevrolet-Perf...19588/10002/-1

Thanks for the help, so if i do what you are describing i should be able to see a major difference.
I see you recommended some things, what exhaust would you recommend along with headers for my engine i linked above?

Thanks sofa