Tadsfast98

I have a 98 ws6 trans am with a tci 3500 convertor, mac headers, off road y, magnaflow exhaust. Before I put the gears in my best et was 12.76 at 105. after the gears my best et was a 12.98 at 103. I figured I would pick up 2 tenths, not loose 2 tenths. Any sugestions?? the guy that installed them does really good work and the are'nt too noisy. They are richmonds. Please help I'm a little confused. thanks.

brandboZ28

iTrader: (2)

What was your 60' both before and after the gears? Also, what were the conditions such as weather and track prep? Same track?

silverbeast

iTrader: (16)

a buddie of mine just put 4.10's in his car. it has like a 3600 stall and after the change he lost 3 mph and 1 tenth in the 1/8. the night he ran the weather was terrible so we hope that was most of the problem. he had around the same 60' so traction was not the problem. he said it felt like the car was bogging after it shifted? he is going to check his shift points and get a tune to see if it helps.

elderon

Weather can make a huge difference. Factoring atmospheric pressure, temperature, and humidity - it can make up to about .8 second difference on each extreme! A 40 degree difference in temperature makes about .3 difference for example. I know a good website that you can use that has a tool to factor for weather.

www.smokemup.com

I thought I had only gained .1 when I installed headers and ported throttlebody, but after i factored in the weather I gained .3 !! Give it a try.

That comment about the 60' times is correct though to. If you are spinning bad off the line now thats gonna mess things up as well.

Tadsfast98

my 60 before the gears was a 1.74 after the gears 1.75 the temperture was 70 before gears and 80 after the gears.

Ragtop 99

iTrader: (7)

You're seeing the effect of tempature. Weather got worse and your 60' didn't get much worse (gears overcame the weather) yet mph was down.

Also make sure that you are not spinning. Its much easier to spin 3.73s. All it takes is just a little slip and you've lost .05 or more on the 60' and .1 in the 1/4 mile.

As mentioned above, make sure your shift points are right. You may be short shifting. It can take some shift point tinkering to get a gear swap to work correctly.

Larry

iTrader: (4)

I lost a few hundredths going from a 2.73 to 3.42 when my car was running mid 12's. Same DA, almost identical 60's. We have a nice low 3.06 first gear ratio in our automatics. With a good loose torque converter lower differential gears can actually hurt et's.