60 foot time

STINKY NINJA · 30-09-2010, 08:10 PM

I have just changed my diff gears from 3.27 to 3.91 but my 60 foot time has barely improved from 2.37 sec to 2.34 sec,doesnt seem right to me.
Car is an auto v8.
It goes faster in the top end but not where it counts at the start.
Should i have expected to drop more time than what i did?
I was expecting to get into the 2.2 second region but i was slightly wrong by a lot haha

GTP owner · 30-09-2010, 09:02 PM

It depends on whether you are spinning the tyres. If you are - a change in ratio will not make a difference

xagsjoe · 30-09-2010, 11:40 PM

What rear tires are you using? Run or the mill street tires will NOT hook but upgrade to a drag radial and you will make the most of your new gears.

STINKY NINJA · 01-10-2010, 01:22 AM

I dont have traction issues at the motorplex the grip is really good,i run a 14.6 so i only need my normal street tyres and they dont lose traction at all.
I try and stall it to the same speed every pass and try not to load up the convertor too much or else it goes slower if its stalled too much.
Im just lost as to where my speed has gone,i have missed something i just know it...
Doesnt make sense to me.

GTP owner · 01-10-2010, 08:18 AM

Alright, If you are not suffering traction issues, then you need to be stall at a higher rev to make the most of the new ratio.
You also have to balance everything. I change in diff ratio will benefit you more if you have a high stall converter and a bigger cam. Just changing diff ratio on a fairly stock car will not make much difference at all. There are other limiting factors that will rob you of any gains (ie the small cam that will produce a faster time using less revs, and low stall speed which will do the same)
Does that make sense?

STINKY NINJA · 01-10-2010, 10:59 AM

I think you lost me a bit on the small cam faster time, robbing me of gains?
I have a matched cam and convertor so if i change from 3.27 to 3.91 my 60 ft time still wont improve unless i get a bigger stall or a bigger cam, is that what you mean because i got the gears to do what a small stall would do and get me off the line quicker.
So my issue is that i used a standard cam and convertor which made me have less to no gains from the gears in the lower revs?

STINKY NINJA · 01-10-2010, 12:19 PM

I just spoke to a torque convertor specialist and he has given me something to try with my takeoffs.
I havent been getting the best out of my convertor by stalling it a bit too much, i need to stall it a couple of hundred above idle and then stomp on it to get a slingshot effect.Ill try it and see how i go because its the last thing to try.
Thanks for the replies

GTP owner · 01-10-2010, 12:21 PM

Yes, you got it right about not getting a gain unless you put a bigger stall or a bigger cam in it. You said it yourself- if you stall it up too high then you go slower. This means you are working the engine beyond its maximum efficiency range.

STINKY NINJA · 01-10-2010, 12:43 PM

Quote:

Originally Posted by GTP owner

Yes, you got it right about not getting a gain unless you put a bigger stall or a bigger cam in it. You said it yourself- if you stall it up too high then you go slower. This means you are working the engine beyond its maximum efficiency range.

You told me i wasnt stalling it enough before, i cant be working beyond my motors efficiency range at 1200 rpm? Can you explain that one to me in detail.
I just explained to you what the expert said to me and you seem to have misunderstood that.
he told me basically im using the torque convertor the wrong way so if anything is out of its efficiency range it would be the convertor wouldnt it.
To get the best of something it must first be used the correct way, not just stall it as hard as it can go.

STINKY NINJA · 01-10-2010, 12:47 PM

Quote:

Originally Posted by stinkydogs

I dont have traction issues at the motorplex the grip is really good,i run a 14.6 so i only need my normal street tyres and they dont lose traction at all.
I try and stall it to the same speed every pass and try not to load up the convertor too much or else it goes slower if its stalled too much.
Im just lost as to where my speed has gone,i have missed something i just know it...
Doesnt make sense to me.

Your next post to this was that i need to stall it up more, when i say it goes slower when i do that.
Maybe read my posts a bit better..

XDOUBLEU · 03-10-2010, 12:50 AM

Whats with the attitude buddy. The man is trying to give a bit of advice and you are winging about him not reading your posts properly!! WTF.

Harden up and figure it out yourself. Either way, your car must be pretty lame to be pulling a 14.6 with no traction issues. The diff guy was laughing all the way to the bank when he saw you.

The only thing you need to do is get more power.

Auslandau · 03-10-2010, 01:02 AM

Quote:

Originally Posted by stinkydogs

Your next post to this was that i need to stall it up more, when i say it goes slower when i do that.
Maybe read my posts a bit better..

You ask for help ..... members are throwing out ideas to try and work things out and you respond with this attitude .....

great stuff.