Grib
To run 200 MPH at 7,800 RPM you will need a 3.18 gear. A 3.25 gear should
get you 200 MPH at 8,000 RPM.
Based on your 195 MPH runs at 6,700 RPM, I'd say a 3.0 gear will get you 200
MPH at 7,400 RPM, but a 3.10 or 3.15 would be better.
As for the trans a 2.20 or 2.30 first gear would be a better deal, but hard
to start off from the line without a push start.
JB
----- Original Message -----
From: "rgribble" <rgribble@carolina.rr.com>
To: <land-speed@autox.team.net>
Sent: Tuesday, May 08, 2001 11:41 PM
Subject: opinions wanted
> Hi Everyone,
>
> I've got some decisions to make regarding transmission & rear gear
selection
> and thought with this vast cache of knowledge, I could get some opinions
that
> would help me with mine.
>
> I have a Busch Grand National (Winston Cup) 97 Tbird that I run at Maxton.
It
> has given me rides at 204+ MPH last year. It's hard to do a direct
comparison
> from last to this year's setup but I've made some changes and now I can't
get
> to Two. I don't know what loss I've got in motor (nothing's been done to
it)
> I'm working on a replacement power plant and hope to have it for this next
> meet.
>
> It seems to me to be a loosing lot in getting through 1st & 2nd gear.
It's
> 3200 lbs.( 45% rear wheels) with approx. 650 HP. The transmission I'm
> presently running is a Super T10 ( w/264,175,133,1 gears) with a 2.75 rear
> gear and twisting about 6700 in the traps. (should be 7500-8000). My tires
are
> Winston Cup/Goodyear 15" x 10"wide and 28"tall.
>
> The biggest problem I experience is that I get a lot of wheel spin in 1st
and
> 2nd gears. Any attempt to go WOT and it spins, so much that I have to use
my
> traction control (lift my big toe) to avoid it. I feel that this is
robbing me
> of a lot of performance.
>
> For the next meet I plan on changing the tires, rear gear and tranny and
would
> welcome any thoughts.
>
> I'm planning on using a 27.5" tall tire with a 12" width. That's a ="
smaller
> which is about 4 MPH, but the additional width may get me a better bite.
> (don't know about the drag the bigger tire would create?)
>
> I have the unique position of being able to put in a Super T101 tranny (w/
> square cut gears and full roller bearings by Tex Racing) with any gear
> selection I want ( which is what I'm not sure of ). I can run any Ford 9"
rear
> gear ratio I want but my target is a 3:00. (3.0 rear gear, 8000 RPM &
27.5"
> tire)
>
> Presently, I'm planning on a 3:00 rear gear with a tranny set up of 2.55
1st
> gear, 1.60 2nd, 1.29 3rd. and 1.0 4th. That appears to me to be the most
> balanced ratios to max my use of available HP. Most of the Winston Cup
> engineers tell me taller (2.55 vs. 264) gears will help with wheel spin,
and
> most Drag Racers talk about using the opposite to avoid the spin.
>
> I would appreciate any opinion(s) regarding the problem(s) and any
solutions.
> Thanks in advance.
>
> Grib
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