Gday everyone,
Im looking at swapping out my current full-spool and running LSD, mainly for better driveability, however I need to decide whether to stick with my current gearing or change it...
My car is an LC coupe, engine specs are;
red 202 40 thou oversize
offsett ground 208 stroker crank
starfire rods
12 port head, ported and flowed but no idea on flow specs
1.5 roller rockers
oil injection to 1st and 7th main
Running camtech cam, 266/266 duration at 50 thou, .531" lift
Triple 45 DCOE webers
Lightened flywheel
Crane Cams HI6 Ignition
100hp N2O Direct port injection / pump and regulated (not planning on running this- but set up is all there)
O-ringed block and copper head gasket
Has a ford 9 inch diff and saginaw 4 speed... Curerntly running 3.89 gears.
Rear tyres are Yokahama 235/60 on 15 inch rims
Car has run 13.1 N/A and 11.7 on N20 (as run by previous owner). Have not run it myself, but plan to...
Since I am already changing the diff center, I was thinking of putting in 4.11 gears for improved response, pickup and launch.
The car sits just over 3000rpm at 110km/h. To be honest I will be rarely driving it on the express way... At present, car is fairly happy sitting at 110... Second gear at 7000rpm car is sitting around 60-65mp/h (haven't noticed where 3rd gear is)
However, the car seems to have a fair slump between 2000-3500rpm (it comes on the cam about 4000)... This makes it hard to launch well- if you get too much spin, the revs drop into the "soft" zone and take a little before coming onto the cam...
The gearbox ratios are great- once on the cam, shifting between each gear about 7000rpm, the engine stays on the cam and absolutely screams (im presuming the sag is a close ratio? not sure).
Should I go with 4:11? What rpm would I be running with 4:11s at 60 mile (100km- wont be going much higher on expressway anyway).
Any help/ advice would be greatly appreciated!
Edited by jkirky, 13 May 2014 - 06:08 PM.