The Latin RX7

So I have a 91 turbo fc that I want to drag race the car is a basic street car it has about 350hp nothing too crazy but how do you guys launch with stock trannies/ diffs? Just drop the clutch? Or do I have to preload a llitle
ive never driven the car with slicks but I suppose the car wont wheel hop with them so can I launch hard? Thanks

scathcart

https://tiltonracing.com/product/flow-control-valve/

Use your two step and dump the clutch with one of these installed in your clutch line. It’ll save you from destroying your drivetrain... tranny would otherwise go first (if it’s an N/A box), and then after that you’ll snap axles.

antman0408

iTrader: (2)

When I launch I preload the driveline first and basically are dumping the clutch. I launch at around 7000 rpm. Best 60’ I got is 1.58 from just free revving launch. Haven’t really tried 2 step or any launch control. Haven’t broken anything yet.
I would suggest starting with the tire pressure high that way you’ll spin before breaking stuff. Did you get bias ply tires?

The Latin RX7

its a T2, and yes I went with a mickey thompson bias ply slick 26x8.5 15 now I just need a pair of gxl/gtu 15 rims to put them on

Chimby

I've always preloaded my T2 before launching. Same tire you're using, a bit more power.
Until I got my hands on one of these...

https://paradiseracing.com/collectio...valve-fcv-2000

Problem solved!

clutchtamer

That valve will help protect your drivetrain, but it's a pretty lazy way to launch a drag car. Same with the Tilton unit mentioned above, both are simple in-line adjustable restrictions that slow the entire clutch engagement cycle. Both will also cause the clutch to slip excessively after WOT clutch assisted shifts.

An improvement over the above is the Magnus unit, which combines simple in-line restriction with an electrically operated bypass valve. The added bypass valve makes it possible for the Magnus unit to be active during launch only, eliminating the problem of excessively clutch slip after WOT clutch assisted shifts. Problem is the Magnus unit still uses simple in-line restriction to control launch, still lazy.

There are better ways to control clutch engagement that don't slow down your reaction time. The first system I designed used a simple hardware store hydraulic screen door closer combined with a sliding dash bracket and an adjustable stop to control clutch pedal movement. It basically allowed the clutch pedal to return instantly to a specific point, then pedal travel was slowed from that point on. Instant clutch release until the pedal reaches the sweet spot, then the cylinder slows pedal travel to keep the pedal in that sweet spot longer. Because the clutch pedal releases instantly to the sweet spot, much less clutch slip after WOT clutch assisted shifts. Worked great, cost me less than $50, no need to pre-load before launch.

The system I use now is quite a bit more complicated, but an improvement over all of the above.

Grant