Drag Racing W/ Forced Induction
 

We need a drag racing thread.

What setup are you guys running. Clutch, SC or TC, Tires, Suspension, misc?

I have p&l's kit and I launch at 4000 on 245/45/17 nitto nt555rs, @ 25 psi it wheel hops nasty, at 18 - 20 psi it wheel hops but not as bad.

What are you guys running, curious to hear other people's setups

Stock clutch, sprintex 210 SC non intercooled, hockey pucks, stock suspension, Tomei EL header, e85


12.9 @ 105.


3750 rpm clutch out slowly for best time.

To be completely honest, I feel we need an entire Drag Racing section. Somewhere where we can talk about different topics suspension adjustments, Tires, clutch tricks, launching aids, 1/4 mile times for N/A, 1/4 mile times for FI, drag car builds, ect..
Yes we all know these cars are great for turns and such, but the type of racing differs per person and preference. Sorry for the rant.

Edit: Thread created
http://www.ft86club.com/forums/showt...68#post2294768

Any idea how much WHP?

No idea, Estimating about 260-270

I did a few more test hits.... on a road in mexico...

I set my air pressure in back to 16 psi. Raised the 2 step to 6000 rpms to build about 4-5 lbs of boost to do a burnout. Lit them up for 6 seconds or so.

Lowered my 2 step to 5250 - 5300, preloaded the drivetrain with the hand brake, and slipped it out aggressively. I spun for about 20 feet and then it hooked and booked. No more wheel hop

The drag strip is going to react very differently than the street unless you are using dat juice they use on Street Outlaws. The strip is going to be prepped and give you a lot more grip so you are probably going to need more RPM to duplicate your results on the street doing the same launch.

Or go to poly bushings in the back, that's typically what causes wheel hop.


The bushings get loaded up then "pop" back into place and it's a never ending see-saw until the car finally hooks up.


Not to mention the continuous shock loads seen under wheel hop will break shit quickly.

I have poly diff bushings,
What else would you reccomend. Subframe bushings and what other suspension bushings?

Definitely do subframe or at least the Whiteline inserts, that's where most of the flex is.

Agree on the need for Drag Race section.

Interesting to see loading the drivetrain with a hand brake, good idea to reduce that initial shock. A hydro hand brake would would real nice for that.

Not as necessary if you slip out the clutch. I just do it for extra assurance. I know if you watch in car video of a manual awd car a lot them preload with the hand brake.

A perfect example is Devin in the red demon, see below.

[ame="https://www.youtube.com/watch?v=lwiE-YAx2S0"]Red Demon - In Car View - 8.0 @ 182MPH - Personal Best ET - Boostin Performance - YouTube[/ame]

Okay, So I did some passes at the strip last Saturday and i'm hitting the rev limiter before attempting to shift into 5th.

Current:
Manual Transmission
Unknown Horsepower. estimating 260-270 RWHP
Bridgestone Turanza El400 Hockey Pucks.


Relevant info:

Factory suspension settings
2013 FRS
Sprintex 210 Supercharger
Tomei Equal Length Headers
E85
70mm Pulley (~11 PSI)
Stock Gearing
215/45/17 tires resulting in a 24.6" tire diameter
7450 RPM rev limit
topping out at 12.9 at 105-106 MPH in 4th gear riding out the top 50 feet or so on the limiter



Due to the limiter I have a choice of attempting to shift to 5th or riding the limiter. 5th gear is impossible to shift into within 50 feet at 105 mph.


The easiest change is to increase the rev limiter to 7800:


Proposed changes option 1:
7800 RPM rev limit
top speed in 4th around 114 or 115


Since my tires are nearing the end of their useful life, I may be interested in changing rear wheels to 17x7.5 and tires to stickier street tires sized at 245/45/17 tires resulting in the following:



Proposed changes option 2:
7800 RPM Rev limiter
245/45/17 tires for a 25.7" tire diameter
top speed in 4th around 119 or 120


The last option is 17x8 wheels and tires with stickier street tires sized at 265/45/17 tires resulting in the following:



Proposed changes option 3:
7800 RPM Rev limiter
265/45/16 tires for a 25.4" tire diameter
top speed in 4th around 118 or 119, still simple




I probably put way too much thought in for a tenth or two, but every tenth counts in drag racing.


Anyway, Which setup makes the most sense realistically, not necessarily monetarily?